Comparative study of physicochemical analysis of prosopis africana seeds fermented with different starter cultures

摘要

Prosopis africana (African mesquite) is one of the lesser known legume seed crops in Nigeria, which in a fermented state, gives a food condiment. Because of its rich protein content (about 34%), efforts are made to utilize some lesser known legumes to improve the nutritional status of the people. This study was carried out by fermenting Prosopis africana seeds with mono and mixed cultures of bacterial isolates to produce a local condiment called Okpehe. Standard AOAC methods were used to determine the pH, total sugar and crude protein content of the fermented seeds. During the production of Okpehe with mono cultures of bacteria, the pH ranged between 6.80 and 8.92; total sugar between 10.2 and 7.5 mg/g, and crude protein between 34.62 and 41.25%. In the mixed culture inoculated samples, the pH increased from 7.00 to 8.92; total sugar decreased from 9.4 to 7.4 mg/g, while the crude protein increased (35.02 – 44.61%) significantly (p < 0.05) as the fermentation progressed. The highest crude protein content of 44.61% was obtained with the combination of Bacillus subtilis and Bacillus licheniformis, while the lowest protein content referred to the combination of Bacillus megaterium and Bacillus pumilus. The result of this study showed that Prosopis africana seeds could be utilized for the production of Okpehe using mixed cultures of B. subtilis and B. licheniformis, so as to increase the protein intake of the populace.