Beuchat Larry R, Mann David A
Center for Food Safety and Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797, USA.
J Food Prot. 2016 Jan;79(1):95-111. doi: 10.4315/0362-028X.JFP-15-357.
Fifty-six foods and food ingredients were analyzed for populations of naturally occurring yeasts and molds using Petrifilm rapid yeast and mold (RYM) count plates, Petrifilm yeast and mold (YM) count plates, dichloran rose bengal chloramphenicol (DRBC) agar plates, acidified potato dextrose agar (APDA) plates, and dichloran 18% glycerol (DG18) agar plates. Colonies were counted after incubating plates for 48, 72, and 120 h at 25°C. Of 56 foods in which either yeasts or molds were detected on at least one medium incubated for 120 h, neither yeasts nor molds were detected in 55.4, 73.2, 21.4, 19.6, and 71.4% of foods plated on the five respective media and incubated for 48 h; 10.7, 14.3, 3.6, 1.8, and 19.6% of foods were negative after 72 h, and 3.6, 1.8, 0, 0, and 0% of foods were negative after 120 h. Considering all enumeration media, correlation coefficients were 0.03 to 0.97 at 48 h of incubation; these values increased to 0.75 to 0.99 at 120 h. Coefficients of variation for total yeasts and molds were as high as 30.0, 30.8, and 27.2% at 48, 72, and 120 h, respectively. The general order of performance was DRBC = APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 48 h, DRBC > APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 72 h, and DRBC > APDA > RYM Petrifilm > YM Petrifilm > DG18 when plates were incubated for 120 h. Differences in performance among media are attributed to the diversity of yeasts and molds likely to be present in test foods and differences in nutrient, pH, and water activity requirements for resuscitation of stressed cells and colony development.
使用3M Petrifilm快速酵母和霉菌（RYM）计数平板、3M Petrifilm酵母和霉菌（YM）计数平板、孟加拉红氯霉素（DRBC）琼脂平板、酸化马铃薯葡萄糖琼脂（APDA）平板以及孟加拉红18%甘油（DG18）琼脂平板，对56种食品和食品成分中的天然酵母和霉菌菌群进行了分析。将平板在25℃下培养48、72和120小时后进行菌落计数。在至少一种培养基上培养120小时后检测到酵母或霉菌的56种食品中，分别在五种相应培养基上培养48小时的食品中，未检测到酵母和霉菌的比例分别为55.4%、73.2%、21.4%、19.6%和71.4%；培养72小时后，10.7%、14.3%、3.6%、1.8%和19.6%的食品为阴性；培养120小时后，3.6%、1.8%、0、0和0%的食品为阴性。考虑所有计数培养基，培养48小时时相关系数为0.0-0.97；培养120小时时，这些值增至0.75-0.99。总酵母和霉菌的变异系数在培养48、72和120小时时分别高达30.0%、30.8%和27.2%。培养48小时时，各培养基的总体性能顺序为DRBC = APDA > RYM 3M Petrifilm > YM 3M Petrifilm ≥ DG18；培养72小时时，为DRBC > APDA > RYM 3M Petrifilm > YM 3M Petrifilm ≥ DG18；培养120小时时，为DRBC > APDA > RYM 3M Petrifilm > YM Petrifilm > DG18。培养基之间性能的差异归因于测试食品中可能存在的酵母和霉菌的多样性，以及应激细胞复苏和菌落发育所需营养、pH值和水分活性的差异。
