Grain yield, nutritional, polyphenols and antioxidant capacity in accessions of sorghum (Sorghum bicolor L. Moench)

Abstract

Sorghum is an economically important crop in developing countries. The objective of this study was to compare the agronomic performance, and the chromatic, nutritional and nutraceutical properties of nineteen sorghum accessions cultivated in Tamaulipas, Mexico. Results showed that the grain yield (15.22 to 70.18 g per plant), days to flowering (73 to 92 days), panicle length (16.63 to 27.67 cm), luminosity (27.14 to 57.75), chromaticity (5.65 to 15.33) and hue angle (38.49 to 82.66) varied. The percentage of protein (7.33 to 3.43%), fiber (0.60 to 3.03%) and carbohydrates (70.17 to 78.39%) also varied. Grains had a high concentration of magnesium, phosphorus and potassium; the content of total phenols and total flavonoids (free + bound) was found in a range of 117.61 to 2367.01 mg GAE/100 g and 22.52 to 613.92 mg CE/100 g, respectively. The antioxidant capacities (free + bound) showed ranges from 65.09 to 2,017.58 μmol TE/100 g, 43.13 to 1,907.99 μmol TE/100 g and 107.20 to 3,523.20 μmol TE/100 g using the ABTS, DPPH and FRAP methods, respectively. A negative correlation (-0.36) was observed between grain yield and days to flowering. In addition, a positive correlation between phenolic compounds and antioxidant capacity. These results confirm an important genetic diversity among the studied accessions of sorghum.