双菌发酵对祛湿汤理化特性及风味的影响

选用乳酸芽孢杆菌DU-106与植物乳杆菌复配的菌粉对茯苓、白扁豆、薏米、杏仁和甘草等药食同源材料制成的祛湿汤进行发酵，比较发酵对祛湿汤的理化性质（pH、还原糖、总酸、多糖、蛋白质、多酚、黄酮、必需氨基酸和有机酸）和风味物质的影响，并进行感官评价。结果表明:在发酵4 d后祛湿汤pH降低至3.0以下，益生菌发酵通过消耗还原糖，提高了总酸含量，最高达11.00 g/kg。益生菌发酵提高了祛湿汤中多糖、蛋白质、多酚和黄酮等活性成分的含量，且均在第7 d达到最大值，最大值分别为20.95、1.66 mg/mL、52.45、53.26 μg/mL。益生菌发酵也显著（P<0.05） 提高了必需氨基酸和有机酸的含量。此外，发酵还赋予了祛湿汤特殊的发酵风味。通过顶空固相微萃取-气质联用分析发现，发酵后祛湿汤的酯类和醇类物质的相对含量有所增加。感官评价结果表明，益生菌发酵改善了祛湿汤的香气和滋味，发酵第7 d的祛湿汤总体感官品质最好。综上，用DU-106和植物乳杆菌发酵祛湿汤有利于提升祛湿汤品质，可为复合菌种发酵药食同源材料复方水煎剂的生产提供理论依据。

Effects of Two-Bacteria Fermentation on Physical,Chemical Properties and Flavor of Danpness-eliminating Decoction

Danpness-eliminating decoction was fermented by Bacillus sp. DU-106 and Lactobacillus plantarum. The effects of fermentation on physical and chemical properties and flavor substances of Danpness-eliminating decoction were compared, and sensory evaluation was conducted. Physical and chemical properties included pH, reducing sugars, total acids, polysaccharides, proteins, polyphenols, flavonoids, essential amino acids and organic acids. The results showed that after 4 days of fermentation, the pH of Danpness-eliminating decoction decreased to below 3.0, and the total acid content was increased by consuming reducing sugar, up to 11.00 g/kg. The contents of polysaccharides, proteins, polyphenols and flavonoids in Danpness-eliminating decoction increased by probiotic fermentation, and the maximum values were 20.95, 1.66 mg/mL, 52.45 and 53.26 μg/mL respectively on the 7th day. Probiotic fermentation also significantly (P<0.05) increased the content of essential amino acids and organic acids. In addition, fermentation also endowed Danpness-eliminating decoction with special fermentation flavor. The relative contents of esters and alcohols in Danpness-eliminating decoction increased after fermentation by headspace solid phase microextraction and GC. Sensory evaluation results showed that the probiotic fermentation improved the aroma and taste of Danpness-eliminating decoction, and the overall sensory quality of Danpness-eliminating decoction on the seventh day of fermentation was the best. In conclusion, the fermentation of Danpness-eliminating decoction with DU-106 and L. plantarum were beneficial to improve the quality of Danpness-eliminating decoction. This study would provide a theoretical basis for the production of compound decoction of medicine-food homologous material fermented by compound strains.