Effects of coca bean shell addition on sensory quality and antioxidant capacity of beer

Abstract

This study was conducted to investigate the effects of cocoa bean shell addition at different ratios of 4, 6, 8 gams CBS (equivalent to 1:0.1/ 1:0.5/1:0.2 L water to kg CBS) into different steps of the brewing process including mashing, boiling and after clarification on antioxidant properties and sensory quality of beer. Determination of pH, alcohol, titratable acidity (TA), color, turbidity, total phenolic content (TPC), antioxidant capacity (AC), theobromine content, catechin content, caffeine content and sensory test were carried out. The results showed that the addition of CBS at boiling step yielded highest antioxidant properties compared to the two remaining methods. Adding 8 g cocoa bean shells in the boiling step (equivalent to the 1:02 ratio of water to CBS) showed highest TPC (818.10 ± 0.62 mg GAE/L), AC (784.39 ± 22.84 mg TE/L), theobromine content (0.34 ± 0.00 g/L), catechin content (0.19 ± 0.00 g/L), caffeine content (0.04 ± 0.01 g/L). The pH, TA, alcohol content, color and turbidity of this beer were 4.43 ± 0.19, 0.28 ± 0.02 % (lactic acid), 5.51 ± 0.29, 26.87 ± 0. 87 SRM, 856.00 ± 67.02 NTU, respectively. This beer sample was chosen for sensory test and it showed no significant differences compared to the commercialized beer. The results of this study suggested that CBS could be a potential ingredient for the brewing industry with higher antioxidant properties and special sensory value.