Abstract

Nutritional attributes of cooked and solid-substrate fermented cooked kernels of Canavalia cathartica of the coastal sand dunes of southwest India by Rhizopus oligosporus were compared. Fermentation resulted in significant increase of crude protein, total lipids and six minerals (Na, K, Ca, Cu, Zn and Se). Fermented kernels meet NRC-NAS standard of four minerals for infants (K, Fe, Cu and Zn). The Na/K ratio of fermented kernels attained desired level (<1) to control the blood pressure. Fermentation significantly enhanced the true protein, albumin, globulin, glutelin and non-protein nitrogen. Among the essential amino acids, lysine was significantly increased, while histidine and tryptophan were confined only to fermented kernels. Except for histidine and tryptophan, rest of the essential amino acids showed high score in cooked as well as fermented kernels fulfilling FAO-WHO-UNU standard for adults. The in vitro protein digestibility was also significantly increased in fermented kernels. In cooked and fermented kernels, the mean protein efficiency ratio ranged between 0.77 and 1.14. The oleic acid was highest followed by plamitoleic acid in cooked as well as fermented kernels. The latter has attained significantly high quantity as a result of fermentation. Overall, fermentation of cooked kernels selectively improved the nutritional attributes favoring desired quantities of bioactive principles.

Keywords: Canavalia cathartica, nutritional qualities, Rhizopus oligosporus, solid-substrate fermentation, wild legume.

Graphical Abstract