Evaluation of some methods to detect milk fat adulteration by palm oil and palm kernel oil mixture

Document Type : Original Article

Authors

1 1Department of Dairy, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt

2 Dairy Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt.

3 Dairy Science Department, Industries and Nutrition Research Institute, National Research Centre.

Abstract

ABSTRACT
Adulteration of milk fat with vegetable oils is one of the most common types of adulteration due to its high economic value. Therefore, the aim of the present study was to examine the accuracy and sensitivity of some simple procedures to detect the milk fat adulteration with vegetable oils including palm oil (PO) and palm kernel oil (PKO) in different levels as a model of commercial adulterated milk samples. The butter oil (BO) was mixed with a mixture of vegetable oils (50% PO + 50% PKO) in order to create 4 treatments representing adulteration of butter oil in different proportions of 25, 50, 75% and 100% compared to control sample of the pure butter oil. The results showed that such adulteration didn't cause significant changes in the fat constants especially when determine the refractive index, melting point, saponification value, ester number and iodine number. Apparent Solidification Time (AST), Reichert-Meissl and Polenske number could be used to detect such milk fat adulteration with PO/PKO mixture especially in the high-level content of vegetable oil ≥ 50% of milk fat content.

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