天麻液混菌发酵工艺优化及品质特性分析

Process Optimization of Gastrodia elata Fermentation by Mixed Strains and Quality Characterization

摘要:

目的 解决单菌发酵天麻（Gastrodie elata）液营养及感官品质较差的问题，探究混菌发酵对天麻液营养品质提升及风味改善的影响。方法 筛选能改善天麻液风味的菌株，优化混菌发酵工艺，比较混菌与单菌发酵天麻液的营养及风味品质差异。结果 优化后工艺为：8种适宜菌（咸海鲜魏斯氏菌、香肠乳杆菌、植物乳植杆菌、短乳杆菌、罗伊氏粘液乳杆菌、戊糖片球菌、酸乳球菌和粪肠球菌）等比例混合发酵，发酵时间3 d，接种体积分数2.25%，发酵温度37 ℃。混菌发酵天麻液的红黄度增加，总酸质量浓度（4.81±0.39） g/mL，黄酮质量浓度（1.28±0.03） mg/mL。与对照组相比，DPPH自由基清除率提升47.96%，显著优于单菌发酵。天麻素及对羟基苯甲醇质量浓度分别为（434.53±14.11） μg/mL和（289.94±0.11） μg/mL，多酚质量浓度降低6.70%，可溶性固形物质量分数降低，显著优于部分单菌发酵。电子鼻分析发现，发酵天麻液的W1W及W5S传感器响应值降低，主要异味成分为硫化物、萜类化合物和氮氧化合物，混菌发酵对异味的协调效果更佳，与感官评价结果一致。结论 混菌发酵具有协同产酸作用，天麻液中多酚及黄酮保留率较高，抗氧化活性增强，风味品质更好，具有推广应用价值。

Abstract:

Objective This study aimed to solve the issue of poor nutritional and sensory quality of Gastrodia elata fermented by single strains, this study explored the improving effects of mixed strain fermentation on the nutritional quality and flavor of Gastrodia elata. Method Strains that could improve the flavor of Gastrodia elata liquid were screened, and the mixed strain fermentation process was optimized. The nutritional and flavor quality were compared between the Gastrodia elata liquids fermented by mixed strains and single strains.Result The optimized process was as follows: eight suitable strains (Weissella halotolerans, Lactobacillus farciminis, Lactiplantibacillus plantarum, Lactobacillus brevis, Lactobacillus mucosae reuteri, Pediococcus pentosaceus, Lactococcus acidophilus, and Enterococcus faecalis) were mixed in equal proportions, fermentation for 3 d, an inoculation volume fraction of 2.25%, and a fermentation temperature of 37 ℃. The red-yellow degree of the Gastrodia elata liquid fermented by mixed strains increased, the mass concentration of total acids was (4.81±0.39) g/mL and the mixed strain fermentation group showed the mass concentration of flavonoids (1.28±0.03) mg/mL. Compared with the control group, the DPPH free radical scavenging rate increasing by 47.96%, being significantly better than single strain fermentation. The mass concentrations of gastrodin and p-hydroxybenzyl alcohol were (434.53±14.11) μg/mL and (289.94±0.11) μg/mL, respectively. The mass concentration of polyphenols decreased by 6.70%, and that of soluble solids also decreased. The data indicated that mixed strain fermentation outperformed single strain fermentation. The analysis of the fermented Gastrodia elata liquid by an electronic nose showed that the response values of the W1W and W5S sensors decreased. The main off-flavor components were sulfides, terpenes, and nitrogen oxides, and the coordination effect of mixed strain fermentation on off-flavors was better, which was consistent with the results of sensory evaluation.Conclusion The mixed strain fermentation has a synergistic acid production effect, producing the Gastrodia elata liquid with a relatively high retention rate of polyphenols and flavonoids, an enhanced antioxidant activity, and improved flavor quality and demonstrating the value of popularization and application.