Comparative Evaluation of the Microflora and Biochemical Constituents of Sorghum-African Breadfruit Blends for Complementary Foods

Abstract

Complementary foods formulated from locally obtainable, underutilized, low-priced sorghum and African breadfruit seeds were assessed for their microbial quality and nutritional values. The fermented gruel produced from sorghum (Ogi-baba) and African breadfruit flour blends were mixed in varying ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 (w/w.) respectively. The microbiological quality, changes in pH and titratable acidity and proximate compositions of the blends were determined using standard analytical methods. The energy value was evaluated using the Atwater factor. Bacteria isolated from the samples were Bacillus species, Escherichia coli, Pseudomonas species, Staphylococcus aureus, Klebsiella species and Lactobacillus species while fungal isolates include Saccharomyces species, Aspergillus niger, Aspergillus flavus and Rhizopus species. The colony-forming units of the bacteria and fungi investigated in the supplemented samples ranged from 1.1×105 ±0.00f to 10.9×107±10.04c cfu/g over the 96 hours of fermentation period. The most predominant bacteria and yeast genera were Lactobacillus and Saccharomyces, respectively in all the blends persisting throughout the fermentation period. The pH of the fermenting samples decreased with a concomitant increase in the titratable acidity with an increase in percentage supplementation and fermentation time. The supplemented product shows significant (p<0.05) increases in the crude protein (18.92±0.02c for 50%), fat (10.36±0.02c for 50%), ash (6.55±0.03b for 50%), and fiber (1.92±0.00 d for 50%) contents with a corresponding decrease in the carbohydrate and moisture content as the levels of substitution with African breadfruit increases from 10% to 50%. The energy value ranged from 340.99±0.11d to 381.76±0.15b kcal/100 g. The use of African breadfruit to supplement sorghum has been shown to have a considerable nutritive effect. Therefore, sorghum- African breadfruit flour blends can serve as a constituent of traditional weaning and adult meals which are low-priced compared to formulated foods. Stamford Journal of Microbiology, Vol.12 (1) 2022: 8-14