尿素包合法富集纯化马齿苋中多不饱和脂肪酸的工艺优化

Optimization of enrichment and purification of polyunsaturated fatty acids in Portulaca oleracea by urea inclusion method

中文关键词:  尿素包合法  新鲜马齿苋全草  高效液相色谱法  多不饱和脂肪酸  理化性质

英文关键词:urea inclusion method  whole grass of fresh Portulaca oleracea  high performance liquid chromatography  polyunsaturated fatty acids  physicochemical property

中文摘要:

      目的 优化尿素包合法富集纯化马齿苋中的多不饱和脂肪酸的工艺条件。方法 将新鲜马齿苋经索氏提取后所得的脂肪油通过尿素包合的方式富集纯化多不饱和脂肪酸(polyunsaturated fatty acids, PUFAs), 并以PUFAs总含量为考察指标, 利用高效液相色谱法测定其含量。在单因素实验的基础上采用响应曲面设计对纯化工艺进行优化, 对比新鲜马齿苋全草油与纯化物PUFAs理化性质上的区别。结果 尿素包合法富集纯化的最佳工艺为: 尿素与乙醇体积比1:10 (V:V), 尿素与脂肪酸质量比12:1 (m:m), 结晶温度?20 ℃, 此时PUFAs含量预测值为110.76 mg/g, 实际值为116.00 mg/g。就理化性质相比较而言, 纯化物PUFAs的酸值无显著差异, 碘值和过氧化值显著提高, 皂化值显著降低(P<0.05), 表明纯化物PUFAs的不饱和度更高, 基本达到本实验的目的。结论 该富集纯化工艺操作简单、方便快捷, 适合分离纯化马齿苋脂肪酸类物质, 可为马齿苋多不饱和脂肪酸向功能食品方向发展提供参考。

英文摘要:

      Objective To optimize the process conditions of enrichment and purification of polyunsaturated fatty acids in Portulaca oleracea by urea inclusion method. Methods Polyunsaturated fatty acids were enriched and purified by urea inclusion from the fat oil, which obtained from the extraction of fresh Portulaca oleracea by Soxhlet. Taking the total content of polyunsaturated fatty acids (PUFAs) as an index, its content was determined by high performance liquid chromatography. On the basis of single factor experiment, the purification process was optimized by response surface design, and the differences of physicochemical properties between fresh Portulaca oleracea whole grass oil and purified PUFAs were compared. Results The optimal enrichment and purification process of urea inclusion method was as follows: The volume ratio of urea to ethanol was 1:10 (V:V), the mass ratio of urea to fatty acid was 12:1 (m:m), and the crystallization temperature was -20 °C, on which condition, the predicted PUFAs content was 110.76 mg/g, and the actual value was 116.00 mg/g. In terms of physical and chemical properties, there was no significant difference in the acid value of the purified PUFAs. The iodine value and peroxide value increased significantly, and the saponification value decreased significantly (P<0.05), indicating that the unsaturated degree of the purified PUFAs was higher, which basically reached the purpose of this experiment. Conclusion The enrichment and purification process is simple, convenient and suitable for the separation and purification of fatty acids in Portulaca oleracea, which can provide reference for the development of polyunsaturated fatty acids in Portulaca oleracea to functional foods.