冷冻和冻干处理对酸面团中乳酸菌活力的影响

[目的]研究冷冻及冻干处理对酸面团中乳酸菌活力的影响。[方法]选取植物乳酸菌M616为发酵菌株制作酸面团,分别进行冷冻(-80℃)和冻干预处理,-20℃冻藏30 d,考察冻藏期内乳酸菌的存活率、产酸能力及酸面团的pH、总酸度(TTA)的变化。[结果]随着冻藏时间的延长,冷冻和冻干酸面团中乳酸菌的存活率均显著下降,但相同冻藏时间下,冷冻酸面团中的乳酸菌存活率显著高于冻干酸面团中的乳酸菌存活率;冻藏第0、7天时,冷冻和冻干酸面团中乳酸菌的产酸能力无显著差异,冻藏第14、21和28天时,冷冻处理条件下乳酸菌的产酸能力高于冻干处理条件。[结论]冷冻处理更有利于保持酸面团中乳酸菌的活力。

Effect of Frozen and Freeze-drying on the Activity of Lactobacillus in Sourdough

[Objective]To study the effect of frozen and freeze-drying on the activity of Lactobacillus in sourdough.[Method]The Lactobacillus plantarum M616 was used as the fermentation strain to make sourdough.Then the sourdough were frozen ( -80 ℃) and freeze-dried respec-tively, and were stored at -20 ℃ for 30 days.The survival rate and acid-producing capacity of L.plantarum M616, pH and TTA of sour-dough were determined.[Result]The results showed that the survival rate of L.plantarum M616 in frozen and freeze-dried sourdough was sig-nificantly decreased with the prolongation of storage time, but the survival rate of L.plantarum M616 in frozen sourdough was significantly higher than that in freeze-dried dough at the same storage time.There was no significantly different between frozen and freeze-dried sourdough on the acid-producing capacity of L.plantarum M616 at 0th and 7th day of storage.While on the 14th, 21st and 28th day of storage, the acid-producing ability of L.plantarum M616 in frozen sourdough was higher than that of freeze-drying.[ Conclusion] Frozen treatment is more con-ducive to maintaining the activity of L.plantarum M616 in sourdough.