STUDIES ON SOME TECHNOLOGICAL PROPERTIES OF PREDOMINANT LACTIC ACID BACTERIA ISOLATED FROM NIGERIAN FERMENTED FOODS

Abstract

In a programme to develop starter cultures for improving the safety and quality of traditional fermented foods in Africa, a study was conducted on lactic acid bacterial (LAB) strains isolated from the traditional selected Nigerian fermented foods kunun-zaki, wara, nono, iru. The LAB strains representing the dominating population of each product, were identified as Enterococcus faecalis (1), Pediococcus pentosaceus (4), and Lactobacillus fermentum (19). All the strains grew at 450°C, an observation which could be attributed to the tropical environment of the fermented foods. They produced a moderate spectrum of enzymes of relevance to food processing, and exhibited similar patterns of enzymatic activity between species, but generally showed weak esterase and lipase activities as compared with peptidases. While no proteinase activity was detected, most strains showed high galactosidase activity. Two strains showed ability to degrade phytic acid. None of the strains produced any detectable bacteriocins or biogenic amines under the test conditions used, and all were unable to hydrolyse bile salt. Eleven (45.8%) of the strains coagulated skim milk at 30°C within 24–36 h, and at 37°C within 12–20 h together with a moderate drop in pH. The results are discussed to highlight the relevance of technological features of starter cultures in food processing in the African environment.