Nutritional composition and oligosaccharide contents of preprocessed and fermented African locust bean (<i>Parkia biglobosa</i> benth.) seed during processing

Abstract

The crude protein, ether extract, glucose, sucrose, total carbohydrate and raffinose-series oligosaccharide contents of African locust bean ( Benth.) seeds were determined following soaking, dehulling, boiling of dehulled seeds for 30 min to hydrate and fermented for 72 h. Mechanically dehulled raw seeds were also obtained from depulped bean seeds with a pair of pliers. There were significant reductions in the levels of raffinose-series oligosaccharides, glucose, sucrose and total carbohydrate of processed seeds, while crude protein and ether extract contents were significantly increased. The raffinoseseries oligosaccharide content decreased from 28.0 ± 2.2 g kg in the raw seeds to 0.1 ± 0.03 g kg in the fermented seeds at 72 h, representing a total reduction of 99.6%. Fermentation gave rise to
69.2% and 99.4% reductions in glucose and sucrose contents respectively. The crude protein content was significantly increased (P < 0.001) by fermentation from 270.1 ± 12.3 g kg in the raw seeds to 328.1 ± 4.0 g kg. Also ether extract increased significantly (P < 0.001) from 198.2 ± 11.0 g kg in the raw seeds to 347.3 ± 14.5 g kg in the fermented seeds at 72 h.

Keywords: Parkia biglobosa, raffinose-series oligosaccharides,
carbohydrates, processing, fermentation