MATERIALS:
Soxhlet extractor , condensor , boiling chips , petroleum ether, cips ,250 mL round-bottom flask, hexane, rotary vacuum evaporator, thimble.

PURPOSE:
In this experiment we determined the fat content of cips sample. We used some apparatus and suitable organic solvent for fat determination. Organic solvents can be used to extract fat from food products. Many fat methods are based on extracting the fat with these organic solvents.Fat content is important for food products.

METHOD

The Soxhlet method is the most commonly used example of a semi-continuous method applied to extraction of lipids from foods. According to the Soxhlet's procedure, oil and fat from solid material are extracted by repeated washing (percolation) with an organic solvent, usually hexane or petroleum ether, under reflux in a special glassware. In this method the sample is dried, ground into small particles and placed in a porous cellulose thimble. The thimble is placed in an extraction chamber (2), which is suspended above a flask containing the solvent (1) and below a condenser (4). The flask is heated and the solvent evaporates and moves up into the condenser where it is converted into a liquid that trickles into the extraction chamber containing the sample. The extraction chamber is designed so that when the solvent surrounding the sample exceeds a certain level it overflows and trickles back down into the boiling flask. At the end of the extraction process, which lasts a few hours, the flask containing the solvent and lipid is removed. In some device a funnel (3) allows to recover the solvent at the end of the extraction after closing a stopcock between the funnel and the extraction chamber. The solvent in the flask (1)  is then evaporated and the mass of the remaining lipid is measured. The percentage of lipid in the initial sample can then be calculated.

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