响应面法优化复合酶提取芦荟多糖工艺及其抗氧化活性分析

研究复合酶提取芦荟多糖的工艺，并测定其抗氧化性。在单因素试验的基础上，利用响应面法对复合酶提取芦荟多糖的条件进行了优化，通过测定芦荟多糖的总抗氧化能力、DPPH自由基和羟自由基清除能力研究其抗氧化性。结果显示，当料液比1∶30（g/mL）、果胶酶与纤维素酶配比1∶3、pH 4.5时，优化最佳提取条件为加酶量0.3%、酶解温度48 ℃、酶解时间40 min，此条件下芦荟多糖的提取率为5.65%，和超声波辅助法相比提取率提高了4.2%。芦荟多糖具有较好的抗氧化性，随着质量浓度的增加，其总抗氧化能力、DPPH自由基和羟自由基清除能力逐渐增强，在25 mg/mL时其DPPH自由基和羟自由基清除率分别达到75%和90%。复合酶法是一种新的、有效的芦荟多糖提取方法；芦荟多糖具有较好的抗氧化性。

Optimization of Enzymatic Hydrolysis Conditions for the Extraction of Aloe Polysaccharides Using Response Surface Methodology and Assessment of Their Antioxidant Activity

The present study focused on the extraction of aloe polysaccharides by enzymatic hydrolysis using pectinase and
cellulase together, and the antioxidant activity of aloe polysaccharides was also evaluated. The extraction conditions were
optimized using response surface methodology on the basis of single factor experiments, and the antioxidant activity was
assessed by measuring total antioxidant capacity, DPPH and hydroxyl radical scavenging capacity. Results showed that the
optimum extraction process was found to be extraction at 48 ℃ with a total enzyme dosage of 0.3% under the pre-established
conditions: solid-to-liquid ratio, 1:30 (g/mL); ratio of pectinase to cellulase, 1:3; and hydrolysis pH, 4.5. The yield of aloe
polysaccharides under the optimized conditions was 5.65%, an increase of 4.2% over that obtained with ultrasonic-assisted
extraction. The aloe polysaccharides obtained possessed potent antioxidant activity, showing a positive concentrationeffect
relationship for total antioxidant capacity, and DPPH and hydroxyl radical scavenging capacity. The concentration
25 mg/mL scavenged 75% of DPPH free radical and 90% of hydroxyl free radical. To conclude, multienzymatic hydrolysis
can provide a new effective method for the extraction of aloe polysaccharides with good antioxidant activity.