Crude Fat (Ether Extract) in Forages

Reference:Fat (Crude) or Ether Extract in Animal Feed. (920.29) Official Methods of Analysis. 1990. Association of Official Analytical Chemists. 15th Edition.

Scope:This method is applicable for the determination of crude fat in dried forages and mixed feeds. It is not applicable for oilseeds, baked and/or expanded products (pet foods), liquid feeds, sugar products, and feeds containing dairy products. For determining fat in oilseeds, consult Official Methods and Recommended Practices of the American Oil Chemists Society.

Basic Principles:A dried, ground sample is extracted with diethyl ether which dissolves fats, oils, pigments and other fat soluble substances. The ether is then evaporated from the fat solution. The resulting residue is weighed and referred to as ether extract or crude fat. Both the ether and the samples must be free of moisture to avoid coextraction of water-soluble components in the sample such as carbohydrates, urea, lactic acid, glycerol, etc. If water-soluble components are present in large amounts in the sample, they are washed out of the sample prior to drying. Low temperatures are used to evaporate the ether and remove residual moisture to prevent oxidation of the fat. Petroleum ether does not dissolve all of the plant lipid material, and therefore it cannot be substituted for diethyl ether.

http://www.foragetesting.org/lab_procedure/sectionC/part8.0.htm

https://books.google.com.ph/books?id=D9RwcUKQsHsC&pg=PA131&lpg=PA131&dq=crude+fat+determination+by+goldfisch+method&source=bl&ots=QhOypQSJcN&sig=IbSj4xszPfA6FwLuVb1C3J213_4&hl=en&sa=X&ei=y8TlVPHyCcrroATX0ICgCg&ved=0CDQQ6AEwAw#v=onepage&q=crude%20fat%20determination%20by%20goldfisch%20method&f=false

Food Analysis

S. Suzanne Nielsen

Springer Science & Business Media, Apr 22, 2010 - Science - 602 pages

3   Reviews

This book provides information on the techniques needed to analyze foods in laboratory experiments. All topics covered include information on the basic principles, procedures, advantages, limitations, and applications. This book is ideal for undergraduate courses in food analysis and is also an invaluable reference to professionals in the food industry. General information is provided on regulations, standards, labeling, sampling and data handling as background for chapters on specific methods to determine the chemical composition and characteristics of foods. Large, expanded sections on spectroscopy and chromatography also are included. Other methods and instrumentation such as thermal analysis, ion-selective electrodes, enzymes, and immunoassays are covered from the perspective of their use in the analysis of foods. A website with related teaching materials is accessible to instructors who adopt the textbook.

Bibliographic information

Title Food AnalysisFood Science Text Series, ISSN 1572-0330Food science. Chemistry

Editor S. Suzanne Nielsen

Edition illustrated

Publisher Springer Science & Business Media, 2010

ISBN 1441914773, 9781441914774

Length 602 pages

Subjects Science

›

Chemistry

›

Analytic

Science / Chemistry / AnalyticScience / Chemistry / Industrial & TechnicalScience / Spectroscopy & Spectrum AnalysisTechnology & Engineering / Chemical & BiochemicalTechnology & Engineering / Food Science