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    UNIVERSITATEA DE TIINE AGRICOLE I MEDICINVETERINAR CLUJ-NAPOCA

    COALA DOCTORALFACULTATEA DE MEDICIN VETERINAR

    Ing. ANGELA CARMEN D. OARGA

    CERCETRI PRIVIND CALITATEA LAPTELUI

    MATERIE PRIM DESTINAT INDUSTRIALIZRII N

    UNITI DE PROCESARE DIN JUDEUL CLUJ

    (REZUMAT AL TEZEI DE DOCTORAT)

    Conductor tiinificProf. Univ. Dr. CORNEL LASLO

    CLUJ-NAPOCA2010

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    CUPRINSTABLE OF CONTENTS

    CUPRINS.............................................................................................................................4TABLE OF CONTENTS.....................................................................................................4

    INTRODUCERE ...............................................................Error! Bookmark not defined.INTRODUCTION .............................................................Error! Bookmark not defined.PARTEA I: STADIUL ACTUAL AL CUNOATERII N DOMENIU.................. Error!

    Bookmark not defined.FIRST PART: LITERATURE REVIEW..........................Error! Bookmark not defined.1. COMPOZITIA LAPTELUI, PROPRIETATILE FIZICO-CHIMICEError! Bookmarknot defined.I TEHNOLOGICE...........................................................Error! Bookmark not defined.1. MILK COMPOSITION, PHYSICO-CHEMICAL AND PROCESSING PROPERTIES

    ............................................................................................Error! Bookmark not defined.1.1. DEFINIREA NOIUNII DE LAPTE.....................Error! Bookmark not defined.1.1. THE CONCEPT OF MILK ....................................Error! Bookmark not defined.1.2. COMPOZIIA LAPTELUI ....................................Error! Bookmark not defined.1.2. MILK COMPOSITION ..........................................Error! Bookmark not defined.1.3. PROPRIETI FIZICO-CHIMICE I TEHNOLOGICE ... Error! Bookmark notdefined.1.3. PHYSICO-CHEMICAL AND PROCESSING PROPERTIES... Error! Bookmark

    not defined.1.4. CERINE DE CALITATE PENTRU LAPTELE DESTINATINDUSTRIALIZRII....................................................Error! Bookmark not defined.1.4. MILK PROCESSING QUALITY REQUIREMENTS ........ Error! Bookmark notdefined.

    2. MICROFLORA LAPTELUI CRUD.............................Error! Bookmark not defined.2. RAW MILK MICROFLORA........................................Error! Bookmark not defined.

    2.1 MICROORGANISME NEPATOGENE .................Error! Bookmark not defined.

    2.1. UNPATHOGENICS MICROORGANISMS .........Error! Bookmark not defined.2.1.1. Microorganisme care acioneaz n principal asupra lactozei din lapte... Error!Bookmark not defined.2.1.1. Microorgansims that mainly act on milk lactose............ Error! Bookmark notdefined.2.1.2. Microorganisme care acioneaz puternic asupra proteinelor din lapte... Error!Bookmark not defined.2.1.2. Microorgansims that strongly act on milk proteins........ Error! Bookmark not

    defined.

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    2.1.3. Microorganisme care acioneaz asupra lipidelor din lapte..Error! Bookmark

    not defined.2.1.3. Microorgansims that act on milk lipids............Error! Bookmark not defined.

    2.2. MICROORGANISME PATOGENE......................Error! Bookmark not defined.

    2.2. PATHOGENICS MICROORGANISMS ...............Error! Bookmark not defined.2.2.1. Virusuri.............................................................Error! Bookmark not defined.2.2.1. Viruses ..............................................................Error! Bookmark not defined.2.2.2. Bacterii i toxine bacteriene .............................Error! Bookmark not defined.2.2.2. Bacteria and bacterial toxins ............................Error! Bookmark not defined.2.2.3. Drojdii i mucegaiuri ........................................Error! Bookmark not defined.2.2.3. Moulds and yeasts ............................................Error! Bookmark not defined.2.2.4. Parazii..............................................................Error! Bookmark not defined.

    2.2.4. Parasites ............................................................Error! Bookmark not defined.2.3. DEFECTELE LAPTELUI PRODUSE DE MICROORGANISME............... Error!

    Bookmark not defined.2.3. MILK DEFECTS PRODUCES BY MICROORGANISMS Error! Bookmark not

    defined.2.4. BOLI TRANSMISIBILE PRIN LAPTE SI PROFILAXIA LORError! Bookmark

    not defined.2.4. MILK-BORNE DISEASE AND THEIR PROPHYLAXIS . Error! Bookmark not

    defined.3. FACTORII CARE INFLUENEAZ CALITATEA IGIENIC A LAPTELUI Error!

    Bookmark not defined.3. SOURCES AND CAUSES THAT INFLUENCE HYGIENIC QUALITY OF RAW

    MILK .................................................................................Error! Bookmark not defined.3.1. CALITATEA IGIENIC A LAPTELUI MATERIE PRIM .... Error! Bookmark

    not defined.3.1. HYGIENIC QUALITYOF RAW MILK................Error! Bookmark not defined.3.2. SURSE DE CONTAMINARE MICROBIOLOGIC A LAPTELUI ........... Error!

    Bookmark not defined.3.2. MILK MICROBIOLOGICAL CONTAMINATION SOURCES.................. Error!

    Bookmark not defined.3.2.1. Contaminarea cu microflora interioar a ugerului ............. Error! Bookmark not

    defined.3.2.1. Microbial contamination from within the udder..Error! Bookmark not defined.

    3.2.2. Contaminarea cu microflora exterioar ugerului............ Error! Bookmark not

    defined.

    3.2.2. Microbial contamination from the exterior of the udder Error! Bookmark notdefined.

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    3.2.3. Influena curirii i a procedurilor de igienizare a echipamentelor......... Error!

    Bookmark not defined.3.2.3. Influence of equipment cleaning and sanitizing procedures . Error! Bookmark

    not defined.

    3.2.4. Temperatura i timpul de depozitare a laptelui Error! Bookmark not defined.3.2.4. Milk storage temperature and time...................Error! Bookmark not defined.

    3.3. PROCEDURI DE IGIENIZARE ............................Error! Bookmark not defined.3.3. SANITATION PROCEDURES..............................Error! Bookmark not defined.

    3.3.1. Proceduri aplicate de la animal la consumator.Error! Bookmark not defined.3.3.1. Procedures applied from animal to consummator.......... Error! Bookmark not

    defined.3.3.2. Proceduri aplicate de la laptele muls la tancul de refrigerare Error! Bookmark

    not defined.3.3.2. Procedures applied from milk to refrigeration tank ....... Error! Bookmark not

    defined.4. MODELAREA N VEDEREA CONTROLULUI MICROFLOREI LAPTELUI CRUD

    ............................................................................................Error! Bookmark not defined.4. MODELLING TO CONTROL SPORES IN RAW MILK......... Error! Bookmark not

    defined.4.1. SURSE DE CONTAMINARE MICROBIAN A LAPTELUI DIN TANCURILE

    DIN FERME ..................................................................Error! Bookmark not defined.4.1. SOURCES OF MICROBIAL CONTAMINATION OF FARM TANK MILK

    ........................................................................................Error! Bookmark not defined.4.1.1. Contaminarea de la exteriorul mameloanelor ..Error! Bookmark not defined.4.1.1. Contamination via the exterior of teats ............Error! Bookmark not defined.4.1.2. Contaminarea din interiorul mameloanelor......Error! Bookmark not defined.4.1.2. Contamination via the interior of teats.............Error! Bookmark not defined.4.1.3. Contaminarea de la echipamentele de muls .....Error! Bookmark not defined.4.1.3. Contamination via surfaces of the milking equipment... Error! Bookmark not

    defined.4.2. PROLIFERAREA N TIMPUL DEPOZITRII LAPTELUI DIN TANCURI NFERME...........................................................................Error! Bookmark not defined.4.2. GROWTH DURING STORAGE OF FARM MILK TANK Error! Bookmark not

    defined.PARTEA II: CERCETARI PROPRII................................Error! Bookmark not defined.SECOND PART: ORIGINAL CONTRIBUTIONS .........Error! Bookmark not defined.5. SCOP I OBIECTIVE...................................................Error! Bookmark not defined.

    5. AIMS AND OBJECTIVES ...........................................Error! Bookmark not defined.6. MATERIALE I METODE ..........................................Error! Bookmark not defined.

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    7.1. INFLUENA CONDIIILOR DE IGIEN ASUPRA CALITII LAPTELUICRUD.............................................................................Error! Bookmark not defined.7.1. INFLUENCE OF HYGIENIC CONDITIONS ON RAW MILK QUALITY Error!

    Bookmark not defined.

    7.1.1. ncrctura microbian a atmosferei din adpost........... Error! Bookmark notdefined.7.1.1. Microbial load of shelter atmosphere...............Error! Bookmark not defined.7.1.2. Igiena recipientelor destinate mulsului.............Error! Bookmark not defined.7.1.2. Milking vessels hygiene ...................................Error! Bookmark not defined.7.1.3. Igiena glandei mamare .....................................Error! Bookmark not defined.7.1.3. Mammary gland hygiene..................................Error! Bookmark not defined.7.1.4. Influena efectului decontaminant al unor substane dezinfectante asupra

    calitii igienice a laptelui materie prim ...................Error! Bookmark not defined.7.1.4. Influence of decontamination effect of some disinfectants on raw milkhygienic quality ..........................................................Error! Bookmark not defined.

    7.2. CERCETRI PRIVIND CALITATEA LAPTELUI MATERIE PRIM

    OBINUT N JUDEUL CLUJ, DESTINAT PROCESRII INDUSTRIALE .. Error!Bookmark not defined.7.2. RESEARCHES REGARDING RAW MILK QUALITY OBTAINED IN CLUJCOUNTY, FOR INDUSTRIAL PROCESSING...........Error! Bookmark not defined.7.3. CERCETRI PRIVIND STABILIREA UNUI MODEL MATEMATIC PENTRUCONCENTRAIA BACILLUS CEREUS N TANCURILE DE RCIRE A

    LAPTELUI DIN FERME MODELARE I MONITORIZAREError! Bookmark notdefined.7.3. RESEARCHES REGARDING ESTABLISING A MATHEMATICAL MODELOF BACILLUS CEREUS GROWTH IN FARM TANK MILK MODELING AND

    MONITORING ..............................................................Error! Bookmark not defined.7.3.1. Modelarea contaminrii tancurilor de rcire a laptelui din ferme cuB. cereus

    ....................................................................................Error! Bookmark not defined.

