Abstract: A continuous method using gaseous carbon dioxide or a pressurized flow of liquefied carbon dioxide is described to reduce microbial and/or enzymatic activity in a liquid product. The carbon dioxide is combined with a pressurized flow of the liquid product, or the mixture is pressurized after the mixture is formed. The pressure and temperature in the flow regions are maintained at a level which is sufficient to keep the carbon dioxide in a continuous liquid state, but which does not freeze the liquid product. The pressurized mixture of the carbon dioxide and liquid product flows through a reaction zone for a sufficient time to reduce harmful microorganisms and/or inactivate enzymes and then enters one or more expansion stages wherein the pressure of the mixture flow is sufficiently decreased to vaporize the carbon dioxide for separation from the liquid product. If necessary, heat is applied in at least one of the expansion stages to prevent a freezing of the mixture.

Abstract: A method of making reduced oil content food chip products, such as potato chips and corn chips, includes circulating liquid carbon dioxide, over the food chip products to extract oil. Reduction of oil content to less than 50% of its initial value, including reductions to 25%, may be achieved while retaining flavor and texture comparable to conventional deep fried chips having an oil content of 30% to 40%. The oil which is recovered from the liquid carbon dioxide used for extraction has an appearance and quality which are substantially the same as virgin frying oil and may be reused to deep fry chips.