Antinutrients, micronutrients and glycemic characteristics of rice bran enriched with yam flour

Abstract

This study investigated the antinutrients, micronutrients and glycemic characteristics of yam flour enriched with rice bran particles at the ratios of 100:0, 95:5, 90:10, 85:15, 80:20 and 0:100 of yam flour: rice bran particles. The flour samples were subjected to antinutrients, minerals and vitamins analyses. The glycemic characteristics of the six flour samples were measured by feeding six out of the seven groups of albino rats with respective six flours and the seventh group was fed with reference feed, white bread. The percentage weights gain for all the rat groups ranged from 2.1 to 36.0%. The antinutrients decreased with increase in the ratio of rice bran particles in the flours and their ranges were: flavonoids 0.2-0.71mg/100g, alkaloids 0.17-1.09mg/100g, tannins 0.22-0.44mg/100g and phenols 0.36-0.56mg/100g. The minerals (calcium, magnesium, potassium and phosphorus) and B-vitamins (riboflavin, thiamin and niacin) of the flours increased with increase in the ratio of rice bran particles. However, there was decrease in the level of vitamin C with increased ratios of rice bran particles in the flours. The glycemic response range was 60.29 to 206.69mg/dl and it was observed to reduce as the ratio of rice bran particles increased. The T-test showed there was a relationship between the dietary fibre and blood serum glucose, but the relationship was not significant. This study showed that the yam flours that were substituted with ≥15% rice bran particles had lower levels of antinutrients, higher micronutrients and lower glycemic characteristics.

Keywords: Nutrients, blood glucose, glycemic response, dietary fibre