The Study Of The Color And Anthocyanins In Red Wine Promoted By Ultrasound Treatment

Ultrasound,a non-thermal processing technology applied to the wine processing,can shorten the aging time of red wine and reduce the cost.It is a potential technique with great application prospect.However,at present,domestic and foreign scholars only mainly focused on the changes of the flavor and taste of the red wine after ultrasonic aging process.Nonetheless,the color change under ultrasonic treatment,especially the growth and decline law and the influence mechanism of the pigments containing anthocyanins and their derivatives,have not been well studied deeply.Therefore,our study focused on the apparent color change of the red wine in the aging process,traced the growth and decline law of anthocyanins and their derivatives,and studied the change of the wine color and the evolution rule of anthocyanin structure.Furthermore,a model wine system was established to analyse the impact of ultrasonic processing to the wine color and anthocyanins,intensive studied the mechanism of wine color influenced by ultrasound,aimed to provide theoretical basis and technical support for the application of ultrasonic technology in wine aging.The following main results and conclusions were obtained.(1)Among the one month storage period,the stability of wine was consistent with the control wine after ultrasonic treatment and did not occurred the situation of “retrogradation”.The wine after ultrasonic treatment could significantly decrease the color index of wine color due to pigments(WCP),which could be increased by the increase of ultrasonic power,time and times.Besides,the wine color characteristics of ?E was significantly decreased ultrasonic treatment,which could also be increased by the increase of ultrasonic power,time and times.the L*,a*,hab,C* increased after different ultrasoinic power,time and frequencies.(2)UPLC-TOF-MS was applied to identify the main anthocyanins structures from red wine.Five anthocyanins were confirmed in this red wine,including the monomer anthocyanin of malvidin 3-glucoside and the anthocyanin derivatives of Vitisin A,Vitisin B,Pinotin A and malvidin-3-glucoside-4-vinylphenol performed which generated by malvidin 3-glucoside and pyruvic acid,aldehyde,caffeic acid,p-coumaric acid respectively.(3)The model wine system of 12% ethanol wine contained 5g/L tartaric acid(p H = 3.68)was established to study the impact of ultrasonic treatment to malvidin 3-glucoside and different copigments,including caffeic acid,p-coumaric acid,pyruvic acid,catechin and epicatechin.After ultrasonic treatment,the results showed that the absorbance at 506 nm and color characteristics of the model system by adding pyruvic acid did not have significant difference.The absorbance at 443 nm and 525 nm of the model system by adding epicatechin or catechin was significantly respectively increased and decreased after treatment,besides,after 4 weeks of storage,the b* value of the model system containing epicatechin was significantly improved.Howerer,ultrasonic treatment inhibited the absorbance at 501 nm and a* value of the model sysem added p-coumaric acid.On the contrary,ultrasonic treatment could significantly incease the absorbance at 510 nm and a* value of the model systmen with caffeic acid.(4)HPLC was applied to study the influence of genenration of anthocyanian derivatives in different model wine systemn with malvidin 3-glucoside and different copigments by ultrasonic treatment.Results showed that ultrasound could not promote the yield of anthocyanin derivatives.The analysis indicated there was no direct correlation between wine color treated by ultrasound and anthocyanin derivatives generated by malvidin 3-glucoside and caffeic acid.(5)Caffeic acid was treated by ultrasound separately,and it was found that the caffeic acid after treatment can promote intensity of its ultraviolet and visible spectrum,and improve the copigmentation between malvidin-3-glucoside.It indicated that ultrasound could change the structure of caffeic and enhance the copigmentation with malvidin-3-glucoside.Conclusion: Ultrasound could accelerate the maturity of wine color,which mechanism is related to that ultrasonic treatment could change the structure of copigments,thereby improving the intermolecular copigmentation with malvidin-3-glucoside.