Nutrient Composition Analysis of African Walnut (Tetracarpidium Conophorum) and Isolation of Microorganisms Responsible for its Spoilage

Abstract

Fruits and nuts are essential components of animal and human diets and desert. They represent diverse genetic resources in tropical and subtropical regions of the world. This study was undertaken to determine the population and diversity of microbes in African walnut as well as to determine the proximate composition of the nut. The nut was analyzed for total coliform, total aerobic heterotrophic bacteria and the presence of indicator and pathogenic bacteria using standard plate count methods. It was discovered that the nut has varying populations of bacteria ranging from 1.45×10⁴ – 5.10×10⁷cfu/ml and 3.10×10⁴ – 4.70×10⁷ for fungi. Bacterial species associated with the spoilt samples were identified as Salmonella typhi, Klebsiella pneumoniae, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis and Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus and Candida albicans. The presence of indicator organism of feacal contamination and pathogenic bacteria in the nuts poses potential risks to the consuming public. The proximate composition analysis of the nut showed that the nut contained 2.36% moisture, 6.04% fat, 52.55% protein, 7.12% fiber, 4.86% ash and 27.17% carbohydrates respectively. The nut contains some essential amino acids which include lysine, isoleucine, leucine, arginine phenylalanine and valine. The highest value was recorded for arginine (17.96 g/100g protein). The study also revealed that the nut a good value source of nutrient with its potential use in food industries.