Paper Title
The Influence of Conditions on Beta-Glucan Extraction From Thai Rice Bran Cultivars and Their Biological Properties

Abstract
Rice bran is one of the important source of cell wall polysaccharides. This research purposes to study of the influence of several operational factors on the aqueous extraction of beta-glucan from three Thai rice bran cultivars, Khao Dawk mali 105 (KD-RB), Khao Pathum Thani 1 (KP-RB), and Khao Chinat 1 (KC-RB). Solvent:bran ratio, extraction time, pH, and temperature were identified as the important parameters affecting the beta-glucan extraction. Among four parameters, temperature seemed to be most influence. The maximum extractable beta-glucan from rice bran was obtained at s:r ratio 12.5; extraction time 3, pH 10, and temperature 60�C, that are defined as an optimal condition. The highest extractable beta-glucans are in the following order, KD-RB, KP-RB, and KC-RB with 1.905�0.06, 1.758�0.05, and 1.415�0.07 mg/100 g of rice bran, respectively. In vitro antioxidant and prebiotic activities assays indicated that three beta-glucan extracts had significant scavenging effect on DPPH radical and inhibition capacity of lipid peroxidation whereas they showed increased growth of probiotic bacteria such as Lactobacillus casei, Enterococcus faecium, and Streptococcus thermophilus. Their biological activity demonstrated that three rice bran beta-glcan extracts should potentially be a natural antioxidant and might serve as a probable ingredient for cosmetic and food products. Keywords - Beta-Glucan, Extraction, Biological Properties, Thai Rice Bran