The Predominant Lactic Acid Microorganisms and Proximate Composition of Spontaneously Fermented Gari and Fufu, Cassava Food Products

Abstract

Aim: The present study is focused on determining if there are differences in the types of organisms responsible for spontaneous fermentation in two types of cassava food products, namely, fufu and gari, while also ensuring that the expected organoleptic properties associated with the fermentation process from this study location is reproducible. Study Design: A Complete Randomized Design (CRD) with three replications was adopted and used to test for significant differences between the two cassava products.  Place and Duration of Study: The roots of two cassava varieties namely, TMS 97/0211 (white pulp) and TMS 97/2205 (yellow pulp) were obtained from the International Institute for Tropical Agriculture (IITA), Ibadan, and were processed at Ede, Nigeria between March and May 2016. Methodology: Using standardized spontaneous fermentation methods, the two varieties of cassava, were sampled eight hourly over a period of 5 days, for lactic acid bacteria and fungi. Samples were incubated anaerobically, representative microbial populations were enumerated and identified using standard microbiological protocols. Proximate analysis and sensory evaluations were conducted. Results: The results showed that the predominant lactic acid bacterial organisms were Lactobacillus brevisand L plantarum. On the other hand, the representative lactic acid fungal isolates were identified as Neurospora crassa, Aspergillus fumigatus and Saccharomyces spp.  Investigation of succession organisms revealed differences between the dry cassava finished product, gari and the wet finished product, fufu. The fungal organisms were the predominant starter organisms found in gari, while, the predominant starter organisms found in fufu were the bacterial types. Conclusion: The present results show that in spite of the spontaneity of the fermentation process, the yellow cassava variety supports the growth and reproduction of similar fermentation organisms as the white variety. Furthermore, the prevailing microenvironment in the fermentation set up, that is, wet or dry is the most important factor in determining the predominating organisms in the fermentation process and the organoleptic and nutritional characteristics of the final product. Results from this study show that it is possible to reproduce the organoleptic and nutritional characteristics peculiar to this test location using the isolated lactic acid microorganisms.