冷冻和冻干处理对酸面团中乳酸菌活力的影响

卢帮贵 陈迪

摘要 [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。

关键词 酸面团；植物乳酸菌；冷冻

中图分类号 TS201.3 文献标识码 A 文章编号 0517-6611（2017）25-0096-03

Abstract [Objective]To study the effect of frozen and freezedrying 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 freezedried respectively， and were stored at -20 ℃ for 30 days. The survival rate and acidproducing capacity of L. plantarum M616， pH and TTA of sourdough were determined. [Result]The results showed that the survival rate of L. plantarum M616 in frozen and freezedried sourdough was significantly decreased with the prolongation of storage time， but the survival rate of L. plantarum M616 in frozen sourdough was significantly higher than that in freezedried dough at the same storage time. There was no significantly different between frozen and freezedried sourdough on the acidproducing capacity of L. plantarum M616 at 0th and 7th day of storage. While on the 14th， 21st and 28th day of storage， the acidproducing ability of L. plantarum M616 in frozen sourdough was higher than that of freezedrying. [Conclusion]Frozen treatment is more conducive to maintaining the activity of L. plantarum M616 in sourdough.

Key words Sourdough；Lactobacillus plantarum；Frozen

酸面團是由面粉和水混合、在微生物作用下形成的传统面制食品（面包、馒头等）发酵剂。酸面团中微生物种类繁多，乳酸菌是其中典型且重要的一类微生物，乳酸菌在面团发酵过程中产生乳酸等有机酸，赋予食品特有的酸味，同时降低面团pH，激活面粉中内源蛋白酶，从而产生各类风味物质[1]，酸面团发酵会降低本身的黏性和弹性，提高面团的延伸性和松软度，改善食品的质构[2-3]。另外，在酸面团发酵过程中，乳酸菌可以产生多种抗菌物质，抑制面包、馒头中多种霉菌的生长，从而延长食品的货架期[4-5]。最近研究表明，酸面团还可用于制作适合“乳糜泻”人群食用的无面筋食品[6-7]。然而由于乳酸菌代谢的活跃性和酸面团组成成分的复杂性，使酸面团在保存过程中难以实现稳定的品质控制，制约其商品化生产。……