Influence Of Peanut Protein Hydrolysate Combined With Resveratrol On The Stability Of Oil-in-water Emulsions

In this experiment,Peanut Protein(PP)was taken as the main research object,and alkaline protease hydrolyzed for 0.5 ? 1 ? 2 and 4 h.First,the antioxidant indexes of peanut protein hydrolysates(PPH)was studied by determining the reduction ability,metal chelation ability and free radical scavenging ability as well as emulsifying activity,emulsifying stability,surface hydrophobicity and ?-potential of PPH.The PPH with the highest emulsifying property and good antioxidant activity was selected.Subsequently,the effects of different concentrations of PPH combined with Tween 20 as a co-emulsifier on the physical and oxidative stability of O/W emulsion were studied.The optimum addition concentration of PPH was selected by measuring the emulsification performance,the ?-potential,particle size,flocculation stability,condensation stability and oxidation stability.The effects of resveratrol(RES)on the preparation of the emulsion at the optimum concentration of PPH were studied through the changes of physical stability and oxidative stability of the emulsion during storage.This study provides experimental basis and theoretical basis for improving the stability of O/W emulsion food.The main research results are as follows:(1)Compared with peanut protein,the antioxidant capacity and emulsifying capacity of the hydrolyzed peanut protein were significantly improved(P < 0.05).With the increase of hydrolysis,the reduction capacity,free radical scavenging capacity and metal chelation capacity of PPH showed an increasing trend(P < 0.05).However,the emulsifying property,surface hydrophobicity,hydroxylation potential of PPH showed a change trend of first increase and then decrease.Under moderate hydrolysis conditions of 7.6%,PPH had the best emulsifying performance(P < 0.05).(2)The O/W emulsion was prepared with PPH and Tween 20 obtained with a hydrolysis of7.6% as a co-emulsifier.The results show that,compared to the emulsion prepared separately with Tween 20,the physical stability and oxidation stability of emulsion prepared by PPH and Tween 20 as co-emulsion were improved.And In addition,5 mg/mL PPH has the best emulsifying stability,the most electric quantity and the smallest particle size.It can best resist the occurrence of flocculation and condensation.In addition,a relatively dense interfacial film is formed at the oil-water interface,which can resist free radicals and inhibit lipid oxidation.(3)The emulsion was prepared with 5 mg/mL PPH and RES.PPH and RES can be crosslinked to form PPH-RES complex.RES can both increase the adsorption amount of PPH on the interface and significantly improve the physical stability and oxidation stability of the emulsion.When the addition amount of RES was 0.2%,emulsion had the best emulsion stability,flocculation stability and condensation stability,with the most electric quantity and the smallest particle size(P < 0.05).Excessive addition of RES may cause molecular entanglement with PPH and affect the adsorption of PPH on the interface.This leads to a decrease in stability.