دانلود گزارش کارورزی و کار آموزی

Abstract

The present study was undertaken to determine whether decreases in fat contents result in lower vitamin E contents. Milk samples of varying fat contents (half and half, whole milk, reduced-fat milk low-fat milk, and nonfat milk) were obtained from a local dairy on six different occasions, α-locopherol was the major form of vitamin E (>85%); γ-tocopherol and α-tocotrienol were present to a lesser extent. As the fat contents of milk products decreased from 11 to 0.3%, the vitamin E contents decreased. For example, raw milk as compared to nonfat milk had both higher α-tocopherol contents (45.5+-4.6 vs. 4.5±0.5 μg/100 g; P<-0.0001) and higher total lipids ( 3.46±0.49 vs. 0.30±0.07 g/100 g; P≤0.0001). Vitamin E, cholesterol, and total lipids increased as cream was added back to nonfat milk during production. For every 1 mg cholesterol increase, there was an increase of approximately 4 μg of α-tocopherol; for every 1 g total lipids increase, the α-tocopherol content increased by 17 μg. These data demonstrate that removal of milk fat markedly decreases the vitamin E content of various milk products