Ultrasonic assisted alkali extraction of protein from defatted rice bran and properties of the protein concentrates

Abstract

Alkaline extraction for the preparation of protein concentrate from rice bran was compared with a range of ultrasonic treatments. Results revealed that the extraction time decreased, and the reaction rate constant increased, with increasing ultrasonic power. The reaction rate constants were 0.0065, 0.0130, 0.0237 and 0.0924 at 40, 60, 80 and 100 W respectively. The defatted rice bran protein concentrate (DRBPC) using ultrasonication (100 W for 5 min) and conventional methods showed no significant difference in bulk densities (P > 0.05) but it had higher yield (%) and was lighter brown using ultrasonication (P £ 0.05). The SEM showed that the residual rice bran after extracting protein using ultrasonication exhibited more damage than the conventional method. The functional properties of both samples were not significantly different (P > 0.05) in terms of foam and emulsifying stability. However, the water and oil absorption, foam capacity and emulsion activity were significantly different (P £ 0.05). The nitrogen solubility index of both DRBPC samples gave similar profiles with the lowest solubility at pH 4-6.

Ultrasonic-Assisted Extraction of Rice Bran Protein Using Response Surface Methodology

“…1. This observation is consistent with Chittapalo and Noomhorm (2009) who also reported that the mechanical effects of ultrasound disrupted the rice bran cell wall, which was observed by scanning electron microscopy. It was observed that the sonication amplitude and extraction time displayed a quadratic effect on protein yield (Fig.…”

“…The foaming activity of rice proteins increased as a function of pH (Fig. This property requires flexible protein molecules with few secondary and tertiary structures (Chittapalo and Noomhorm 2009 ). All PHs exhibited higher foaming activity than RBPC (13.97-32.18%) at all pH values.…”

Comparative analysis of prodigiosin isolated from endophyte Serratia marcescens

“…() also found that sonication was the most efficient extraction method for a unicellular cyanobacterium Synechococcus bacillaris . Similarly, previous reports also suggest that extraction of pigment increased many folds using ultrasonication than other known methods of pigment extraction (Chittapalo and Noomhorm ; Casullo et al . ; Heeyong et al .…”

Influence of Water Activity on Physico-Chemical Properties of Proteins from Selected Oilseed Flours

“…Protein solubility of quinoa flour was 14% at start of storage study and significant decrease of solubility was found during storage time (Abugoch et al, 2009). Chittapalo and Noomhorm (2009) reported that the nitrogen solubility index profile for defatted rice bran concentrate extracted with conventional and ultrasonic method showed lowest value at pH 4.0 − 6.0 but below and above this pH, nitrogen solubility index increased. At pH 2.0 they showed 40 and 30% solubility respectively.…”