Chemical composition and microbiological changes during spontaneous and starter culture fermentation of Enam Ne-Setaakye, a West African fermented fish-carbohydrate product

Abstract

Enam Ne-Setaakye, a fermented fish-carbohydrate meal was made from minced fish flesh (75%), yam (20.5%), onions(1%), ginger(1%) and salt(2.5%). A total of 113 isolates belonging to the genus Lactobacillus, Pediococcus, Bacillus, Pseudomonas, Klebsiella, Staphylococcus, Debaromyces and Candida were obtained from the natural fermentation process of the product. Lactobacillus brevis and Pediococcus pentosaceus were the dominant species with 24% and 19% occurrence respectively, while Candida species least occurred (3%). Changes in the viable count of the microflora showed the dominance of lactic acid bacteria from the 48 h of fermentation period (5.8×10 cfu/g) to the end (2.3×10 cfu/g). Enterobacteriaceae which was detected at a level of 10 cfu/g at 0 h, were not detectable after 72 h. Moulds were not isolated, while the yeast population became detectable from 72 h reaching 10 cfu/g at the end of fermentation. On the other hand, a shorter fermentation period of 72 h with a LAB count of 10 cfu/g, nondetection of enterobacteriaceae, moulds and a yeast population of 10 cfu/g were obtained when the fermentation was carried out using L. brevis and P. pentosaceus as starter cultures. A pH level of 4.3, 3.1% titratable acidity and 2.1% (w/wp) salt content were obtained in the starter culture fermented Enam Ne-Setaakye. There were significant differences in the moisture and free fatty acid contents of both naturally and starter culture fermented samples, but the protein content (16%) was not significantly different. Sensory evaluation of the products showed consumer preference for the steamed samples. © Springer-Verlag 2002.