Nutritional quality of raw and cooked flours of a high β-glucan sorghum inbred line

Abstract

This study investigated the protein fractions, in vitro protein digestibility (IVPD), in vitro starch digestibility (IVSD), antinutritional factors, hydrolysis index (HI), and estimated glycemic index (eGI) of the raw and cooked flours of a new sorghum inbred line (high β-glucan type I non-tannin sorghum) compared to two popular Sudanese sorghum cultivars (low β-glucan type 1 non-tannin and type II tannin sorghums). Significant differences (P < 0.05) were observed in protein fractions, antinutritional factors, IVPD, IVSD, rapidly digestible starch (RDS), resistant starch (RS), HI, and eGI. Low β-glucan type II tannin sorghum showed the highest antinutritional factors and RS values, whereas high β-glucan type I non-tannin and low β-glucan type 1 non-tannin sorghum cultivars showed the least values (P < 0.05). Low β-glucan type 1 non-tannin sorghum had the highest IVPD, RDS, HI, and eGI values. Cooking significantly (P < 0.05) reduced the protein fractions, antinutritional factors, IVPD, and RS and increased the IVSD, RDS, HI, and eGI of sorghums. Based on low eGI of high β-glucan type I non-tannin sorghum cultivar, it can be considered a low glycemic index sorghum and could thus be the best choice for diabetic people.