冷冻干燥植物乳杆菌全麦酸面团的制备及其对全麦面包品质影响研究

Preparation of freeze-dried whole-wheat sourdough fermented by Lactobacillus plantarum and its effect on the quality of whole-wheat bread

为提升真空冷冻干燥酸面团在全麦面包中的应用效果,以存活率、产酸能力和产酸稳定性为评价指标,探究基于海藻糖保护的冻干酸面团中植物乳杆菌的生物活性,并优化此冻干酸面团在全麦面包中的添加量。结果显示:海藻糖能够显著地提高植物乳杆菌生物活性。当海藻糖添加量为15%时,冻干并保藏90 d后,植物乳杆菌存活率仍保持在80%以上,是对照组的3.69倍,且产酸能力无明显降低。添加10%上述冻干酸面团时,全麦面包外表皮和面包芯色泽最佳。相较对照组,其比容提高10.16%,焙烤损失降低6.85%;内聚性、回复性和弹性分别提高18.03%、20%和27.27%,硬度和咀嚼性分别下降35.31%和12.49%;老化速率降低29.06%;植酸降解率是对照组的2倍。海藻糖保护的冻干植物乳杆菌全麦酸面团对全麦面包的品质改善起到了较好的效果,为冻干酸面团的规模化应用提供了实践参考。

To enhance the application effect of vacuum freeze-drying whole-wheat sourdough in whole-wheat bread,it has been carried out to explore the bioactivity of Lactobacillus plantarum in freeze-dried sourdough protected by trehalose,taking the survival rate,acid-producing capacity and acid-producing stability as evaluation indicators,and optimize the amount of this freeze-dried sourdough added to whole-wheat bread.The results showed that trehalose could significantly improve the bioactivity of Lactobacillus plantarum.When the amount of trehalose added was 15%,the survival rate of Lactobacillus plantarum remained above 80%after freeze-drying and storage for 90 days,3.69 times higher than control group,and there was no significant decrease in acid-producing capacity.Adding 10%of this freeze-dried sourdough,the whole-wheat bread has achieved the most pleasant color on the outer skin and crumb,with the specific volume increased by 10.16%and the baking loss decreased by 6.85%compared to the control group.Meanwhile,the cohesiveness,resilience and springiness increased by 18.03%,20%,and 27.27%,respectively;while the hardness and chewiness were decreased by 35.31%and 12.49%,respectively.The aging rate of whole-wheat bread was 29.06%lower than that of the control group.Moreover,the degradation rate of phytic acid was twice that of the control group.The freeze-dried whole-wheat sourdough fermented by Lactobacillus plantarum protected by trehalose has achieved positive results in improving the quality of whole-wheat bread,providing practical references for the large-scale application of freeze-dried sourdough.