辣椒油中酸价测定方法的探讨分析

目的:本文运用不同前处理方法进行比较,解决国家标准方法1]测定辣椒油中的酸价时,由于辣椒油中的色素存在而影响滴定终点的判断问题。方法:利用添加适量中性饱和食盐水及用活性碳吸附两种方法前处理后再按照国标法测定酸价,其结果与准确度和精密度都较高的自动电位滴定法相比较。结果:用添加中性饱和食盐水法和活性碳吸附法都可以清晰观察到滴定终点;辣椒油试样量在3~4 g,用添加中性饱和食盐水法与自动电位滴定法结果无统计学差异,结果准确;活性碳吸附法测定低浓度酸价的油脂相对偏差较大,高浓度的与自动电位滴定法无统计学差异。结论:对于深色油脂如辣椒油中的酸价首选自动电位滴定法,如没有自动电位滴定仪的基层单位,低浓度的可以用添加中性饱和食盐水方法,中、高浓度的可以用活性碳吸附法和添加中性饱和食盐水方法,两种方法都可以清晰地观察到滴定终点,结果精密度都较好,准确度较高。可以作为国标法中测定辣椒油中酸价的有效补充。

Discussion and analysis of methods for determination of acid value in hot chili oil

Objective:The article compared different pretreatment methods in determination of the acid value in hot chili oil to remove the influence in the end point of the titration as the existing of pigment.Methods:Pretreatment the sample though adding neutral saturated salt water and adsorbing by carbon respectively,then determined the acid value as the GB,compared the results to method of automatic potentiometric titration which have a higher accuracy class.Results:With the sample at 3.0~4.0 g,both of the two res...