| Plant protein has become an important resource for continuous development in the food industry.There are many plant protein products in food industry.However,the main raw materials of plant protein products are soybean protein isolate,followed by peanut protein and walnut protein.This suggests that it is urgent to develop new plant protein resources to supplement the vacancy of plant protein raw material.Elaeagnus mollis oil(EMO)meal is rich in protein and is a natural plant protein resource.Therefore,EMO meal protein was used to raw material to study the effects of different treatment methods on structural,functional properties and antioxidant capacity of EMO meal protein.The main results are as follows:1.The preparation optimum conditions of EMO meal protein was obtained by single factor and orthogonal analysis,and the functional properties of protein were determined.The results showed that the the highest extraction rate and purity of protein were 74.19% and 84.03% under the conditions of material-liquid ratio 1:75,p H=11,extraction temperature 55 ° C and extraction time of 55 min.The solubility,water or oil holding and foaming properties of EMO meal protein was similar to those of soybean protein isolate,except that the emulsifying properties were lower than that of soybean protein isolate.2.The basic conditions of enzymatic hydrolysis of EMO meal protein were determined,and the effects of enzymatic hydrolysis on the structural and functional properties of EMO meal protein were studied.The optimum conditions were as follows: substrate concentration 4%,enzyme dosage 10000 U/g,p H=11 and temperature 50 ° C.After alcalase treatment,the molecular weight of EMO meal protein was decreased,the disulfide bond was hydrolyzed,the hydrophobic group was destroyed,the surface hydrophobicity and intrinsic fluorescence intensity was decreased,and the molecular structure of protein was more flexible,functional properties and antioxidant capacity were enhanced.At the same time,it was found that when the degree of hydrolysis was more than 10%,the rigid structure was completely hydrolyzed,and the molecular weight of the protein was too small,which was not enough to stabilize the foam and emulsion,leading to the decrease of foaming and emulsifying stability.Therefore,hydrolysis degree 10% was considered to be the most suitable hydrolysis degree to improve the functional properties and antioxidant ability of EMO meal protein.3.In order to further improve the functional properties and antioxidant capacity of EMO meal protein,the effects of anthocyanin binding method and enzymatic hydrolysis on the structural and functional properties of EMO meal protein were studied.Under the conditions of p H=3 and p H=7,the complex of anthocyanin EMO meal protein or anthocyanin enzymolysis protein(DH 10%)with anthocyanin concentrations of 0.025%,0.05% and 0.1% were prepared.The results showed that the colloidal particles were formed between anthocyanins and proteins through hydrophobic interaction and hydrogen bonding,which increased the turbidity and decreased the solubility.At the same time,anthocyanins attached to the surface of protein molecules,covered part of the hydrophobic groups of protein,reduced the fluorescence intensity and changed the protein conformation.With the increase of anthocyanin concentration,the complex had better foaming property,emulsifying property and antioxidant capacity.Meanwhile,the functional properties of the anthocyanin enzymatic protein complex were higher than those of the anthocyanin EMO meal protein complex,EMO meal protein and enzymatic protein.Therefore,the synergistic effect of anthocyanin binding and enzymatic hydrolysis can further improve the functional properties and antioxidant activity of EMO meal protein. |
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