    7.3.1. Modeling the contamination of farm tank milk withB. cereus spores .... Error!Bookmark not defined.7.3.2. Monitorizarea n ferme a contaminrii cuBacillus cereus a tancului de rcire alaptelui ........................................................................Error! Bookmark not defined.7.3.2. Monitoring the contamination of tank milk farms withBacillus cereus.. Error!

    Bookmark not defined.8. CONCLUZII I RECOMANDRI...............................Error! Bookmark not defined.8. GENERAL CONCLUSIONS AND RECOMMENDATIONS .. Error! Bookmark not

    defined.ABREVIERI ......................................................................Error! Bookmark not defined.

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    ABBREVIATIONS ...........................................................Error! Bookmark not defined.BIBLIOGRAFIE................................................................Error! Bookmark not defined.REFERENCES ..................................................................Error! Bookmark not defined.REZUMAT AL TEZEI DE DOCTORAT...........................................................................3

    SUMMARY OF PhD THESIS ..........................................................................................31

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    JUSTIFICAREA TEMEI DE CERCETARE

    Laptele este unul din alimentele de baz n nutriia noastr deoarece conine toate

    substanele hrnitoare necesare creterii, dezvoltrii i funcionrii normale aorganismului. Procesarea laptelui n produse lactate acide confer laptelui cteva

    proprieti noi, de mare nsemntate i anume: creterea valorii alimentare, biologice,

    nzestrarea lor cu proprieti dietetice i terapeutice. Sub aspect tehnologic, produsele

    lactate dietetice (iaurt, chefir, lapte btut), comport o serie de faze comune tuturor

    sortimentelor, dar i unele faze distincte care imprim anumite proprieti organoleptice,

    fizico-chimice ce le individualizeaz ca produs.

    n cadrul studiilor efectuate, s-a urmrit investigarea, aprofundarea i completarea

    datelor din literatura de specialitate cu observaii proprii. Prima parte cuprinde un studiu

    bibliografic, cu date asupra subiectului cercetat, iar n a doua parte sunt descrise

    cercetrile proprii. Lucrarea aduce la zi informaii referitoare la stadiul actual al

    cunoaterii n domeniul cerinelor calitative i igienice ale laptelui materie prim destinat

    industrializrii n uniti de procesare din judeul Cluj. Partea a doua a lucrrii, contribuii

    personale este structurat n 4 capitole n care sunt prezentate date ale cercetrilor privind

    unele aspecte calitative i igienice ale laptelui materie prim.

    Calitatea i starea igienic a laptelui depind de o serie de factori legai de starea de

    sntate a animalelor, condiiile igienice de muls, condiiile igienice de transport,

    manipulare, pstrare. Sub raport calitativ laptele trebuie s corespund n primul rnd

    calitilor nutritive avnd n vedere c el intr n consumul zilnic al copiilor, bolnavilor,

    vrstnicilor i chiar a adulilor. Din punct de vedere igienic, laptele trebuie s fie liber de

    orice nox fizic, chimic, biochimici microbiologic.Lucrarea Cercetri privind calitatea laptelui materie prim destinat

    industrializrii n uniti de procesare din judeul Cluj este conceput ca un tot unitar,

    sistematizat pe 8 capitole bine conturate i bibliografia.

    n prima parte (I), aceast tez cuprinde un studiu de literatur privind compoziia

    laptelui, proprietile fizico-chimice i tehnologice, aspecte legate de microflora laptelui

    crud i factorii care influeneaz calitatea igienic a laptelui materie prim, precum i

    modelarea ca metod de control a microflorei laptelui crud. n partea a doua (II) sunt

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    prezentate cercetrile proprii cu design-ul experimental, metodele de lucru, rezultate i

    discuii (structurate pe obiectivele principale, fiecare avnd obiective specifice i

    activiti n vederea ndeplinirii scopului tezei), concluzii i recomandri.

    Termenul de valabilitate i implicit durata de via a produselor lactate depinde ngeneral de concentraia bacililor sporulai, i n special de concentraia luiBacillus cereus

    n laptele crud. n funcie de translaia cilor de contaminare n lanul operaional au fost

    dezvoltate dou modele de simulare pentru identificarea cantitativ a factorilor cu impact

    crescut asupra concentraiei bacililor sporulai n tancul de rcire a laptelui din ferme

    (TLF). Pe lng aceasta, modelele au fost folosite pentru a determina reducerea

    concentraiei acestor spori prin msuri implementate la nivel de exploataie. Elaborarea

    unui model predictiv al concentraiei bacililor sporulai n condiiile n care solul este

    singura surs de contaminare selecteaz calea de contaminare cea mai relevant ca fiind

    punatul i stabulaia animalelor n grajd/staul.

    n situaia contaminrii mameloanelor cu pmnt s-a estimat c 33% din TLF

    conin bacili sporulai deBacillus cereus peste Limita Maxim Admis (LMA) de 3 log10

    spori/l. n cazul n care nutreurile reprezint sursa principal de contaminare, doar 2%

    din TLF sunt contaminate. Pe baza concentraiilor previzibile de bacili sporulai, a fost

    calculat concentraia medie deBacillus cereus n TLF ca fiind n laptele crud depozitat

    la procesator n timpul perioadei de punat de 3.4 log10 spori/l de lapte iar pe parcursul

    perioadei de stabulaie a animalelor n staul de 2.2 log10 spori/l. S-a estimat c, n

    perioada de punat poate fi atins o reducere de 99%, n cazul n care toate exploata iile

    fermiere minimizeaz contaminarea mameloanelor cu solul i optimizeaz procedurile de

    igienizare a mameloanelor. n timpul adpostirii i acomodrii animalelor n staul, este

    posibil o reducere a concentraiei cu 60% prin meninerea concentraiei de bacilisporulai din furajele pentru animale sub 3 log10 spori/g i un pH de nsilozare raportat la

    nutre sub 5. Punerea n aplicare a acestor msuri la nivel de ferm asigur o concentraie

    a bacililor sporulai deB. cereus din laptele crud ce rareori depete LMA.

    Creterea concentraiei de B. cereus adesea limiteaz termenul de valabilitate al

    produselor lactate pasteurizate pstrate la temperaturi de refrigerare. Produsele lactate

    infectate cu B. cereus prezint defecte senzoriale cum sunt modificrile de arom,

    coagulare dulce, neacidi gust amar al smntnii (OVERCAST i ATMARAM, 1971;

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    STONE i ROWLANDS, 1952). Incidena luiB. cereusn produsele lactate provine, cel

    puin parial, din contaminarea de la nivelul fermei. Datorit proprietilor bacililor deB.

    cereus, acetia nu sunt capabili sa supravieuiasc proceselor de pasteurizare. Totui,

    poate s apar recontaminarea n timpul prelucrrii laptelui datorat unei implementriimproprii a procedurilor de igienizare a echipamentului de pasteurizare (LIN i col., 1998,

    SVENSSON i col., 2000; Te GIFFEL i col., 1996). Pentru a preveni alterarea

    produselor lactate pasteurizate, B. cereus ar trebui s fie controlat i monitorizat prin

    sisteme de management al calitii aplicate lanului alimentar aceasta se poate realiza

    prin introducerea unei noi proceduri n Sistemul de Management al Calitii Produselor

    Alimentare i anume modelarea i monitorizarea contaminrii microbiene prin stabilirea

    unui algoritm predictiv pentru evoluia unor parametrii n timp, precum i contaminarea.

    Este important reducerea concentraiei de spori B. cereus n lapte, prin msuri

    implementate corect la nivel de ferm sau prin bacto-centrifugare (HSC High Speed

    Centrifugation) i pentru a preveni recontaminarea i creterea bacteriilor n timpul

    procesrii. Legat de aceste aspecte exist puine studii referitoare la msurile necesare

    pentru reducerea la un nivel semnificativ n ferme precum i asupra efectului

    potenialelor msuri de control a contaminrii TLF. Concentraia bacililor sporulai deB.

    cereus n laptele crud reprezint media ponderat a concentraiilor de B. cereus din

    diferite arje livrate din TLF. Cea mai mare concentraie se ntlnete la sfritul verii i

    nceputul toamnei (SLAGHUIS i col., 1997; Te GIFFEL i col., 1995). n funcie de

    termenul de valabilitate necesar pentru o perisabilitate redus a produselor lactate

    pasteurizate s-a stabilit o limit maxim admis (LMA) a bacililor sporulai de 3 log10

    spori/l (WALSTRA i col., 2005).

    Tancul de rcire a laptelui din ferme (TLF) este contaminat cu spori de B. cereusprin intermediul murdriei externe mameloanelor vacilor i prin intermediul

    echipamentelor de muls impropriu igienizate (GRIFFITHS i PHILLIPS, 1990, SARAN,

    1995). O cretere suplimentar a concentraiei ar putea avea loc ca urmare a creterii i

    sporulrii lui B. cereus pe durata depozitrii laptelui n TLF. Contaminarea datorat

    murdriei exterioare mameloanelor se ntlnete n situaia n care mameloanele sunt

    contaminate cu noroi. n timpul punatului murdria de la nivelul mameloane este

    reprezentat n special de pmnt. Pe durata adpostirii animalelor n staul, sursa

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    principal de murdrie o constituie materiile fecale i materialul folosit la aternut

    (CHRISTIANSSON i col., 1999). Murdria de pe suprafaa exterioar a mameloanelor

    este splat n timpul mulsului. Ca urmare bacilii sporulai splai vor contamina laptele.

    Concentraia de bacili sporulai deB. cereus ce vor contamina laptele depinde de gradulde murdrie limpezit de pe mameloane i concentraia iniial a bacililor n murdria de

    la nivelul mameloanelor. Diferite msuri pot reduce concentraia de B. cereus n TLF,

    variind de la cele legate de calitatea (microbian) crescut a nutreurilor pn la msuri

    legate de splarea i igienizarea adecvat a mameloanelor naintea mulsului. Pentru

    managementul eficient al fermei este important identificarea celor mai eficiente msuri

    pentru reducerea concentraiei de B. cereus n TLF. n funcie de calea de contaminare,

    VISSERS i col. (2003) au stabilit un model de simulare pentru a identifica o strategie

    pentru controlul concentraiei bacteriilor butirice sporulate n TLF. Modelul conine

    variabile interpretabile i msurabile i reprezint efectele variabilelor incontrolabile. O

    strategie de control a fost elaborat utiliznd modelul de simulare Monte-Carlo.

    Rezultate pariale din partea experimental au fost publicate n articolele tiinifice

    care sunt listate n bibliografie.

    BIBLIOGRAFIE SELECTIV

    1. Overcast, W.W., K. Atmaram. 1971. The role ofBacillus cereus in sweet curdling offluid milk.Journal of Milk and Food Technology37, 233-236

    2. Stone, J.M., A. Rowlands. 1952. 'Broken' or 'bitty' cream in raw and pasteurized milk.Journal of Dairy Research19, 51-62.

