Impact of Auricularia cornea var. Li polysaccharides on the physicochemical, textual, flavor, and antioxidant properties of set yogurt

This study evaluated quality attributes and in vivo antioxidant activity of Auricularia cornea var. Li polysaccharide (ACP)-fortified set yogurt during 21 days of storage (4 °C). Set yogurt was manufactured using a commercial yogurt culture, and 3% (w/v) ACP was added. Physicochemical (pH, titratable acidity, and water-holding capacity), textural, rheological, microstructural, flavor, and antioxidant properties of set yogurt were investigated. The results showed that the addition of ACP significantly enhanced WHC, viscosity, firmness, and cohesiveness, while inhibiting post-acidification of set yogurt during storage. The yogurt supplemented with ACP showed a larger hysteresis area and higher G' and G″ values, formed a porous, dense, mesh-like structure and exhibited a unique mushroom flavor. Antioxidant results showed that administration of ACP-fortified yogurt significantly decreased serum alanine aminotransferase and aspartate aminotransferase enzyme activities and malondialdehyde levels, while increasing superoxide dismutase, catalase, phospholipid hydroperoxide glutathione peroxidase, and total antioxidant capacity in the liver and hippocampus of the mice. ACP-fortified yogurt might alleviate hepatic damage and hippocampal neuroinflammation induced by d-galactose. Additionally, ACP-fortified yogurt downregulated the expression of Keap1 and upregulated the expression of Nrf2 and HO-1 in the liver. In conclusion, ACP may be used as an ingredient to produce yogurt with desired properties.