响应面法优化藜麦秸秆饲料发酵工艺的研究

研究乳酸菌、乳酸菌与酵母菌混合菌剂以及黑曲霉对藜麦秸秆发酵饲料品质的影响,为藜麦秸秆在饲用方面的开发利用提供参考。利用微生物发酵以期改善藜麦秸秆的营养价值。乳酸菌单一发酵时,设定发酵时间、含水量和菌剂添加量3个试验因子,乳酸菌与酵母菌混合菌剂发酵藜麦秸秆试验中设定发酵时间、含水量和混合比例3个试验因子,均采用L₉（3⁴）正交原理设计试验,对粗纤维、粗蛋白、粗脂肪和可溶性糖4个营养指标做响应面法处理。同时做了黑曲霉对藜麦秸秆发酵饲料的对比试验。1）相同发酵条件下,混合制剂降解纤维素的作用比单一发酵剂明显;2）发酵处理后的藜麦秸秆饲料较未发酵的藜麦秸秆粗蛋白平均含量提高了约2.70%;3）发酵过程中粗脂肪含量变化较小,在0.24%~0.31%;4）发酵处理后,藜麦秸秆可溶性糖含量提高了约3%;5）黑曲霉具有明显的降解纤维素和提高可溶性糖含量的作用,但黑曲霉发酵的饲料感官品质较差。微生物发酵对藜麦秸秆饲料品质具有一定的提升作用,一定条件下,混合菌协同发酵优于单一菌株发酵。

Optimization of fermentation technology for production of quinoa straw feed using response surface methodology

Microbial fermentation can improve the nutritional value of straw, including quinoa straw. The aim of this study was to determine the effects of lactic acid bacteria alone and in combination with yeast, compared with the effect of Aspergillus niger, on the quality of fermented quinoa straw feed. The overall aim of this research was to provide a reference for the development and utilization of quinoa straw in feed. In the single fermentation with lactic acid bacteria, the three variable factors were fermentation time, water content, and amount of inoculant added. In the fermentations with lactic acid bacteria and yeast, the three variable factors were fermentation time, water content, and ratio of inoculants to quinoa straw. All experiments were designed using the L₉（3⁴） orthogonal principle, and the response surface method was used to analyze the four nutritional indicators crude fiber, crude protein, crude fat, and soluble sugar contents. At the same time, a comparative test of the effect of fermenting quinoa straw with A. niger was conducted. The results showed that： 1） Under the same fermentation conditions, cellulose degradation was greater in the mixed fermentations than in those with lactic acid bacteria alone. 2） The average crude protein content was 2.7% higher in fermented quinoa straw than in unfermented quinoa straw. 3） During the fermentation process, the crude fat content showed little change, ranging from 0.24% to 0.31%. 4） After fermentation, the soluble sugar content of quinoa straw was increased by about 3%; 5） A. niger degraded cellulose and increased the soluble sugar content, but the sensory quality of the feed was poor. Our results confirm that microbial fermentation can improve the quality of quinoa straw feed, and show that the synergistic fermentation with mixed inoculants is better than fermentation with a single strain.