Contribution and Interactions of Hydroxycinnamic Acids Found in Bran and Wholegrain Sorghum (Sorghum bicolor L. Moench): Effects on the Antioxidant Capacity and Inhibition of Human Erythrocyte Hemolysis

Received Mar 16, 2017; Accepted Aug 24, 2017

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1. Introduction

An imbalance between free radicals and antioxidants in the cell is known as oxidative stress, which favors cellular aging and the development of some chronic noncommunicable diseases including diabetes, cardiovascular disease, and some types of cancer, among others [1–3]. Dietary choices can mitigate oxidative stress by delivering bioactive compounds with high antioxidant capacity, thereby inhibiting the development and progression of cellular damage. Some cereals are sources of phenolic compounds with a high antioxidant capacity that can efficiently transfer electrons and/or hydrogen atoms. In addition, these cereals maintain health by modulating numerous cellular processes [4]. Sorghum (Sorghum bicolor L. Moench) is a source of phenolic compounds with low molecular weights and simple structures, specifically hydroxycinnamic acids [5, 6]. Among these compounds, ferulic acid is present at the highest concentration, and it is found both in its free form and covalently bound to the arabinoxylans that are present in the cell walls of the endosperm, aleurone layer, and pericarp [6–9]. In humans, bound ferulic acid is poorly bioaccessible and bioavailable in the small intestine because the indigestible matter transports it to the large intestine, where it can be metabolized by the resident microbiota. The arabinoxylan matrix can be modified before consumption by acid or basic hydrolysis, fermentation, extrusion, or other processes. These processes yield free ferulic acid or feruloylated oligosaccharides in which the bioaccessibility and bioavailability of ferulic acid is improved [10]. These methods can be used to improve the bioactivity of sorghum and can...