Comparison of mineral and cholesterol composition of different commercial goat milk products manufactured in USA.

摘要

Concentrations of 12 major and trace minerals and cholesterol in commercial goat milk, evaporated milk, dried milk, yoghurt and cheeses manufactured in the USA were evaluated. Minerals were determined by an Inductively Coupled Argon Plasma EmissionSpectroscopy, while cholesterol was analysed using colorimetric and gas chromatographic (GC) methods. Mean TS content (%) of goat milk, evaporated milk, dried milk, yoghurt, soft cheese and Monterey Jack cheese were: 11.3, 20.9, 94.1, 11.5, 40.2, and 58.3, respectively. Mean calcium and phosphorus contents (ppm, DM basis) were: 104, 125; 440, 393; 7715, 7471; 161, 144; 691, 1105; and 3492, 3067, respectively. The iron and zinc contents (ppm, DM basis) were: 0.062, 0.349; 1.518, 1.635; 3.33, 30.21, 0.117, 0.388; 7.16, 3.64; and 8.86, 3.81, respectively. The content of K in cheeses were lowest among all the products, suggesting that a significant amount of K was lost during cheesemaking processes. Levels of all trace minerals were higher in yoghurt and cheeses than in fluid milk. The levels of trace minerals in cheeses were greater than those in yoghurt. Iron and aluminium contents of some goat milk products were considerably higher than normal, possibly due to contamination of minerals from manufacturing utensils and product metal cans. Sulfur contents of cultured milks were significantly greater than those of fluid milk, which may be due to the microbial synthesis of sulfur-containing proteins during manufacture of products. Cholesterol contents (mg/100 g) of milk, evaporated milk, dried milk and Monterey Jack cheese determined by GC were: 11.0, 24.9, 119.5 and 91.7, respectively. Cholesterol contents of the goat milk products analysed by the colorimetric method were substantially greater than thosedetermined by GC.