扇贝脂肪的提取和分析

The Extraction and Analysis of Scallop Fat

以快速脂肪提取法取代素氏提取法，提取扇贝脂肪仅需４５ｍｉｎ，提取率９８．８％。利用４０ｍ×０．３５ｍｍｉ．ｄ．ＰＥＧ－２０Ｍ玻璃毛细管柱分离测定扇贝脂肪中脂肪酸。分离出４６个峰，结合气相色谱／质谱（ＧＣ／ＭＳ），鉴定出３６个峰，占脂肪区总量的９９．４％，其中饱和脂肪酸占３２％，不饱和脂肪酸占６７．４％。

In this paper, scallop fat was extracted by means of rapid fat extractor instead of Soxhlet extractor. It took only 45min for fat extraction, and the ratio was over 98. 8%. Concentration was normally achieved by evaporating the excess ether solvent under a stream of nitrogen. After being extracted, fat was dissolved in 1mL of benzene and ether (1:1),and esterified with lmL of potassium hydroxide and methanol.After centrifugation,fatty acid esters in upper benzene and ether layer were separated and determined by a 40m× 0. 35mm i. d.PEG-20M glass capillary column and hydrogen flame ionization detector (FID).Three columns have been chosen, and a 40m× 0.35mm i.d.PEG-20M glass capillary column was considered to be the best one to separate fatty acid methyl esters. Fig.1 showed the separation of fatty acid methyl esters in scallop fat. The injector and detector temperature was 280℃.The column temperature was programmed,from 165℃ to 175℃(6min) at 5℃/min and then from 175℃ to 192℃ at 10℃/min. Forty-six peaks were separated. Thirty-six of them were identified with gas chromatography/mass spectrometry, and quantified with area normalization method.The compositions and contents of fatty acids in scallop were shown in Table 1. From it , the amount of identified fatty acids attained 99.4% of total amount of them,of which the amount of saturated fatty acids was only 32%,the unsaturated reached 67.4% and EPA+DHA was 37. 5 %,higher than that of most fishes.