Effects of Fermentation on Nutritional and Microbial Qualities of Ash Neutralized Roselle (Hibiscus sabdariffa L.)

Abstract

The study was conducted to investigate the effect of fermentation on the nutritional and microbial qualities of Roselle calyces from two States in Nigeria. Roselle calyx was fermented naturally (FN), fermented with coconut husk ash (FWCHA), Fermented with cocoa pod ash (FWCPA), Fermented with Gmelina tree ash (FWGTA) separately for 72 hours. The chemical and antinutrient compositions of raw and fermented calyx were determined using standard procedures. The microbial assessment of the samples was also determined. Moisture, ash, protein and carbohydrate contents increased significantly in fermented samples compared to raw calyx, however, the fat content reduced and crude fibre varied significantly likewise the antinutrients (Tannin, Hydrogen cyanide, Phytate) significantly reduced by the fermentation process (α=0.05). A total of 8 organisms were isolated during fermentation, which included four (4) bacteria, one (1) yeast, and three (3) moulds. Pseudomonas aeruginosa was isolated before fermentation. Staphylococcus aureus, Escherichia coli were isolated before and during fermentation at 24 hours and could not be isolated after. Bacillus subtilis, Saccharomyces cerevisiae  Aspergillus flavus and Aspergillus niger, Mucor mucedo were isolated throughout the fermentation. Microorganisms isolated during fermentation include Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa. Saccharomyces cerevisiae, Mucor mucedo, Aspergillus niger, Aspergillus flavus.