Studies On Antioxidant Enzymatic Hydrolysates From Swim Bladder

Antioxidant peptide is concerned by many scholars. Some antioxidant peptides from enzymatic hydrolysates were isolated. Swim bladder is an important medicinal and edible aquatic resources. The swim bladder, which is rich in protein and low in fat, is the ideal high-protein, low-fat foods. At present the utilization is relatively low. In this study, we use the swim bladder of sparidae for enzymolysis, study on the process of enzymolysis, preparation technology of antioxidant oligopeptides, antioxidant activity of oligopeptides, in hope of finding a kind of antioxidant oligopeptides. The specific work is as follows:1. Study on the enzymolysis process of swim bladder to get antioxidant oligopeptidesThe technology of produced antioxidant hydrolysates by enzymolysis was studied and evaluated with DPPH radical scavenging rate. Based on the single factor experiment, the suitable enzymolysis process was optimized by Box-Behnken test. The prioritized enzymolysis process was as followes:pH value of6.0, hydrolysis time of4.1h, hydrolysis temperature of63℃. Under these conditions, the DPPH radical scavenging rate reached to76.06%.2. Study on the ultrasound assisted enzymolysis process of swim bladder to get antioxidant peptidesThe technology of produced antioxidant hydrolysates by ultrasonic assisted enzymolysis was studied and evaluated with DPPH radical scavenging rate, the appropriate enzymolysis process was optimized by Box-Behnken test.The prioritized enzymolysis process was as followes:ultrasound time of5.5min, enzymolysis time of45min, ultrasonic temperature of38.7℃. Under these conditions, the DPPH radical scavenging rate reached to75.00%.3. Study on the technology of removing fishy odor and decoloration for the enzymic hydrolysates of swim bladderThe technology of removing fishy odor and decoloration for the enzymic hydrolysates of swim bladder was studied. Activated carbon was used as the adsorbent, the rate of protein loss and sensory evaluation as the evaluation criterion. Based on the single factor experiment, the optimum process of removing the fishy odor and decoloration was optimized by orthogonal table L9(34). The optimized removing fishy odor and decoloration process was as follows:activated carbon added 2%, temperature50℃for30min and pH value of6.0. Under these conditions, the swim bladder enzymatic hydrolysates is yellow, clear. The fishy odor smell is getting decreased, with a protein loss rate of8.03%.4. Study on antioxidant activity of swim bladder oligopeptideThe antioxidant activities of swim bladder antioxidative peptides from enzymolysis was analyzed. The antioxidant activity was measured by the DPPH method. ABTS method, hydroxyl radical method, reducing power method. Compared with10mg/mL VE, DPPH free radical scavenging rate, ABTS free radical scavenging rate, the hydroxyl free radical scavenging rate, reducing capacity of the same concentration of swim bladder hydrolysates were higher. Using gel permeation chromatography(GPC) to determinate the number average molecular weight (Mn) of swim bladder antioxidant peptide and the result is the number average molecular weight (Mn) is mainly4596.55Da and597.55Da.