Bioactive compounds, antioxidant activities and flavor volatiles of lager beer produced by supplementing six jujube cultivars as adjuncts.

Lager beer with high content of cyclic adenosine monophosphate (c-AMP) and strong antioxidant activity was produced by supplementing six jujube cultivars (Ziziphus Jujuba cv. Hetian , Muzao , Huizao , Goutou , Jinsixiaozao , and Banzao) as adjuncts. Jujube supplementation significantly increased total phenolic and flavonoids contents of final beers, and therefore improved antioxidant activities based on DPPH, ABTS and FRAP methods, especially for Banzao supplementation, exhibiting the highest antioxidant activities, increasing by 31.00%, 20.81% and 43.66%, respectively, which were positively correlated with protocatechuic acid, p-coumaric acid and rutin levels. Furthermore, hierarchical cluster analysis revealed that jujube supplementation significantly influenced flavor formation in final beers. There were 17 new volatile compounds formation after jujube supplementation, including one alcohol, 11 esters, two acids and three aldehydes, suggesting the improved complexity of beer flavor. In addition, high contents of c-AMP ranging from 4.02 to 15.14 μg/mL were observed in final beers fermented by jujube supplementation, endowing beer with a new health function. [Display omitted] • Jujube was suggested as a promising adjunct for beer brewing. • Beer fermented by jujube supplementation exhibited stronger antioxidant capacity. • Jujube adjunct improved protocatechuic acid, p-comaric acid, and rutin contents. • Beer fermented by jujube supplementation exhibited high c-AMP level. • Jujube supplementation improved the aroma complexity of beer. [ABSTRACT FROM AUTHOR]