Rice Bran Stabilization by Solid-State Fermentation: Effect on Chemical Composition, Functional Properties and Antioxidant Activity

Abstract

Rice bran is the main by-product of rice grain processing. It is produced in large quantities worldwide and it contains a high amount of valuable nutrients and bioactive compounds with significant health-related properties. Despite that, its application in the food industry is still scarce because of its sensitivity to oxidation processes, instability, and poor technological suitability. Thus, this study aimed to investigate the chemical composition, functional properties, and antioxidant activity of rice bran fermented by lactic acid bacteria (Lactobacillus plantarum), and Saccharomyces cerevisiae as active dry yeast in the solid state. Bioactive compounds (free, bound, and total phenolic acids), antioxidant activity, water-extractable arabinoxylans and functional properties were evaluated. Similarly, phytic acid degradation was determined in fermented and non-fermented rice bran. After fermentation processes, protein, fiber, and ash contents in modified bran were raised compared to non-modified bran. Total, free phenolic content, and antioxidant activity increased after solid-state fermentation. Phytic acid content decrement of 40.01% and water-extractable arabinoxylans increment four times were observed in fermented bran. As well as, protein solubility, water holding capacity, water-solubility, oil holding capacity of fermented rice bran were enhanced. Thus, the solid-state fermentation is an efficient technique and can be applied to improve the nutritional and functional properties of rice bran, as well as utilized as ingredients in food applications.