    3. Lin, S., H. Schraft, J.A. Odumeru, M.W. Griffiths. 1998. Identification of contaminationsources of Bacillus cereus in pasteurized milk. International Journal of Food

    Microbiology 43, 159-171.

    4. Svensson, B., A. Eneroth, J. Brendehaug, G. Molin, A. Christiansson. 2000. Involvementof a pasteurizer in the contamination of milk by Bacillus cereus in a commercial dairyplant.Journal of Dairy Research 67, 455-460.

    5. Te Giffel, M.C. 2003. Good hygiene practice in milk processing. Pages 68-79 in Dairyprocessing - improving quality. G. Smit, ed. Woodhead Publishing Limited, Cambridge,UK.

    6. Te Giffel, M.C., R.R. Beumer, B.A. Slaghuis, F.M. Rombouts. 1995. Occurrence andcharacterization of (psychrotrophic) Bacillus cereus on farms in the Netherlands.

    Netherlands Milk and Dairy Journal49, 125-138.

    7. Slaghuis, B.A., M.C. Te Giffel, R.R. Beumer, G. Andre. 1997. Effect of pasturing on theincidence ofBacillus cereus spores in raw milk.International Dairy Journal7, 201-205.

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    8. Walstra, P., J.T.M. Wouters, T.J. Geurts. 2005. Dairy Science and Technology.Taylor&Francis, New York.

    9. Griffiths, M.W., J.D. Phillips. 1990. Incidence, source and some properties ofpsychrotrophic Bacillus found in raw and pasteurized milk. Journal of the Society for

    Dairy Technology 43, 62-66.

    10.Saran, A. 1995. Disinfection in the dairy parlour. Rev. Sch. tech. off. int. Epiz. 14 (1),207-224

    11.Christiansson, A., J. Bertilsson, B. Svensson. 1999.Bacillus cereus spores in raw milk:factors affecting the contamination of milk during the grazing period. Journal of DairyScience82, 305-314

    12.Vissers, M.M.M. and P. De Jong. 2003. Development and application of a modelpredicting viscosity loss of yoghurt in processing equipment. IDF bulletin on

    fermented milks, 1, 233-240

    13.Regulamentul (CE) nr. 853/200414.Regulamentul 1441/2006.15.SR 2418:200816.Regulamentul (CE) nr. 1.664/2006

    CONTRIBUII PERSONALE

    Scopul tezei const n aplicarea unor abordri moderne de analiz matematici

    modelare alturi de abordri clasice legate de metodologii validate n decursul timpului

    privind calitatea laptelui materie prim n vederea elaborrii unor metodologii aplicabile

    n cadrul sistemelor de management al calitii n fermele productoare de lapte destinat

    procesrii.

    Cercetrile tezei au fost structurate n cadrul a treiobiective principale:

    Obiectiv 1: Cercetri privind influena unor factori de igien asupra calitii

    laptelui crudObiectiv 2: Cercetri privind calitatea laptelui materie prim obinut n judeul

    Cluj, destinat procesrii industriale

    Obiectiv 3: Cercetri privind stabilirea unui model matematic pentru concentraia

    Bacillus cereus n tancurile de rcire a laptelui modelarei monitorizare

    Cercetrile au fost realizate n gospodrii i ferme mici din judeul Cluj

    (Obiectivul 1), n ferme de pe rute destinate unitilor de procesare a laptelui din judeul

    Cluj (Obiectivul 2), precum i n cadrul bursei Erasmus (mai septembrie 2004) la

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    Universitatea Wageningen (parial Obiectivul 3) si cu studiu experimental aplicat n

    ferme din judeul Cluj, ianuarie-decembrie 2006.

    n cercetrile efectuate n cadrul acestei teze s-a urmrit evaluarea corelrii

    parametrilor de calitate igienic a laptelui crud prin determinarea factorilor care depindde microclimatul din adpost, de igiena recipientelor destinate mulsului, de igiena glandei

    mamare precum i de aciunea decontaminant a unor substane dezinfectante. De

    asemenea cercetrile ntreprinse au urmrit s cuantifice eficacitatea msurilor de control

    ale contaminrii tancurilor de lapte din ferme (TLF) cu spori deB. cereus prin aplicarea

    unui model de simulare (modelare). Rezultatele ar trebui s conduc la stabilirea unei

    strategii de control. n primul rnd au fost stabilite modelele predictibile pentru a estima

    nivelul concentraiei deB. cereusn TLF.

    n cadrul obiectivului 1 Cercetri privind influena unor factori de igien asupra

    calitii laptelui crud, destinat procesrii industriale au fost propuse urmtoareleobiective

    specifice:

    ncrctura microbiana atmosferei din adpost; igiena recipientelor destinate mulsului i transportului laptelui pn la centrul

    de colectare; igiena glandei mamare; influena efectului decontaminant al unor substane dezinfectante asupra

    calitii laptelui materie prim

    n studiul de fa s-a urmrit calitatea igienica (microbiologic NTG, stafilococi

    coagulazo-pozitivi, bacterii coliforme) n diferite condiii experimentale determinndu-se

    la nivelul microaeroflorei, recipientelor de muls i transport, glandei mamare precum i

    efectul decontaminat al diferitelor substane de igienizare asupra calitii laptelui. Studiile

    au fost efectuate comparativ att in gospodarii individuale ct i n ferme, n cursul anului

    2005, cu variaie sezonier.

    n cadrulobiectivului 2 Cercetri privind calitatea laptelui materie prim obinut n

    judeul Cluj au fost propuse urmtoareleobiective specifice:

    determinarea parametrilor fizico-chimici: coninutul n grsime, protein,substan uscat negras (S.U.N.), punct de nghe (apa adugat) i compararea cu

    limitele maxime/minime admise de SR 2418:2008;

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    determinarea numrului de celule somatice (NCS) i numrul total de germeni(NTG) i compararea lor cu limitele maxime admise prevzute nRegulamentul (CE) nr.

    853/2004, respectiv Regulamentul 1441/2006.

    n studiul de fa s-a urmrit calitatea laptelui crud provenit de la 13 ferme dinjudeul Cluj prin urmrirea unor parametrii fizico-chimici i microbiologici prevzui n

    cerinele de calitate pentru laptele crud. n urma investigaiilor, laptele crud a putut fi

    declarat ca fiind conform (C)/neconform (NC) pentru procesare.

    n cadrul obiectivului 3 Cercetri privind stabilirea unui model matematic pentru

    concentraiaBacillus cereus n tancurile de rcire a laptelui modelare i monitorizare au

    fost propuse urmtoareleobiective specifice:

    modelarea contaminrii tancurilor de rcire cu Bacillus cereus; monitorizarea n ferme a contaminrii cu Bacillus cereus a tancului de rcire

    a laptelui.

    Rezultatele obinute prin simulare au fost validate prin aplicarea unui studiu n

    cmpul de cercetare pe durata a 12 luni (ianuarie decembrie 2006) n 20 ferme din

    judeul Cluj. S-au realizat msurtori n anumite puncte critice ale cii de contaminare

    (nsilozare, transmiterea murdriei n timpul mulsului).n cadrul cercetrilor ntreprinse n acest obiectiv s-a urmrit controlul

    contaminrii TLF cu spori de B. cereus. n cadrul modelrii contaminrii TLF cu B.

    cereus se urmrete dezvoltarea unui model matematic i simulare prin aplicarea lui.

    Strategia de control stabilit este validat i optimizat cu ajutorul datelor din cmpul

    experimental (monitorizarea n ferme a contaminrii cu spori a TLF).

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    Figura 5.1. Schema cercetrilor structurate pe obiective generale, obiective specific

    A

    Obiective specificeObiective generale

    Ob1. CERCETARI PRIVINDINFLUENTA UNOR FACTORI DE

    IGIENA ASUPRA CALITATII

    LAPTELUI

    Ob2. CERCETARI PRIVINDCALITATEA LAPTELUI MATERIE

    PRIMA OBTINUT IN JUDETUL

    CLUJ, DESTINAT PROCESARIIINDUSTRIALE

    Ob3. CERCETARI PRIVINDSTABILIREA UNUI MODEL

    MATEMATIC PENTRU

    CONCENTRATIA BACILLUS

    CEREUS IN TLF MODELARE SIMONITORIZARE

    ObS1.1 NCRCTURA MICROBIAN AATMOSFEREI DIN ADPOST

    ObS1.3 INFLUENA EFECTULUI DECONTAMINANTAL UNOR SUBSTANE DEZINFECTANTE ASUPRACALITII IGIENICE A LAPTELUI

    ObS2.1 DETERMINAREA COMPOZIIEICHIMICE I A NCRCTURII MICROBIENEDIN LAPTE

    ObS3.1 MODELAREA CONCENTRATIEISPORILOR DEBACILLUS CEREUS

    ObS3.2 MONITORIZAREA CONCENTRATIEISPORILOR DEB. CEREUS IN TLF

    Metoda s

    Examenu

    Determinchimici

    Determin(NCS) i n

    Stabilirea

    Simulare f

    Recoltarea

    Analiza m

    Analiza st

    ObS1.2 IGIENA RECIPIENTELOR DESTINATEMULSULUI SI IGIENA UGERULUI

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    MATERIALE I METODE

    METODELE UTILIZATE N ATINGEREA OBIECTIVELOR SUNT:

    6.1. DETERMINAREA AEROMICROFLOREI DIN ADPOSTURI

    6.1.1. Metoda sedimentrii Koch6.1.2. Examenul bacteriologic calitativ

    6.2. DETERMINAREA MICROFLOREI DE PE GLEI, BIDOANE, TANCURI DE

    RCIRE A LAPTELUI I MAMELOANE

    6.3. DETERMINAREA COMPOZIIEI CHIMICE I A NCRCTURII

    MICROBIENE DIN LAPTE

    6.4. MODELAREA CONCENTRAIEI SPORILOR DEBACILLUS CEREUS

    6.4.1. Stabilirea i elaborarea modelului matematic6.4.2. Simulare folosind modelul elaborat (modelare)

    6.5. MONITORIZAREA CONTAMINRII TANCURILOR DE RCIRE A

    LAPTELUI DIN FERME CU SPORI DEBACILLUS CEREUS

    6.5.1. Recoltarea probelor

    6.5.2. Analiza microbiologic

    6.5.3. Analiza statistic

    REZULTATE I DISCUII

    O.G. 1: Cercetri privind influena unor factori de igien asupra calitii laptelui

    crud

    n studiul de fa s-a urmrit msura n care calitatea igienic a laptelui crud este

    influenat de factorii care depind microclimatul din adpost, de igiena recipientelor

    destinate mulsului, de igiena glandei mamare precum i de aciunea decontaminant aunor substane dezinfectante.

