Identification of phenolics and functional analysis of their activity in light/sauce-flavor Baijiu distiller's grain

Abstract

In this study, the content of phenolics was determined from light/sauce-flavor (Qing/Jiangxiangxing) Baijiu distiller's grain, and the compositional structures of free and bound phenolic compounds were identified using ultra-performance liquid chromatography-electrospray-tandem mass spectrometry (UPLC-ESI- MS/MS) coupling technique. Meanwhile, the antioxidant activities of the phenolic compounds were analyzed. In addition, the modulatory effects of polyphenols from light/sauce-flavor Baijiu distiller's grain on fecal microbiota and short-chain fatty acids (SCFAs) were explored by simulating the gastrointestinal digestion model in vitro. The results showed that the content of bound phenols (6.11 mg/g) was 2.3 times that of free phenols (2.64 mg/g), and naringin (116.12 μg/g) was the highest phenolic compound in free phenols, while fisetin (379.6 μg/g) was the highest phenolic compound in bound phenols. The polyphenols from light/sauce-flavor Baijiu distiller's grain had high antioxidant activity, and the antioxidant activity showed a significant positive correlation with total phenolic content (P<0.01). Furthermore, the polyphenols of light/sauce-flavor Baijiu distiller's grain increased the relative abundance of total bacteria, butyric-producing bacteria, Akkermansia, Lactobacillus, Ruminococcus, Bifidobacterium, and increased the content of SCFAs, acetic acid, propionic acid, valeric acid, isovaleric acid and isobutyric acid.

Keywords

• light/sauce-flavor baijiu distiller's grain|phenolics|antioxidant|fecal microbiota|short-chain fatty acids