Effect of Germination on the Nutrient and Antioxidant Properties of Tigernut (Cyperus esculentus).

Abstract

This study aims to add value to tigernut tuber by revealing its health benefits and food value on germination. In this study, tigernut tubers were germinated and the proximate composition,  mineral constituents and  the anti-oxidant properties  were analyzed to evaluate the effect of germination on these nutritive properties.The total phenolic content of raw and germinated seeds was measured by the Folin-Ciocalteu method, and the antioxidant activity determined by the 2,2-diphenyl-1-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid assay. The results of the evaluation shows that the protein content increases from 10.50-13.24 %, crude fiber  from  4.73-5.39 % on germination and the fat content from 25.40-25.70 %. The mineral analysis showed an increase in the parameter analyzed and that tiger-nut is rich in macro elements. Sodium increases from 32.10-65.50 (ppm); calcium from 158.00-206.00 (ppm); potassium from 541-597.00 (ppm); there is no detection of heavy elements, and germination were observed to have significant effect on the tiger-nut mineral composition (P≤0.05). The functional properties equally reveal the potentials of tiger-nut. The water absorption capacity reduces on germination from 1.89-1.78 g/g; the bulk density from 27.50-25.20 g/ml. The DPPH inhibition activity of the germinated tigernut was significantly higher than the DPPH inhibition activity of fresh tigernut. The various parameters investigated shows that germinated tiger-nut could be useful in food formulations as well as in weaning and in baking.

Key words:  Germination, proximate composition, antioxidant properties, functional properties, tiger-nut.