    Pentru ndeplinirea acestui obiectiv general (O.G.) au fost propuse urmtoarele

    obiective specifice (O.S.):

    ncrctura microbian a atmosferei din adpost; igiena recipientelor destinate mulsului i transportului laptelui pn la centrul

    de colectare;

    igiena glandei mamare;

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    influena efectului decontaminant al unor substane dezinfectante asupracalitii laptelui materie prim.

    O.S. 1.1. ncrctura microbian a atmosferei din adpost

    Design experimentalA fost monitorizat numrul total de germeni mezofili aerobi (NTGMA),

    stafilococii i bacteriile coliforme. Probele au fost recoltate dintr-o exploataie de tip

    gospodresc, dimineaa i seara, pe parcursul a 4 luni din an (fiecare lun aparinnd unui

    anotimp) prin metoda sedimentrii (Koch). Plcile cu medii de cultur au fost expuse

    timp de 10 minute, n incinta adpostului, n apropierea trenului posterior al animalului,

    aproximativ la nlimea ugerului (35-45 cm).

    Recoltarea probelor s-a efectuat pe medii de cultur selective: pentru numrul total

    de germeni mezofili aerobi (NTGMA) geloz nutritiv; pentru stafilococi mediul

    Baird-Parker; pentru bacterii coliforme mediul Istrati-Meitert. Dup recoltare s-a

    procedat la incubarea plcilor la 37C timp de 48 de ore. Exprimarea numrului de

    germeni s-a fcut la 1 m3 de aer.

    284955

    859653.5

    724310736352.7

    606413.2

    407339.7

    450365.7

    248429

    250000250000250000250000

    0

    100000

    200000

    300000

    400000

    500000

    600000

    700000

    800000

    900000

    A B C D

    N/m3

    Dimineata/Morning Seara/Evening LMaxA

    Figura 7.1. NTGMA dimineaa i seara

    n timpul programului de diminea s-au nregistrat valori mai ridicate n toate

    etapele determinrii (Figura 7.1). Cea mai ridicat ncrctura microbian s-a nregistrat

    n cazul administrrii i consumului de furaje fibroase (B) iar cea mai mic, la 25-30

    minute dup evacuarea dejeciilor i aerisire (A). Limita maxim admis pentru NTGMA

    a microflorei din adposturi este de 250.000 uniti formatoare de colonii/m3 (DECUN,

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    1997). Aceast valoare a fost depit n aproape toate cazurile, cu excepia cazului A (la

    25-30 minute dup evacuarea dejeciilor i aerisire), seara.

    310954 301553.5234876 219384.5

    892194960463

    615863

    723492.5

    431591.5496970.5

    374530412319

    680249

    250000250000250000250000

    0

    100000

    200000

    300000

    400000

    500000

    600000

    700000

    800000900000

    1000000

    1 4 7 9

    Luna/Month

    N/m3

    A

    B

    C

    D

    LMaxA

    Figura 7.2. NTGMA n cele 4 luni

    Cea mai ridicat ncrctura microbian s-a nregistrat n luna aprilie pentru 3 din

    cele 4 operaii tehnologice luate n studiu, iar cea mai sczut n luna iulie. O excepie o

    constituie cazul A (la 25-30 minute dup evacuarea dejeciilor i aerisire), n care cea mai

    mare ncrctur microbian s-a observat n luna ianuarie iar cea mai mic n lunaoctombrie. Limita maxim admis pentru NTGMA a microflorei din adposturi a fost

    depit n aproape toate cazurile, cu excepia cazului A, n lunile iulie i octombrie.

    O.S. 1.2. Igiena recipientelor destinate mulsului

    n acest subcapitol s-a urmrit eficiena igienizrii recipientelor destinate mulsului,

    transportului, colectrii i depozitrii laptelui att n sistem gospodresc ct i n

    exploataii de tip semiintensiv.

    n vederea ndeplinirii acestui obiectiv specific au fost urmrite urmtoareleactiviti (A):

    ncrctura microbian a gleilor de muls dup igienizare n 3 gospodrii (G1,G2 i G3);

    ncrctura microbian a bidoanelor transportoare dup igienizare n 3gospodrii (G1, G2 i G3);

    ncrctura microbian a bidoanelor de muls dup igienizare n 4 ferme (F1,F2, F3 i F4);

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    ncrctura microbian a bazinului de stocare i rcire a laptelui crud dupigienizare n 4 ferme (F1, F2, F3 i F4).

    Design experimental

    Pentru testarea eficienei igienizrii (splare cu ap cald i detergent) n sistemgospodresc, a fost monitorizat numrul total de germeni mezofili aerobi (NTGMA),

    stafilococii i bacteriile coliforme de pe suprafaa interioar a gleilor de muls, dup

    igienizarea acestora, din 3 gospodrii. Din fiecare gospodrie au fost recoltate cte 10

    probe de sanitaie.

    Cea mai ridicat ncrctur microbian a gleilor a fost nregistrat la gospodria

    G2, urmat de gospodriile G1 i G3. Diversitatea rezultatelor obinute denot

    variabilitatea individual n contiinciozitatea aplicrii msurilor de igienizare i a

    substanelor utilizate n acest proces. Datorit ncrcturii microbiene ridicate este

    necesar folosirea unor substane decontaminante mai complexe.

    469.9

    315.9

    129.8

    15.7

    1 1 1 10

    50

    100

    150

    200

    250

    300

    350

    400

    450

    500

    F1 F2 F3 F4

    N/cm

    2

    NTGMA LMaxA

    Figura 7.12. NTGMA n tancurile de rcire i stocare a laptelui

    Conform OMS 976 din 1998 limita maxim admis pentru numrul total de

    germeni este de 1/cm2. n cazul n care bacteriile coliforme sunt absente, se admit 20/cm2.

    n bazine, tancuri i aparate, bacteriile coliforme trebuie s fie absente/10 cm2.

    Att n cazul NTGMA ct i n cazul bacteriilor coliforme aceste limite au fost cu

    mult depite.

    n cazul stafilococilor nu este prevzut o limit maxim admis.

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    n cazul fermei n care s-a aplicat o substana decontaminant, parametrii

    microbiologici s-au situat cel mai aproape de limita maxim admis.

    Igienizarea tancurilor de stocare i rcire const n cltire cu ap rece, splare cu

    ap caldi detergeni i limpezire cu ap rece n fermele F1, F2 i F3, iar in ferma F4sunt folosite i substane decontaminante. Diversitatea rezultatelor obinute n cazul

    fermelor F1, F2 i F3 denot variabilitatea individual n contiinciozitatea aplicrii

    substanelor utilizate n procesul de igienizare. Cea mai redus ncrctur microbian s-a

    nregistrat n cazul fermei F4, la care, n procesul de igienizare a fost folositi substane

    decontaminante.

    O.S. 1.3. Igiena glandei mamare

    Igiena ugerului i igiena animalului este foarte important, mai ales n exploataiile

    de tip gospodresc, unde se practic mulsul manual, n vase deschise, astfel nct

    posibilitatea contaminrii laptelui ca urmare a contactului direct cu tegumentele este

    foarte ridicat. n acest studiu s-a urmrit efectul igienizrii ugerului animalelor crescute

    n sistem gospodresc i exploataii semiintensive asupra ncrcturii microbiene a

    mameloanelor.

    n vederea ndeplinirii acestui obiectiv specific au fost urmrite urmtoarele

    activiti (A):

    ncrctura microbian de pe suprafaa mameloanelor animalelor crescute nsistem gospodresc att n perioada de stabulaie ct i de punat;

    ncrctura microbian de pe suprafaa mameloanelor animalelor crescute nsistem gospodresc, nainte i dup igienizare;

    ncrctura microbian de pe suprafaa mameloanelor animalelor crescute nexploataii semiintensive (ferme), nainte i dup igienizare, att n perioada de stabulaiect i de punat.

    Design experimental

    Pentru a urmri eficiena igienizrii ugerului n sistem gospodresc, s-au luat n

    studiu 5 vaci de lapte aparinnd celor 3 gospodrii i s-a urmrit ncrctura microbian

    (NTGMA, stafilococii i bacteriile coliforme) recoltnd tampoane de sanitaie de pe

    suprafaa mameloanelor animalelor nainte i dup igienizare, in numr de cinci repetiii.

    De asemenea s-a mai urmrit NTGMA n perioada de stabulaie i de punat n cele 3

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    gospodrii (G1, G2 i G3). n cele 3 gospodrii s-a realizat o igienizare diferit a glandei

    mamare, dup cum urmeaz:

    S - splare cu ap curat; S+Sp+L - splare cu ap curat, spunire, limpezire; S+Sp+L+D - splare cu ap curat, spunire, limpezire, decontaminare cu

    Premacid (1.5%);

    Dc - protecie cu Diemacid color ntre cele dou mulsori.254660

    88250

    2209.4 217.4

    55052

    0

    30000

    60000

    90000

    120000

    150000

    180000

    210000

    240000

    270000

    FS S S+Sp+L S+Sp+L+D Dc

    N/cm

    2

    NTGMA

    Figura 7.15. NTGMA nainte i dup procedeele de igienizare

    Coroborarea a ct mai multor procedee de igienizare i aplicarea acestora asupra a

    ct mai multor operaiuni tehnologice, a crescut eficiena acestora comparativ cu efectul

    lor separat.

    Obinerea unei ncrcturi microbiene ct mai reduse la suprafaa mameloanelor,

    depinde n mare parte i de ncrctura microbian iniial.

    Concluzii pariale

    Aeromicroflora adpostului a nregistrat valorile cele mai ridicate n toate

    operaiile tehnologice, dimineaa. Cea mai ridicat ncrctura microbian s-a nregistrat

    n cazul administrrii i consumului de furaje fibroase (B), urmat de ncrctura

    microbian a atmosferei din adpost, n timpul administrrii i consumului de furaje

    concentrate (C), de ncrctura microbian a atmosferei din adpost, n timpul mulsului

    (D) iar cea mai mic de ncrctura microbian la 25-30 minute dup evacuarea

    dejeciilor i aerisire (A).

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    Recipientele folosite la obinerea, stocarea i transportul laptelui sunt fiecare n

    parte, surs suplimentar de contaminare microbian a laptelui. Cea mai ridicat

    ncrctur microbian att n cazul gleilor ct i n cazul bidoanelor de transport a fost

    nregistrat la gospodria G2, urmat de gospodriile G1 i G3. Diversitatea rezultatelorobinute denot variabilitatea individual n contiinciozitatea aplicrii msurilor de

    igienizare i a substanelor utilizate n acest proces. n urma procedeelor de igienizare a

    bidoanelor de muls n ferme, ncrctura microbian a sczut n ordinea: F1 (cltire cu

    ap la temperatura la care este furnizat de reeaua de distribuie, fr s se foloseasc

    detergeni sau substane decontaminante)> F2 (splare cu ap caldi detergeni urmat

    de cltire) > F3 (splarea cu ap caldi detergeni urmat de cltire) > F4 (splarea cu

    ap cald i detergeni urmat de cltire i folosirea unei substane decontaminante).

