Cholesterol contents of U.S. and imported goat milk cheeses as quantified by different colorimetric methods

Abstract

Cholesterol concentrations of 15 varieties of U.S. and imported commercial goat milk cheeses were evaluated by different extraction and colorimetric determination procedures. The majority of the caprine milk cheeses were high moisture containing soft type varieties, where moisture contents of the products were not exactly equated with cholesterol contents. The range of cholesterol levels (wet basis) in the experimental cheeses was 80–147 mg/100 g. Cholesterol contents of Texas Chevre, U.S. goat milk Gouda, and white hard goat cheeses were: 120.8, 124.8, and 95.4 mg/100 g cheese on a wet basis, and 39.3, 71.5, and 59.2 mg/100 g on a dry basis, respectively. On a wet basis, the Texas Chevre with pepper and herbs variety had the lowest (80.9 mg/100 g), while the imported variety of Royal Province with garlic and herbs contained the greatest amount of cholesterol (146.8 mg/100 g). However, cheese with the highest dry matter (Norwegian Gjetost) showed the greatest cholesterol (107.0 mg/100 g) among all tested goat cheese varieties on a dry basis. Cholesterol in goat milk cheeses of this study determined by the colorimetric method was higher than in cow milk cheeses determined by the gas chromatographic (GC) method in previous reports. It was concluded that the differences in cholesterol between goat and cow milk cheeses may be attributable to the differences in analytical procedure rather than species of milk or cheese, because cow milk reportedly contains slightly higher cholesterol than goat milk. The turbidity of the sample solution in colorimetric procedures might also be partially accountable for differences in cholesterol among different varieties especially in spice added cheeses. The colorimetric method using o-phthalaldehyde was more consistent and about 20% less variable than using FeSO 4-acetic acid as the color developing agent in the determination of cholesterol.