Abstract: Effects of five homogenization conditions for extracting total anthocyanin from blueberry fruits such as pH of extraction solvent (acidic ethanol solution), ethanol concentration, material/liquid ratio, and homogenization time and number on total anthocyanin yield and 2,2-azinobis-(3-ethylbenzthiazoline-6-sulfonate (ABTS) radical scavenging capacity of blueberry fruits extract examined by Trolox equivalent antioxidant capacity (TEAC) assay were evaluated by single-factor method. Based on this, three main affecting factors (pH of acidic ethanol solution, ethanol concentration and material/liquid ratio) were screened by Plackett-Burman (PB) design and then optimized by Box-Behnken experimental design and response surface methodology (RSM). The optimum conditions for extracting total anthocyanin from blueberry fruits were determined as follows: using acidic 75% ethanol solution at pH 2.5 as an extraction solvent for once homogenization for 20 s at a material/liquid ratio of 1:17 (g/ml). Under these conditions, the average extraction yield of total anthocyanin was 1.132% and the capacity to scavenge ABTS radicals 416.8 g/ml.

Key words: blueberry, total anthocyanin, homogenization extraction, response surface methodology (RSM), antioxidation