关键词: 紫山药, 色素, 提取工艺, pH示差法, 抗氧化

Abstract: The extraction technology of pigment from purple yam (Dioscorea alata Linn. .sp.) was studied using orthogonal test design .Yield of total anthocyanins through a orthogonal test with pH differential method as an index were investigated in order to get the optimum extraction technology.Furthermore,the antioxidant activity of anthocyanins was analyzed by DPPH assay .The results showed that the optimal extraction conditions were as follows: temperature 60 ℃, ,extraction duration 80 min, ,the ratio of material to liquid 1:30 ,and the extraction solvent 1.1% HCl ethanol solution and the anthocyanins content arrived 2.075 mg/g in this condition.In addition,the strong DPPH radical scavenging ability (IC50 = 98.14 μg/mL) indicates that purple yam has the potential to be a good functional pigment resource. .

Key words: purple yam, pigment, extraction technology, pH differential method, antioxidant