Studies On Preparation And Copigmentation Effect Of Malvidin From Vitis Davidii Foex

Anthocyanins are a widespread source of natural pigment of foods. Due to their bright attractive color, high solubility in water and health benefits, anthocyanins could be a replacement for synthetic colorant. But anthocyanins were easy attacked by nucleophile to be hydrolyzed, this limits its application in actual production. In the study of the effect of anthocyanins, the mixed crude extract was used as the research object, which could not explain the copigment and degradation mechanism of anthocyanins. As a quality resources of anthocyanins extraction, the main types of anthocyanin in Vitis davidii Foex is malvidin. This article aims to establish large-scale production technology of malvidin reference, improve its map data. In this paper, anthocyanin monomer (Malvidin-3,5-O-diglucoside-coumary) as the object of study, comparing different copigmentation effect of copigment on monomeric anthocyanin. The color stability, thermal degradation and component change of anthocyanin monomer after copigmentation were also studied.The main results are as follows:(1) Anthocyanins were extracted from Vitis davidii Foex skin and then purified orderly by macroporous resin HP-20 column, polyamide resin column, Sephadex LH-20 column chromatography (eluted by 50% methanol containing 0.1% TFA). The anthocyanins were characterized by MSE method using UPLC-QTOF. Moreover, the relationship between the fluorescence spectrum and the structure of the anthocyanins was explored by fluorimetry. The results showed that some anthocyanin was absorbed by polyamide resin, while Sephadex LH-20 could be used to separate and purify the anthocyanin. Three anthocyanins were identified as Malvidin-3,5-O-diglucoside (Pigment ?), Malvidin-3,5-O-diglucoside-coumary (Pigment ?), mixture of Delphinidin-3-rutinoside and Malvidin-3-rutinoside (Pigment ?). The purities of Pigment ? and Pigment ? were determined by analytical HPLC, and estimated to be 98.64% and 98.33%, respectively.(2) A semi-preparative high performance liquid chromatographic method was established for the preparation of anthocyanins monomers with high purity from Vitis davidii Foex crude extracts purified with macroporous resin HP-20. The effects of experimental conditions, including mobile phase gradient elution conditions, flow rate and injection volume were investigated on a XCharge C18 preparative column (20×250 mm,10 ?m). The optimal chromatographic conditions were as follows:mobile phase:methanol-3% formic acid water by gradient elution, flow rate:15 mL/min, injection volume:1.2 mL. Under the optimal chromatographic conditions, the isolation and preparation of two major anthocyanins monomers were achieved within 18 min. Two anthocyanins were identified by MSE method using UPLC-QTOF as Malvidin-3,5-O-diglucoside and Malvidin-3,5-0-diglucoside-coumary with purities 99.54% and 98.28%, respectively.(3) Anthocyanin monomer (Malvidin-3,5-O-diglucoside-coumary) as the object of study, comparing different copigmentation effect, color stability, thermal degradation and component change of anthocyanin monomer after copigmentation. The study found that the greater the concentration of copigment, the better the copigmentation effect, and the best copigment is ferulic acid. Different concentrations of the same pigment can affect the color value of the monomer anthocyanins solution, with the increase of copigments concentration, a* and C* increased, while L* decreased. After Copigmentation by ferulic acid, the retention of monomer anthocyanins was significantly higher than before, and did not produce anthocyanins derivatives. Only after a long time high temperature treatment, anthocyanins components will change.