Bacteriological Quality of Packaged and Unpackaged Processed Yam Flour

Abstract

This study evaluated the bacteriological quality of packaged and unpackaged processed yam flour samples obtained from Tombia Market in Yenagoa, Bayelsa State, Nigeria. Yam flour, a staple food in West Africa, is prone to microbial contamination during processing, storage, and handling. Samples were analyzed for total heterotrophic bacteria (THB), coliform counts, and bacterial diversity using standard microbiological techniques, including nutrient agar, MacConkey agar, and biochemical tests. Results revealed significant bacterial contamination in both packaged and unpackaged samples, with THB counts ranging from 1.14 ± 0.10 × 10² CFU/g to 1.94 ± 0.07 × 10² CFU/g for packaged samples and 1.27 ± 0.20 × 10² CFU/g. Concurrently, coliform counts ranged from 0.45 ± 0.08 × 10² CFU/g to 0.84 ± 0.10 × 10² CFU/g across both sample types. Unpackaged samples exhibited higher mean THB (5.10 ± 1.11 × 10² CFU/g) and coliform (2.60 ± 0.19 × 10² CFU/g) counts compared to packaged samples (3.73 ± 1.94 × 10² CFU/g and 2.10 ± 0.92 × 10² CFU/g, respectively), indicating greater susceptibility to environmental contamination. Bacterial isolates included Escherichia coli (25% in unpackaged, 17% in packaged), Bacillus species (20% in unpackaged, 29% in packaged), Lactobacillus species, Staphylococcus species, Pseudomonas species, Micrococcus species, Citrobacter species, and Streptococcus species, with E. coli and Bacillus being predominant. The presence of pathogens like E. coli suggests potential health risks, emphasizing the need for improved hygiene and packaging practices. Proximate analysis was conducted but not fully reported. Statistical analysis (ANOVA, P < 0.05) confirmed significant differences in microbial loads between samples. These findings highlight the importance of good manufacturing practices and effective packaging to enhance the safety and quality of yam flour for consumer health.