TAILIEUCHUNG - oil extraction and analysis phần 6

Trong xem xét này, chúng tôi khám phá các khái niệm cơ bản của chất lỏng siêu tới hạn và dịch nhổ siêu tới hạn. Carbon dioxide và các dung môi khác được thảo luận lý thuyết hòa tan được giới thiệu cùng với việc tính toán mật độ của carbon dioxide. Thiết bị nhà nước-of-the-nghệ thuật được trình bày về các thành phần cơ bản | Chapter 6 Oil Content Analysis Myths and Reality . Barthet and . Daun Canadian Grain Commission Grain Research Laboratory Winnipeg Manitoba R3C 3G8 Canada Abstract The FOSFA Federation of Oils Seeds and Fats Associations Limited extraction method harmonized as AOCS Am 2-93 or ISO 659 is considered to be the reference method to measure the oil content of oilseeds. The method is based on the extraction of neutral lipids with hexane or petroleum ether and the extracted components are estimated gravimetrically and defined as crude fat or oil content. The method requires a triplicate grind extraction making it lengthy and very detailed for the analyst. Compared with other official methods AOAC the FOSFA extraction method gave the highest oil recoveries in all oilseeds tested. Accelerating the extraction through the use of new instrumentation which combines solvent extraction with a physical disruption such as pressure or microwave heating has not been able to give oil recovery equal to the FOSFA extraction. Although the FOSFA method remains the reference method both ISO and AOCS have identified a need to develop new rapid methods for oil extraction that yield oil equivalent to that from the FOSFA method and that can be used for determination of other factors such as methyl esters or free fatty acids. This study examined the lipid components extracted by each stage of the FOSFA method First Extraction FOSFA1 Second Extraction FOSFA2 and Third Extraction FOSFA3 . In a typical analysis FOSFA1 accounted for 86 FOSFA2 for and FOSFA3 for as much as of the total oil extracted. Although mainly triacylglycerols TAG were found the extracts contained small amounts of other lipid components including nonesterified fatty acids partial glycerides fat-soluble vitamins long-chain alcohols or aldehydes and sterol or cholesterol esters. More nonpolar material was extracted in the first early stage of the extraction whereas the later stages contained more polar .

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