Microbiological and Chemical Changes During Fermentation of Crabs for ogiri-nsiko Production

摘要

Fresh water crab ( Sudananautes africanus africanus ) was processed and fermented to produce ogiri-nsiko , a type of condiment in Nigeria. During fermentation, bacterial populations, changes in pH, titratable acidity and proximate composition were measured over a 72 h period. The main microorganisms involved in the spontaneous fermentation of the crabs were, Bacillus subtilis , B. pumilis , Staphylococcus saprophyticus , Micrococcus luteus and Pseudomonas sp. Variations in the important microbial groups showed that Bacillus species were the most prevalent species and occurred until the end of the fermentation. However, significant contributions were made by Staphylococcus sp. which were present in low numbers until the end of the fermentation. Fermentation increased the pH of the substrate from 6.2 to 8.4. The titratable acidity increased in the first 24 h and then dropped as fermentation progressed. Proximate composition changes showed increase in protein, ash and crude fiber contents whereas crude fat decreased significantly in fermented samples. Fermented crab as a rich source of protein, offer potential substitute for meat and cultured dairy products.