Effect of Fermentation on the Nutrient and Anti-nutrient Contents of African Bush Mango (Irvingia gabonensis) Seeds

Abstract

Aim: Effect of fermentation on nutrient and anti-nutrient contents of defatted and un-defatted African bush mango seeds. Study Design: Ground African bush mango seeds used in this study were divided into two portions; A, and B. Portion A was defatted while portion B was not defatted; both portions were fermented. Place and Duration of Study: Department of Microbiology and Chemistry Department, Federal University of Technology Akure, Ondo State between November 2017 and July 2018. Methodology: Microbial analysis was carried out using pour plate technique. The temperature, pH and total titratable acidity were monitored throughout the fermenting period. Proximate, mineral and anti-nutrient contents of the samples were carried out using standard methods. Results: Seventeen microorganisms comprising 11 bacteria and 6 molds were isolated and identified as; Staphylococcus aureus, Bacillus subtilis, B. cereus, S. epidermis, B. licheniformis, Micrococcus luteus, Proteus vulgaris, Enterococcus faecalis, Lactobacillus fermentum, L. plantarum, L. brevis, Aspergillus clavatus, A. flavus, A. niger, Rhizopus stolonifer, Penicillium chrysogenum and A. fumigatus. The pH and TTA values reduced and increased respectively while the temperature varied significantly as the fermentation day increases. The non-defatted fermented sample showed increase in protein (10.34-12.09%), moisture (6.98-7.84%) and carbohydrate contents (24.98-29.20%); while there was a reduction in the ash (3.91-2.93%), fibre (1.55-1.30%) and fat (52.24-46.64%) contents. The defatted fermented sample showed an increase in the protein content (17.39-26.44%) while there was a reduction in the moisture (26.60-26.46%), carbohydrate (41.02-38.96%) ash (4.07-3.01%), fat (9.44-4.02%) and fibre contents (1.48-1.11%). The mineral composition of the fermented samples increased significantly when compared to the raw samples. The anti-nutrient content of the samples decreased significantly with fermentation. Conclusion: This study revealed that African bush mango seeds can be defatted and fermented to produce food of enhanced nutritional value.