| The industrialized production of pig blood antioxidant peptides was conducive to the development and utilization of cheap animal byproducts, greatly increasing the added value and ensure the safety of food products. The study on the ultrasonic assisted enzymatic hydrolysis of porcine blood antioxidant peptide preparation, used modern biological preparation technology of crude enzyme solution purification and antioxidant peptide stability research, in order to provide a theoretical basis for industrialized production and the main conclusion are as follows:1.Used porcine hemoglobin as raw material, contrast three different proteases (trypsin, flavourzyme, protamex enzyme solution solution of DPPH free radicals clearance rate and the rate of extraction.then, selected single enzyme for hydrolysis experiments. Experimental results:Trypsin enzymolysis liquid, protamex enzyme solution and flavourzyme enzyme solution solution of DPPH free radicals clearance rate was 56.34% respectively.45.76% and 31.43%, degree of hydrolysis were 11.58%, 12.67%9.41%. Choose trypsin experiments for single enzyme preparations, and the trypsin was selected as the single enzyme preparation.2.By SDS-PAGE gel electrophoresis analysis of distribution of ultrasound before and after trypsin and explore the effects of ultrasound on the activity of trypsin and by ultrasonic assisted enzymatic hydrolysis.Experimental results:After ultrasonic treatment, the trypsin activity was 1.34×106u/g, and the solubility of 104.9%. trypsin was increased by 4.78% compared to the non treated group, and the 2.36%. was improved by compared to the non treated group.Trypsin by ultrasonic treatment before and after SDS-PAGE electrophoresis bands of uniform distribution and ultrasonic treatment group of electrophoresis a color is deeper than the untreated group of electrophoresis with. Appropriate ultrasonic treatment could improve the activity of trypsin and increase its solubility, and does not destroy the molecular structure of trypsin.3. Used ultrasonic assisted enzymatic solution by DPPH free radical clearance rate as the index, the trypsin is a single enzyme preparation, single factor experiments and orthogonal optimization pig blood antioxidant peptides of preparation technology. The results show that the ultrasonic frequency of 20 kHz, ultrasonic time was 8min, the ultrasonic power 540W, trypsin added amount of 0.8%, maintain a system of ph8.0,2h enzymatic hydrolysis degree was 11.73%, DPPH radical scavenging rate of 6h solution for 75.78%. conventional enzyme, hydrolysis degree was 11.42%. Thus, ultrasonic can accelerate the rate of hydrolysis of trypsin.4.Further isolation and purification of Porcine blood hemoglobin hydrolysate, Evaluation of the antioxidant properties of peptides with molecular weight below 10KD.By DPPH free radical scavenging rate as the evaluation index, purification results:crude enzyme solution through hollow fiber ultrafiltration obtained molecular weight less than 10KD antioxidant peptides, by gel chromatography to get with strong anti-oxidation peak ? and peak ? into reverse high performance liquid phase of preparative chromatography to obtain the main antioxidant compounds A1, by low resolution mass spectra were obtained for the Al main molecular mass is antioxidant peptide prepared by 453.350,475.543,498.435.5.Compared with trypsin hydrolysate, molecular mass of more than 10 Dalton, molecular mass of less than 10 Dalton, peak ?, peak ? of the DPPH radical scavenging rate, reducing power and total antioxidant capacity. By contrast<10KD antioxidant peptides to delay the corn oil, the effect of soybean oil and homemade lard, exploring antioxidant peptides in delaying lipid oxidation. The results show that after gel filtration chromatography peak ? the strongest antioxidant activity. IC50.DPPH,7.5mg/ml; reducing force,1.36; Total antioxidant capacity (ABTS), 2.45mM. In each experimental group, the induced oxidation time of the relative blank group was delayed by 18.10h,3.37h and 30min.6.The stability of 10KD antioxidant peptides in different pH, temperature, salt concentration, sugar concentration, citric acid concentration and simulated gastrointestinal digestive juice were studied, and the DPPH free radical scavenging rate and total antioxidant capacity (ABTS) were the indexes. Antioxidant peptides showed good antioxidant capacity in alkaline environment, Within 100 degrees Celsius heat 160min can maintain a good antioxidant capacity, The concentration of NaCl was less than 6%, and it could promote the oxidation resistance, Citric acid content reached more than 0.12% of its antioxidant capacity decreased. Simulated gastrointestinal fluids, the DPPH free radical scavenging rate can be maintained at more than 75%, and total antioxidant capacity (ABTS) in the intestinal maintain in 2.45mM in gastric juice decreased to 0.44mM. |
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