两种方法测定有色油脂脂肪酸价的探讨  

DETERMINATION OF FATTY ACID VALUE OF COLORED OIL WITH TWO METHODS

作　　者：王平东 徐宗季 袁华山 胡庆燕 宋加良 Wang Pingdong;Xu Zongji;Yuan Huashan;Hu Qingyan;Song Jialiang(Nanjing Sinograin grain and Oil Quality Supervision Center Co.,Ltd,211151)

机构地区：[1]南京中储粮粮油质监中心有限公司,211151

出　　处：《粮食储藏》2020年第6期47-50,共4页Grain Storage

摘　　要：研究了花生油、大豆油、芝麻油、大豆色拉油、花生色拉油食用油脂肪酸价的国标滴定法和双液相滴定法的不同,并作比较。向待测样品中加入乙醚:乙醇(2∶1)混合液50 mL(国标法)或石油醚25 mL+75 mL 50%乙醇混合溶液(双液相法),以酚酞为指示剂,以KOH为标准溶液滴定至下层溶液呈微红色,由于油脂的黄色色素不溶于水相,故在双液相法中不会干扰终点判断。试验结果表明:与国标法相比,双液相法的精密度和选择性更强,滴定终点的变化更加敏锐。The national standard and two liquid phase method were campared for testing fatty acid value in peanut oil,soybean oil,sesame oil,soybean salad oil,peanut salad oil.The 50 mL mixed liquid combined with ether and alcohol by 2∶1(the national standard),the mixed liquid combined with 25 mL petroleum ether+75 mL 50%content ether were added seperately to samples,take the phenolphtalein as indicate,take KOH as the standard liquid to titrate to the bottom layer to tiny red.Due to the yellow pigment of the oil does not be dissolve in the water,it’s can’t interfere terminal point judyment with two liquid phase.The result showed that two liquid phase method has better precison,and sensitivity to judge terminal ponit selectivity that the national standard.

关 键 词：有色油脂 油脂脂肪酸价 滴定法测定油脂脂肪酸价 国标法 双液相法 

分 类 号：TS227[轻工技术与工程—粮食、油脂及植物蛋白工程]