为提高发酵乳的黏度和风味,改善发酵乳口感及后酸化现象,试验以pH、酸度、黏度、持水率、活菌数、产香成分为评价指标,从云南特色发酵食品分离鉴定的乳酸菌中筛选出5株具有较强产黏和产香特性的菌株进行互配制备直投式发酵剂(directed vat set, DVS),综合评价其发酵性能。结果表明:嗜酸乳杆菌、嗜热链球菌、类干酪乳杆菌、罗伊氏乳杆菌、德式保加利亚乳杆菌亚种5株乳酸菌具有较强发酵性能,当其按1:2:1:2:1(体积比)的菌株组合发酵时表现出良好发酵性能。此时发酵乳各项指标分别为酸度98.12 °T、黏度8 800 mPa·s、活菌数8.2×107 CFU/mL、乙醛含量7.51 μg/mL、双乙酰含量9.36 μg/mL,发酵乳黏性高,组织状态良好,后酸化平缓,感官评分值高。该研究可为开发出一种产黏性、产香性好和后酸化平缓的直投式发酵剂提供科学依据。
The purpose of this study is to improve the viscosity, flavor, mouthfeel and post-acidification of the yogurt fermentation. The directed vat set (DVS) was prepared using 5 strains of lactic acid bacteria (LAB) with strong adhesion and aroma characteristics. These 5 strains were isolated and identified from Yunnan specialty fermented foods, and were evaluated by their pH, acidity, viscosity, water holding capacity, viable count, and aroma components. The results showed that the 5 strains with desirable fermentation performance were identified to be Streptococcus thermophilus, Lactobacillus acidophilus, L. casei, L. reuteri, and L. delbrueckii subsp. bulgaricus. The most satisfying yogurt was fermented with a strain mixing ratio of 1:2:1:2:1, with the acidity index of 98.12 °T, viscosity of 8,800 mPa·s, viable count of 8.2×107 CFU/mL, acetaldehyde content of 7.51 μg/mL, and diacetyl content of 9.36 μg/mL. In other words, this yogurt had high viscosity, good tissue state, mild acidification and high sensory score. This finding provided a scientific basis for developing a direct-injection starter with good viscosity, good aroma and gentle post-acidification.
[1] DONOVAN S M, SHAMIR R. Introduction to the yogurt in nutrition initiative and the first global summit on the health effects of yogurt[J]. American Journal of Clinical Nutrition, 2014, 99(5):1 209S-1 211S.
[2] P0SSA G, DECASTO M A, MARCHIONI D M, et al. Probability and amounts of yogurt intake are differently affected by sociodemographic, economic, and lifestyle factors in adults and the elderly-results from a population-based study[J]. Nutrition Research, 2015, 35(8):700-706.
[3] 杨洋, 高航. 国内直投式乳酸菌发酵剂研究进展[J]. 中国奶牛, 2016, 314(6):44-47.
[4] 苏敦, 任发政, 刘松玲,等. 菌株发酵特性研究及复合酸奶发酵剂的筛选[J]. 中国奶牛, 2017, 329(9):50-57.
[5] 孙灵霞, 张秋会, 李红,等. 直投式酸奶发酵剂在酸奶制作中应用的初步研究[J]. 食品与发酵科技, 2011, 47(6):63-69.
[6] 弓耀忠. 一种新型乳酸菌复合发酵剂的应用及效果[J]. 食品与发酵工业, 2014, 40(4):87-90.
[7] REZA H F,MOHAMMAD B H N S F B, MOHAMMAD R E,et al. Identification, typing and functional characterization of dominant lactic acid bacteria strains from Iranian traditional yogurt[J]. European Food Research and Technology, 2016, 242(4):517-526.
[8] 穆明道, 吕铭洋, 郑晓楠,等. 中国传统乳制品中优良乳酸菌的筛选及复合菌株发酵的初步研究[J]. 中国奶牛, 2011(2):52-57.
[9] 刘宁宁, 郭红敏, 葛春美, 等. 酸奶中乙醛和双乙酰含量对其风味的影响[J]. 中国食品添加剂, 2012, S1:269-273.
[10] 吕嘉枥, 李成涛. 酸奶中双乙酰含量的测定方法初探[J]. 中国乳品工业, 2006, 34(1):21-22.
[11] ANNA L, ROSSANA C, MARCO M, et al. Use of selected lactic acid bacteria and quinoa flour for manufacturing novel yogurt-like beverages[J]. Foods, 2018, 7(4):51-71.
[12] 史甜甜. 副干酪乳杆菌胞外多糖对酸乳质构形成的影响及其机制研究[D]. 合肥:合肥工业大学, 2018.
[13] 孙懿琳, 田辉, 方伟,等. 保加利亚乳杆菌关键糖代谢机制的研究[J]. 食品工业科技, 2012, 33(22):202-205.
[14] SETTACHAIMONGKON S, NOUNT M J R, AUTUNES F E C, et al. The impact of selected strains of probiotic bacteria on metabolite formation in set yoghurt[J]. International Dairy Journal, 2014, 38(1):1-10.
[15] CASAROTTI S N, PENNAAUTHOR A L B. Influence of the combination of probiotic cultures during fermentation and storage of fermented milk[J]. Food Research International, 2014, 59(4):67-75.
[16] HAN X, ZHANG L, YU P, et al. Potential of LAB starter culture isolated from Chinese traditional fermented foods for yoghurt production[J]. International Dairy Journal, 2014, 34(2):247-251.
[17] 刘曜综,曾小群,潘道东,等. 高效水解乳糖乳酸菌的筛选及发酵条件优化[J]. 食品科学, 2015, 36(3):90-93.
[18] 丹彤, 包秋华, 孟和毕力格,等. 发酵乳风味物质乙醛、双乙酰的合成途径及其调控机制[J]. 食品科技, 2012,7:75-79.
[19] 杨扬,李小佳,任学良,等. SIM-GC-MS法检测酸奶中的香味物质[C]// 第21届全国色谱学术报告会及仪器展览会会议论文集, 2017.
[20] 魏小雁, 冀林立, 刘建军,等. 酸奶发酵剂菌种的产香物质及发酵特性研究[J]. 乳业科学与技术, 2008, 31(1):21-23.
[21] 白娜, 于洁, 王宏梅, 等. 发酵乳后熟期间嗜热链球菌和保加利亚乳杆菌产乙醛特性[J]. 乳业科学与技术, 2014,37(1):1-5.
