白酒糟与玉米油渣协同固态发酵工艺优化及体外营养价值评定

Process Optimization and In Vitro Nutritional Value Evaluation of Solid-State Co-Fermentation of Distiller’s Grains and Corn Oil Residue

中文关键词:  白酒糟  玉米油渣  固态发酵工艺  响应面法  体外仿生消化法

英文关键词:Distiller

中文摘要:

      本研究采用蒸汽爆破预处理的白酒糟为主要原料、玉米油渣为辅料构建混菌固态发酵体系，旨在实现白酒糟资源的高效饲料化利用。首先以活菌数为主要指标确定白酒糟基料中玉米油渣的最适添加比例，随后在单因素基础上通过响应面试验进一步优化发酵工艺，并对发酵前后白酒糟基料的常规营养成分、氨基酸组分、霉菌毒素含量和营养物质体外消化率进行测定。结果表明：当发酵基料中玉米油渣的质量分数为40%时菌群密度最大；最佳发酵工艺为发酵时间6 d、温度28℃、含水量60%、接菌量10%。在此工艺下，与发酵前相比，白酒糟基料的中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）质量分数分别降低22.25%和28.14%（P<0.01），酸性洗涤木质素（ADL）质量分数降低6.82%（P<0.05），粗蛋白质（CP）和还原糖质量分数分别提高12.27%和78.04%（P<0.01）。总氨基酸质量分数增加17.92%（P<0.05），霉菌毒素水平极显著降低（P<0.01）。此外，干物质、粗蛋白质、总能的消化率分别提高20.57%、42.01%和12.36%（P<0.01）。综上所述，协同利用白酒糟与玉米油渣进行固态发酵可有效改善其饲用品质。

英文摘要:

      This study employed steam-exploded distiller's grains as the main raw material and corn oil residue as the supplementary material to establish a mixed-strain co-fermentation system, aiming to achieve efficient feed utilization of distiller's grains resources. We first determined the optimal proportion of corn oil residue in the distiller's grains substrate based on viable cell count as the key indicator. We then further optimized the fermentation process using response surface methodology following single-factor experiments. We also analyzed the substrate before and after fermentation for conventional nutritional components, amino acid composition, mycotoxin content, and in vitro nutrient digestibility. The results showed that the highest microbial density was achieved with a substrate containing 40% corn oil residue. The optimal fermentation process parameters were: fermentation time of 6 days, temperature of 28℃, moisture content of 60%, and inoculation amount of 10%. Under these conditions, the contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) decreased by 22.25% and 28.14% (P<0.01), respectively, while the acid detergent lignin (ADL) content decreased by 6.82% (P<0.05). The crude protein (CP) content and reducing sugar contents increased by 12.27% and 78.04% (P<0.01), respectively. In addition, the total amino acid content increased by 17.92% (P<0.05), and mycotoxin levels were significantly reduced (P<0.01). The results of in vitro simulated digestion showed that the digestibility of dry matter, crude protein, and gross energy increased by 20.57%, 42.01%, and 12.36% (P<0.01), respectively. In conclusion, the synergistic utilization of distiller’s grains and corn oil residue through mixed-strain solid-state fermentation can effectively improve their feed quality.