Study On Extraction And Copigmentation Of Anthocyanins From Blackberry

Different extraction methods of anthocyanins in blackberry puree were compared, then the resulted most appropriate method, namely, citric acid-ethanol combination was optimized in this paper. The effects of ferulic acid, caffeic acid and chlorogenic acid on visible absorption spectrum and components of blackberry anthocyanin was studied in blackberry juice and model wine system. And then effects of caffeic acid on colour and anthocyanins compositions of blackberry wine were investigated. The ultimate goal was to research methods and mechanism for increasing stability of blackberry anthocyanins in food system and to provide basement for the application of blackberry anthocyanins. The main results and findings were as follows:1、Citric acid-ethanol combination was the best of the selected methods for anthocyanins extraction of blackberry puree. The optimization of extraction parameters were conducted using response surface methodology with Box-Behnken design. The obtained optimum conditions are ratio of material to liquid1:4.4(g/mL), temperature35.4℃, ethanol concentration42.8%, and process duration1h.2、Four peaks were detected in blackberry anthocyanins by HPLC nalysis and the first peak accounted for75.1%of the total anthocyanins. The result of MS analysis indicated the first peak was cyanidin-3-glucoside.3、Ferulic acid, caffeic acid and chlorogenic acid produced hyperchromic effect (△Amax) and bathochromic effect (△λmax) on anthocynins in model wine system and blackberry juice, namely, copigmentation effect. The needed time was more than60days for ferulic acid copigmentation in model wine system and caffeic acid copigmentation, while that was about2h for chlorogenic acid copigmentation, which was an exothermic reaction. The blackberry juice added with200mg/L ferulic acid showed more intense red colour than that without ferulic acid after storage of5months. The anthocyanins in blackberry juice copigmentated with chlorogenic acid showed the better thermal stability than before.4、Chlorogenic acid copigmentation can’t produce anthocyanins derivants. Ferulic acid copigmentation in model wine system and caffeic acid copigmentation began to generate anthocyanins derivants at60th day. Meanwhile, lots of anthocyanins derivants were detected in blackberry juice with100mg/L ferulic acid. The obtained anthocyanins derivants were Cyanidin-3-glucoside-vinylguaiacol, Cyanidin-3-dioxalylglucoside-vinylguaiacol,Cyanidin-3-glucoside-arabinoside-vinylguaiac ol for ferulic acid copigmentation and Cyanidin-3-glucoside-vinylcatechol, Cyanidin-3-dioxalylglucoside-vinylcatechol for caffeic acid copigmentation.5、The colour changed from bright red into dark red with degradation of anthocyanins components and no obvious trends in the colour were observed during aging of blackberry wine. Caffeic acid produced copigmentation effect shown by increseasing maximum abosorbance of anthocyanins by13.51%～19.19%in the visible range on anthocyanins in blackberry wine, and but had no influence on CIELab values of blackberry wine. No significant difference was found in copigmentation effect between100mg/L and200mg/L caffeic acid, nor between caffeic acid addition before fermentation and after menentation.6、Two kinds of anthocyanins derivants, which can be speculated to be Cyanidin-3-glucoside-vinylcatechol and Cyanidin-3-dioxalylglucoside-vinylcatechol by comparative HPLC analysis appeared at120th day during aging of blackberry wine and reached their maximum at180th day of aging, while no anthocyanins derivants were found in blackberry wine control of aging of10months.