Optimizing the Brewing Process, Metabolomics Analysis, and Antioxidant Activity Analysis of Complexed Hongqu Rice Wine with Kiwiberry

Hongqu rice wine is a traditional Chinese yellow wine produced from a single ingredient. To enhance the competitiveness of the product and better adapt to market development trends, the development of a complexed Hongqu rice wine using a variety of ingredients is necessary to enhance the nutritional value of the product and diversify its flavor. This study explored production technology for the development of a complexed Hongqu rice wine using kiwiberry as the raw material. The mixed fermentation process was optimized using single-factor experiments and response surface methodology (RSM). The optimal conditions were a juice addition time of 93 h, a fermentation temperature of 31 degrees C, and a juice addition amount of 75 g/100 g. Under these conditions, the complexed Hongqu rice wine had an alcohol content of 8.7% vol, a total phenolic content of 0.42 mg GAE/mL, and a total flavonoid content of 0.32 mg CE/mL. In total, 27 metabolites were identified. The relative levels of 15 metabolites, including quercetin-3-glucoside and rutin, increased significantly after the adding of the kiwiberry (VIP > 1.0, p < 0.05, FC > 2). Antioxidant activity experiments showed that the Hongqu rice wine had notable antioxidant capacity and that adding the kiwiberry significantly enhanced this capacity. Additionally, the complexed Hongqu rice wine exhibited hypoglycemic and bile acid-binding properties. It achieved 78.68 +/- 0.44% inhibition of alpha-amylase and 58.02 +/- 0.50% inhibition of alpha-glucosidase. The binding activities with sodium glycocholate, sodium cholate, and sodium taurocholate were 40.25 +/- 0.64%, 49.08 +/- 1.05%, and 60.58 +/- 0.80%, respectively. Consequently, a complexed Hongqu rice wine rich in quercetin-3-glucoside and rutin, with notable antioxidant activities, was developed. This wine has potential applications in functional food development.