Studies On The Extraction And Purification, Component Analysis And Properties Of Anthocyanin From Purple Eggplant-peel

Anthocyanin was a plant polyphenols, which was an anthocyanin compound with a sugar and a glycosidic bond. It was widely distributed in nature and many flowers, fruits and vegetables coloring substances. Currently, the food industry were mostly multi-use synthetic colors had different degrees of toxicity. People long-term used it would endanger human health, so the natural pigment attracted the attention of a growing number of research areas. Anthocyanin pigments not only had good coloring ability, but also had some health functions, such as antioxidant, inhibiting tumor, prevention of cardiovascular disease and so on. In recent years, anthocyanin has become a hot research. In this study, purple eggplant-peels were used as raw materials for the research of extraction and purification, component analysis, stability and antioxidant activity. The main results were as follows:1. Anthocyanin extracted with an organic solvent and optimized by single factor experiment and response surface methodology to get purple eggplant-peel anthocyanin optimum extraction conditions:extraction temperature 38℃, solid-liquid ratio 19:1mL/g, extraction time 95min. Under this condition, the effect of anthocyanins extraction A525V/m (V:extract dosage, m:sample mass) is 12.752, and which with the theoretical prediction value of 12.876 was differ 0.124.2. Screening of macroporous resin for the purification of anthocyanin from purple eggplant-peel and performed static and dynamic process conditions to optimize adsorption and desorption. Experimental results showed that:in the tested four kinds of resin, AB-8 macroporous resin was the best purified anthocyanins optimum adsorbent resin for purple eggplant-peel. Experimental studies had shown that purple eggplant-peel anthocyanin around 6h that can reach adsorption equilibrium on this static adsorption resin. Optimum pH of the sample was 3.0, the optimum concentration of ethanol was 80%, the best of eluent pH was 3.0. Experimental study on dynamic showed that:the dynamic liquid sample flow rate of 3mL/min was the best one, and under the sample concentration of 0.8mg/mL and dynamic desorption flow rates of 4mL/min was the best of dynamic adsorption and desorption. At last purple eggplant-peel color price purified anthocyanins was 68.9, which unpurified color value than 9.4 times.3. Experiments used UPLC-ESI-MS combined with techniques to speculate purple eggplant-peel anthocyanin component which analyzed 12 major anthocyanins. They were Cyanidin, Delphinidin, Malvidin, Cyanidin-3-glucoside, Malvidin-3-arabinoside, Delphinium-3-glucoside, Malvidin-3-glucoside, Cyanidin-3-rhamnosides, Delphinium-3-α-rhamnosides-5-β-glucoside, Delphinium-3,5-glucoside, Malvidin-3-α-rhamnosides-5-β-glucoside, Cyanidin-3-sophoroside-5-glucoside.4. Experimental studied of temperature, light, oxidizing agents, reducing agents, preservatives, metal ions, sugars and salt, organic acids on purple eggplant-peel anthocyanin stability. The results showed that:hypothermia could significantly maintain the stability of purple eggplant-peel anthocyanin and save purple eggplant-peel anthocyanin should be indoors and dark conditions to avoid outdoor and UV irradiation. H2O2、Na2SO3 had a damaging effect on eggplant-peel anthocyanin. Potassium sorbate and sodium benzoate had no significant effect on the stability of anthocyanin. There were many differences in the effects of metal ions, such as Fe3+ had obvious influence on the stability of anthocyanin; Ca2+, Cu2+, Zn2+, Al3+ made the absorbance of anthocyanins increased, with hyperchromic effect, they also could increase the stability of anthocyanin from purple eggplant-peel; Mg+ and K+ had little effect on the stability of anthocyanin; Sucrose, maltose oligosaccharide, salt and Vc had hyperchromic effect; High concentrations of Vc had larger impact on the purple eggplant-peel anthocyanin stability. Organic acid had a hyperchromic effect on purple eggplant anthocyanins, and with the increase of concentration, hyperchromic effected enhancement.5. Experimental results showed that the antioxidant ability of purple eggplant-peel color in the total reducing capacity, DPPH radical scavenging, hydroxyl radical, ABTS+ free radical scavenging and superoxide anion radical scavenging showed strong activity. And as the sample concentration increased the antioxidant activity of purple eggplant-peel anthocyanins had been enhanced, showed a good dose effect relationship, but lower than that of ascorbic acid in control group.