Sorghum Non-extractable Polyphenols: Chemistry, Extraction and Bioactivity

Abstract

Sorghum grain is rich in polyphenols, and the consumption of these grains could provide antioxidant and anti-inflammation health benefits to humans. Based on their ease of solvent extractability, two types of polyphenols are present in sorghum grain - extractable and non-extractable - with the non-extractable forms being covalently bound to cell wall components such as structural proteins, non-starch polysaccharides (e.g. arabinoxylans, hemicellulose and cellulose) and lignin. Alkaline and acid hydrolysis, with the assistance of microwaves or ultrasound, have been used to release and extract these non-extractable polyphenols. The level of non-extractable polyphenols in sorghum is also influe..