Preparation Of Antioxidant Active Peptides By Complex Enzymatic Hydrolysis Of Defatted Coconut Meal And Its Application In Cosmetics

Coconut meal is a kind of by-product after coconut oil extraction,and the content of protein is range up to 20%with a variety of amino acids.It has certain physiological functions such as reducing blood press,degrading cholesterol and inhibiting hyperlipidemia.It is often used as feed or discarded because of poor palatability.There is more arginine in the coconut meal and some researches have showed that the arginine has strong activity to scaveng free radical.So coconut protein is a kind of high quality amino acid and peptide resource.In this paper,the coconut protein was extract from coconut meal by ultrasound-assisted dissolving in alkaline-solution and acid-isolation,and optimized the extraction technology by orthogonal experiment.The free radical scavenging activity and the chelating activity of Fe²⁺were used evaluation index,the single enzymatic hydrolyzed and compound enzymatic of coconut protein was studied.Using single factor experiment and response surface experiment to optimize process conditions.The coconut peptide as a functional component added to cosmetics,the results of the study for high value and using coconut protein meal provide some useful reference.The specific research content is as follows:(1)The extraction rates of protein was used evaluation index,using alkaline-solution and acid-isolation and the ultrasonic assisted to prepare coconut protein.Selected extraction temperature,solid-liquid ratio,p H and ultrasonic power as research factors.The results of single factor experiment and the orthogonal experiment showed that the optimum extraction condition:,extraction temperature of 65?,solid-liquid ratio of 1:30,p H value of 10,ultrasonic power of 100 W.(2)Degree of hydrolysis and free radical scavenging were used evaluation index.The coconut protein was hydrolyzed by Alcalase,Neutral protease,Papain protease,Pineapple protease and Flavor protease,under their optimal conditions,respectively.The results showed that the Alcalase has the highest degree of hydrolysis and free radical scavenging,Papain and Neutral protease followed,which confirm that Alcalase was selected as the single enzymatic proteinase,Alcalase-Neutral protease and Alcalase-Papain protease was used in the compound enzymatic hydrolysate proteinase.Single factor experiment was used to investigate the different conditions on the effects of productions of antioxidant peptides from coconut protein with Alcalase.The resultes of single factor experiment and response surface experiment showed that the optimum hydrolysis conditions:the substrate concentration of3.26%,enzymolysis temperature of 56.43?and the enzyme solution p H of 8.09,which offer the:DPPH radical scavenging activity of 72.95%,hydroxyl radical scavenging activity of67.84%,the chelating activity of Fe²⁺of 79.45%;The results of single factor experiment showed that the antioxidant activity of Alcalase-Papain compound enzymatic hydrolysate was higher than that of the hydrolysate prepared by Alcalase-Neutral protease.Hence,selected the Alcalase-Papain compound enzymatic hydrolysate proceed the response surface experiments,and the results showed that the optimum hydrolysis conditions:the ratio of Alcalase and Papain of 1.86:1,temperature of 55.92?,and the enzyme solution p H of 7.68,which offer the:DPPH radical scavenging activity of 86.42%,hydroxyl radical scavenging activity of 74.91%,the chelating activity of Fe²⁺of 89.26%.The enzymolysis liquid was separated by ultrafiltration membrane with different molecular weight,and the results showed that the DPPH radical scavenging activity of the permeate which molecular weight less than 2k Da was highest and it was 91.37%,the value of IC₅₀ was 0.8579 mg/m L.(3)The application of coconut peptides in the cosmetic was studied,by W/O anti-aging cream.According to orthogonal test and fuzzy comprehensive evaluation method,the optimum formulation system consists of 16/18 Alcohol 2.5 wt%,Glycerol stearate 3 wt%,Mineral oil 3 wt%,Gold jojoba oil 2 wt%,Glycol 5 wt%,Dimethyl polysiloxane 1.5 wt%,Glycerol 4 wt%,Squalene 2 wt%,Garbomer 0.4 wt%,Coconut peptide 4 wt%,Butyl glycol 2 wt%.A randomized double-blind controlled clinical trial showed that the anti-aging cream prepared by adding coconut peptides could significantly improve the skin elasticity and skin moisture,reduces the content of skin oil to a certain extent.The results of this study will provide theoretical basis and technical support for the in-depth research and commercial development of coconut peptides in the field of cosmetics.