Optimization of ultrasound-assisted extraction of anthocyanins from lowbush blueberries (Vaccinium Angustifolium Aiton)

Abstract

BACKGROUND: A considerable body of evidence has associated the consumption of blueberries to health-related benefits, mainly because of their anthocyanin content. The extraction of these compounds could contribute to their application in functional foods and value-added products. OBJECTIVE: In this study, we investigated the ultrasound-assisted extraction (UAE) of anthocyanins from lowbush blueberries in a bench-scale system. METHODS:Two statistical design methods, namely full factorial and Box-Behnken, were used for the screening and optimization of the variables that significantly affect the UAE of anthocyanins. Extraction temperature, time, solvent concentration (acidified ethanol), and solvent to solid ratio were selected to determine higher anthocyanin extraction (assessed by the pH-differential method). RESULTS: When evaluated by response surface methodology, solvent to solid ratio and solvent concentration had a significant effect onUAE followed by ultrasound bath temperature. The mathematical model indicated that the highest anthocyanin extraction would be obtained with 60% acidified ethanol, solvent to solid ratio of 50 mL/g, at 65°C for 11.5 min. CONCLUSION: Ultrasound-assisted extraction was shown to be an effective method of extracting total anthocyanins from Nova Scotia lowbush blueberries. A statistical model to predict optimum conditions for extraction was developed using a Box Behnken design.