Value-Added Products From Baijiu Distillers' Grains: Bioactive Flavonoids and the Evaluation of Its Potential Function.

Baijiu distillers' grains (BDGs) are the largest by-products in the Baijiu brewing industry. As the main raw material for Baijiu brewing, sorghum contains rich bioactive flavonoids. During the brewing of Baijiu, the bioactive flavonoids are primarily retained in BDGs. In this study, flavonoids from BDGs (BDF) were extracted using an ethanol-assisted ultrasonic method, and their bioactivities and functions were assessed in vitro and in Caenorhabditis elegans (C. elegans). The results showed that the extraction rate of BDF reached 4.73 mg/g under optimal extraction conditions (extraction time: 78 min, extraction temperature: 40°C, liquid-to-solid ratio: 47:1 mL/g, ethanol percentage: 76%). In vitro, BDF exhibited superior antioxidant and anti-amyloid fibrosis activities. In C. elegans, BDF effectively delayed aging and enhanced stress resistance. Functions of BDF in vivo could be explained by the fact that BDF significantly reduced the ROS and protein deposition level, and activated antioxidant defense system. Genetic analyses showed BDF activated the stress-regulated transcriptional factors HSF-1 and SKN-1. These findings suggested BDF has application potential in anti-aging and enhancement of resistance and offered a novel strategy for utilizing BDGs.