| Key technologies of efficient utilization of Corn gluten meal to develop antioxidativepeptides were granted by the National Science and Technology Pillar Program during the12thFive-year Plan Period (No.2012BAD33B03). Corn gluten meal (protein content of79.4%,sieving mesh of180) were used as raw material. The key technologies of high efficienthydrolysis of Corn gluten meal, optimization of Corn antioxidant peptides (CAPS) with highactivity, toxicological safety evaluation of CAPS with high activity, preparation of high active ofCAPS, and the technology of pulsed electric field (PEF) improving the activity of CAPS wereresearched. The specific research content as follows:(1) The efficient hydrolysis technologies of Corn gluten meal were researched. Alacalse,Neutral protease and Papain were used to hydrolyze corn protein, and degree of hydrolysis (DH)was used as indexs. One-factor-at-a-time (OFAT) and response surface metrology (RSM)experiment were used to optimize the hydrolyze process. The results of hydrolysis process of3enzymes were obtained, and it showed that Alcalse was optimized for the efficient enzyme ofCorn gluten meal. The final equation in terms of actual factors was:Y=36.85333-1.48375X1-9.94125X2+1.12X3-0.5225X1X2+0.78X1X3-0.31X2X3+0.024583X12-11.8954X22-1.74292X32，in the equation：X1was enzyme solution temperature (℃)；X2was pHvalue；X3was [E]/[S](%). The optimized processing parameters were: temperature50℃, pH8.6,[E]/[S]9.13%, the predicted value of DH was40.26±0.23%. Then, irradiation doses(0-138.7kGy) were used for further improvement of the DH. The influence of differentirradiation dose DH of Corn protein was discussed. The optimal irradiation dose (65.0kGy) wasselected by OFAT experiment. The DH of the Corn gluen meal was48.23±6.1%. And themicrocosmic surface features of material were analyzed by scanning electron microscope test.The results showed that, the particle surface of Corn gluten meal powder with irradiationincreased, compared with blank sample.(2) The Corn protein hydrolysate prepared with optimal hydrolysis process was separatedby ultrafiltration. Different fractions of Corn antioxidant peptides (CAPS) were compared byantioxidant capacity in vivo and in vitro. The results indicated that CAPS-1had the highest antioxidant capacity. The DPPH inhibition of CAPS-1was84.75±4.19%. And GSH-Pxcapacity of CAPS-1-MD was114.09±5.4U/mL, the CAT capacity of CAPS-1-MD was14.18±0.58U/mL, and the MDA content of CAPS-1-MD was15.35±3.09U/mL.(3) Toxicity and safety evaluation of CAPS-1obtained by ultrafiltration were researched.The sperm deformity rate, micronucleus rate, NK cell activity and organ coefficients were tested.The results indicated that, CAPS-1group had no significant toxic harm in mice, and had certainimmune activities.(4) CAPS-1was separated by Sephadex G-25purification. The diameter to height ratio ofchromatography column was1.6:100, sampling amount was50mg/mL, and flow was60mL/h.DPPH inhibition test was used to evaluate the oxidation capacity of the fraction collected. Theresults showed that, CAPS-1-Ⅲ had highest antioxidant activity, with DPPH inhibition of84.51±1.3%. And the results of amino acid analysis showed that, the content of Glu and Leu inpurified Corn antioxidative peptides were significantly increased, the content of hydrophobicamino acids were decreased.(5) Pulsed electric field (PEF) was used to improve the activity of CAPS-2and EWAPS.OFAT and RSM test were used to optimaze technological parameters of PEF. The final equationin terms of actual factors was: Y=-152.29-4.57X1+7.93X2+0.18X3+0.01X1X2-0.002X1X3-0.002X2X3+0.53X12-0.13X22-0.00003X32, in the equation：X1was concentration of CAPS-2(mg/mL);X2was electric strength (strength)；X3was frequency (Hz). And the optimizedprocessing parameters were: concentration6mg/mL, electric field strength11.11kV/cm,and frequency2333.57Hz. In this condition, DPPH inhibition was86.88±0.41%, was increasedby21.3%compared with untreated sample. |
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