不同乳酸菌发酵燕麦浆的营养特性和风味品质分析

Analysis of nutritional characteristics and flavor quality of oat slurry fermented by different lactic acid bacteria

采用乳酸菌对燕麦进行生物加工,是改善燕麦风味、提升功能价值的新方法。但目前缺乏燕麦适配性发酵菌株,且未明确发酵燕麦的品质特征。该文评价了20株乳酸菌的性能,优选2株性能优良的植物乳杆菌,采用纯菌发酵及与牛乳发酵菌株嗜热链球菌和保加利亚乳杆菌组合的混菌发酵模式,对燕麦浆进行发酵,对比不同菌种组合发酵对燕麦浆理化指标和风味品质的影响。结果表明,植物乳杆菌普遍表现出较高的生长量、产酸性能及淀粉酶活性,且植物乳杆菌的淀粉酶活性均在7.69 U/mL以上。发酵燕麦浆活菌数均增加至10^(9)CFU/mL以上;发酵显著降低了燕麦浆中的还原糖,积累了有机酸,促进了多酚和黄酮的释放,提高了燕麦浆的抗氧化性;发酵增加了燕麦浆的持水力,产生了大量挥发性物质。植物乳杆菌有利于提高植物化学素含量和抗氧化性;添加嗜热链球菌和保加利亚乳杆菌的组中呈奶油香气的3-羟基-2-丁酮含量更高;植物乳杆菌F-嗜热链球菌L1-保加利亚乳杆菌L4组的感官品质、抗氧化性及风味品质最佳,是适宜发酵燕麦浆的菌种组合,具有更大的研究开发价值。

Lactic acid bacteria(LAB)fermentation of oats is a new processing method for oat products.However,there is still lack of suitable strains for oak,and the quality traits were not well characterized.This study evaluated the fermentation performance of 20 different strains of LAB in MRS broth,and two optimal strains(Lactobacillus plantarum)were screened.These two strains were combined with common milk fermentation strains Streptococcus thermophilus and Lactobacillus bulgaricus to ferment oat.The fermentation performance of different stains combinations in oat and their effects on physicochemical parameters and flavor quality of oat were studied.Results showed that L.plantarum generally exhibited higher growth and acid production performance,and the amylase activity of L.plantarum was above 7.69 U/mL.The viable count of fermented oat increased to above 10^(9)CFU/mL.Fermentation significantly reduced the reducing sugar,accumulated organic acids,promoted the release of polyphenols and flavonoids,and improved the antioxidant activities of oat.Fermentation increased the water holding capacity of oat and produced more volatile substances.The fermentation with L.plantarum improved the phytochemistry content and antioxidant capacity of mixed stains fermentation group.Fermentation increased the water holding capacity of oat pulp and produced a large number of volatile substances.Compared to pure fermentation of L.plantarum,the mixed fermentation group contained a higher content of 3-hydroxy-2-butanone with a creamy aroma.Among them,L1-L4-F showed the best overall sensory quality,antioxidant activities,and flavor quality,making it a suitable fermenting combination for oat,with greater research and development value.