Every day, we use cooking oil to prepare our food. There are different types of cooking oil, derived from both animals (e.g. butter and lard) and plants (e.g. olive oil and corn oil). As cooking oil is heated to high temperature during food preparation, it may undergo various changes (e.g. chemical reactions, increase in viscosity, darker in colour and even develop rancidity) and produce substances which may affect human health. In general, these substances increase with the duration of heating of cooking oil at high temperatures.

The food trade is reminded to control the hazards associated with prolonged heating of cooking oil by adopting a Good Manufacturing Practice (GMP), which includes the following points:

• choose cooking oil of good quality and consistent stability;
• use properly designed equipment and cleanse the equipment frequently;
• select the lowest possible cooking temperature;
• filter cooking oil frequently to remove food particles; and
• replace cooking oil as needed to maintain quality.