酿酒酵母制备固态发酵饲料的参数优化及品质评价

Parameters Optimization and Quality Evaluation of Solid-state Fermented Feed Prepared by Saccharomyces cerevisiae

试验旨在研究利用酿酒酵母(Saccharomyces cerevisiae)Yn制备发酵饲料的合适参数及发酵后饲料品质。试验以酵母活菌数为检测指标,对发酵原料添加量、糖化酶添加量、接种量、料水比和发酵温度等参数进行单因素试验,通过响应面设计进一步确定糖化酶添加量、接种量和发酵温度的最优条件,同时评价最优固态发酵条件下发酵饲料的营养品质。结果表明:最适的发酵配方为玉米粉50%,豆粕20%;酵母菌Yn最佳的发酵条件为糖化酶添加量220 U/g、接种量1.4%(w/w)、料水比1:0.8(w/v),优化后的酵母菌数(折算干重)达到1.30×10^(10) CFU/g;粗蛋白、总酚、维生素B_2和低分子量肽含量在发酵后显著提高(P<0.05),而粗脂肪含量显著降低(P<0.05)。以上结果表明,该发酵条件在饲料发酵方面具有较好的应用前景。

The aim of this study was to determine the suitable parameters for preparing the fermented feed by Saccharomyces cerevisiae Yn and its nutritional quality after fermentation. Single factor analysis was performed to optimize the addition content of saccharifying enzyme, inoculation amount, the ratio of raw material to water and the fermentation temperature by using the yeast viable number as metrics. Further, the optimal parameters were studied by the response surface design. Meanwhile, the nutrient quality of fermented feed was evaluated under the optimal solid-state fermentation conditions. The results showed that the optimum fermentation conditions were as follows： 50% of corn flour and 20% of soybean meal, 220 U/g of saccharifying enzyme, 1.4% of inoculation amount and a material to water ration of 1：0.8. Under these conditions, the concentrations of crude protein, total phenolics, vitamin B_2 and low molecular-weight peptides were increased（P〈0.05） after fermentation, whereas the crude fat content was decreased（P〈0.05）. The total yeast viable number could reach 1.30×10^10 CFU/g（dry weight） after fermentation. Our result may suggest a good application prospect of the optimal fermented conditions in feed fermentation.