Study On Preparation And Physiological Activity Of Rice Residue Hydrolyzate And Its Effect On Growth Performance Of Weaned Piglets

Rice residue is a by-product during producing organic acids,starch sugars,and fermentation industry using rice as a raw material.The protein content is as high as50% and has almost the same nutritional value as rice protein.The ratio of amino acids is reasonable.However,because of lower digestibility at low and neutral pH,rice residue was usually used as a cheap animal feed.The functional and nutritional properties of rice residue protein can be improved after enzymolysis,which can not only improve the utilization rate of rice residue,but also develop functional active rice protein peptide.In this study,we prepared the rice residue protein peptides by physical-assisted enzymolysis to improved it's functional properties,and investigated the anti-tumor activity of rice residue protein peptides.Then the rice residue hydrolyzate was used as the microcapsule wall material to prepare a kind of dietary supplement for weaned piglets diet.The effects of microcapsules on the growth performance of weaned piglets were studied,which provide a theoretical basis for the development and comprehensive utilization of rice protein active peptide drugs.The main research contents and results are as follows:(1)The physico-chemical properties of six kinds of peptides by ultrafine comminution combined with enzymatic modification were investigated.According to the degree of hydrolysis,protein recovery and short peptide content,three kinds of proteases(trypsin,neutral protease and flavorzyme)mixture ratio was 2:5:1 the optimal enzymolysis condition.Under this condition,the amino acid ratio is reasonable,the emulsifying property of rice residue protein peptide was generally not high,the solubility was greater than 90%.The faming property of RDPH-e is excellent,probably because the structure mainly secondary and tertiary of some proteins was changed by ultrafine grinding,which makes the molecules more easily adsorbed at the air interface.Determination the antioxidant property of protein peptides has illustrated that the antioxidant activity of each protein peptide increased to different extent with the concentration increased.It is obivious that rice residue protein peptide has strong antioxidant capacity,so it is necessary to futher explore the biological activity of rice protein peptide and related products.(2)The rice residue protein hydrolysate was prepared by ultrafiltration according differfent molecular weight marked as RDPH-e-1(3-10k),RDPH-e-2(1-3k),RDPH-e-3(<1k).After that,the effect of rice protein peptide on HepG2 cellproliferation,apoptosis and migration cycle was studied.Results showed that compared with the control group,the proliferation of HepG2 cells was inhibited in various degrees,The highest inhibitory rate of RDPH-e-1?RDPH-e-2 was up to 60%,with a good dose-response relationship.The half-inhibitory concentration of RDPH-e-1 was(63.51 ±0.10)?g/mL,which was significantly different from other groups.Detection of apoptosis showed that chromatin condensation and nuclear shrinkage were observed in the protein peptide-treated groups compared with the blank control group,and the apoptosis rate was positively correlated with the concentration.Flow cytometry was used to detect the cell cycle of HepG2 cells.The results showed that HepG2 cells were blocked in G1 phase by protein peptides,which prevented HepG2 cells from transiting to S phase.Therefore,the DNA replication of Hep G2 cells was inhibited.Transwell chamber migration test showed that different molecular weight peptide components can effectively inhibit the migration of HepG2 cells,and the inhibition ability of RDPH-e-1 is minimal.There results illustrated that rice residue enzymatic peptide has potential anti-tumor activity,can be used as functional food ingredients.(3)According to the embedding rate of microcapsules and single factor experiments,response surface test was carried out.The optimal response results was:emulsifier containing 3.01%,wall material ratio of 3.35: 1,core content of 29.17%,theoretical embedding rate was 81.78%.Considering the actual situation,the process parameters were set as the emulsifier content of 3.0%,wall material ratio of 3: 1,the core content of 30.00%.Physical and chemical analysis of the coconut oil microcapsules showed that the moisture content was 2.07% and the embedding rate was 81.68%.The coconut oil microcapsules prepared from rice syrup and rice residue enzymolysis peptide had low moisture content,high embedding rate,and outstanding solubility.About 90% of the microcapsules with a particle size <10?m,indicating that the particle size distribution of the coconut oil microcapsules is even and concentrated.Most of the microcapsules are spherical with a smooth surface.The peroxide values of coconut oil and coconut oil microcapsules on the 30 d were 6.21 meq/kg and 5.02meq/kg,respectively,at 25?,Under the condition of accelerated oxidation at 60?,the peroxide value of raw coconut oil increased rapidly,and the microencapsulated coconut oil increased slowly.The peroxide value of coconut oil stored for 30 d reached 36.42 meq/kg.The peroxide values of the coconut oil microcapsules in the three kinds of humidity conditions were 4.49 meq/kg,6.64 meq/kg,and 11.46 meq/kg,respectively,so the microcapsules should be stored in a ventilated and dry environment.(4)The determination of growth performance,serum biochemical indexes and intestinal microflora of weaned piglet,it was found that after adding 3% coconut oil microcapsules containing rice protein peptide-syrup as wall material to the diet of weaned piglets,the average daily gain was 24.00% higher than that of the control group,and the daily feed intake was 14.81% higher.The apparent digestibility of substances,crude fat,and crude protein was 4.51%,17.34%,and 18.76% higher than that of the control group,respectively.it has a significant effect on total serum albumin,albumin,globulin,and triglyceride,and it has a tendency to improve intestinal flora.Above results indicated that the coconut oil microcapsule can be used as a new feed additive for piglets,has scientific direction of protein,oil balance in the production of basical animal feed.