Anthocyanin extracts from purple sweet potato by means of microwave baking and acidified electrolysed water and their antioxidation in vitro

作者：Lu Li Zhen; Zhou Yu Zhen; Zhang Yu Qing^*; Ma Yong Lei; Zhou Li Xia; Li Lin; Zhou Zhen Zhen; He Tian Zhen

来源：International Journal of Food Science and Technology, 2010, 45(7): 1378-1385.

DOI：10.1111/j.1365-2621.2010.02271.x

• Acidified electrolysed water
• antioxidation
• anthocyanins
• ethanol
• extraction
• microwave baking
• purple sweet potato

P>Two anthocyanin extracts from purple sweet potato (PSP) were prepared by means of microwave baking (MB) and acidified electrolysed water (AEW) or 95% ethanol. The extraction yield in AEW (pH 3.0) was up to 35.0% nearly 2.5 times higher than in ethanol. When pH < 3.0, the lower the pH values of the extracts in solution were, the darker the red extracts were. Total flavonoids, phenolic and monomeric anthocyanin contents in AEW extract were 132.13, 64.52 and 102.31 mg g-1, respectively, whose values were the similar to or slightly lower than those in ethanol extract. On the contrary, its total sugar content (61.31 mg g-1) was nearly five times higher than that of the ethanol extract. In vitro assay indicated that the scavenging capability of DPPH free radicals of AEW extracts (IC(50) = 12.0 mu g mL-1) was stronger than that of the ethanolic ones. The reducing power and inhibiting lipid peroxidation of the two extracts were similar. Thus, the new extraction of MB-AEW described here was not only simple and low in cost, but also had much higher extraction yield. The anthocyanin extracts with a strong antioxidation and a stable red colour could be widely used as food colouring additives and anti-ageing health foods.

• 出版日期2010-7
• 单位苏州大学