Study On Color Stability Of Pigment Derived From Dry Red Wine Aging

In this study,the anthocyanins of Cabernet Sauvignon dry red wine separated and purified by different macroporous resins were analyzed by high performance liquid chromatography(HPLC),in order to determine the optimal macroporous resin which can efficiently separate monomer and polymeric anthocyanins in wines.Then,the influence of different factors on the the color stability of the derived pigments was studied,using HPLC and spectrophotometer.The research content and results are as follows:1.Four kinds of macroporous resins,AB-8,D101,HPD-100 and NKA-9 were selected to separate monomer and polymeric anthocyanins in aged Cabernet Sauvignon dry red wine.The results of the static test found that the best static adsorption time,static desorption and eluent of wine anthocyanins purification by macroporous resin were 9 h,1 h and 70%ethanol solution respectively,and AB-8,D101 and NKA-9 macroporous resins were first selected to the better separation.The dynamic test results show that the best dynamic adsorption volume of the macroporous resin for purifying wine anthocyanins was 800 m L,and the best dynamic adsorption flow rate was 2 BV/h.Based on the comprehensive consideration of the purification result of malva anthocyanins,acylated malva anthocyanins,and polymerized anthocyanins,NKA-9 macroporous resin was determined as the best resin.In this research,monomer and polymeric anthocyanins were better separated:the average content of polymeric anthocyanins reached 80.28 mg/L,which was 9.42 times that in the original wine,and the average content of purified monomeric anthocyanins was 174.78mg/L,which was 10.45 times that in the original wine.2.The influence of p H,light,hydrogen peroxide and acetaldehyde solution on the stability of the monomeric and polymerized anthocyanins separated and purified from wines were studied.The results showed that:(1)Within a certain p H range,the higher the p H,the lower the stability of monomeric anthocyanins,while the stability of polymerized anthocyanins was basically unaffected.The hue,color density(CD),anti-SO₂ derivatives(CDRSO₂),large molecule polymeric pigments(LPP),small molecule polymeric pigments(SPP),and tannins in the seperated polymerized anthocyanins were all higher than those of monomeric anthocyanins,and all the parameters increased with aging except small molecular polymers and malva anthocyanin.(2)Under different light conditions,the stability of polymerized anthocyanins was also higher than that of monomeric anthocyanins,and the stability of light-shielding treatment was better than that of light treatment.The CD,hue,CDRSO₂,LPP and tannin content of polymerized anthocyanins solution were higher than those of monomeric anthocyanins,and monomeric anthocyanins decreased with treatment time,while the content of polymerized anthocyanins increased.(3)After treatment with different concentrations of H₂O₂,the stability of polymerized anthocyanins was better than that of monomeric anthocyanins.Treatment with high concentration of H₂O₂had a significant degradation effect on monomer anthocyanins,and the higher the concentration,the more degradation,while the impact on polymerized anthocyanins was relatively small.With the extension of time,the monomer mallow anthocyanin was almost lost with the effect of high concentration of H₂O₂,and the polymerized pigment increased with extension of aging time.(4)Under different acetaldehyde concentrations,the stability of polymerized anthocyanins was better than that of monomeric anthocyanins,and the high-concentration acetaldehyde treatment was also slightly better than the low-concentration treatment.The CD,hue,CDRSO₂,LPP,SPP,and tannin content of polymerized anthocyanins solution were all higher than those of monomeric anthocyanins.The CD,hue,CDRSO₂,LPP and tannins in the two anthocyanins solutions all increased with aging time;while monomer anthocyanins and SPP decreased with aging time.Overall,H₂O₂ treatment had the greatest impact on the stability of the two types of anthocyanins,and was directly proportional to the concentration;light also had a certain impact on the stability of anthocyanins;the lower the p H,the higher the stability of the monomer anthocyanins,however,the polymerized anthocyanins were basically unaffected by p H;acetaldehyde could accelerate the formation of polymerized pigments,and had a certain promoting effect on the stability of polymerized anthocyanins.