Flavor partition and fat reduction in cheese by supercritical fluid extraction: processing variables

Abstract

Developing low-fat cheese with flavor to match that of full-fat cheese has been a chal- lenge in the dairy industry. The objective of this investigation was to develop lower fat Cheddar and Parmesan grated cheese using supercritical fluid extraction (SFE) and characterize its flavor profile comparative to a full-fat product. Specifically, enabling flavor compound partition between the matrices of cheese and extracted lipids. Carbon dioxide (CO2) was the supercritical fluid for fat extraction. Extraction took place in a 500 mL SFE vessel using 100 g of grated cheese. Frac- tional factorial design was utilized to investigate two levels of treatment for each pressure (200 and 350 bar), temperature (35 and 40 ◦ C) and CO2 level (500 and 1000 g) for each extraction trial. The most efficient parameters for lipid removal resulted in 51.00% fat reduction (wet basis) for Cheddar extracted at 200 bar, 40 ◦ C, 1000 g CO2, and 55.56% fat reduction for Parmesan extracted at 350 bar, 35 ◦ C, 1000 g CO2. Thin layer chromatography (TLC) was utilized to assess the lipid composition of each cheese and the lipids extracted by SFE. TLC analysis for Cheddar and Parmesan cheeses showed only nonpolar lipids (triaclyglycerides and free fatty acids) in the recovered lipids extracted by SFE; indicating that polar lipids such as phospholipids are being retained in the cheese matrix. Gas chromatography/mass spectroscopy techniques were used to characterize volatile flavor com- pounds for each cheese sample. SFE treatment of the cheeses altered the ability to detect flavor compounds and allowed partitioning of those compounds, which varied with the type of cheese. This study suggests that SFE technology can be used in the dairy industry to develop cheese prod- ucts lower in fat, which retain flavor compounds that may not be typically fully developed with alternative methods of low-fat cheese processing. supercritical fluid extraction / carbon dioxide / Parmesan cheese / Cheddar cheese / fat