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

Abstract

Rice bran was used for isolating protein through ultrasonic‐assisted extraction. The protein was converted into protein hydrolysates (PH) with three commercial enzymes. The optimal condition for rice bran protein production was 76% sonication amplitude, 18 min extraction and 0.99 g/10 mL solid–liquid ratio, which gave protein yield of 4.73 ± 0.03%. The degree of hydrolysis for the rice bran protein by Subtilisin A (SPH), Actinase E (APH) and Neutrase 0.8L (NPH) was 20.03 ± 0.24%, 13.84 ± 0.04% and 5.54 ± 0.07%, respectively. The molecular weight of the isolated proteins ranged between <11 to 75 kDa. The NPH exhibited greater scavenging activity on 1,1‐diphenyl‐2‐picryhydrazyl radical and ACE‐inhibitory activities. The SPH was efficient in reducing power and metal chelating activities. In addition, NHP displayed the highest positive effect for foaming activity (66.25%), then followed by APH (57.50%) and SPH (52.50%). The results suggest that the partial hydrolyzed rice bran protein is more suitable for application in food systems rather than the non‐hydrolyzed form. Practical Application Optimizing the condition for rice bran protein extraction is desirable and practical for related plant materials. Understanding the optimal conditions is important because it could enable an extraction method that could be used instead of conventional methods that take a long time for extraction. This study also suggests some enzymes for producing rice bran protein hydrolysates (PH) that have desired properties for specific usage such as for antioxidant activities and/or functional properties. The method for producing PH and controlling the degree of hydrolysis could be promptly applied.

Fractionation and characterization of antioxidant peptides from rice bran protein hydrolysates stimulated by in vitro gastrointestinal digestion

“…However, only few studies applied in vitro GI digestion to stimulate antioxidant activity of rice bran protein. Mostly, the nonpurified rice bran protein hydrolysates were directly used to determine its bioactivity (Phongthai et al, ; Thamnarathip et al, ; Wattanasiritham et al, ); meanwhile, the purification of those mix peptides by using chromatography techniques has never been reported. According to our previous study (Phongthai, D'Amico, Schoenlechner, & Rawdkuen, ), it was clearly seen that total aromatic amino acid content in nonpurified rice bran protein hydrolysates had a strong positive correlation with free radicals scavenging activity and reducing power (Pearson's correlation coefficients; r > .83).…”

“…Enzymatic hydrolysis is usually chosen to expose and release some active peptides from various protein sources. The hydrolysis of rice bran protein with actinase and neutrase (Phongthai, Lim, & Rawdkuen, 2016b), trypsin (Wang et al, 2017), and alcalase (Thamnarathip, Jangchud, Nitisinprasert, & Vardhanabhuti, 2016) was previously studied. Peptide bonds in the polypeptide chain can be enzymatically hydrolyzed in order to create a range of oligopeptides with different molecular weight and/or amino acid sequences that provide a diverse activity.…”

Recovery of protein hydrolysates from brewer’s spent grain using enzyme and ultrasonication

“…A Previous study reported that BSG particle size has a significant effect on the separation and structure of arabinoxylans from BSG (Reis et al, 2015). Several studies reported that ultrasound pretreatment improved protein separation from agricultural products such as rice bran (Phongthai et al, 2016), defatted soy flakes (Karki et al, 2010) and olive kernels (Rosell o-Soto et al, 2015). To date and to our best knowledge, no study has reported using ultrasonication to improve the enzymatic separation of protein from BSG and characterise the properties of protein produced from the ultrasound-assisted enzymatic extraction.…”

Properties of Peanut (KAC431) Protein Hydrolysates and Their Impact on the Quality of Gluten-Free Rice Bread

“…This is due to the restricted functional properties of the native protein, leading to poor bread quality. However, in some reported studies it was discovered that the functional properties of protein can be effectively modified and extended by enzymatic hydrolysis [ 6 , 7 , 8 ], resulting in a wider range of applications. Therefore, the use of protein hydrolysates to improve bread quality may be useful for the development of high-quality gluten-free bread.…”