Crude Fat

Introduction Crude fat is the term used to refer to the crude mixture of fat-soluble material present in a sample. Crude fat also known as the ether extract or the free lipid content the traditional measure of fat in food products. The lipid materials may include triglycerides, diglycerides, monoglycerides, phospholipids, steroids, free fatty acids, fat soluble vitamins, carotene pigments, chlorophylls, etc. The common approach for total crude fat determination is based on the solubility of lipids in non-polar organic solvents such as hexanes, petroleum ether, or supercritical liquid carbon dioxide with or without a solvent modifier. The two methods most commonly used to determine crude fat are wet extraction and dry extraction. Wet extraction is performed with the water remaining in the sample while a common dry extraction method is Soxhlet extraction. It is performed with anhydrous ether. It is common crude fat determination method in many foods. This technique extracts the crude fat into ether which is finally evaporated. Dry extraction is preferred when it is inconvenient to remove most of the water from a food. After extraction the solvent is evaporated, the residue weighed and reported as percent crude fat.
Objectives
This experiment aimed to: To determine the percentage fat present in a powdered milk sample and to use dry method extraction specifically the soxhlet method.

Methodology

Chemicals and Apparatus

The materials and apparatus that were used in the experiment were: Soxhlet, reflux condenser, extraction flask, analytical balance, iron stand, stove, filter paper, stove, spatula, milk sample, petroleum ether, and rubber hose.

Procedure
Two grams of milk sample was weighed and was placed into filter paper. The filter paper was then folded and was inserted in the tube of a soxhlet extractor. The extraction flask was connected and about 200 ml of petroleum