Anti-nutritional factors and antioxidant capacity in selected genotypes of sorghum [Sorghum bicolor (L.) Moench]

Abstract

The health benefits of sorghum grains with healthful antioxidants compared to fine cereals are fairly known, still, the extent of research on the nutritional quality as well as its improvement through breeding or molecular approaches is meager. Grains of 200 sorghum genotypes comprising popular cultivars and parental lines, advance breeding lines and selected germplasm accessions were characterized for the levels of total phenolic compounds, phytate, trypsin inhibitor, cyanogens and antioxidant activity (TEAC). Significant variation was observed for all the factors studied. The total polyphenols ranged from 44 to 1272 mg gallic acid eq./100 g, and the highest polyphenols were present in SSG 59-3 followed by Urja (1135-1272 mg gallic acid eq./100 g). Phytate content varied between 720 and 3909 mg/100g. The maximum phytate was found in the germplasm line IS 8525 (3909 mg/100g) followed by IS 14131 (3903 mg/100g). Diversity was also observed for trypsin inhibitor (1.6-12.8 TIU/g) and cyanogens (14.2-173.6 ppm). The highest TEAC was shown by SSG 59-3 followed by IS 8525 and Urja. Results were confirmed with high repeatability and high correlation (r = 0.6-0.9, p < 0.01) for polyphenols, phytates, cyanogens and TEAC using selected genotypes. The identified genotypes for different nutritional factors can act as donor sources in breeding programs aimed at development of trait-specific sorghum genotypes suitable as functional foods.