Resumen
There is an increasing trend to develop beers supplemented with local plant ingredients in order to increase their bioactivity. Carob (Ceratonia siliqua L.) is a xerophytic endemic tree typically found in Mediterranean ecosystems. The aim of this study was to develop a strong dark ale hybrid beer enriched with carob syrup prepared by using carob fruits from the University Campus (Athens, Greece). Three batches of beer were fermented, a dark ale (6% alcohol by volume or ABV) without carob and two strong dark ale beers (8% and 10% ABV) with carob syrup. After the second fermentation (bottle conditioning, 60 days), both carob beers had significantly increased bioactivity. The total phenolic content (176.4 mg GAE/100 mL), the antiradical activity (206.6 mg Trolox Equivalent (TE)/100 mL), and the antioxidant activity (838.2 mg Fe2+/100 mL) of the carob strong dark ale 10% ABV beer was increased by more than three times, six times, and eight times, respectively, compared to the standard dark ale (6% ABV) without carob. Moreover, LC-QToF-MS analysis ascertained the enhancement of the phenolic profile of carob beers by ten phenolic compounds compared to the control dark ale beer without carob, indicating their significant antioxidant activity.