Optimization Of Separation Technology Of Oil And Protein From Cinnamomum Camphora Seed And Study Of Protein Structure And Properties

Cinnamomum camphora seed is a kind of oil seed with high nutritional value and rich oil and protein content.The kernel of Cinnamomum camphora seed contains more than 55%and 18%of medium carbon chain oil and protein,so it can be used as a new source of plant oil and protein.Our country is rich in Cinnamomum camphora seed resources,according to estimates in our country Cinnamomum camphora seed annual output of up to 3 million tons,but at present insufficient understanding of its potential value,development and utilization is not high,every year the mature Cinnamomum camphora seed natural fall off,cause a waste of resources at the same time also polluted the environment.Aqueous enzymatic extraction（AEE）of Cinnamomum camphora seed kernel（CCSK）oil is simple,safe and solvent free,previous studies only focused on the extraction of CCSK oil by aqueous extraction,and the research on CCSK protein,a by-product of aqueous extraction,was less.In order to make full use of Cinnamomum camphora seed resources,this study used CCSK as raw material to optimize the technological parameters of extracting CCSK oil by AEE,and to explore the influence of the aqueous enzymatic oil extraction process on the structure and function of CCSK protein,which provided theoretical reference for the deep processing of Cinnamomum camphora seed.The main research contents are as follows:（1）The oil of CCSK was extracted by AEE（cell wall polysaccharide hydrolase and protease enzymatic hydrolysis step by step）.The residual rate of CCSK oil in residue phase was used as the evaluation index,andα-amylase and alkaline protease were selected as the best enzyme preparations.And the optimal process parameters of enzymatic hydrolysis were determined by single factor test and orthogonal test as follows:the solid-liquid ratio was 1:4,the addition ofα-amylase was 3000 U/g,and the hydrolysis time was 2.0 h.The addition of alkaline protease was 1000 U/g,and the hydrolysis time was 3.0 h.Under these conditions,the residual rate of CCSK oil in residue phase was 5.86%.（2）The purity of CCSK protein and hydrolyzed protein was 80.23%and 76.24%,respectively.The main molecular weight distribution of CCSK protein was 60,45 and12 k Da,and the hydrolysis degree of CCSK protein was 23.28%,and the molecular weight distribution was mainly 12 and 3.5 k Da.There were 17 kinds of amino acids in CCSK protein,of which 8 kinds of essential amino acids accounted for more than the FAO/WHO recommended standard of 29.26%,and the content of essential amino acids,free amino acids and free sulfhydryl groups of the protein after oil extraction increased compared with CCSK protein.In the process of oil extraction by AEE,CCSK protein aggregation phenomenon occurred,resulting in larger particle size,decreased Zeta potential absolute value,and unstable in aqueous solution.Compared with CCSK protein,the secondary structure of the protein after AEE was significantly changed,the degree of protein disorder increased,the fluorescence quenching phenomenon occurred in the tertiary structure,the protein structure was more loose,the protein structure was unfolded,the hydrophobicity was reduced,and the thermal stability was enhanced.（3）The solubility and oil absorption capacity of CCSK protein were significantly improved after oil extraction by AEE.The solubility of CCSK protein reached 89.65%,and the oil absorption capacity of protein was 5.92 g oil/g protein.The foaming and emulsifying properties of CCSK protein were worse.At p H 3,the foaming ability of protein was 26%,and the emulsifying ability was 17.82 m²/g.The Fe³⁺reducing ability,DPPH,ABTS and O₂^-·free radical scavenging ability and Fe²⁺chelating ability of CCSK protein were significantly improved after AEE,and the IC₅₀ values were 0.02,2.23,0.05 and 18.51 mg/m L,respectively.