    Diversitatea rezultatelor obinute ntre F2 i F3 denot variabilitatea individual n

    procesele de igienizare. n urma procedeelor de igienizare a bazinelor de stocare i rcire,

    ncrctura microbian a sczut n ordinea: F1 > F2 >F3 > F4. Igienizarea const n

    cltire cu ap rece, splare cu ap caldi detergeni urmat de limpezire cu ap rece n

    fermele F1, F2 i F3, iar n ferma F4 sunt folosite i substane decontaminante.

    Diversitatea rezultatelor obinute ntre F1, F2 i F3 denot variabilitatea individual n

    procesele de igienizare.

    Att n sistem gospodresc, ct i n exploataiile de tip semiintensiv, ncrctura

    microbian de pe mameloane a fost mai mare n stabulaie dect pe punat, fiind

    probabil influenat i de microflora din adposturi. Coroborarea a ct mai multor

    procedee de igienizare a ugerului, a crescut eficiena acestora n ceea ce privete

    reducerea ncrcturii microbiene comparativ cu efectul lor separat n ordinea: FS > L >

    S+Sp+L > S+Sp+L+D. n urma procedeelor de igienizare a ugerului n ferme, aceasta asczut n ordinea: F1 (splare uger cu ap curat, schimbat la 2-3 animale) >F2 (splare

    uger cu ap curat, schimbat la fiecare animal) >F3 (splare uger cu ap curat,

    schimbat la fiecare animal precum i folosirea unei substane protectoare la nivelul

    mameloanelor ntre cele 2 mulsori) >F4 (folosirea unei substane decontaminante nainte

    i dup splarea ugerului).

    Evoluia ncrcturii microbiene din laptele obinut n gospodrii i ferm,

    nregistreaz un trend descendent odat cu fiecare msur de corecie aplicat n

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    tehnologia de exploatare a vacilor de lapte n ordinea: Lci > Ia+R > Im+Iu > Ic+T+I+Pm.

    Rezultate bune n ameliorarea calitilor igienice ale laptelui crud materie prim, se obin

    numai dac se acioneaz simultan asupra tuturor operaiilor tehnologice.

    O.G. 2: Cercetri privind calitatea laptelui materie prim obinut n judeul Cluj,

    destinat procesrii industriale

    n studiul de fa s-a urmrit calitatea laptelui crud provenit de la 13 ferme din

    judeul Cluj prin urmrirea unor parametrii fizico-chimici i microbiologici prevzui n

    cerinele de calitate pentru laptele crud. n urma investigaiilor, laptele crud a putut fi

    declarat ca fiind conform/neconform pentru procesare.

    Pentru ndeplinirea acestui obiectiv general (O.G.) au fost propuse urmtoarele

    obiective specifice (O.S.):

    determinarea parametrilor fizico-chimici: coninutul n grsime, protein,substan uscat negras (S.U.N.), punct de nghe (apa adugat) i compararea cu

    limitele maxime/minime admise de SR 2418:2008;

    determinarea numrului de celule somatice (NCS) i numrului total degermeni (NTG)/ml la 30C si a numrului de celule somatice/ml i compararea lor culimitele maxime admise prevzute nRegulamentul (CE) nr. 1.664/2006.

    Design experimental

    Au fost prelevate probe de lapte de la 13 ferme din judeul Cluj, la care au fost

    monitorizai parametrii fizico-chimici i microbiologici anterior menionai pe parcursul a

    6 luni (ianuarie-august) a anului 2009.

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    71.13

    1916.92

    4043.67

    27.75 139.93134.27464.9

    1232.84

    5682.89

    635.07

    1571.56

    144.736.091000

    1000

    2000

    3000

    4000

    5000

    6000

    1 2 3 4 5 6 7 8 9 10 11 12 13

    N/cm

    3x1

    03

    NTG/TBC LMaxA

    Figura 7.30. Numrul total de germenin figura 7.30 este reprezentat grafic valoarea medie a numrului total de

    germeni. Pentru acest parametru, Regulamentul (CE) nr. 853/2004 prevede o valoare

    maxim admis de 100.000 uniti formatoare de colonii/cm3. Cea mai mic valoare a

    fost nregistrat la ferma 4 (F4) iar cea mai mare valoare s-a nregistrat la ferma 10 (F10).

    NTG a depit limita maxim admis la laptele provenit de la fermele 2 (F2), 3 (F3), 8

    (F8), 9 (F9), 10 (F10), 11(F11) i 12 (F12), ceea ce reprezint 61.53% din totalul

    unitilor luate n studiu.

    Concluzii pariale

    n 23.08% din ferme (cazul fermelor F1, F4, F5), laptele a fost conform att din

    punct de vedere fizico-chimic ct i din punct de vedere microbiologic.

    n 38.46% din ferme (cazul fermelor F2, F7, F8, F9, F12), laptele a fost conform

    doar din punct de vedere fizico-chimic, dar nu i microbiologic.

    n 38.46% din ferme (cazul fermelor F3, F6, F10, F11, F13) laptele nu a corespuns

    nici din punct de vedere fizico-chimic, nici din punct de vedere microbiologic.

    O.G. 3: Cercetri privind stabilirea unui model matematic pentru concentraia

    Bacillus cereus n tancurile de rcire a laptelui din ferme modelare i monitorizare

    n studiul de faa s-a efectuat o abordare similar a obiectivelor legate de

    contaminarea TLF cuB. cereus.

    Activitile (A) studiului au constat n:

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    identificarea cantitativ a factorilor ce afecteaz concentraia bacteriilorsporulate deB. cereus la nivelul TLF;

    i determinarea scderii concentraiei ce poate fi realizat prin intermediulunor msuri implementate la nivelul fermelor.

    Pe baza acestor informaii s-a elaborat ostrategie de control a contaminrii cuB.

    cereus.

    A 1. Strategia de control

    Concluzii pariale

    Concentraia sporilor de B. cereus din laptele crud depozitat n bazinele de

    colectare de la procesatorii de lapte este determinat de 15% din laptele livrat din

    tancurile de rcire a laptelui din ferme (TLF) cu cea mai mare concentraie de spori. n

    cazul n care instalaiile de muls nu sunt curate n mod corespunztor, cele mai mari

    concentraii ale sporilor de B. cereus se observ n timpul perioadei de punat atunci

    cnd solul conine mai mult de 4 log10 spori/g.

    Pe parcursul perioadei de punat, o concentraie a sporilor B. cereus n TLF sub

    LMA poate fi asigurat dac contaminarea mameloanelor ugerului cu spori de la nivelulsolului este limitat i msurile de curire a ugerului sunt optimizate. Comparativ cu

    situaia actual, punerea n aplicare a acestor msuri are ca urmare o reducere de

    aproximativ 99% a concentraiei medii din laptele crud n timpul perioadei de punat.

    Pentru a asigura o concentraie n TLF sub LMA pe parcursul stabulaiei, furajele

    animalelor ar trebui s conin spori deB. cereus sub LMA i pH-ul raiei s fie mai mic

    de 5.

    Acest studiu a artat c, n timpul punatului i stabulaiei sporii de B. cereusprezeni n TLF, provin cel mai probabil din furaje i sunt transmii la TLF prin fecale i

    murdria exterioar a ugerului. Cu toate acestea, n acest studiu nici una dintre probele

    TLF nu conine o concentraie a sporilor care s depeasc LMA (3 log10 spori/l),

    indicnd faptul c transmiterea sporilor deB. cereus prin intermediul acestei ci este, se

    pare, sub control. Cu toate acestea, este foarte important s se previn contaminarea

    mameloanelor ugerului cu spori de la nivelul solului n timpul punatului, deoarece

    concentraiile de B. cereus n sol sunt de aproximativ 100 de ori mai mari dect n ali

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    factori de mediu (furaje, materii fecale i materialul folosit la aternut). Acest lucru

    presupune faptul c transmiterea unor cantiti relativ mici de sol, 1 la 13 mg/l, poate

    duce la o concentrare mai mare n TLF care s depeasc LMA.

    A 2. Controlul concentraiei B. cereus n TLF

    Concluzii pariale

    ConcentraiaB. cereusn TLF depinde de transmiterea bacteriilor la TLF prin ci

    externe de contaminare i anume prin intermediul mameloanelor ugerului de la

    exteriorul acestora i prin intermediul echipamentului de muls. n plus cretereaB. cereus

    n timpul depozitrii n TLF poate determina creterea concentraiei. Cercetrile efectuate

    n cadrul obiectivului 3 confirm faptul cB. cereus este transmis n general la TLF de la

    exteriorul mamelelor ugerului contaminat cu spori. B. cereus transmis de pe suprafaa

    exterioar contaminat a mamelelor ugerului provine n special din nutreul contaminat.

    n cazul n care concentraia de B. cereus din TLF depete LMA, solul este probabil

    surs principal de contaminare (Obiectivul 3 capitolul 7, 7.3.2). n aceast tez a fost

    acordat o atenie redus transmiterii B. cereus la TLF avnd ca surs de contaminare

    echipamentul de muls. Aceasta reprezint o cale de contaminare mai rar, dar un calcul

    fundamental arat c aceast posibilitate de contaminare nu poate fi neglijat fr

    consecine semnificative (7.3.2). Cu toate acestea, o cretere a B. cereus n timpul

    depozitrii n TLF este neglijabil n cazul n care tancul de rcire din ferme este

    proiectat i funcioneaz n conformitate cu specificaiile standardizate ISO 5708

    (7.3.1).

    Tabelul 8.1 prezint metodele necesare pentru a menine concentraiaB. cereus n

    TLF sub LMA. n primul rnd, riscul transmiterii B. cereus prin intermediul celei maiimportante ci de contaminare (nutre-materii fecale-TLF) trebuie minimizat. Msurile

    eseniale constau n meninerea unui nivel redus al contaminrii iniiale a nutreului (sub

    3 log10 spori/g) i n msuri necesare preveniei creterii i proliferrii B. cereusn cile

    de transmitere. Cea mai bun metod de prevenire a creterii B. cereus este meninerea

    unui pH sub 5 (7.3.1). Experimentele trebuie s fie realizate pentru a stabili daci n ce

    msurB. cereus poate s creasc n silozul amestec i n materialul utilizat ca aternut.

