摘要
为解决腊八豆发酵中、后期菌种发酵力不足的问题,本研究筛选具有优良蛋白酶活力的毛霉菌株,并研究混合制曲发酵工艺。采用添加1 g/L脱氧胆酸钠的酪素平板,初筛得到菌落直径、透明圈菌落直径比(K值)大的菌株。制曲复筛得到中、酸性蛋白酶活力高的菌株。以蛋白酶活力为指标,研究中、酸性蛋白酶高活力菌株混合制曲的菌种配比、接种量及制曲时间。对发酵后腊八豆理化指标、挥发性风味化合物及感官评分进行对比,优化混合菌种制曲工艺。结果表明,从菌株M1分离的20株菌种中筛选出7株K值>1.00的优良菌株,经制曲复筛测定酸性和中性蛋白酶活力值,最终获得酸性蛋白酶活力最高(260.48 U/g干基)和中性蛋白酶活力最高(103.56 U/g干基)的总状毛霉各1株,分别命名为M2-3和M2-4。混合菌种制曲最佳工艺条件为M2-3与M2-4体积比6∶4、接种量1×10^(8)个孢子/mL、制曲时间48 h。在此条件下腊八豆曲的中、酸性蛋白酶活力分别达172.33 U/g干基和50.32 U/g干基。密封发酵后,腊八豆氨基酸态氮、蛋白水解度和总酸较M1发酵组分别提高了53.19%,17.96%和33.33%;挥发性风味物质种类较M1发酵组增加了15种,总含量达421.98 mg/kg,分别比M1、M2-3和M2-4单一菌种发酵组提高了50.42%,28.22%和80.81%,说明混合菌种制曲发酵的腊八豆风味明显优于单一菌种。本研究为混合菌种发酵生产品质优良的腊八豆奠定了基础。
In order to solve the problem of insufficient fermentation power of Laba bean in the middle and late stages of fermentation,Mucor spp.with excellent protease activity were screened and the fermentation technology of mixed koji was studied.Preliminary screening was carried out on casein plates supplemented with 1 g/L sodium deoxycholate,and the strains with larger colony diameters and higher diameter ratio of the hyaline zone to the colony(K values)were selected.Secondary screening with koji making focused on strains with high activity of neutral and acidic proteases.The optimal ratio,inoculum size,and koji making time of the two Mucor for the koji making process were studied based on neutral and acidic protease activity,and the physicochemical indicators,volatile flavor compounds,and sensory scores of Laba beans after fermentation were compared to optimize the mixed strain koji making process.The results showed that 7 excellent strains with K values greater than 1.00 were selected from 20 strains isolated from the commercial strain M1.After the determination of the activities of acid protease and neutral protease,two strains of Mucor racemosus with the highest acidic protease activity(260.48 U/g dry weight)and the highest neutral protease activity(103.56 U/g dry weight)were designated as M2-3 and M2-4,respectively.The optimal mixed strain koji making conditions were determined to be a 6∶4 volumetric ratio of M2-3 to M2-4,an inoculum size of 1×10^(8) spores per milliliter,and a koji maturation time of 48 h.Under these conditions,the neutral and acidic protease activities of the Laba bean koji reached 172.33 U/g dry weight and 50.32 U/g dry weight,respectively.After sealed fermentation,the amino acid nitrogen,protein hydrolysis degree and total acidity of the Laba beans increased by 53.19%,17.96%and 33.33%,respectively,compared to the M1 fermentation group.In addition,15 new volatile flavor compounds were identified,and the content of total volatile flavor compounds reached 421.98 mg/kg,representing increases of 50.42%,28.22%,and 80.81%.compared to the single strain fermentation groups of M1,M2-3 and M2-4,respectively.The flavor of Laba bean fermented with mixed strains was significantly better than those fermented with the single strain groups.This study provides a basis for the production of high quality Laba beans through mixed strain fermentation.
作者
孙千汝
蒋雪薇
杨锦辉
廉明珠
唐建立
罗晓明
陈江柱
SUN Qianru;JIANG Xuewei;YANG Jinhui;LIAN Mingzhu;TANG Jianli;LUO Xiaoming;CHEN Jiangzhu(School of Food Science and Bioengineering,Changsha University of Science&Technology,Changsha 410114;Changsha Xinjingyuan Foods Co.,Changsha 410148;Hunan Provincial Engineering Technology Research Center for Condiment Fermentation,Changsha 410600;Hunan Provincial Engineering Technology Research Center of Prepared Dishes,Changsha 410114)
出处
《中国食品学报》
北大核心
2025年第11期250-264,共15页
Journal of Chinese Institute of Food Science and Technology
基金
湖南省重点研发计划项目(2023NK2035)
湖南省自然科学基金青年科学基金项目(2024JJ6022)
湖南省教育厅优秀青年基金项目(23B0306)。
