不同发酵方式对啤酒糟发酵品质和微生物多样性的影响

Effects of different fermentation methods on fermentation quality and microbial diversity of brewer's grains

试验旨在探究不同发酵方式对啤酒糟发酵品质和微生物多样性的影响。试验利用功能性寡糖和复合益生菌发酵啤酒糟,试验设计分为4组,A组为对照组(未发酵组),B组为桶装发酵组,C组为青贮池传统压实发酵组,D组为薄膜水压封顶发酵组,发酵时间为14 d。结果显示,B组啤酒糟中粗蛋白、可溶性碳水化合物和中性洗涤纤维含量均显著高于A组(P<0.05)。B组、C组和D组的pH值和氨态氮含量均显著低于A组(P<0.05);乳酸和乙酸含量均显著高于A组(P<0.05),此外B组乳酸含量显著高于C组和D组(P<0.05),D组乳酸含量显著高于C组(P<0.05)。各组中均未检测到丁酸。B组、C组和D组的厚壁菌门相对丰度均高于A组,而变形菌门的相对丰度均低于A组;A组和C组的优势菌属为芽孢杆菌属;B组和D组的优势菌属为乳酸菌属。研究表明,桶装发酵法发酵啤酒糟的品质最好,其次是薄膜水压封顶法,最差的是青贮池传统压实法。

This experiment was conducted to investigate the effects of different fermentation methods on the fermentation quality and microbial diversity of brewer's grains.The experiment was used functional oligosaccharides and compound probiotics to ferment brewer's grains,and divided into 4 groups:Group A was the control group(unfermented group),Group B was the barreled fermentation group,Group C was the traditional compaction fermentation group,Group D was water-sealed fermentation group.The fermentation time was 14 days.The results showed that the concentrations of crude protein,soluble carbohydrate and neutral detergent fiber in brewer's grains in group B were significantly higher than those in Group A(P<0.05).The pH value and ammonia nitrogen content of Groups B,C and D were significantly lower than those of the Group A(P<0.05).The lactic acid and acetic acid concentrations of Groups B,C,and D were significantly higher than those of Group A(P<0.05).In addition,the content of lactic acid in Group B was significantly higher than that in Groups C and D(P<0.05),and the content of lactic acid in Group D was significantly higher than that in Group C(P<0.05).Butyric acid was not detected in any of the groups.The relative abundances of firmicutes in Groups B,C,and D were higher than that in Group A,but the relative abundances of proteobacteria were lower than that in Group A.The dominant species in Groups A and C were Bacillus,while the dominant species in Groups B and D were Lactobacillus.The study indicates that the quality of fermented brewer's grains is best when using the barrel fermentation method,followed by the hydraulic pressure capping method,and worse when using the traditional compacting method in silos.