All low-fat or reduced-fat spreads contain less fat than butter or standard block margarine and a great deal more water. This means that while they can be used like butter or margarine as a spread on bread and so forth, they are not always suitable for cooking. They can be used successfully for all-in-one sauces and cakes, for choux pastry and, if mixed with full-fat butter or block margarine, can sometimes be used for other pastry. To make a cheesecake base, normally done by mixing butter with biscuit crumbs, melt the low-fat spread carefully over a low heat and then add the crumbs.
Low-fat spreads are generally not suitable for shallow or deep-fat frying because they contain too much water. However, they can be used in a nonstick saucepan to fry foods such as onions or mushrooms, as long as it is gently done over a low heat. They are also unsuitable for traditional biscuits and cakes, and preserves such as lemon curd, because they do not set firm.
Very low-fat spreads, which have an even higher proportion of water and contain less than 25 percent fat, are quite unsuitable for frying or sauteing because they will spit and are liable to burn very easily.
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