益生性植物乳杆菌的温度胁迫处理及其对发酵冰淇淋品质和菌活性的影响  

Effect of Temperature Stress Treatment of Lactobacillus plantarum K25 on the Quality of Fermented Ice Cream and Survival of the Strain

作　　者：赵雯[1] 吴凤玉[1] 郑义[1] 张健[1] 姜芸云 赵笑[1] 杨贞耐[1] ZHAO Wen;WU Fengyu;ZHENG Yi;ZHANG Jian;JIANG Yunyun;ZHAO Xiao;YANG Zhennai(Beijing Advanced Innovation Center for Food Nutrition and Human Health,Beijing Laboratory of Food Quality and Safety,Beijing Technology and Business University,Beijing 100048,China)

机构地区：[1]北京食品营养与人类健康高精尖创新中心食品质量与安全北京实验室北京工商大学,北京100048

出　　处：《食品科学》2019年第2期65-72,共8页Food Science

基　　金：国家自然基金面上项目(31571857)

摘　　要：为提高冰淇淋中的益生菌活性,对1株分离自西藏灵菇的益生性植物乳杆菌K25进行不同温度的胁迫处理。实验分为低温处理组(4、10、20℃)和高温处理组(45、50、55℃),对菌株K25的处理时间为0.5、1.5、3、5、8、18、24 h,测定上述不同温度和时间组合处理对菌株于-20℃贮存1、15、30 d后活菌数的影响,以未经处理的菌株作为对照组。结果表明,4℃-18 h与55℃-0.5 h胁迫预处理后的菌株在-20℃贮存30 d后活菌数分别为对照组的12倍和15倍,选取4℃-18 h(C-K25)和55℃-0.5 h(H-K25)胁迫处理后的菌株制作冰淇淋并添加巧克力酱作为辅料。对产品理化性质测定结果表明,使用胁迫处理后的K25菌株可以降低冰淇淋产品的酸度,显著提高产品的黏度和硬度(P<0.05),且使用低温胁迫处理后的菌株能够改善冰淇淋的膨胀率和融化率。活菌数测定结果表明,对照组冰淇淋在-20℃贮存60 d后活菌数为5.63(lg(CFU/mL)),而H-K25与C-K25发酵的冰淇淋在-20℃贮存60 d后其活菌数分别为7.26(lg(CFU/mL))和7.32(lg(CFU/mL)),表明温度胁迫预处理对K25低温条件下的存活具有有益影响。而C-K25-巧克力组冰淇淋终活菌数最高为7.56(lg(CFU/mL)),表明巧克力对植物乳杆菌K25具有一定的低温保护作用。产品贮存30 d后,所有组别冰淇淋中的菌株在模拟胃酸和胆盐溶液环境中活菌数均无显著下降(P>0.05)。Lactobacillus plantarum K25, isolated from Tibetan Kefir, was pretreated at low (4, 10 or 20 ℃) and high temperatures (45, 50 or 55 ℃) for different times (0.5, 1.5, 3, 5, 8, 18 or 24 h). Subsequently, the survivability of L. plantarum K25 was determined after 1, 15 and 30 days of storage at-20 ℃. L. plantarum K25 without any treatment was used as a control. The results showed that after pretreatments at 4 ℃ for 18 h and at 55 ℃ for 0.5 h the viable counts were 12 and 15 times higher than those of the control after 30 days of storage at-20 ℃. Fermented ice cream using K25 (control), C-K25 (pretreated at 4 ℃ for 18 h) and H-K25 (pretreated at 55 ℃ for 0.5 h) with or without chocolate were prepared. The acidity of the C-K25 and H-K25 fermented ice cream was lower than that of the control, whereas the viscosity and firmness were significantly increased as compared to those of the control (P < 0.05). In addition, melting rate and overrun were improved in the C-K25 and H-K25 fermented ice cream. The viable counts of the control, H-K25 and C-K25 ice cream were 5.63, 7.26 and 7.32 (lg(CFU/mL)), respectively after 60 days of storage at-20 ℃, indicating that cold and heat pretreatments facilitated bacterial survival in the frozen environment. The highest viable count (7.56(lg(CFU/mL))) was found in the C-K25-fermented ice cream with chocolate, indicating that chocolate provided protection for L. plantarum K25 against cold damage. Finally, after storage at-20 ℃ for 30 days, all the experimental groups showed no significant decrease in the survival rate of L. plantarum K25 upon mimic gastric acid and bile salt stress (P > 0.05).

关 键 词：冰淇淋 温度胁迫处理 植物乳杆菌 活菌数 耐酸耐胆盐特性 

分 类 号：TS201.3[轻工技术与工程—食品科学]