Influences of UV-B treatment and cooking methods on bioactive components in germinated highland barley

This study explored the impacts of UV-B radiation and cooking methods on the content and release of bioactive components in germinated highland barley. Optimal UV-B radiation (0.2 W m−2 for 6 h/d) increased flavonoid content by the third day, whereas excessive radiation (0.4 W m−2) caused a decrease. Under 0.1 W m−2 UV-B radiation for 9 h/d, polyphenol content rose by 34.40%, and under 0.2 W m−2 for 6 h/d, it increased by 49.40%. After three days of germination under 0.2 W m−2 irradiation for 12 h/d, riboflavin content reached up to 2.5 μg/g. GABA content in the control group increased by 40.21% on the third day compared to the initial, with the highest content in samples irradiated for 3 h/d under 0.2 and 0.4 W m−2. β-glucan content in the control group decreased by 20.15% on the third day compared to the initial, with a more pronounced decrease under long-time high radiation. Different cooking methods affected the release of these components during in vitro digestion. Microwaving proved to be the most effective treatment for promoting the release of flavonoids, polyphenols, riboflavin, and β-glucan, but it was less favorable for GABA release. These findings offer insights for optimizing the nutritional quality of germinated highland barley.