预处理方法对盐效应辅助水剂法提取山桐子油的影响Effect of pretreatment method on salt-assisted aqueous extraction of Idesia polycarpa oil

为了寻找一种高效提取山桐子油的方法，拓展山桐子油的应用范围，分别采用微波和高压对山桐子进行预处理后采用盐效应辅助水剂法提取其中的油脂。探究液固比、NaCl质量浓度、提取温度、微波功率和微波时间、高压温度和高压时间对山桐子油提取率的影响；以有机溶剂提取法作为参照，研究微波和高压预处理对盐效应辅助水剂法山桐子油提取率、理化性质、色泽及DPPH自由基清除率的影响。结果表明：微波协同盐效应辅助水剂法在微波功率420 W、微波时间90 s、液固比1.2∶ 1、NaCl质量浓度0.15 g/mL和提取温度50 ℃时对山桐子油提取效果最好，山桐子油提取率为87.07%，比高压协同盐效应辅助水剂法（高压温度110 ℃和高压时间5 min）高2.86%；与高压预处理相比，微波预处理的山桐子油具有更高的DPPH自由基清除率（83.03%）和更低的酸值（KOH）（10.73 mg/g），但这两种方法提取的山桐子油的脂肪酸组成和过氧化值均无显著差异；与有机溶剂提取法相比，盐效应辅助水剂法山桐子油提取率降低，但具有更高的DPPH自由基清除率和更低的硫代巴比妥酸值，且透明度更高，红色更浅。综上，微波协同盐效应辅助水剂法可以有效提取山桐子油，提取率较高且油脂品质良好，可用于高品质山桐子油的生产。In order to explore an efficient method for extracting Idesia polycarpa oil for expanding the application of Idesia polycarpa oil, the Idesia polycarpa was pretreated by microwave or high-pressure, followed by salt-aqueous extraction of oil. The effects of liquid-solid ratio, NaCl mass concentration, extraction temperature, microwave pretreatment (power and time), and high-pressure pretreatment (temperature and time) on the extraction rate of Idesia polycarpa oil were investigated. Furthermore, using organic solvent extraction method as reference, the influence of microwave and high-pressure pretreatment on the extraction rate, physicochemical properties, color and DPPH radical scavenging rate of Idesia polycarpa oil extracted by salt -assisted aqueous method were studied.The results showed that the optimal conditions for the extraction of Idesia polycarpa oil by microwave pretreatment synergistic salt-assisted aqueous extraction method were microwave power 420 W, microwave time 90 s, liquid-solid ratio 1.2∶ 1, NaCl mass concentration 0.15 g/mL, and extraction temperature 50 ℃. The oil extraction rate of microwave pretreatment synergistic salt-assisted aqueous extraction method was 87.07%, which was 2.86% higher than that of high-pressure pretreatment synergistic salt-assisted aqueous extraction method with the temperature 110 ℃ and time 5 min. The microwave pretreatment synergistic salt-assisted aqueous extraction method resulted in relatively higher DPPH radical scavenging rate (83.03%) and lower acid value (10.73 mgKOH/g) of Idesia polycarpa oil compared with the high-pressure pretreatment method. There was no significant difference in fatty acid composition and peroxide value of Idesia polycarpa oil extracted by the two methods. In addition, the oil extraction rate of salt-assisted aqueous extraction method was lower than that of organic solvent extraction method,but had higher DPPH radical scavenging rate, lower thiobarbituric acid value, higher transparency and lighter red color of Idesia polycarpa oil. To sum up,microwave pretreatment synergistic salt-assisted aqueous method can effectively extract Idesia polycarpa oil, with high oil extraction rate and good oil quality, which can be used in the production of high quality Idesia polycarpa oil.