Studies On The Antioxidant Activities Of Seed Coat Ethanol Extracts And Protein Hydrolysates From Torreya Grandis

Torreya grandis is a large,evergreen and ornamental coniferous tree belonging to the Cephalotaxaceae family and Torreya genus.Torreya fruit is Torreya grandis.Data showed that Torreya grandis planted area continues to expand,production continues to rise,the price gradually return,and Torreya grandis from basic processing?nut products?to deep processing,especially as a wood grain and oil crops,the future comprehensive utilization will become an important part of deep processing of Torreya grandis.In this research,Torreya grandis defatted flour and Torreya grandis seed coat were used as the research object,we studied the antioxidant activity of the hydrolysates of Torreya grandis protein,Torreya grandis defatted flour water extraction and endosperm ethanol extract and the application in O/W emulsions and identified some of the components in the endosperm ethanol extract of Torreya grandis.It is expected to provide a basis for the comprehensive utilization of defatted flour.First,a simple study about that the extraction of Torreya grandis protein,protein content of Torreya grandis defatted flour is about 26%,the isoelectric point of the protein is pH 4.0,degree of hydrolysis constant h_tot 7.75 mmol·g^-1,Bailing 1 Torreya grandis protein extraction rate was much lower than the extraction rate of Tedazi and it was difficult to get available protein from Bailing 1 Torreya grandis.Then,we measured antioxidant properties of the hydrolysates of Tedazi Protein by Pepsin,Alcalase,Trypsin,Neutrase and papain;hydrolysates of Tedazi water extraction by Pepsin and Alcalase.The result showed that hydrolysates of Torreya grandis Protein had good ability to scavenging ABTS,DPPH,superoxide anion free radicals;hydroxyl radical scavenging ability is slightly weaker,the reducing power was also very low,much lower than the reference substance GSH,but they had very strong ferrous ion chelating ability.Free radical(DPPH·,ABTS^·+,O^2-·)scavenging ability and ferrous ion chelating ability of hydrolysates by pepsin and Alcalase are stronger than that hydrolysate by Trypsin,Neutrase and papain.Hydrolysates of Pepsin and Alcalase from Tedazi defatted flour water extraction had strong ABTS scavenging activity,scavenging rate of ABTS free radical was over 93% at 5 mg/mL;as to the ability of scavenging DPPH free radical was near to that of GSH,but have weak ability to scavenge hydroxyl radicals.Moreover,water extraction Hydrolysate by Alcalase also had strong superoxide anion scavenging ability.In the course of the study,it was found that the endosperm extraction had strong antioxidant activity,in this paper,the antioxidant properties and the identification of some phenolic compounds were studied in the extracts of Bailing 1 and Tedazi.The study found that in the scavenging free radicals,the extract of Bailing 1 Torreya grandis was stronger than that of the large seed coat,especially with the ability to remove hydroxyl radicals more than Vc,and when the concentration was less than 1 mg?p<0.05?.In addition,the extracts of Bailin 1 Torreya grandis had strong reducing power.Five compounds were identified from the extracts of the seed coat,and 2-hydroxy-2-?4-hydroxyphenylethyl?malonic acid was the newly discovered compound.The other four compounds were protocatechuic acid,catechu?+C?,epigallocatechin gallate?EGCG?and epicatechin gallate?ECG?,both strains of Torreya grandis contain these five compounds.On the basis of the above research,the paper further explored the effect of hydrolysates of protein,hydrolysates of defatted powder extract and seed coat extract on the antioxidant capacity of oil in O/W emulsions.The result showed that two kinds of enzymatic hydrolysates,two kinds of enzymatic hydrolysate of defatted powder extract and two kinds of extracts of two species of Torreya grandis were prepared at two concentrations?the concentration of enzyme hydrolysates,1 mg/m L and 5 mg/mL,the concentration of alcohol extraction,100 ?g/m L and 200 ?g/m L?could effectively inhibited the oxidation of fat in the emulsion system.On the 23 rd day of storage,inhibition rate can reach more than 90%.In the emulsion of MDA production inhibition of Torreya grandis protein hydrolysate was stronger than Tedazi defatted powder water extraction hydrolysates,Bailing 1 Torreya grandis seed coat ethanol extract to be slightly stronger than that Tedazi Torreya grandis.