响应面优化红米原花青素提取工艺

采用响应面法优化红米原花青素的提取条件。以产自哈尔滨延寿县红香米为原料,在单因素实验的基础上,通过响应面实验,得出红米原花青素最佳提取条件为:丙酮浓度76%,温度39℃,料液比1∶25(g/m L),p H5,提取次数2次,时间40 min,原花青素得率是现有文献报道的红米原花青素含量最高的传统斯里兰卡Sudu Heenati红米的1.925倍,为(4.37±0.02)mg/g。红外图谱分析发现红米原花青素纯化物主要是由(表)儿茶素的结构单元构成的原花青定聚合物。清除DPPH自由基实验显示红米原花青素的抗氧化活性强于VC,表明红米原花青素有较强的抗氧化活性,可作为原花青素天然植物来源。 

Optimization of extracting proanthocyandins from red rice by response surface methodology

Response surface methodology was employed to optimize the extraction conditions of proanthocyanidins from red rice grown in Yanshou,Harbin. Based on single experiments,response surface methodology was employed to optimize the extraction conditions of the red rice,the optimum extractive conditions were ascertained as follows: acetone concentration 76%,extraction temperature 39 ℃,material- to- liquid ratio 1 ∶ 25( g / m L),extraction p H5,extraction twice,extraction time 40 min,the yield of proanthocyanidins of this optimized procedure was( 4.37 ± 0.02) mg / g,1.925 times than Sudu Heenati red rice of tradition Sri Lanka which was the highest procyanidins content of red rice reported. The result of infrared spectra showed that the proanthocyanidins of the red rice is mainly composed of structure unit of( epi)- catechin consisting of procyanidin polymers. The proanthocyanidins of red rice have stronger scavenging effects to DPPH radicals than VC,suggesting that the red rice reveals better antioxidant activity,and has the potential to be the source of proanthocyanidins.