Bài giảng Phụ gia thực phẩm: Phụ gia chống vi sinh vật - ThS. Đặng Bùi Khuê

Trong bài giảng này gồm có một số nội dung như: Selecting a food antimicrobial agent, benzoic acid and Benzoates, dimethyl dicarbonate, propionic acid and propionates,... Mời các bạn cùng tham khảo để nắm bắt các nội dung chi tiết.
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Bài giảng Phụ gia thực phẩm: Phụ gia chống vi sinh vật - ThS. Đặng Bùi KhuêPhụgiachốngvisinhvật ThS.Đặng BùiKhuê• Selectingafoodantimicrobialagent – antimicrobialspectrumofthecompoundtobeused – chemicalandphysicalpropertiesofboththe antimicrobialandthefoodproduct – conditionsofstorageoftheproductandinteractions – foodmustbeofthehighestmicrobiologicalquality initially – thetoxicologicalsafetyandregulatorystatus• BenzoicAcidandBenzoates – Benzoicacidisfoundnaturallyinapples,cinnamon, cloves,cranberries,plums,prunes,strawberries,and otherberries• BenzoicAcidandBenzoates – stable,odorless,whitegranularorcrystallinepowder thatissolubleinwater – Benzoicacidlesssolubleinwaterthansodium benzoate – Antimycoticagents – Mostyeastsandmoldsareinhibitedby20–2000µg benzoicacidpermLatpH5.0• BenzoicAcidandBenzoates – Oneyeastthatitisparticularlyresistantis Zygosaccharomycesbailii:upto0.3%sodium benzoate(salsamayonnaise) – Somebacteriaassociatedwithfoodpoisoningare inhibitedby1000–2000µg/mLundissociatedacid Zygosaccharomycesbailii salsamayonnaise• BenzoicAcidandBenzoates – BenzoatesaremosteffectiveatpH2.5–4.0and significantlyloseeffectivenessatpH4.5 – Theundissociatedfromofbenzoicacid(pKa4.19)is themosteffectiveantimicrobialagent• BenzoicAcidandBenzoates – destroyedtheprotonmotiveforceofthecytoplasmic membranebycontinuoustransportofprotonsintothe cellcausingdisruptionofthetransportsystem• BenzoicAcidandBenzoates – inhibitenzymesinbacterialcellssuchasthose controllingaceticacidmetabolismandoxidative phosphorylation • αketoglutarateandsuccinatedehydrogenasesin thecitricacidcycle • lipaseproductionbyPseudomonasfluorescens • trimethylamineNoxidereductaseactivityof Escherichiacoli Pseudomonasfluorescens • BenzoicAcidand BenzoatesCladosporiumherbarum PichiamembranefaciensByssochlamysnivea• BenzoicAcidandBenzoates – carbonatedandstillbeverages(0.03–0.05%) – syrups(0.1%) – cider(0.05–0.1%) jams – margarine(0.1%) relishes – olives(0.1%) – Pickles(0.1%) cider pieandpastryfillings – relishes(0.1%) jellies – soysauce(0.1%)• Glycine• Hippuricacid• Glucuronicacid• Dimethyldicarbonate – colorlessliquid – slightlysolubleinwater – primarytargetmicroorganisms:Saccharomyces, Zygosaccharomyces,Rhodotorula,Candida,Pichia, Torulopsis,Torula,Endomyces,Kloeckera,and Hansenula (CH3–O–O–C–O–C–O–O–CH3) Torulopsis• Dimethyldicarbonate – moreeffectivethansorbate/benzoateincontrolling aerobicplatecounts – bactericidalat30–400µg/mL:Acetobacter pasteurianus,E.coli,Pseudomonasaeruginosa, Staphylococcusaureus,severalLactobacillusspecies, andPediococcuscerevisiaeAcetobacterpasteurianus Pseudomonasaeruginosa E.coli Staphylococcusaureus• Dimethyldicarbonate – MoldsaregenerallymoreresistanttoDMDCthan yeastsorbacteria – 21CFR172.133 • wine,dealcoholizedwine,andlowalcoholwinethathasless than500yeastCFU/mLat≤200ppm • readytodrinkteas(• PropionicAcidandPropionates – Swisscheese:Propionibacteriumfreudenreichiissp. shermanii. – primarilyagainstmolds – Someyeastsandbacteria,particularlygramnegative strains – dependsuponthepH – breaddoughthatcausesropeformation,Bacillus subtilis(mesentericus),wasinhibitedat0.19%atpH 5.8 Bacillussubtilis Propionibacterium• PropionicAcidandPropionates – retardthegrowthofS.aureus,Sarcinalutea,Proteus vulgaris,Lactobacillusplantarum,Torula(Candida), andSaccharomycescerevisiaevar.ellipsoideusforup to5days Sarcinalutea Proteusvulgaris Lactobacillusplantarum Torula• PropionicAcidandPropionates – ...