Journal of Agriculture and Food Research (Mar 2023)
Potential of sodium benzoate additive to control food-borne pathogens and spoilage microbes on cassava (Manihot esculenta Crantz) fufu and shelf-life extension
Abstract
Cassava (Manihot esculenta Crantz) is often transformed locally into a wet fermented mash called fufu in western Africa by unskilled individuals with risk of contamination and reduction of its shelf-life, but information on the microbial status of stored fufu is scarce and preservation techniques are inadequate. We investigated microbial development on fufu and the potential of sodium benzoate as a preservative to increase the shelf-life and quality of stored fufu. Fufu samples from four (Muyuka, Bolifamba, Melong and Lelem) localities in Cameroon were treated with sodium benzoate and stored at room temperature in the laboratory for 8 weeks. Morphological, biochemical and molecular techniques were employed to assess microbial development on stored fufu, while the acceptability of stored fufu was evaluated on a 9-point hedonic scale. A total of six bacterial species were identified on fufu, including four pathogenic (Actinobacter, Bacillus cereus, Pseudomonas auruginosa, and Pseudomonas plecoglossicida) and two non-pathogenic (Chryseobacterium sp. and Lactobacillus ceti). Five fungal species were identified, including four pathogenic (Aspergillus flavus, Aspergillus niger, Penincillium chrysogenum and candida albicans) and one low virulent pathogenic fungus (Saccharomyces cerevisiae). Multivariate analysis revealed significant effect of sodium benzoate and storage duration on bacterial and fungal counts, while the interaction of sodium benzoate and field sites additionally affected fungal count. Bacterial count increased significantly in untreated fufu by 69%, 45.7%, 30.8% and 55%, respectively, for Muyuka, Bolifamba, Melong, and Lelem compared to sodium benzoate treatments. Fungal count also increased significantly in untreated fufu, by 32%, 22.4%, 24.3% and 50%, respectively, for Muyuka, Bolifamba, Melong, and Lelem compared to treated fufu. After six weeks storage, treated fufu was still acceptable with 5.33 hedonic score and low microbial counts, while untreated fufu was completely unacceptable with 2.3 hedonic score and high microbial counts, which highlights the potential of sodium benzoate as preservative for fufu.
