| Whey is the by product of the industrial production of cheese and casein, whey proteins is the main component. The low molecular weight whey protein peptides can be available through hydrolysis whey protein by enzyme technology, these peptides have a variety of physiological functions, which is of great significance in preventing disease and the development of natural health products. In this study, whey protein peptides was prepared by enzymatic hydrolysis, and separated, purified, identified, the components with the highest antioxidant activity was selected, and the experiments of animal behavior and physiological and biochemical parameters were made.effects of whey protein antioxidant peptides on learning and memory abilities of aging mice were measered.In this study, whey protein concentrate (WPC80) was as raw material, alcalase was as the experiment enzyme, the degree of hydrolysis and DPPH radical scavenging rate was as the improved index, the hydrolysis conditions were optimized, the effects of various factors on hydrolysis were investigated, the result was that:the amount of enzyme5000U/g, pH8.5, temperature60℃, substrate concentration of5%, hydrolysis time2h, under this condition, the degree of hydrolysis was19.32%, DPPH radical scavenging was53.57%.In order to achieve the purpose of the preliminary separation and purification, whey protein peptides was desalinated by DA201-C macroporous resin. First, the effects of desorption agent, sample flow rate and sample concentration on desalination was examined, the results showed that70%ethanol was as the desorbent, the best sample flow rate was1.5mL/min, the sample concentration was30mg/mL, under this condition, the effect of dynamic desalination was best, after desalination, desalination rate was96.81%, the recovery was90.37%, DPPH radical scavenging rate was significantly increased and antioxidant activity was increased. Whey protein peptides was separate to three components by using different molecular weight ultrafiltration membrane, identified by Tricine-SDS-PAGE electrophoresis, The results showed that the effect of ultrafiltration was good, and the peptides that molecular weight was less than3KDa has the strongest antioxidant activity.To study the effects of whey protein peptides on passive avoidance and spatial learning and memory abilities of aging mice by behavioral methods. Natural aging mice was as the aging model, young mice was as the blank control, piracetam was as the positive control, the results showed that after gavage with whey protein peptides, jumping latencies of aging mice was increased, the number of jumping errors was decreased, shock time and the number of shocks was reduced in the avoid black box, the escape latency, swimming distance, swimming speed and orientation angle was decreased in the water maze test, the target quadrant time, the percentage of the target quadrant time, the percentage of the target quadrant distance, the number through the platform was increased in the space exploration experiments, the initial time through platform was reduced, while swimming trajectory developed to tend and linear. It is visible that the behavior ability of aging mice can be enhanced by whey protein peptides.In vivo animal experiments, in order to investigate the protective effect of whey protein peptides on aging mice, SOD, MDA, GSH-Px, protein carbonyl and AChE in serum, liver and brain was as an indicator. The experimental results showed that after gavage by whey protein peptides, SOD and GSH-Px activity was significantly increased, MDA and protein carbonyl content was significantly decreased, high-dose group and the piracetam tablets control group has similar results; meanwhile, AChE activity was also decreased. These showed that aging can be delayed and the activities of the central cholinergic nervous system can be adjusted by whey protein peptides, thus, learning and memory in aging mice can be improved by whey protein peptides. |
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