Bioactive compounds and microbial evaluation of African walnuts (<i>Tetracarpidium conophorum</i> (Mull. Arg.) Hutch & Dalziel) retailed in Ilorin Metropolis

Abstract

The African walnut (Tetracarpidium conophorum) is a nutrient-dense tropical fruit that provides numerous health benefits and offers a wealth of nutritional value. This study investigated the bioactive compounds and microbes associated with African walnuts retailed in the Ilorin Metropolis. After preparing stock solutions from the obtained nuts, microbial isolations were carried out on Potatoes Dextrose Agar (fungi), Nutrient Agar, and Eosin Methylene Blue Agar (bacteria) using the pour plate method. Sixteen bioactive compounds of very significant therapeutic values were identified in the raw nuts using Gas Chromatography-Mass Spectrometry (GC-MS). Also, molecular identification of the fungal species and biochemical characterization of the bacterial species isolated from the nuts revealed the presence of four fungal species, namely Aspergillus niger, Penicillium rolfsii, Rhizopus delemar and Rhizopus arrhizus, as well as three bacterial species, namely Bacillus cereus, Staphylococcus aureus, and Escherichia coli. The GC-MS results revealed the nutritional and medicinal benefits of consuming cooked African walnuts; however, the microbial screening serves as a precaution for those consuming cooked African walnuts retailed in the Ilorin metropolis.