The Study On Relieving Physical Fatigue Function And Product Design Of Soybean Peptide

In this thesis, soybean protein was used as the raw material and biologicalenzyme technology, ultra-filtration and freeze-drying technology was used to preparesoybean peptide of different molecular sizes; visible light colorimetric technique andfluorescence technique was used to compare the activity of scavenging free radical ofdifferent peptides; on this basis, acute fatigue animal model and D-galactosesub-acute fatigue animal model was constructed to carry out deeper study on howsoybean peptide relieve physical fatigue; in the end, the design of soybean biscuit wasfinally done. The main results of this research was as follows:There were four kinds of soybean peptides we made using Alcalase Alkalineprotease, and their molecular size are about>10K、3K-10K、1K-3K、<1K. Theexperiment of scavenging free radical activity shows: the activity to scavenge DPPHfree radical and ABTS free radical of four kinds soybean peptides enhances accordingto the concentration, and their sequence was SP3>SP2>SP1>SP; the soybean peptideORAC value increased with concentration, and SP3were the optimal one at theconcentration of0.8mg/mL; in concentration between0.01mg/mL to1.0mg/mL, fourkinds soybean peptide’s hydroxyl radical scavenging rate changes very little withconcentration, and only when the concentration was up to10mg/mL the scavengingrate got a significant increase, and the ranking of four components differ underdifferent concentration condition. At the concentration of10mg/mL, the ranking wasSP3>SP2>SP>SP1, which suggests that soybean peptide’s activity to scavengehydroxyl radical has little relationship with it’s concentration. Four kinds soybeanpeptide’s ability to chelate divalent iron increases according to concentration among0.5mg/mL to5mg/mL significantly, and the trend got insignificant when theconcentration was more than5mg/mL. The ability to chelating divalent iron ranks asSP3>SP>SP2>SP1at the concentration of5mg/mL. Among the same peptide, it’s capacity to reduce iron increases with concentration increasing, and SP3behavesbetter than other peptides under the same concentration condition. Therefore, SP3waschosen as the optimal one to do the following experiments.In the acute fatigue animal model, soybean peptide can improve glycogenstorage, lower serum urea nitrogen and blood lactate content; each dose of soybeanpeptide can increase animal’s content of glycogen synthase, though the effect was notsignificant. Peptide in SP-M dose group and SP-H group can significantly improvethe total mouse liver peroxidase activity; each dose of peptide had no effect on thecontent of MDA and the activity of CPK.In the D-galactose sub-acute fatigue animal model, each dose of peptide cansignificantly increase mice’s swimming time, lower the content of serum ureanitrogen, but had no effect on liver glycogen、MDA and CPK; SP-L dose group has noeffect on blood lactate content, while SP-M and SP-H dose group can largelyaccelerate the clearance of blood lactate. All dose of peptide can improve the totalsuperoxide dismutase activity, however, the effect was not as significant as in acutefatigue animal model. The results show that soybean peptide can relieve physicalfatigue more significantly in normal animal than in aging animal.Sensory evaluation experiment was carried out to determine the add amount ofsoybean peptide in biscuit and the proper amount was1%. The L9(34) orthogonal testof soybean peptide biscuit’s production process showed that the optimal productionprocess was: water4%, baking temperature210℃,baking time11min.