In this study, soybean whey soy sauce was prepared using ssoybean whey to replace fermented grain-brine mixture for high-salt dilute-state fermentation. The chemical composition and water quality indexes of soybean whey were determined, and the quality and volatile flavor components of soybean whey soy sauce were analyzed through using traditional brewing soy sauce as a control. The results showed that the soybean whey contained many kinds of chemical components, and was rich in carbon source, nitrogen source and inorganic salts, indicating its suitability for soy sauce brewing. The contents of amino acid nitrogen, soluble salt-free solids, total nitrogen of the soybean whey soy sauce were 0.96, 18.73 and 1.56 g/100 mL, respectively, which were all superior to those of traditional brewing soy sauce and met the special grade soy sauce standard in GB 18186-2000 for "Brewed soy sauce". The free amino acid content of soybean whey soy sauce was 49.79 mg/mL, with a higher umami amino acid content (13.26 mg/mL). A total of 77 volatile flavor substances were determined in the soybean whey soy sauce, mainly including alcohols (839.93 μg/L) and esters (808.23 μg/L). The application of soybean whey in the production of brewed soy sauce can enhance the flavor and sensation of soy sauce, improve the quality of soy sauce, and save energy effectively, thereby providing a new idea for realizing high-value waste utilization.
