Effects of Processing Techniques on the Microbial Quality, Nutritional and Mineral Composition of Black-eyed Bean (Vigna unguiculata)

Introduction: Black eye pea (Vigna unguiculata), because of its preferred taste and nutritional value is one of the commonly eaten beans in Nigeria.

Aim: The effect of processing techniques like soaking, dehulling and drying on microbial quality, nutritional and mineral composition of black-eyed bean was studied.

Study Design: One cup of black-eyed beans was divided into two portions. One portion was manually selected, soaked, dehulled and sundried. The other portion received no treatment. Both portions were ground and sieved.

Methodology: One gram of each sieved sample was serially diluted and enumerated of bacteria using standard microbiological procedures. Proximate and mineral compositions were determined by standard analytical procedures.

Results: The presence of Staphylococcus, Klebsiella, Bacillus, Enterobacter and Salmonella species were observed in both samples. Species of Lactobacillus and E. coli were found in treated and untreated sample, respectively. The protein, ash and moisture contents of the treated sample were higher compared to the untreated sample while that of carbohydrate, fibre and fat were lower in the treated sample. Analysis of zinc and iron revealed higher values in the treated sample than in the untreated sample. In contrast, the concentration of magnesium was slightly lower in the treated sample.

Conclusion: Processing of raw food items such as beans by soaking, dehulling, drying, etc. before cooking confer quality, nutritional and health benefits on the final edible food products.