冷榨与热榨亚麻饼粕木酚素提取工艺优化及抗氧化性能比较

Optimization of extraction process of SDG from cold pressed and hot pressed flaxseed cake and comparison of antioxidative activity

研究冷榨与热榨亚麻饼粕中亚麻木酚素提取工艺及抗氧化活性。在单因素实验基础上,采用响应面法探讨了超声温度、超声处理时间、料液比3个因素对亚麻木酚素提取效果的影响。确定了超声波辅助提取的最佳工艺参数为超声温度50℃、超声处理时间22 min、料液比1:25 g/m L,在此条件下热榨饼粕中木酚素得率为9.85 mg/g,冷榨饼粕中木酚素得率为7.74 mg/g。此外,以抗坏血酸为对照,采用清除DPPH自由基、超氧阴离子、羟基自由基的方法来评价木酚素粗提物的抗氧化性能。结果表明:亚麻饼粕木酚素具有较好的清除DPPH自由基、超氧阴离子自由基和羟基自由基的能力。其中清除羟基自由基能力最强,与抗坏血酸接近,其中冷榨亚麻饼粕木酚素清除羟基自由基的EC_(50)值为1.13 mg/m L、热榨亚麻饼粕木酚素清除羟基自由基的EC_(50)值为0.98 mg/m L。相同浓度下,热榨亚麻饼粕木酚素的抗氧化能力高于冷榨,但是差异不显著(p>0.05)。

The extraction process and antioxidant activity of SDG from cold and hot pressed flaxseed cake were studied. To explore the effects of different ultrasonic temperature, solid-liquid ratio, ultrasonic time on the yield of SDG, the response surface methodology was used. The optimum condition for extracting SDG from flaxseed cake was obtained as follows： ultrasonic temperature 50 ℃, ultrasonic time 22 min, solid-liquid ratio 1：25 g/m L. Under these conditions, the average extraction yields from cold and hot pressed flaxseed cake were 7.74 mg/g and 9.85 mg/g. The antioxidative capacity of SDG from cold and hot pressed flaxseed cake were assayed with Vc as control, DPPH, O_2~– and OH-removal ability as the index. As the results, the extraction from cold and hot pressed flaxseed cake showed strong capability of eliminating DPPH, O_2~– and OH-. The scavenging OH-was the strongest and similar to Vc. IC_（50） of SDG from hot pressed flaxseed cake was 0.98 mg/m L, the IC_（50） of SDG from cold pressed flaxseed cake was 1.13 mg/m L. The antioxidant activity of SDG from hot pressed flaxseed cake was higher than the cold pressed flaxseed cake at the same concentration, but it had not significant difference（p0.05）.