Ultrasound-Assisted Anthocyanin Extraction of Purple Sweet Potato Variety TNG73, Ipomoea batatas, L

Abstract

The acidic-ethanol anthocyanin extraction process of TNG73 sweet potatoes was improved with introducing the sonication treatment. The linear terms of sonication time and extraction temperature were determined to be significant factors. Response surface methodology (RSM) models were successfully established to perform the extraction study and energy requirement analysis. After calculating the required energy for collected anthocyanins (J/µg), the process with higher extraction temperature became less effective. Based on the combined results of extraction study and energy requirement analysis, the recommended operating condition of anthocyanin extraction process was at 25°C with 22 min sonication.

Keywords:

• anthocyanins
• purple sweet potato
• response surface methodology
• ultrasound

ACKNOWLEDGEMENTS

This research was funded by the Agricultural and Food Agency, Council of Agriculture, Taiwan, No. 99AS-4.2.1-FD-Z2.

Notes

^a (−1.41), (−1), (0), (1), and (1.41) are coded symbols for levels of independent factors.

^b Response values were means of three replicates.

*Significant at p ≦ 0.05.

*Significant at p ≦ 0.05.