Triumpheta cordifolia gum extract in the clarification of Safrari sorghum wort

This study aimed to investigate Triumpheta cordifolia A. Rich. gum extract as a clarifying agent in sorghum wort brewing. The biological materials used in this study included the Safrari sorghum cultivar and the bark of T. cordifolia. We determined the key physicochemical characteristics, such as turbidity, pH, Brix (soluble solids), as well as color and polyphenol content of Safrari sorghum wort. The response surface methodology employing a Box-Behnken experimental design with three factors was used to investigate the impact of adding T. cordifolia gum extract to Safrari sorghum wort during its clarification. The physicochemical properties of Safrari sorghum demonstrated satisfactory results for malting. The sorghum was malted and subsequently brewed, and the resulting wort was clarified according to the experimental design. The design factors included the volume of the gum extract (from 1.5 to 3.5 mL) for a fixed wort volume of 200 mL, the stirring speed (from 30 to 160 rpm), and the settling time (from 10 to 60 min). The responses were analyzed during 15 trials and included turbidity, pH, Brix, color, and polyphenol content. These responses were subjected to mathematical and statistical modeling. All obtained models were validated against several criteria, including the correlation coefficient (R2 > 0.90), the absolute average deviation (absolute average deviation < 0.3), as well as the bias and accuracy factors (Af and Bf between 0.75 and 1.25). The optimal results suggested that the gum extracted from T. cordifolia could be effectively used as a clarifying agent in the brewing industry.