The many dog foods available today are typically composed of protein, fat and carbohydrates. The percentages of these components vary from one brand to another. Sometime this is done to optimize one food for a specific purpose such as weight control. Other times it’s a cost cutting measure.
For many years, a key component, fat, has been extracted by the Soxhlet method. The Soxhlet extraction requires the use of flammable solvents such as petroleum ether. These solvents are toxic, and can cause damage to the eyes, skin and lungs. This procedure is time consuming, taking an average of 4 hour to completely extract the fat. Additional time is required to evaporate the solvent before performing a gravimetric analysis to the determine the weight percent of fat.
A good alternative is supercritical carbon dioxide (SCCO2) extraction. CO2 may be used in place of organic solvents to perform the same extraction. In addition to being non-toxic, SCCO2 is an inexpensive solvent and does not have the high waste disposal costs associated with organic solvents. Productivity is greatly increased because a SCCO2 extraction takes about an eight the amount of time that a Soxhlet extraction requires. There is an additional post-extraction time savings because there is no solvent to evaporate prior to gravimetric analysis.
The SFT-120 SFE, along with the Nex10 CO2 Pump, is an affordable, easy to use extraction system that’s very well suited for fat extraction. It offers interchangeable vessels ranging in size from 5 ml to 100 ml. Direct contact vessel heaters and an integrated pre-heater provide rapid fluid warm up. A thermocouple through the vessel wall into its interior provides precise measurement of fluid temperature. Quick disconnects for the heaters and the thermocouple make changing vessels fast and easy. The Nex10 is a robust, pneumatically driven liquid CO2 pump. It takes liquid CO2 from tank pressure (800-900 psi) up to 10,000 psi (68.9 MPa) at flow rates up to 50 ml/min.