Applying huaimi (flos sophorae immaturus) as a brewing adjunct and its impact on sensory properties of beer

Huaimi is a precious Chinese herbal medicine mainly containing rutin. In this study, Cyan Huaimi (CH) and Golden Huaimi (GH) were introduced at various stages of beer production. A total of 8 beer groups and 1 control group were set up to compare their physicochemical, bioactivity, volatile compounds and sensory characteristics. The results indicated that compared with the control group, adding Huaimi significantly reduced the pH and real extract of beer, and improved the other Physicochemical parameters. Furthermore, the addition of Huaimi brought higher levels of total polyphenols, flavonoids, and phenols compounds in 8 beer groups, particularly rutin content, reaching as high as 212.69 mg/L. Moreover, through the evaluation of DPPH, ABTS, and reducing power methods revealed that adding Huaimi at the boiling stage benefited most in improving antioxidant capacity. However, the results of sensory evaluation demonstrated that panelists preferred the beer with Huaimi added at the saccharification stage because of its smoother foam. Volatiles analysis revealed that adding Huaimi introduced twelve new volatiles to the beer, enhancing its flavor and taste complexity.