動、植物油脂中游離態固醇類之快速氣相層析分析   全文下載

A Rapid Gas Chromatographic Method for Direct Determination of Free Sterols in Animal and Vegetable Fats and Oils

本研究建立了動、植物油脂中游離態固醇類之簡便、快速分析定量法。0.1 g之油脂樣品以1 mL 0.2% 之5α-cholestane正已烷／丙酮混合溶液（1／1, v／v）溶解後，即可直接注入氣相層析儀分析之，使用廣口徑、非極性之DB-1短管柱（0.53 mm × 5.0 m, 1μm）。添加回收實驗中，cholesterol、campesterol、stigmasterol及β-sitosterol之回收率為89-106%，變異係數小於12%。經皂化後，油脂中的總固醇類含量亦可以本法分析定量之。以本方法測定14種動、植物油脂，包括橄欖油、葵花油、花生油、大豆沙拉油、芝麻油、豬油及蛋黃油等之總固醇類及游離固醇類含量。結果顯示，總cholesterol （含α-tocophenol）、brassicasterol、campesterol、stigmasterol、β-sitosterol 、Δ5-avenasterol、Δ7-stigmasterol及Δ7-avenasterol含量分別依序為：193-34384、0-1222、0-2356、0-1365、0-5414、0-608、0-1296及0-129μg／g；而游離態cholesterol （含α-tocophenol）、brassicasterol、campesterol、stigmasterol、β-sitosterol、Δ5-avenasterol、Δ7-stigmasterol及Δ7-avenasterol含量分別依序為：98-30340、0-1057、0-634、0-724、0-3087、0-404、0-558及0-23μg／g；另外，酯化態之固醇類則可以總固醇類與游離固醇類含量之差值計算得之。結果顯示，橄欖油、葵花油及花生油中之固醇類主要以酯化態方式存在；而大豆沙拉油、芝麻油、豬油及蛋黃油則主要以游離態固醇類存在。本研究方法可作為動物油脂是否摻有植物油之簡便檢測方法。"

In this study, a rapid and simple method without a derivatization process for determination of the free sterols in vegetable and animal oils was developed. A direct injection gas chromatography with a non-polar megabore column (DB-1, 5 m x 0.53 mm, 1μm) was used. The recoveries of cholesterol, campesterol, stigmasterol and -sitosterol from lard were at the range of 89%-106% with a coefficient of variation less than 12%. Total sterols were determined using the same method after saponification of the oil sample. Fourteen samples, including olive oil, sunflower oil, peanut oil, soybean oil, sesame oil, lard and egg yolk oil, were quantitatively analyzed for total and free sterols. The contents of total cholesterol, brassicasterol, campesterol, stigmasterol, -sitosterol, 5-avenasterol, 7-stigmastenol and 7-avenasterol in test samples were at the range of 193-34384, 0-1222, 0-2356, 0-1365, 0-5414, 0-608, 0-1296 and 0-129 μg/g, respectively; while the contents of free cholesterol, brassicasterol, campesterol, stigmasterol, -sitosterol, 5-avenasterol, 7-stigmastenol and 7-avenasterol were 98-30340, 0- 1057, 0-634, 0-724, 0-3087, 0-404, 0-558 and 0-23 μg/g, respectively. The amounts of esterified sterols were calculated by subtracting the free sterol contents from total sterol contents. Results showed olive oil, sunflower oil and peanut oil primarily contain esterified sterols; while soybean oil, sesame oil, lard and egg oil contain mostly free sterols. The developed method is recommended as a rapid method to determine if animal fats/oils are adulterated with vegetable oils. 本研究建立了動、植物油脂中游離態固醇類之簡便、快速分析定量法。0.1 g之油脂樣品以1 mL 0.2% 之5α-cholestane正已烷／丙酮混合溶液（1／1, v／v）溶解後，即可直接注入氣相層析儀分析之，使用廣口徑、非極性之DB-1短管柱（0.53 mm × 5.0 m, 1μm）。添加回收實驗中，cholesterol、campesterol、stigmasterol及β-sitosterol之回收率為89-106%，變異係數小於12%。經皂化後，油脂中的總固醇類含量亦可以本法分析定量之。以本方法測定14種動、植物油脂，包括橄欖油、葵花油、花生油、大豆沙拉油、芝麻油、豬油及蛋黃油等之總固醇類及游離固醇類含量。結果顯示，總cholesterol （含α-tocophenol）、brassicasterol、campesterol、stigmasterol、β-sitosterol 、Δ5-avenasterol、Δ7-stigmasterol及Δ7-avenasterol含量分別依序為：193-34384、0-1222、0-2356、0-1365、0-5414、0-608、0-1296及0-129μg／g；而游離態cholesterol （含α-tocophenol）、brassicasterol、campesterol、stigmasterol、β-sitosterol、Δ5-avenasterol、Δ7-stigmasterol及Δ7-avenasterol含量分別依序為：98-30340、0-1057、0-634、0-724、0-3087、0-404、0-558及0-23μg／g；另外，酯化態之固醇類則可以總固醇類與游離固醇類含量之差值計算得之。結果顯示，橄欖油、葵花油及花生油中之固醇類主要以酯化態方式存在；而大豆沙拉油、芝麻油、豬油及蛋黃油則主要以游離態固醇類存在。本研究方法可作為動物油脂是否摻有植物油之簡便檢測方法。