苹果皮渣固态发酵生产菌体蛋白饲料工艺优化及产物品质分析

Solid-state Fermentation Parameters Optimization and Quality Analysis of Protein Feed From Apple Pomace

为提高苹果皮渣中粗蛋白的含量,以黑曲霉为发酵菌种发酵苹果皮渣,通过单因素试验对影响苹果皮渣固态发酵的参数进行优化,在此基础上进一步采用响应面试验筛选最佳发酵工艺参数,并对最佳工艺条件下的发酵产物品质进行分析。结果表明,黑曲霉发酵苹果皮渣的最佳工艺条件为:黑曲霉接种量10%、发酵温度32℃、水料比3.5、发酵时间6 d。此条件下苹果皮渣经发酵后粗蛋白含量从7.05%提高到33.56%,粗脂肪含量从4.75%提高到5.57%,粗纤维含量从21.80%降低到13.53%,氨基酸总含量从45.10 mg·g^(- 1)提高到126.30 mg·g^(- 1),必需氨基酸含量从16.13 mg·g-1提高到50.40mg·g^(- 1)。综上,黑曲霉发酵可以显著提高苹果皮渣的营养价值,这为苹果皮渣资源化利用、缓解蛋白质供需矛盾提供了有效途径。

To improve the content of crude protein in apple pomace,Aspergillus niger was chosen to ferment apple pomace in this research. Important influence factors of solid-state fermentation such as inoculation size,fermentation time,water-material ratio and fermentation temperature were separately employed as the important influence factors of solid-state fermentation to carry out the optimization firstly according to single factor experiment. Response surface methodology was then designed based on the results of the single-factor experiment. By single factor test and response surface test,the optimal fermentation conditions were obtained as follows： 10%（ v / w） inoculum size of A. niger,fermentation temperature at 32 ℃,3. 5 of water-material ratio,cultivation for 6 d. Under the optimized condition,in the final product crude protein was increased from 7. 05% to 32. 56%,crude fat was increased from 4. 75% to 5. 57%,crude fiber was yet decreased from 21. 8% to 13. 53%,total amino acids were increased from 45. 17 mg·g-1to 126. 3mg·g-1,and the essential amino acids were increased from 16. 13 mg·g-1to 50. 4 mg·g-1respectively. The result shows that solid-state fermentation with A. niger can significantly enhance the nutritional value of apple pomace. It also provides an effective way for apple pomace utilization and alleviating the contradiction between protein feedstuffs supply and demand.