Study On Extraction, Purification And Antioxidation Of Anthocyanins From Chinese Bayberry

Chinese bayberry is a specialty fruit of our country, the cultivation area is more than 99% of the world. People like it very much because of its unique flavor and various necessary nutrients for human body. But the mature season of Chinese bayberry is during June to July, when it is high temperature and rainy in south China, Chinese bayberry is perishable after harvest because of no skin. Therefore it is a great significance to research on processing. In this paper, we used "DONGKUI" bayberry as the test materials, using "Australia heat pump dehydration technology" to dry fresh bayberry, and it is effective to save the materials. Based this, we study the extraction, purification, antioxidation and inhibition activity of anthocyanins from bayberry to provide the basis to comprehensive utilization of bayberry. The main conclusions as follows:1. After 18h’s dehydration with Australia heat pump, the conservation rates of anthocyanins, flavonoids and polyphenols are 92.4%,96.1%,92.6%, and after 6 months’storage of dried bayberry at-18℃, the loss rates of anthocyanins, flavonoids and polyphenols are 33.3%,20.9%,42.9%.2. Using the ultrasonic wave to assist the extraction of anthocyainis from bayberry, and the optimal extraction conditions are extraction with 50% ethanol(pH=3)at 50℃ and at the ratio of material to liquid 1:50. After 20 minutes the anthocyanins extraction is 424.68 mg/100g, and the extraction rate of anthocyainis from bayberry is 96.2%.3. Analysis of the frequency of the experimental data with the extraction rates over 384.80 mg/100g showed industrial production parameters should be the ratios of material to liquid 1:43.68～1:47.26; extracting time 18.39～19.93 mins; pH:3.23～ 3.67; extracting temperature 51.76～53.91℃.4. The purification of anthocyanins was studied with four resins (AB-8, X-5, S-8, LSA-21). The results showed that LSA-21 is the best. After the resin adsorption saturation, dynamic elution with 70% ethanol, rotary evaporation and freeze drying, the anthocyanins content of the product is 218.4 mg/g, and the color value is 37.2, and no As, Hg checked out.5. The results in studying the antioxidation of bay berry anthocyanins showed that: bayberry anthocyanins have strong antioxidant capacity, the TAC value is 5.195 mmol/g, higher than the Vc (2.846 mmol/g). Its IC50 of hydroxyl radical, DPPH radical, superoxide anion are 0.164 mg/mL,0.092 mg/mL,0.22 mg/mL, and it can scavenge these free radicals effectively.6. Preliminary study on the inhibition activity of bayberry anthocyanins against Staphylococcus aureus, Salmonella typhimurium, E.coli and Salmonella enteritidis, showed that:with the increase of concentration of anthocyanins, the inhibition activity is improved obviously. The MIC are respectively 6.25 mg/mL,12.5 mg/mL,6.25 mg/mL,12.5 mg/mL. Adding MIC of anthocyanins to E.coli culture medium, the colony growth was affected significantly, and in decline phase after 10 h.