Preparation and characterization of high‐quality rice bran proteins

Abstract

Rice bran contains 120-200 g kg −1 protein in addition to a large amount of fat, carbohydrate, and phytic acid. Rice bran protein (RBP) fractions were refined by a two-step preparation to eliminate residual carbohydrate. The first step involved the sequential extraction of defatted rice bran into RBP fractions using their distinct solubility to give 37 g kg −1 of albumin, 31 g kg −1 of globulin, 27 g kg −1 of glutelin, and 2 g kg −1 of prolamin. In the second step, carried out by dissolving in respective solvent and isoelectric precipitation, the protein content of each fraction increased from 69% to 97% for albumin, from 71% to 90% for globulin, from 74% to 83% for glutelin, and from 18% to 20% for prolamin. The low protein content in the prolamin fraction might be due to its low solubility in the protein assay. Emulsifying stability index and surface hydrophobicity increased in the second-step preparation of albumin and globulin, but not of glutelin. Emulsifying properties of RBPs were lower than that of a soybean protein isolate. Denaturation temperatures and enthalpy values of denaturation for albumin, globulin, glutelin, and prolamin were 50.1• C/1.2 J g −1 , 79.0 • C/1.8 J g −1 , 74.5 • C/3.0 J g −1 , and 78.5• C/8.1 J g −1 , respectively. No significant differences in the denaturation temperatures and enthalpy values of denaturation of RBP fractions were obtained with these two-step preparations (P < 0.05).

Functional properties of protein fractions obtained from commercial yellow field pea (Pisum sativum L.) seed protein isolate

“…In addition to providing essential amino acids, the ultimate success of utilising any seed protein as a food ingredient depends largely on its functional properties (Adebiyi, Adebiyi, Ogawa, & Muramoto, 2007;Chavan, McKenzie, & Shahidi, 2001). Although, pea is a widely consumed legume seed, protein-based ingredients of pea are not yet well utilised in food applications.…”

“…This is probably due to limited information on the structural and functional properties of pea proteins. For plant proteins to be useful and successful in food application they should ideally possess several desirable characteristics, referred to as functional properties (Adebiyi et al, 2007;Ragab, Babiker, & Eltinay, 2004).…”

Processing and Functionality of Rice Bran Proteins and Peptides

“…Elevated temperature released proteins from the complexes with fi ber, other carbohydrates, and minerals. Viscozyme is another enzyme used for producing isoelectric precipitation of isolated protein fractions has further increased the quantity (Adebiyi et al 2007 ). Many other procedures have been reported to prepare the concentrates and isolates for the enrichment of proteins and bran product development (Lynn 1969 ;Landers 1992 ;Prakash and Ramanathan 1994 ;Chen 2000 ;Chen and Houston 1970 ).…”

Sensory aroma characteristics of alcalase hydrolyzed rice bran protein concentrate as affected by spray drying and sugar addition

“…It is used in animal feed or rice bran oil. Rice bran is an excellent source of protein, minerals, fatty acids, and dietary fiber content (Adebiyi et al 2007). Defatted rice bran has protein content of 15-20 % (Pan et al 2005;Chandi and Sogi 2007) and is considered as a source of hypoallergenic ingredients (Agboola et al 2005;Chandi and Sogi 2007;Jarunrattanasri et al 2007;Tang et al 2003).…”

“…Therefore, rice bran has a potential to be used as a novel protein source. However, rice bran protein concentrate (RBPC) has a low consumer acceptance because of its undesirable flavor (Adebiyi et al 2007;Jarunrattanasri et al 2007).…”