    Pe lng controlul cii dominante de contaminare trebuie instituite i implementate o

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    serie de msuri de prevenie a incidentelor, definite ca situaii excepionale, n care se

    produce creterea concentraiei deB. cereus n TLF peste LMA. Incidentele ce pot aprea

    constau n contaminarea mameloanelor ugerului cu cantiti considerabile de sol

    contaminat (risc de transmitere aB. cereus n cazul unei cantiti de sol de 1 mg/l n TLF)sau n cazul currii i igienizrii improprii a echipamentului de muls (GRIFFITHS i

    PHILLIPS, 1990). n scopul stabilirii necesitii lurii de msuri care s reduc

    probabilitatea transmiterii B. cereus n situaiile identificate anterior trebuie evaluate n

    primul rnd frecvena i impactul acestor incidente, situaii de risc.

    CONCLUZII GENERALE

    Rezultatele experimentelor efectuate n cadrul obiectivului 1 au dus la concluzia c

    n fermele unde se folosete un sistem nchis de adpost, mulsul se face n glei, cltirea

    ugerului cu ap, i unde nu se folosesc msuri de dezinfecie pre - i post-muls, calitatea

    microbiologic a tancurilor de colectare a laptelui este n general mai redus. Aceste

    rezultate subliniaz importana msurilor de igienizare i dezinfecie optim implementate.

    n opinia noastr, dei n fermele mari condiiile tehnice i de mediu ce intervin i

    influeneaz calitatea i producia laptelui sunt mai favorabile, n circumstane adecvate i

    prin respectarea cerinelor de igien fermele mici ce utilizeaz un mod de adpost nchis

    i muls n glei pot produce lapte cu calitate igienic ridicat.

    Cercetrile ntreprinse n cadrul obiectivului 1 i 2 ne determin s concludem c

    procedurile de muls i modalitile de pregtire a ugerului au efecte semnificative asupra

    numrului total de germeni - NTG (TPC - Total Plate Cont) comparativ cu ali factori ce

    au fost analizai. n fermele mici i medii, combinarea modalitilor de muls n flux i

    sistem de adpostire nchis, pregtirea igienici dezinfecia ugerului reprezint msurice mbuntesc semnificativ calitatea igienic a laptelui. n fermele mari combinaia

    ntre msurile de igien implementate n sala de muls sistem de stabulaie liber i

    pregtirea uscat a ugerului duce la o producie de lapte de calitate semnificativ

    mbuntit.

    Rezultatele studiilor efectuate asupra probelor de mediu arat ct de importante

    sunt condiiile de igien la nivelul microaeroflorei fermelor de lapte n timpul adpostirii,

    mulsului, manipulrii i procesrii laptelui (aruncarea regulati ndeprtarea gunoiului

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    Avnd in vedere ca n unele ferme a fost depit limita maxima admis n ceea ceprivete ncrctura microbian a laptelui, se recomandrespectarea condiiilor de

    igien impuse de GHP (Good Hygiene Practices) Proceduri de Bun Igien - n

    ferme.Instruirea permanent a mulgtorilor icreterea contiinciozitiin executarea

    manoperelor de igienizare devin astfel sarcini permanente.

    Introducerea unui set de proceduri de verificare i monitorizare a concentraieimicrobiene la nivelul TLF stabilite prin aplicarea modelelor matematice n cadrul

    sistemului HACCP (introducerea unei noi etape n sistemul HACCP aplicat n

    vederea meninerii calitii i conformitii igienice a laptelui materie prim

    destinat procesrii modelarea matematic pentru monitorizarea contaminrii

    laptelui n tancul de rcire a laptelui din ferme cu B. cereus).

    ELEMENTE DE ORIGINALITATE

    Aplicarea unor modele matematice n determinarea predictibil aconcentraiei microbiene a bacteriilor sporulate Bacillus cereus

    (microbiologie predictiv) asociate cu abordri clasice

    Abordarea conceptului de calitate i conformitate igienic a laptelui materieprim prin metode matematice modelare i monitorizare inclus n

    Sistemele de Management al Calitii HACCP i PBI (Practici de Bun

    Igien)

    PERSPECTIVE DESCHISE DE STUDIILE EFECTUATE

    Aplicarea modelrii matematice i n alte cazuri de contaminare cumicroorganisme (NTG), n special pentru microorganisme ce pot altera

    considerabil calitatea laptelui materie prim destinat procesrii industriale

    (cu repercusiuni economice) precum i cu impact asupra strii de sntate a

    consumatorului (aspecte legate de sigurana i securitatea alimentar)

    pentru a stabili riscurile de contaminare i a elabora masuri/aciuni

    corective n cadrul sistemului de analiz a risculuii de management al

    riscului;

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    n afara modelrii se pot efectua studii privind aplicarea reelelorneuronale artificiale pentru constituireamodelelor de predictibilitate;

    Aplicarea modelelor de simulare n sistemul de calitate al fermei prinincluderea unei etape de modelare matematic (n care s se aplicealgoritmi matematici adecvai) n vederea mbuntirii sistemului de

    management al calitii HACCP;

    Studii exhaustive pe un numr mare de ferme pentru a obine seturi de dateextensive utile prelucrrilor i abordrilor informatice i modelrii;

    Extinderea studiilor pe lanul alimentar lapte de consum i produselactate.

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    UNIVERSITY OF AGRICULTURAL SCIENCES ANDVETERINARY MEDICINE CLUJ-NAPOCA

    DOCTORAL SCHOOLVETERINARY MEDICINE FACULTY

    SPECIALIZATION: VETERINARY FOOD TECHNOLOGY AND

    EXPERTISE

    Eng. ANGELA CARMEN D. OARGA

    RESEARCH ON THE QUALITY OF THE RAW MILK

    FOR INDUSTRIALIZATION IN PROCESSING UNITS

    FROM CLUJ COUNTY

    (SUMMARY OF Ph.D. THESIS)

    Scientifical coordinatorProf. Univ. Dr. CORNEL LASLO

    CLUJ-NAPOCA

    2010

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    JUSTIFICATION OF THE RESEARCH TOPIC

    Milk is one of our staples in nutrition because it contains all the nutrients

    necessary for growth, normal development and function of the body. Milk processingdairy sour milk gives some new properties of great importance, namely: increased food

    value, biological, providing them with dietary and therapeutic properties. In terms of

    technology, dairy foods (yogurt, kefir, buttermilk), involves a series of common stages of

    all sorts, but also some distinct phases that prints certain organoleptic properties, physico-

    chemical processes that produced them individually. In the studies, we aimed to

    investigate, deepening and completing the data from the literature with own observations.

    The first part includes a bibliographical study, data on the subject studied, and the

    second part are described researches. The thesis brings up to date information on the

    current state of knowledge in the field of quality and hygiene requirements of raw

    materials for industrialization in milk processing units in the county of Cluj. The second

    part of the work, individual contributions is structured in four chapters of the surveys are

    presented data on quality and hygienic aspects of different types of sour milk products.

    Milk quality and hygienic condition depend on a number of factors related to the

    health of the animals, milking hygiene conditions, hygienic conditions of transport,

    handling, storage.

    The thesis " Research on the quality of raw milk processing units for

    industrialization in Cluj County" is conceived as a whole, clear-cut systematic chapters 8

    and references.

    In the first part (I), this thesis includes a literature study on milk composition,

    physico-chemical properties and technological aspects of raw milk microflora and factorsthat influence the hygienic quality of raw milk as a method of modeling and

    control microflora of raw milk. In the second part (II) are given your own research with

    experimental design, methods, results and discussion (structured main objectives, each

    with specific objectives and activities to fulfill the purpose of sentence), the conclusions

    and recommendations.

    The term of validity and hence the life of dairy products depends partly on the

    concentration of bacilli spores in general, and especially the concentration of Bacillus

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    cereus in raw milk. Depending on the translation in the operational chain pathways have

    been developed two simulation models for quantitative identification of high-impact

    factors on the concentration of bacilli spores in farm tank milk (FTM). In addition,

    models were used to reduce the concentration that can be achieved by measuresimplemented at farm level. Developing a predictive model of concentration bacilli spores

    in the soil conditions is the only source of contamination select the most relevant route of

    contamination as grazing and sheltering animals in the barn/stable.

    In the case of soil teats contamination with an estimated 33% of TLF than the

    maximum admissible containing bacillus spores of Bacillus cereus (LMA) of 3 log10

    spores/l. If the fodder is the main source of contamination only 2% of the FTM are

    contaminated. Based on the predicted concentrations of bacillus spores ofBacillus cereus

    concentration in TLF - was calculated as the average concentration in raw milk stored at

    a processor during the grazing period being 3.5 log10 spores/l milk and fold during the

    housing of animals being 2.1 log10 spores/l. It is estimated that during the grazing season

    can be achieved a 99% reduction, where all farm holdings minimize contamination of

    teats with soil and optimize sanitation procedures teats. While animals in the stable

    housing and accommodation, it is possible to reduce the concentration by 60% by

    keeping the concentration of bacilli spores in animal feed as 3 log10 spores/g and reported

    to feed silage pH below 5. Implementation of these measures at farm level that the

    concentration ofB. cereus bacteria in raw milk sporulailor that rarely exceeds MSL.

    B. cereus growth often limited shelf life of pasteurized dairy products stored at

    refrigeration. Milk products contaminated withB. cereus defects such as sensory changes

    of aroma, coagulation sweet and bitter taste of the cream neacid (OVERCAST and

    ATMARAM, 1971, STONE and ROWLANDS, 1952). The incidence of B. cereus inmilk products comes at least partly, by the contamination at the farm level. Because B.

    cereus bacilli owners they are not able to survive the pasteurization process. In addition,

    recontamination can occur during the processing of milk due to improper implementation

    of sanitation procedures for pasteurisation equipment (LIN et al., 1998, SVENSSON et

    al., 2000, Te GIFFEL et al., 1996). To prevent spoilage of pasteurized milk, B. cereus

    should be controlled and monitored through quality management systems applied in the

    food chain - this can be achieved by introducing a new procedure in the Quality

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    Management System Food namely modeling and monitoring microbial contamination by

    establishing a predictive algorithm for the evolution of parameters over time, and

    contamination. It is important to reduce the concentration of B. cereus spores in milk,

    properly implemented measures at farm level or bacto-spin (Belgian process of removingbacteria from the milk by centrifugation at high speed - (HSC - High Speed

    Centrifugation) and prevent recontamination and growth of bacteria during processing.

    Regarding these issues, there are few studies on the measures necessary to achieve a

    significant reduction at the farm level and the quantitative effects of potential

    contamination control measures FTM. Raw milk from the milk tank industrial processors

    is a relatively large amount of milk from the dairy tanks (FTM). Concentration ofB.

    cereus sporulated bacilli in raw milk represents a weighted average concentrations ofB.

    cereus in different batches delivered from FTM. The most common sources of spores in

    the farm environment are feed, feces, bedding material and soil. Spores from these

    sources are transferred to milk in a number of steps. Basically two overlapping routes or

    contamination pathways for bacterial spores can be distinguished.

