The Study Of On Properties, Function And Application Of Anthocyanidin From Purple Sweet Potato

Purple sweet potato, convolvulaceae, was a special kind of sweet Potato with mauve flesh.Anthocyanins from Purple sweet potato(Purple Sweet Potato Anthocyanins,PSPA), which were nontoxic and multi-functional sueh as nutrition, pigmentation, health protection, had broad future of development.The aim of this work was to tentatively identify anthocyanins from purple sweet potato using HPLC-MS and study the stability and function of anthocyanidin from Purple sweet potato.1. Anthocyanins from five Chinese purple sweet potato varieties were analysed and tentatively identified using HPLC-MS. the anthocyanin content of purple sweet potato 038 extract is the highest, 9.66mg/g.Twelve different anthocyanins were identified from the five varieties. The component of each varieties varies. Moreover, a new component was isolated from purple sweet potato 038 and ji18, respectively. The mass charge ratio (m/z) is 1083. Its structure was tentatively identified as peonidin-3-feruloyl-p-hydroxybenzoylsophoroside-5-glucoside.2. The anthocyanin content and compositions of the purple sweet potato was evaluated by HPLC-MS methods. Results: Each treatment decreased the anthocyanin content. The anthocyanin residual rate of the frying, steaming, and roasting were 93.7%, 87.1%, and 60.0%, respectively. Moreover, the diacylated anthocyanin showed a stronger stability than the acylated ones. The stability of the caffeoyl anthocyanin was stronger than that of the hydroxybenzoyl anthocyanin. Conclusion: The frying and steaming were effective to hold the anthocyanin content of the purple sweet potato.3. Anthocyanin stability of Anthocynins from Purple Sweetpotato was studied at different temperature,pHs,metallic ion and food additive.The result shows that the stability of anthocyanin from purple sweet potato significantly affected by pH value. And its degradation rate is the fastest at pH 6.0 and the lowest at pH 4.0. Low temperature is effective in maintain the stability of anthocyanin from Purple Sweet Potato. Fe³⁺ had no effect on the stability of anthocyanins. K⁺,Ca²⁺,Mg²⁺,Cu²⁺ had enhanced the stability of purple sweetpotato anthocyanins. Glucose had a certain color enhancement function. Potassium sorbate had no effect on the stability of anthocyanins.Hydrogen peroxide were obviously harmful to the stability of purple sweet potato; Vc had a certain color enhancement function, but is harmful to the stability of it.4. In this paper, the antioxidant activities of Anthocynins from purple sweet potato were studied and evaluated by determining the reducing capacity, free radical-scavenging activity on ABTS. The results showed that they had stronger reducing capacity and scavenging effects on ABTS radical. In the range of test concentration, the maximum scavenging was 53.15%. In addition, the protection of anthocyanin of purple sweet potato on DNA were investigated by spectrofluorometric method. Fluorescence integration intensity of DNA and Ethidium Bromide(EB) mixture in the presence of total anthocyanin were determined. The results showed that anthocyanin of purple sweet potato can protect DNA. In addition, The fluorescence intensity of DNA-EB compound was decreased gradually along with the addition of anthocyanin contents of purple sweet potato.