Aroma and Amino Acid Composition of Hydrolyzed Vegetable Protein from Rice Bran

Abstract

Hydrolyzed vegetable protein (HVP) is an important ingredient of many process flavors. HVP was produced from rice bran protein by acid hydrolysis with aqueous 4.0 N HC1 for 72 h at 95 °C. Predominant free amino acids were glutamic acid (16.7% of total), arginine (11.8%), aspartic acid (10.1%), alanine (8.1%), leucine (7.6%) and glycine (6.8%). Aroma components were identified by GC-olfractometry (GCO), including aroma extraction dilution analysis (AEDA) and GCO of decreasing dynamic headspace samples (GCO-DHS), and by GC-MS. The overall "malty", "soy sauce-like" and "smoky" aroma character of rice-bran HVP was dominated by Strecker aldehydes and acidic/phenolic compounds. Methylpropanal and 2/3-methylbutanal were responsible for malty and dark chocolate-like notes, while 3-(methylthio)propanal provided a cooked potato-like character and phenylacetaldehyde imparted a rosy, styrene-like note. Acidic compounds with high odor impact included sotolon, and phenylacetic and 3-methylbutanoic acids. 2-Methoxyphenol, and to a lesser extent 2,6-dimethoxyphenol, provided intense smoky notes. 2-Acetyl-1-pyrroline also exhibited a relatively high odor impact in RB-HVP.

Effect of drying and proline addition on aroma volatile compounds of acid‐hydrolysed rice bran protein concentrate

“…Amino acid compositions of hydrolysate powder showed high aspartic acid and glutamic acid (Table 2). This is similar to the results of Jarunrattanasri et al. (2005) who reported that aspartic acid was the predominant free amino acid in hydrolysate from RBPc prepared with 0.5 N HCl for 12 h. Jarunrattanasri et al.…”

“…Jarunrattanasri et al. (2007) supported that vanillin was one aroma impact component of RBPc and was also a predominant odorant of both hydrolysates created from RBPc prepared with 0.5 N HCl for 12 and 36 h. In a previous study, vanillin was not reported as a predominant odorant in hydrolysate produced from RBPc by hydrolysis with concentrated (4 N) HCl (Jarunrattanasri et al. , 2005).…”

Preparation, aroma characteristics and volatile compounds of flavorings from enzymatic hydrolyzed rice bran protein concentrate

“…A large portion of the amino acids in RPC hydrolysate were arginine, leucine and lysine. Generally, these free amino acids are flavor precursors of the Maillard reaction . The precursors of 2‐methylpropanal, 2‐methylbutanal, 3‐methylbutanal and phenylacetaldehyde were valine, isoleucine, leucine and phenylalanine.…”

“…Hydrolyzed vegetable protein from soy protein (HVP) is produced commercially by acid hydrolysis and has been used for more than 100 years to impart meat‐like flavor, representing the earliest form of process flavorings . Jarunrattanasri et al . found that malty, soy‐sauce‐like and smoky aromas were important characteristics of HVP produced from RPC by using 4 mol L −1 hydrochloric acid (HCl) at 95 °C for 72 h. Moreover, Jarunrattanasri et al .…”

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

“…In addition, Kaewka et al (2009) also found that spray-dried acid hydrolyzed rice bran protein powders had lower rice bran-like odor intensities and received a higher overall liking score compared to the liquid hydrolysate in which cracker-like aroma was not detected. Jarunrattanasri et al (2005) reported that hydrolyzed vegetable protein from rice bran protein had predominant free amino acids such as glutamic acid, arginine, aspartic acid, alanine, leucine and glycine. These amino acids generated malty, dark chocolate-like notes and soy sauce-like character of hydrolyzed rice bran protein.…”