    The first contamination pathway starts with feed. Spores in feed such as silages

    pass the gastrointestinal tract of cows unharmed and accumulate in feces. Feces and

    bedding material contaminate the cows teats. Teat cleaning prior to milking only partly

    reduces attached dirt and spores (VISSERS and DRIEHUIS, 2003). During milking,

    feces, bedding material and spores on the surface of teats are transmitted to milk (Te

    GIFFEL et al., 2002).

    The second contamination pathway starts with soil. Especially during grazing, soil

    can contaminate the exterior of teats and, as in the first pathway, spores originating from

    soil are transmitted to FTM during milking. Elevated B. cereus spore concentrationsduring the summer months have been associated with the transmission of soil to FTM

    (CHRISTIANSSON et al., 1999 SLAGHUIS et al., 1997). In the remainder of this thesis

    the mixture of feces, bedding material and/or soil attached to the teats is referred to as dirt.

    For efficient management of the farm is important to identify the most effective measures

    to reduce the concentration of B. cereus in FTM. Depending on the route of

    contamination, VISSERS et al. (2003) have established a simulation model to identify a

    strategy for controlling the concentration of butyric acid bacteria spores in the FTM. The

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    model contains variables is interpretable and measurable effects of uncontrollable

    variables. A control strategy was developed using Monte-Carlo simulation model.

    Experimental results from this thesis were published in scientific papers that are

    listed in the bibliography.

    REFENCES

    1. Overcast, W.W., K. Atmaram. 1971. The role ofBacillus cereus in sweet curdling offluid milk.Journal of Milk and Food Technology37, 233-236

    2. Stone, J.M., A. Rowlands. 1952. 'Broken' or 'bitty' cream in raw and pasteurized milk.Journal of Dairy Research19, 51-62.

    3. Lin, S., H. Schraft, J.A. Odumeru, M.W. Griffiths. 1998. Identification ofcontamination sources ofBacillus cereus in pasteurized milk. International Journalof Food Microbiology 43, 159-171.

    4. Svensson, B., A. Eneroth, J. Brendehaug, G. Molin, A. Christiansson. 2000.Involvement of a pasteurizer in the contamination of milk by Bacillus cereus in acommercial dairy plant.Journal of Dairy Research 67, 455-460.

    5. Te Giffel, M.C. 2003. Good hygiene practice in milk processing. Pages 68-79 inDairy processing - improving quality. G. Smit, ed. Woodhead Publishing Limited,Cambridge, UK.

    6. Te Giffel, M.C., R.R. Beumer, B.A. Slaghuis, F.M. Rombouts. 1995. Occurrence andcharacterization of (psychrotrophic) Bacillus cereus on farms in the Netherlands.

    Netherlands Milk and Dairy Journal49, 125-138.

    7. Slaghuis, B.A., M.C. Te Giffel, R.R. Beumer, G. Andre. 1997. Effect of pasturing onthe incidence ofBacillus cereus spores in raw milk. International Dairy Journal7,201-205.

    8. Walstra, P., J.T.M. Wouters, T.J. Geurts. 2005. Dairy Science and Technology.Taylor&Francis, New York.

    9. Griffiths, M.W., J.D. Phillips. 1990. Incidence, source and some properties ofpsychrotrophicBacillus found in raw and pasteurized milk.Journal of the Society for

    Dairy Technology 43, 62-66.10.Saran, A. 1995. Disinfection in the dairy parlour.Rev. Sch. tech. off. int. Epiz. 14 (1),

    207-224

    11.Christiansson, A., J. Bertilsson, B. Svensson. 1999.Bacillus cereus spores in rawmilk: factors affecting the contamination of milk during the grazing period. Journalof DairyScience82, 305-314

    12.Vissers, M.M.M. and P. De Jong. 2003. Development and application of amodel predicting viscosity loss of yoghurt in processing equipment. IDF

    bulletin on fermented milks, 1, 233-240

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    13.Regulamentul (CE) nr. 853/200414.Regulamentul 1441/2006.15.SR 2418:200816.Regulamentul (CE) nr. 1.664/2006

    PERSONAL CONTRIBUTION

    The aim of the thesis involves the application of modern approaches with

    mathematical analysis and modeling methodologies related classical approach validated

    over time the quality of raw milk in developing applicable methodologies in quality

    management systems on farms producing milk for processing. Thesis research was

    structured inthree main objectives:Objective 1:Research on the influence of some factors on the quality of raw milk

    hygiene

    Objective 2: Research on the quality of raw milk produced in the county of Cluj,

    for industrial processing

    Objective 3: Research on the establishment of a mathematical model for the

    concentration of Bacillus cereus in milk cooling tanks - modeling and monitoring

    The research was conducted in households and small farms in the county of Cluj

    during 2005 (Objective 1), the routes for farm milk processing units in the county of Cluj

    during 2009 (Objective 2), and started under Erasmus fellowship (May-September 2004)

    to Wageningen University andfollow-up during 2006 on Cluj county farms (Objective 3).

    In research conducted in this thesis was aimed to evaluate the correlation between quality

    parameters of raw milk by determining hygienic factors depend on the microclimate of

    shelter, hygiene containers for milking hygiene mammary gland and decontaminated

    action of disinfectants. Researches have also sought to quantify the effectiveness of

    pollution control measures in farm milk tanks (FTM) with B. cereus spores by applying a

    simulation model (modeling).

    The results should lead to the establishment of a control strategy. First predictive

    models were established to estimate the concentration ofB. cereus in FTM.

    In Objective 1 Research on the influence of objective factors on hygienic quality

    of raw milk for industrial processing have been proposed followingspecific objectives:

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    MATERIAL AND METHODS

    The methods used to achieve objectives are:

    6.1. ASSESMENT OF AIRBORNE MICROFLORA IN SHELTERS

    6.1.1. Koch sedimentation method6.1.2. Qualitative bacteriological test

    6.2. ASSESMENT OF MICROFLORA FROM BUCKETS, CANS, MILK

    TANKS AND TEATS

    6.3. ASSESMENT OF MILK CHEMICAL COMPOSITION AND MICROBIAL

    LOAD

    6.4. MODELING THE CONCENTRATION OFBACILLUS CEREUS SPORES

    6.4.1 Model development

    6.4.2. Model simulation

    6.5. MONITORINIG THE CONTAMINATION OF FARM TANK MILK WITH

    BACILLUS CEREUS SPORES

    6.5.1. Sample collection

    6.5.2. Microbial analyses

    6.5.3. Statistical analyses

    RESULTS AND DISCUSSIONS

    G.O. 1: Research on the influence of some factors on the quality of raw milk hygiene

    The present study aimed to measure the hygiene quality of raw milk is influenced

    by factors that depend on the microclimate of shelter, hygiene containers for milking

    hygiene mammary gland and decontaminated action of disinfectants.

    To achieve this general objective(G.O.) the followingspecific objectives (S.O.)were proposed:

    microbial load of the atmosphere in the shelter; milking hygiene and transport containers designed to milk collection center; hygiene mammary gland; decontaminant influence of substances inhibiting effect on the hygienic quality

    of raw milk.

    S.O. 1.1. Microbial load of the atmosphere in the shelter

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    Experimental Design

    Was monitored mezofili total aerobic plate count (NTGMA), staphylococci and

    coliform bacteria. Samples were collected from a farm household type, morning and

    evening, during the four months of the year (every month belongs to a season)sedimentation method (Koch). Plates with culture media were exposed for 10 minutes

    inside the house, near animal's hindquarters about udder height (35-45 cm). Sampling

    was conducted on selective culture media: for total aerobic bacteria mezofili (NTGMA) -

    nutrient agar, for staphylococci - Baird-Parker medium, for coliform bacteria - Istrati-

    Meitert environment. After harvest, we proceeded to incubate the plates at 37C for 48

    hours. Expression of germ number was 1 m3 of air, using the Omeleanschi formula.

    284955

    859653.5

    724310736352.7

    606413.2

    407339.7

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    250000250000250000250000

    0

    100000

    200000

    300000

    400000

    500000

    600000

    700000

    800000

    900000

    A B C D

    N/m3

    Dimineata/Morning Seara/Evening LMaxA

    Figure 7.1. NTGMA in the morning and evening

    During the morning program have higher values in all stages of the determination

    (Figure 7.1). The highest microbial load was recorded for use and consumption of forage

    fiber (B) and the lowest at 25 to 30 min after the evacuation of manure and air (A).

    Maximum permissible limit of microflora NTGMA housing is 250.000 ufc/m3 (DECUN,

    1997). This value was exceeded in almost all cases except A (25-30 min after manure

    removal and ventilation), in the evevening.

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    310954 301553.5234876 219384.5

    892194

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    200000

    300000

    400000

    500000

    600000

    700000

    800000

    900000

    1000000

    1 4 7 9

    Luna/Month

    N/m3

    A

    BC

    D

    LMaxA

    Figure 7.2. NTGMA in the four monthsThe highest microbial load was recorded in April for three of the four operations

    studied technology and lowest in July. An exception is when A (25-30 minutes after the

    evacuation of manure and ventilation), the highest microbial load was observed in

    January and lowest in October. Maximum permissible limit of microflora in shelters

    NTGMA was exceeded in almost all cases, except A, in July and October.

    S.O. 1.2. Milking vessels hygiene

    In this subchapter keep track of containers for milking hygiene, transport,collection and storage of milk in both environmental conditions and semi-type holdings.

    In order to meet this specific objective were pursued the following activities (A):

    microbial load after cleaning milking buckets in three households (G1, G2 andG3);

    microbial cargo containers after cleaning conveyor in 3 households (G1, G2and G3);

    microbial cargo containers after cleaning milking the four farms (F1, F2, F3and F4);

    microbial load storage tank and cooling of raw milk after cleaning the fourfarms (F1, F2, F3 and F4).

    Experimental Design

    To test the effectiveness of hygiene (wash with warm water and detergent) in

    environmental conditions was monitored mezofili total aerobic plate count (NTGMA),

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    staphylococci and coliform bacteria on the inner surface of milking buckets after cleaning

    them, 3 households. From each household were collected for 10 samples of sanitation.

    The highest microbial load was recorded at the household buckets G2 followed by

    G1 and G3 households. Diversity results show individual variability in the measures ofhygiene consciousness and substances used in this process. Due to high microbial load of

    decontaminating substances is necessary to use more complex.

