Determination of nutritional value of turmeric flour and the antioxidant activity of Curcuma longa rhizome extracts from agroecological and conventional crops of Valle del Cauca-Colombia

Abstract

This research presents the results of the proximal analysis of turmeric rhizome flour (Curcuma longa) from different areas of Valle del Cauca (Colombia) and the quantitative estimation of the uptake of the radical 2,2-diphenyl-1-Picrylhydrazyl (DDPH) of the methanolic extracts of the flour. The results of the proximal analysis evidence that some parameters do not show evident differences. However, others, such as total fat, show differences between the turmeric crops with conventional and agroecological fertilization. The values obtained from the different samples for proteins and carbohydrates are in an average normal range (9.3% and 70.5%, respectively), which fulfills the requirement to be a nutritional supplement. The free radical uptake (FRS) test of the extracts showed an antioxidant activity of the different samples tested for FRS50 (%) of 2.11 ± 0.06 µg / mL (Yumbillo, Y), 1.34 ± 0.26 µg / mL (Guacas, G), 4.22 ± 0.06 µg / mL (Magdalena, M), 9.16 ± 0.32 µg / mL (Commercial, C), 1.29 ± 0.26 µg / mL (Santa Rosa de Tapias, SR), and 1.33 ± 0.05 µg / mL (Limonar, L), which were contrasted with the values of quercetin (Q) 1.01 ± 0.51 µg / mL, vitamin C (V) 2.07 ± 0.45 µg / mL, and piperine (P ) (0,0) µg / mL. The proximal nutritional value plus the oxidizing activity, due to the concentration of phenolic compounds, make turmeric flour a functional food.