Microbiological and Proximate Analysis of Okpehe, a Locally Fermented Condiment

Abstract

The high cost and harmful health effect of animal protein has directed interest towards several leguminous seed as potential sources of vegetable protein for human food. This study is therefore designed to determine the physicochemical, microbiological and nutritional quality of okpehe (Prosopis africana). Enumeration and identification of microorganisms in okpehe samples was carried out employing standard methods. The physiochemical, nutritional, anti-nutritional and mineral content of the okpehe samples were determined. The bacterial count in the okpehe samples ranged from 9.5 × 10 5-1.7 × 10 6 cfu/g while for fungal count; 1 × 10 4-3 × 10 4 cfu/g. Bacterial isolates were identified as Bacillus subtilis, Bacillus licheniformis, Bacillus megaterium, Staphylococcus aureus and Escherichia coli with their occurrence varying with sampling points. Fungal isolates were Aspergillus niger, Mucor sp. and Paecilomyces sp. The physicochemical parameters examined showed that pH values ranged from 6.7-7.8 and titratable acidity ranged from 0.27-0.50 g/L. The nutritional content ranges; moisture (4.74-8.64%), crude protein (31.76-40.28%), crude fibre (3.24-4.86%), carbohydrate (41.56-51.63%), ash (5.31-6.23%) and lipids (7.34-11.45%) varied significantly with physical characteristics such as texture and various sampling points. Higher nutritional content was observed in softer samples with more offensive ammoniacal smell while harder samples appeared to have reduced nutritional quality. The soft okpehe samples contained high amounts of potassium, calcium, iron, copper, zinc and manganese although the drier samples had the highest potassium content (3.496 mg/g). Cadmium and lead were Below Detection Limits (BDL) in all the samples. Anti-nutritional factors such as alkaloids, steroids, flavonoids, resins and phenols were present. Saponin content was very high as compared to the other phytochemicals. This study demonstrates that okpehe possess immense microbiological and nutritional benefits.