The High Utilization Research Of Goat Placenta Extract Residue

Goat placenta contain pentiful bioactive substances,which have antioxidant,hypoglycemic,anti-viral and the immunity of organism enhancing. China is abundant in goat placenta resources, but the utilization rate of goat placenta is less than 3% and most of them being thrown away, So it there will be wide marketing prospect and great practical significant to fully develop and utilise goat placenta.In this study, the high utilization of goat placenta which was extracted water-soluble substance as an important aim, With goat placenta residue as raw material together with antioxidant activity, peptide yield and immune cell proliferation rate as main quality evaluation indexes to value possibility of Bacillus subtili,Aspergillus oryzae, Bacillus licheniformis and Aspergillus niger as fermentation strains to prepare placenta peptides. The major research work as follows: the nutritional value analysis of goat placenta without water-soluble protein, screening of strains, optimization of controlled-fermentation hydrolysis conditions, analysis of the stability of bioactive peptides, the performance of peptide powder under the circumstances of dying, purification and analysis of biological activity.The major results are showed as follows:(1)The nutritional value analysis of goat placenta which was extracted water-soluble protein: goat placenta is a high quality protein which the protein efficiency ratio(PER) was 1.27 and the total protein content of dry basis was 97.67%. The amino acid content of it as follows: Glu(10.24%), Gly(9.51%), Asp(6.56%), Arg(5.65%), Leu(5.46%), Pro(5.41%). After making amino acid score, the first limiting amino acid were Ile and Val, which the amino acid score was 0.71.(2) With goat placenta residue as raw material together with antioxidant activity, peptide yield and immune cell proliferation rate as main quality evaluation indexes to value possibility of B.acillus subtili, A.spergillus oryzae, B.acillus licheniformis and A.spergillus niger as fermentation strains to prepare placenta peptides. Then the results indicated that peptides content are respectively 29.67%、27.58%、26.04%、24.3% of A.spergillus niger,B.acillus subtili,B.acillus licheniformis and A.spergillus oryzae fermentation broth;Fermentation products of A.spergillus niger has the highest antioxidant activity and the highest immune cell proliferation rate of Bacillus subtili.(3)The best fermentation conditions of A.spergillus niger were as follows:inoculum at 5%. fermentation temperature 30℃, fermentation time 76.4 h, value p H 5.6,glucose content 2.8%, rate of peptide yield is 30.90% and ability of scavenging DPPH free radicals is to 83.78% under these conditions. Meanwhile the fermentation products of B.acillus subtili rate of peptide yield is 27.89% and ability of immune cell of proliferation rate is 24.38% under the best fermentation conditions: fermentation temperature 37 ℃, fermentation time 43.5 h, value p H 5.4,glucose content 1.7%.(4)The antioxidant and immune activity stability of hydrolysate was evaluated in different conditions such as : different concentrations of products, p H, dry processes, simulated in vitro digestionAntioxidant peptides of free radical clearance rate that increases with the increase of concentration, under the same concentration of free radical scavenging ability to slightly higher than that of glutathione(GSH) removal ability.Immune active peptide protein concentration in the range of 6.25~200 μg/m L of spleen lymphocytes in mice has obvious proliferation, in less than 100 mu g/m L concentration, with the increase of fermented liquid protein concentration, stimulation index increase, there is a clear concentration-response relationship, when 100 μg/m L concentration lymphocyte proliferation rate reached 23.25%The results showed that the A.spergillus niger fermentation hydrolysate could keep highly biological activity between p H5-8, but lost its activity in p H less than 5 or p H greater than8.The influences of two dying methods were significant, but they can keep highly activity. The antioxidant activity retention rate was 97.6% and 91.7% under by spray drying and freeze-drying. The biological activity retention rate was more than 90% under by spray drying and freeze-drying.The antioxidant activity of hydrolysate were kept higher than immune activity under simulating in vitro digestion includes simulated gastric digestion, simulated intestinal digestion and simulated in vitro digestion. The ability of scavenging DPPH and ·OH free radicals is to 53. 87% and 63.18% when hydrolysate was digested 300 min in simulated gastric digestion, and the antioxidant activity retention rate was 53.87% and 63.18% meanwhile antioxidant activity retention rate was 68.28% and 73.13%. The immune activity retention rate of B.acillus subtili was respectively 44.61% and 52.89% in simulated gastric and intestinal digestion.(5) The productions were separated by ultrafiltration. The components were measured the peptide yield and biological activity in vitro.The results showed that the antioxidant activity of molecular weight<3KDa and 3KDa~10KDa was significantly higher than the other four groups, and the fermentation broth of A.spergillus niger including 60% of the products were less than 10 KDa molecular weight,content distribution curve of antioxidant peptides functional relation equation y = 0.0006 X2-0.0932 X+ 3.1345.At the same time, molecular weight < 3KDa and 3KDa~10KDa has 85% in fermentation broth of B.acillus subtili and molecular weight 3KDa~10KDa play an important role in immune cell proliferation while molecular weight<3KDa in antioxidant activity, but they have a synergistic reaction in immune cell proliferation.