Kinetic changes of polyphenols, anthocyanins and antioxidant capacity in forced aged hibiscus ale beer

Abstract

Three craft ale beers contained 5, 10 and 20 g/L Hibiscus sabdariffa L. aqueous powered extract (HS) were submitted to a forced aging process for 7 days at 45°C, and the changes with time of physicochemical parameters, anthocyanins, total phenolic compounds (TPC) and antioxidant activities (AOX) were monitored. The determination of the individual characteristics of the 20 g/L HS beer after forced aging indicates that it was characterized by low pH and browning index, slight red hue, and high TPC content and AOX. It becomes clear that HS extract had a noticeable effect on the acidity and colour of beer and it was an important source of phenolics and anthocyanins, compounds with AOX. When the evolutions of the general parameters were compared, hibiscus beer showed the weakest tendency to age, giving as result lesser red colour loss and AOX owing to a low anthocyanin degradation and brown pigment formation. Copyright © 2017 The Institute of Brewing & Distilling.