| Commercial pea protein was the by-products of the pea starch processing and one kind of high-quality hypoallergenic protein resource, which the isoflavone and the phytic acid were low. However the protein feature was poor, the protein used as a feed, and the utilization was low, so the application of the pea protein was limited. So it was important to explore an effective method for the commercial pea protein to improve its value. The purpose of the study was to introduce the spray cooking processing technology into the deep processing of the field of the pea protein, establish a proper processing to produce high soluble protein, and simultaneously produce the antioxidation peptide by the depth enzymatic hydrolysis. The results were as follows:1) The improvement of the solubility of the commercial pea protein by the HTC was studied in this research. The result suggested:The commercial pea protein was dealed by the jet cooking directly. NSI increased from25%to75%, which meaned that property of the protein solubility and emulsifying was improved. However after freeze-drying, NSI decreased to65%, the protein solution was instable and easily layered. After this method was adjusted, the soluble protein of the pea can be prepared by the the jet cooking with amylase. NSI of the protein was80%, and the protein solution is stable, not hierarchical although after the freeze-drying.2) The optimum condition of this method was studied in this research. The optimum condition was that:the feed solution concentration was4%, amylase enzymatic hydrolysis time was1h, the solution was adjusted to pH8.0, jet cooked under1400C by60s.3) The mechanism of the amylase with HTC was study in the research. During the process, because of the high temperature, the pressure and shear stress, the insoluble protein depolymerized, part of the protein or subunit reaggregated to formatted the soluble aggregation through a covalent bond or a disulfide bond, thereby the solubility of the protein was improved; As more groups exposed, particle surface charges increased, and enhanced particle electrostatic repulsion, particles distributed well, thus the protein solution was stable; the protein reacted with the sugur produced by the amylase, the protein structure became soft, more hydrophobic groups exposed, the surface hydrophobicity enhanced, protein adsorption enhanced, so the emulsification was improved; the surface hydrophobicity enhanced, thus the protein to hold the oil characteristics was improved. The commencement of protein tertiary structure, increased the enzyme binding sites, thereby the in vitro digestibility of the protein was improved.4) The commercial pea protein was dealed by the mild trypsin enzymatic hydrolysis. The more hydrolysis degree, the better the solubility will be. However, with the increase of the hydrolysis degree, the emulsifying capacity of pea protein decreased gradually. That was, there was no obvious improvement on the emulsifying properties of the pea protein by the protease mild-enzymatic hydrolysis.5) The commercial pea protein protein was hydrolyzed by the M-protease, neutral protease, and the alkaline protease. The study suggested that:the hydrolysis, the protein utilization and peptide yield of the M-protease was the lowest, but the bitterness of the enzymatic solution was weakest and the hydroxyl radical scavenging ability and the DPPH scavenging ability was the strongest, the reduction of the enzymatic solution was the strongest weakest which was hydrolyzed by trypsin M-protease. Also the method was optimized by the response surface. The optimum condition of this method was concluded:The enzyme concentration was1.5%, hydrolysis time was3.75h, hydrolysis temperature was48℃. There was on significant difference (P>0.05) between the actual value (21.6±0.93mg/mL) and the predictive value (20.2464mg/mL). |
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