The present invention pertains to a method of purifying crude polyol fatty acid polyesters synthesized and/or purified by a process involving contact with alkali metal ions under alkaline conditions, comprising the step of reducing the level of alkali metal ions to less than 5 ppm by weight. The invention further pertains to polyesters having such reduced residual levels of alkali metal ions, and to food compositions in particular for frying purposes, comprising such polyesters as fat- replacers.