Effects of fermentation with different coarse cereals on antioxidant capacity, flavor profiles and sensory characteristics of Huangjiu

Huangjiu, an ancient Chinese alcoholic beverage, is primarily brewed through the fermentation of steamed grains using Jiuqu as starter. This study systematically investigated the effects of five nutritionally rich coarse cereals (oats, quinoa, sorghum, buckwheat and black rice) on the physicochemical, antioxidant and flavor profiles of Huangjiu (CCHJ: MQHM, MQLM, MQYM, MQGL, and MQKQ) fermented with Maiqu. The results demonstrated that five types of CCHJ samples exhibited strong antioxidant capacity, with MQLM and MQHM showing particularly high α-glucosidase inhibition rates, exceeding 95%. Functional component analysis revealed that MQHM contained the highest levels of amino acids, total flavonoids and polyphenols, while MQKQ exhibited the highest organic acid content. A total of 203 volatile flavor compounds (VFCs) were identified, with MQGL having the highest concentration, followed by MQHM. Furthermore, 12 common compounds, including ethanol, isopropanol, acetoin, 4-ethyl-2-methoxyphenol, ethyl palmitate, 3-methyl-1-butanol, 2-methoxy-4-vinylphenol, (S)-2-heptanol, phenethyl alcohol, 3,4-dimethylbenzaldehyde, methanol, and octanoic acid, were identified as key aroma compounds in CCHJ samples based on their odor activity value (OAV). The distinctive sweet profile of MQHM was strongly correlated with these compounds. These findings provide valuable insights into how to optimize the use of traditional coarse cereals and advancing the development of novel functional Huangjiu products.