Extraction parameter studies for anthocyanin extraction from purple sweet potato variety TNG₇₃, Ipomoea batatas, L.

摘要

Anthocyanins were successfully extracted from TNG73 purple sweet potatoes (PSP), which were provided by Agricultural Research Institute (ART), Chia-Yi Agricultural Experiment Station, Taiwan. An acidic-ethanol extraction method was used, and the extraction parameters were carefully evaluated. The experimental design and process data for anthocyanin extraction were analyzed by statistical software. The HCl concentration, extraction time, and extraction temperature were significant factors in the extraction of anthocyanins from PSP. Using 15% HCl (1.5 N HCl in ethanol) with a 9 g/100 mL PSP solid/solvent ratio at 25 degrees C for 30 min was adequate for PSP anthocyanin extraction. The extraction performance was increased 15-25% by running a second extraction. Under the same process conditions, the performance was improved about 80% when sonication was applied. The difference caused by the sonication treatment was more significant for the high solid/solvent ratio system. Ultrasound-assisted extraction was a useful tool for PSP anthocyanin extraction. The goals of this study were to collect detailed process data for further process scaling-up and to develop an ultrasound-assisted anthocyanin extraction process.