Storability and potability of pasteurized and sterilized "Kunun-zaki": a fermented sorghum beverage

The possibility of extending the shelf-life of "Kunun-zaki", a nonalcoholic sorghum based fermented beverage after pasteurization and sterilization was investigated. The traditional method of production was adopted and microbiological studies carried out. The predominant microorganisms isolated from the fermented beverage were Lactobacillus plantarum and Bacillus subtilis. Enterobacter spp. and Saccharomyces spp. occurred in small numbers. Proximate analysis of unpasteurized samples showed a decrease in total sugar and increased moisture content after one week storage at refrigeration temperature. Pasteurized samples were most acceptable to the taste panel up to two weeks of refrigerated storage, but rejected thereafter. Although the sterilized "kunun-zaki" was shelf-stable for the two weeks of investigation, its flavor and color were adversely affected, and therefore unacceptable to the panelists. This study has shown that the shelf-life of "kunun-zaki" (usually 24-36 h) can conveniently be prolonged without serious effects on the usual organoleptic properties for up to two weeks with pasteurization