Abadias M, Teixidó N, Usall J, Benabarre A, Viñas I
Postharvest Unit, CeRTA, Centre UdL-IRTA, Lleida, Catalonia, Spain.
J Food Prot. 2001 Jun;64(6):856-61. doi: 10.4315/0362-028x-64.6.856.
Viability, efficacy against Penicillium expansum on Golden Delicious apples, and storage stability of freeze-dried Candida sake strain CPA-1 were studied. The effect of several protective agents and rehydration media was investigated in the freeze drying of C. sake. Skimmed milk at 10% concentration was a good rehydration medium for all protectants tested. In general, good viability results were obtained when the same solution was used as a protectant and as a rehydration medium. The best survival was obtained when C. sake cells were protected with 10% lactose + 10% skimmed milk and rehydrated with skimmed milk (85% viability). The potential for biocontrol of the best freeze-dried treatments against P. expansum on apples was compared with that of fresh cells. Freeze-dried treatments at 1 x 10(7) CFU/ml reduced the incidence of decay by 45 to 66%. The best biocontrol effect was obtained with cells that had been freeze dried using 10% lactose + 10% skimmed milk as a protectant and 1% peptone as a rehydration medium, with a 66% reduction in rot incidence. However, in all treatments, the efficacy of freeze-dried cells was significantly lower than fresh cells. The stability of freeze-dried samples decreased during storage and was influenced by storage temperature. In the best treatment, storage of C. sake cells for 60 days at 4 degrees C resulte in final concentrations of 2.5 x 10(8) CFU/ml, which was a 10-fold reduction in relation to the initial starting concentration of cells prior to freeze drying.
研究了冻干清酒假丝酵母菌株CPA-1的活力、对金冠苹果上扩展青霉的防治效果以及储存稳定性。在清酒假丝酵母的冻干过程中，研究了几种保护剂和复水介质的效果。10%浓度的脱脂牛奶对所有测试的保护剂来说都是一种良好的复水介质。一般来说，当使用相同的溶液作为保护剂和复水介质时，能获得良好的活力结果。当清酒假丝酵母细胞用10%乳糖 + 10%脱脂牛奶保护并用脱脂牛奶复水时，存活率最高（85%活力）。将最佳冻干处理对苹果上扩展青霉的生物防治潜力与新鲜细胞的进行了比较。1×10⁷CFU/ml的冻干处理使腐烂发生率降低了45%至66%。使用10%乳糖 + 10%脱脂牛奶作为保护剂和1%蛋白胨作为复水介质冻干的细胞获得了最佳生物防治效果，腐烂发生率降低了66%。然而，在所有处理中，冻干细胞的防治效果均显著低于新鲜细胞。冻干样品的稳定性在储存期间下降，并受储存温度影响。在最佳处理中，清酒假丝酵母细胞在4℃储存60天后，最终浓度为2.5×10⁸CFU/ml，相对于冻干前细胞最初的起始浓度降低了10倍。
