The application of Vernonia Amygdalina extract as a substitute for hops in sorghum beer production

Abstract

Recently, considerable attention has been focused on the brewing industry that are helping transform Uganda’s business landscapes with alcoholic beverage industries having a lion’s share in terms of investment and market. However, the country`s requirement of hops are met through import. Thus, the need to investigate some Ugandan plants that could substitute hops in beer brewing. In this research work bitter leaf (Vernonia amygdalina) was investigated using a reflux condenser extraction unit and appropriate solvent material to obtain the extract. Thereafter, the extract was characterized in order to determine its suitability for use in brewing by comparing it with those of standard commercial hops values. The optimization of process parameters for the bitter leaf extract were monitored following A.O.A.C methods. The three parameters were temperature of 80 0C, time of 2 hours, and particle size of 0.25 mm were chosen. The physicochemical analysis of the bitter leaf showed that the sample extract had brewing properties or variables as follows: protein content (%) of 0.18%, ash (%) of 0.22, moisture content (%) of 9.7 alcohol content (%) of 12.37 v/v and fat content (%) of 2.81. The Analytical Bitterness Unit (ABU) was found to be adequate and ranged from 16.55-17.1. Based on the comparison, it was observed that the brewing qualities of hops are present in bitter leaf to an appreciable level with variation in the fat and soluble solids (mineral) contents. Consequently, the results obtained showed that bitter leaf presents an acceptably high level of their hop properties that is adequate for beer brewing.