INFLUENCE OF DRY HEAT TREATMENT ON ANTIOXIDANT ACTIVITY AND TOTAL POLYPHENOL CONTENT OF DIFFERENT SORGHUM PARTICLE SIZES

Abstract

Sorghum is the fifth most used cereal and contains many bioactive compounds which enhance the antioxidant capacity. The aim of this study was to investigate the antioxidant capacity and the total phenolic content by applying different organic solvents and extraction times on sorghum grain at different particle sizes which were subjected dry heat treatment. The antioxidant capacity values varied between 53.5% to 100%, and the total phenols content ranged from 6.58 mg GAE/g to 54.90 mg GAE/g for the sorghum flour particles sizes, indicating a significant increase when the dry heat treatment was applied. From the solvent used point of view, it can be seen a rise in antioxidant capacity and concentration of total phenols extracted in the following order: methanol > water > ethanol. Also, when the particle size of sorghum flour decreased and extraction time increased, the values of antioxidant capacity and total polyphenols components increased. This study revealed the potential of different sorghum particles size from the total polyphenols and antioxidant capacity point of view and to use them as ingredients to raise the shelf life of food products.