索氏抽提法制备裂果枣红色素及其理化性质分析

Preparation of Red Pigment from Cracked Jujube by Soxhlet Extraction Method and Its Physicochemical Properties

以裂果枣粉为原料,采用索氏抽提法对裂果枣红色素进行提取,分别采用单因素试验和响应面试验进行提取条件的优化,并对裂果红枣色素进行理化性质研究(抗氧化活性及色素稳定性)。结果表明:索氏抽提法提取最佳条件为裂果枣粉添加量2.0 g/100 mL、乙醇体积分数69%、加热温度89℃、浸提时间26 min、抽提时间1.5 h,裂果枣红色素提取率4.540 mg/g,裂果枣红色素提取率较高。通过研究裂果枣红色素对DPPH自由基,·NO_(2)^(-)和ABTS+自由基的清除能力,结果显示裂果枣红色素浓度达到1.2 mg/mL时,DPPH自由基清除率可达67.8%,当裂果枣红色素浓度达到2.0 mg/mL时,NO_(2)^(-)清除率为69.4%,当裂果枣红色素浓度达到1.5 mg/mL时,ABTS^(+)自由基清除率达到63.5%。裂果枣红色素稳定性试验结果表明,索氏抽提法提取的裂果枣红色素具有良好的热稳定性,光照对其稳定性有一定的影响,pH值对裂果枣红色素稳定性的影响较大。

The red pigment in cracked jujube was extracted by Soxhlet extraction method with cracked jujube powder as the raw material.Single factor test and response surface test were used to optimize the extraction process conditions,respectively,and the physicochemical properties(antioxidant activity and pigment stability)of the red pigment in cracked jujube were studied.The results showed that the optimal extraction conditions of Soxhlet extraction method were as follows:the addition amount of cracked jujube powder was 2.0 g/100 mL;the volume fraction of ethanol was 69.00%;the heating temperature was 89℃;the leaching time was 26 min;the extraction time was 1.5 h;and the extraction rate of red pigment in cracked jujube was the highest(4.540 mg/g).Free radical scavenging activities of red pigment in cracked jujube on DPPH·,NO_(2)^(-)and ABTS^(+)·were studied,the results showed that when the concentration of red pigment in cracked jujube reached 1.2 mg/mL,the DPPH free radical scavenging rate could reach 67.8%;when the concentration of red pigment in cracked jujube reached 2.00 mg/mL,the NO_(2)^(-)scavenging rate was 69.4%;when the concentration of red pigment in cracked jujube reached 1.5 mg/mL,the ABTS+free radical scavenging rate reached 63.5%.The stability test of red pigment in cracked jujube showed that the red pigment extracted from cracked jujube by Soxhlet extraction had good thermal stability,light had a certain influence on its stability,and pH had a greater influence on the stability of red pigment.