14B-47

N. TIPSRISUKOND, A. D. CLARKE, I. U. Gruen, and L. N. Fernando. Department of Food Science, University of Missouri-Columbia, 122 Eckles Hall, Columbia, MO 65211-5200

The reduced use of edible animal fats has renewed interest in extracting and concentrating their flavor volatiles, as well as in reducing cholesterol content. Supercritical carbon dioxide (SC-CO2) has many desirable properties as a solvent for biomaterials. In addition, CO2 is readily available, nonflammable, nontoxic, and eliminates use of hazardous solvents.

The objective of this study was to determine the ability of SC-CO2 to fractionate lard on the basis of the obtained free fatty acid (FFA) and headspace volatiles.

Lard was extracted with SC-CO2 at each of four pressures (8, 20, 35, and 50MPa) and at each of three temperatures (40, 50, and 60ºC). Obtained extracts were analyzed for their percent FFA, FFA, and volatile profiles using titration, GC, and GC-MS methods, respectively.

Titratable FFA of SC-CO2 extracts increased with increasing extraction pressures and temperatures (P<0.05). The retrograde behavior of lipid solubility was observed around 30MPa. The predominant fatty acids of lard, including C16:0, C18:1, and C18:2, increased with increasing extraction pressures and temperatures (P<0.05). Conversely, short and medium chain free fatty acid concentrations increased with decreasing extraction pressures and temperatures (P<0.05). Total volatiles were concentrated over controls by 5-150 fold depending on extraction conditions. In addition to total volatiles, aldehydes, enals, alkanes, alkenes, branched alkanes, branched alkenes, and aromatic compounds were affected by extraction conditions (P<0.05). Decreasing density of SC-CO2 tended to result in increasing concentrations of these volatiles.

Lipids or fats by-products from commercial slaughter operations are typically used to enhance the palatability of dried pet food. Concentration of volatiles from fat or oil by fractionating free fatty acids using SC-CO2 will enable both pet and food industries to increase the utilization of these by-products in human applications.