本文選題：植物油 + 脂肪酸�。� 參考：《湖南農(nóng)業(yè)大學(xué)》2013年碩士論文

【摘要】：不同油種具有不同脂肪酸組分及含量,油脂經(jīng)過加熱之后,其脂肪酸組分和含量也會發(fā)生巨大變化。脂肪酸是評價食用油品質(zhì)的重要指標之一,其組成、含量和比例在很大程度上決定了食用油的營養(yǎng)價值。本試驗通過比較不同升溫程序和氣體流速等色譜參數(shù)條件下脂肪酸甲酯混合標準品以及反式脂肪酸甲酯標準品的分離情況,優(yōu)化分離效果的色譜參數(shù)。在氣相色譜條件優(yōu)化的前提下,從我國10個地區(qū)以及網(wǎng)上商城采集了11個品種共計141個樣品的植物油,利用氣相色譜法檢測各植物油的脂肪酸組分,分析我國代表性植物油的脂肪酸特點,并且選擇富含n-6脂肪酸的玉米油,富含n-9脂肪酸的茶油,富含n-3脂肪酸的亞麻籽油進行加熱試驗。得到以下結(jié)果： 1.選用CP-sil88毛細管氣相色譜柱(100mx0.25mm id×0.2μm),進樣口和檢測器溫度分別為250℃,260℃；流速和柱流速分別為68.8ml/min,0.65ml/min;線速率為14.3cm/s；吹掃流量為3.0ml/min;分流比為100：1；進樣量為1ul時,可使各脂肪酸組分達到基線分離。該方法的精密度試驗和加標回收率結(jié)果良好,適合植物油的脂肪酸檢測尤其是反式脂肪酸的檢測。 2.食用植物油中花生油的飽和脂肪酸含量最高,為18.54g/100g；菜籽油和核桃油的飽和脂肪酸含量均低于其他植物油種,低于8g/100g。茶油和橄欖油富含單不飽和脂肪酸,分別為78.02g/100g和73.88g/100g；核桃油單不飽和脂肪酸含量最低,為7.70g/100g。核桃油和亞麻籽油富含多不飽和脂肪酸,含量分別為68.38g/100g、64.37g/100g。核桃油中多不飽和脂肪酸主要為n-6脂肪酸,含量為59.56g/100g；亞麻籽油中多不飽和脂肪酸主要為n-3脂肪酸,含量為47.90g/100g。市售桶裝植物油中,橄欖油不含反式脂肪酸,其他植物油中都含有微量的反式脂肪酸。不同種類植物油各脂肪酸比例存在較大差異,采集的植物油中飽和脂肪酸/單不飽和脂肪酸/多不飽和脂肪酸的比值范圍為1：1.5～8.6：0.5～8.9,n-6/n-3的比值范圍為0.3～317.1：1。 3.低溫以及短時間的加熱對植物油的影響比較小,高溫、長時間的加熱會明顯影響植物油的脂肪酸組分和含量。在同一加熱溫度下,隨著加熱時間的延長,三種試驗油的各脂肪酸與時間均具有相關(guān)性。與未加熱試驗油相比,隨著加熱時間的延長以及加熱溫度的升高,加熱后試驗油的過氧化值,茴香胺值和總氧化值均出現(xiàn)明顯增加。
[Abstract]:Different kinds of oil have different fatty acid composition and content. After heating, the fatty acid composition and content of oil will change greatly. Fatty acid is one of the important indexes to evaluate the quality of edible oil. Its composition, content and proportion determine the nutritive value of edible oil to a great extent. The chromatographic parameters of separation effect were optimized by comparing the separation of mixed standard and trans fatty acid methyl ester under different temperature program and gas flow rate. On the premise of optimizing the gas chromatography conditions, the vegetable oils of 11 varieties and 141 samples were collected from 10 regions and online shopping malls in China, and the fatty acid components of each vegetable oil were detected by gas chromatography. The fatty acid characteristics of typical vegetable oils in China were analyzed, and the heating test was carried out with corn oil rich in n-6 fatty acids, tea oil rich in n-9 fatty acids and flaxseed oil rich in n-3 fatty acids. The results are as follows: 1. A CP-sil88 capillary gas chromatographic column (100mx 0.25mm id 脳 0.2 渭 m) was used, the injection port and detector temperature were 250 鈩，

本文編號：2002980