冷榨芝麻油与浸出精炼芝麻油品质差异研究

Quality differences of cold-pressed and refined sesame oil

通过对冷榨芝麻油和浸出精炼芝麻油样品的特征指标、质量指标、芝麻素含量、芝麻酚含量、VE含量及氧化诱导时间的测定,分析比较冷榨芝麻油与浸出精炼芝麻油的品质差别。结果表明:冷榨芝麻油与浸出精炼芝麻油在特征指标上的最大差别是不皂化物含量和反式脂肪酸含量,冷榨芝麻油中不皂化物含量约为浸出精炼芝麻油的2.5倍,冷榨芝麻油未检出反式脂肪酸,浸出精炼芝麻油检出反式脂肪酸,其含量为0.88%,其中反式油酸含量0.34%,反式亚油酸含量0.54%;冷榨芝麻油与浸出精炼芝麻油在质量指标上的主要差别是过氧化值,浸出精炼芝麻油的过氧化值高出冷榨芝麻油2倍多,其风味也明显逊色于冷榨芝麻油;冷榨芝麻油中芝麻素、芝麻酚及VE含量都高于浸出精炼芝麻油,冷榨芝麻油中芝麻素含量约是浸出精炼芝麻油的2.14倍,VE含量约是其3.41倍,冷榨芝麻油中芝麻酚含量约为0.2 mg/100 g,浸出精炼芝麻油中未检出芝麻酚;冷榨芝麻油与浸出精炼芝麻油氧化诱导时间差别不大。

The characteristic index, quality index, sesamin content, sesamol content, tocopherol content and oxidation induction time of cold - pressed and refined sesame oil were determined The results showed that the most striking differences in characteristic indexes of cold - pressed and refined sesame oil were unsaponifiable matter content and trans - fatty acid content. The unsaponifiable matter content of cold - pressed sesame oil was 2.5 times as high as that of refined sesame oil. No trans - fatty acid was detected in cold-pressed sesame oil,but there were 0.88% of trans -fatty acids in refined sesame oil including 0.34% of trans - oleic acid and 0.54% of trans - linoleic acid. The main difference in quality index be- tween the two kinds of sesame oils was peroxide value. The peroxide value of refined sesame oil was twice higher than that of cold - pressed sesame oil. Moreover, the flavor of refined sesame oil was less palata- ble. Compared with refined sesame oil, cold - pressed sesame oil contained more sesamin, sesamol and to- copherol. Sesamin content and tocopherol content in cold - pressed sesame oil were 2.14 times and 3.41 times as high as that in refined sesame oil respectively, and sesamol content in cold -pressed sesame oil was 0.2 mg/100 g. Sesamol was not detected in refined sesame oil. The oxidation induction time of cold - pressed and refined sesame oil had no significant difference.