Influence of different baking temperatures of red kojic rice on the physicochemical properties, antioxidant capacity, and functional components of red starter wine

Abstract BACKGROUND To improve the quality of red starter wine, this study explored the effects of baking red kojic rice at varying temperatures on the physicochemical characteristics of red starter wine. Baking was predicated on understanding crucial enzyme activities and starch granule structure of red kojic rice at 75, 95, and 105 °C, leading to the production of three red starter wine variants (BHQW1, BHQW2, and BHQW3). RESULTS The results revealed an increased alcohol (increase 0.50%), total sugar (increase 0.14 g L −1 ), and total acid (increase 0.54 g L −1 ) content in red starter wine fermented using baked red kojic rice compared with the control group (wine fermented with unbaked rice, HQW). Furthermore, both the 105 °C baked red kojic rice and its resulting BHQW3 demonstrated significantly higher red color values than HQW (increase 2.03 U g −1 and 0.15 U mL −1 respectively). The highest lovastatin content was presented in red kojic rice baked at 105 °C and its corresponding fermented wine (1420.63 ± 507.9 μg g −1 and 3368.87 ± 228.16 μg L −1 respectively). Additionally, BHQW groups displayed higher total flavonoids and phenols content than HQW. Regarding antioxidant capacity, all BHQW groups showed stronger overall antioxidant capacity than HQW. The determination of volatile components revealed the highest content of volatile compounds in BHQW2 (2621.19 ± 548.24 μg L −1 ) and significantly higher volatile esters in BHQW1 (254.46 ± 16.63 μg L −1 ). Moreover, 16 volatile compounds were identified only in BHQW groups, including isoamyl caprylate, 2‐ethylhexyl alcohol, and benzaldehyde. CONCLUSION Our findings suggested that the baking technique of red kojic rice could enhance the quality of red starter wine through enhancing antioxidant properties, increasing functional components, and enriching volatile flavor compounds, thus providing a foundation for new techniques in red starter wine production. © 2023 Society of Chemical Industry.