    469.9

    315.9

    129.8

    15.7

    1 1 1 10

    50

    100

    150

    200

    250

    300

    350

    400

    450

    500

    F1 F2 F3 F4

    N

    /cm2

    NTGMA LMax A

    Figure 7.12. NTGMA in the freezing and storage tank

    According to the WHO maximum permissible limit of 976 in 1998 for the totalnumber of germs is 1/cm2, if coliform bacteria are absent, allowed 20/cm2.

    In ponds, tanks and apparatus, coliform bacteria must be absente/10 cm2. So if

    NTGMA and if these limits coliforms were far exceeded, if staph is not provided for a

    maximum permissible limit. If a farm has been applied decontaminating substances,

    microbiological parameters were closest to the maximum extent permissible. Sanitation

    of storage tanks and cooling is rinse with cold water, wash with hot soapy water and rinse

    with cold water in farms F1, F2 and F3 and F4 are used in farm and decontaminating

    substances. Diversity results for farms F1, F2 and F3 show the individual variability in

    conscientiousness applying chemicals used in cleaning. The lower microbial load was

    recorded for F4 farm, where, in the process of cleaning and decontaminating substances

    was used.

    S.O. 1.3. Mammary gland hygiene

    Udder hygiene and animal hygiene is very important, especially in household type

    farms, where hand milking is practiced in open vessels, so that the possibility of milk

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    contamination due to direct contact with the skin is very high. In this study we followed

    the effect of udder hygiene and environmental conditions of animals raised on farms semi

    microbial load of teates. In order to meet this specific objective were pursued the

    followingactivities (A): microbial load on the surface of the teates reared animals both in the

    environmental conditions indoors and grazing;

    microbial loads on animals kept nipple area environmental conditions beforeand after cleaning;

    microbial load on the surface of semi teates farmed animals (farm) before andafter cleaning, both in the stalls and pasture.

    Experimental Design

    To track the effectiveness of udder hygiene environmental conditions were studied

    five cows belonging to the three microbial load households and was intended (NTGMA,

    staphylococci and coliform bacteria) Harvesting sanitation pads on the surface of animals

    before and after cleaning teates. May also pursued NTGMA calves during grazing and in

    the three farms (G1, G2 and G3). In the three households was done a different cleaning

    mammary gland, as follows:

    S - washing with clean water; S+Sp+L - washing with clean water, soap, rinse; S+Sp+L+D - washing with clean water, soap, rinse with decontamination

    solution of Premacid (1.5%);

    Dc - Diemacid color protection between two milking.254660

    88250

    2209,4 217,4

    55052

    0

    30000

    60000

    90000

    120000

    150000

    180000

    210000

    240000

    270000

    FS S S+Sp+L S+Sp+L+D Dc

    N/cm

    2

    NTGMA

    Figure 7.15. NTGMA before and after sanitation procedures

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    Bridging as many cleaning processes and their application on as many

    technological operations, increased their efficiency compared with their effect separately.

    Obtaining a microbial load as low to the teates area, and depends largely on the initial

    microbial load.Partial conclusions

    Aeromicroflora shelter highest values recorded in all technological operations in

    the morning. The highest microbial load was recorded for use and consumption of forage

    fiber (B), followed by microbial load of the atmosphere in the shelter, during the

    administration and use of feed concentrates (C), the microbial load of the atmosphere in

    the shelter during milking (D) and the microbial load of less than 25-30 minutes after the

    evacuation of manure and air (A). Containers used for obtaining, storing and transporting

    milk are each, an additional source of microbial contamination of milk. The high

    microbial load in both buckets and containers for transport to the farm was registered G2

    followed by G1 and G3 households.

    Diversity and variability of the results show individual variability in the measures

    of hygiene consciousness and substances used in this process. Following procedures cans

    milking sanitation on farms decreased microbial load in the order: F1 (rinsing water is

    supplied to the temperature distribution network, without using detergents or

    decontaminating substances)> F2 (washing with water followed by rinsing soapy)> F3

    (washing with hot water and detergent followed by rinses)> F4 (washing with hot water

    and detergent followed by rinsing and using a decontaminating substances). Diversity

    between F2 and F3 results show individual variability in cleaning processes. Following

    cleaning procedures of storage and cooling tanks, microbial load decreased in the order

    F1> F2> F3> F4. Sanitation is to rinse with cold water, wash with warm water anddetergent followed by rinsing with cold water in farms F1, F2 and F3 and F4 are used in

    farm and decontaminating substances. Diversity results from F1, F2 and F3 show the

    individual variability in cleaning process.

    Both the environmental conditions and type semi holdings, microbial load on teats

    was higher indoors than grazing, probably influenced by the microflora in shelters.

    Bridging as many methods of udder hygiene, increased their effectiveness in reducing

    microbial load compared with their effect separately in the order: FS>S> S + Sp + L> S +

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    Sp + L + D. Following the udder hygiene procedures on farms, it has dropped in the

    order: F1 (udder washing with clean water, changed from 2-3 animals)> F2 (udder

    washing with clean water, changed every animal)> F3 (washing bag clean water, changed

    every animal and the use of protective substances in the nipple between the twomilking)> F4 (decontaminating substance use before and after washing the udder).

    Evolution of microbial load of milk produced in the household and farm recorded

    a downtrend with each correction as applied in mining technology in order to dairy cows:

    LCI> Ia + R> Im + Iu> Ic + T + I + Pm. Good results in improving the hygiene quality of

    raw milk raw material is obtained only if it acts simultaneously on all technological

    operations.

    G.O. 2: Researches regarding raw milk quality obtained in Cluj county, for

    industrial processing

    In the present study was aimed at quality from raw milk from 13 farms in the

    county of Cluj by the pursuit of physical-chemical and microbiological quality to

    requirements for raw milk. Following investigations, raw milk could be said to be

    consistent / inconsistent for processing.

    To achieve this general objective(G.O.) the followingspecific objectives(S.O.)

    were proposed:

    determining physico-chemical parameters: fat content, protein, non-fat drymatter (SUN), freezing point (water added) and comparison with the maximum

    / minimum allowable SR 2418:2008;

    determination of somatic cell count (SCC) and total plate count (TBC) / ml at300C and the number of somatic cells / ml and their comparison with themaximum limits laid down in Regulation (EC) no. 1.664/2006.

    Experimental Design

    Milk samples were taken from 13 farms in the county of Cluj, who were

    monitored physico-chemical and microbiological parameters mentioned above for 6

    months (January-August) of 2009.

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    quantitative identification of factors affecting the concentration of spores ofB.cereus bacteria in the FTM;

    lower concentration determination can be achieved through measuresimplemented at farm level.

    Based on this information we developed a strategy to control contamination with

    B. cereus.

    A 1. Control strategies

    Partial conclusions

    Concentration ofB. cereus spores in raw milk stored in collection tanks to dairy

    processors is determined 15% of the milk delivered in milk cooling tanks in farms (FTM)

    with the highest concentration of spores. If the milking facilities are not cleaned properly,

    the highest concentrations of spores of B. cereus is observed during the grazing period

    when the soil contains more than 4 log10 spores/g.

    During grazing, a B. cereus spore concentration in the FTM in MSL can be

    ensured if the udder teates spore contamination of the soil is limited and udder cleaning

    measures are optimized. Compared with the current situation, implementation of these

    measures has resulted in a reduction of approximately 99% of the average concentration

    in raw milk during the grazing period. To ensure a concentration in MSL during

    stabulaiei FTM, animal feed should contain spores ofB. cereus in MSL and pH ratio is

    less than 5.

    This study showed that during grazing and housingB. cereus spores present in the

    FTM, most likely derived from feed and FTM are transmitted through feces and dirt from

    outside of the udder. However, in this study none of FTM samples did not contain aconcentration of spores in excess of MSL (3 log10 spores/l), indicating that transmission

    of B. cereus spores through this way is apparently under control. However, it is very

    important to prevent contamination of the teats of the udder with increasing soil during

    grazing, because concentrations ofB. cereus in soil are approximately 100 times higher

    than in other environmental factors (feed, feces and the material used in bedding). This

    means that the transmission of relatively small amounts of soil, 1-13 mg/l, may lead to a

    higher concentration in excess of MSL in the FTM.

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    A 2. Concentration ofB. cereus in FTM control

    Partial conclusions

    Concentration of B. cereus in FTM depends on the transmission of bacteriacontamination by external means, namely through the udder, teats of their exterior and

    through the milking equipment. In additionB. cereus growth during storage in FTM may

    increase concentration. Research conducted under Objective 3 confirms that B. cereus is

    generally transmitted from outside the udder udder FTM contaminated with spores. B.

    cereus sent from the external surface of the udder udder contamination is derived

    primarily from contaminated fodder. If the concentration ofB. cereus in FTM is above

    MSL than the soil is most likely the main source of contamination (objective 3 - Chapter

    7, 7.3.2). This thesis has been paid little attention to the transmission ofB. cereus FTM

    as sources of contamination of milking equipment. This is a less common route of

    contamination, but a fundamental calculation shows that the possibility of contamination

    can not be neglected without significant consequences ( 7.3.2). However, a B. cereus

    growth during storage in FTM is negligible if the cooling tank is designed SS farms

    operating under ISO 5708 standard specifications ( 7.3.1). Table 8.1 presents the

    methods necessary to maintain the concentration ofB. cereus in FTM in MSL. First, the

    risk of transmission ofB. cereus by means of the major routes of contamination (feed-

    feces-FTM) should be minimized. Measures is essential in maintaining a low level of

    initial contamination of forage (less than 3 log10 spores/g) and prevention measures

    required for growth and proliferation ofB. cereus in the ways of transmission.

    The best way to prevent the growth ofB. cereus is to maintain a pH below 5 (

    7.3.1). Experiments should be conducted to determine whether and to what extent B.cereus can grow in mixed silage and used as bedding material. Besides dominant ways of

    contamination control should be established and implemented a series of measures for the

    prevention of incidents, defined as emergency situations, which produces increased

    concentrations of B. cereus in FTM than MSL. Incidents that may occur is the udder

    contamination with significant quantities of contaminated soil (risk of transmission ofB.

    cereus in soil where a quantity of 1 mg / L in FTM) or where hygiene and improper

    cleaning of milking equipment (Griffiths and Phillips, 1990). In order to determine the

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    necessity of taking measures to reduce the likelihood of transmission ofB. cereus in the

    situations identified above must be assessed first frequency and impact of such incidents,

    situations of risk.

    GENERAL CONCLUSIONS

    Results of experiments conducted under Objective 1 have led to the conclusion

    that the farms where the use of a closed system housing, milking is done in buckets,

    rinsing with water udder, and where no disinfection measures are used pre-and post-

    milking, microbiological quality of milk collection tank is generally lower. These results

    highlight the importance of cleaning and disinfection measures implemented optimally.

    In our opinion, although large farms technical and environmental conditions that occur

    and aff