1. Field of the Invention
The present invention relates to a method for the determination of the degree of deterioration of oils or fats used for frying foods.
2. Description of Related Art
For determining the degree of deterioration of oils and fats for frying foods, it is known to measure the dielectric constants of the heated oils or fats or, after addition of reagents, the color change thereof in the course of time.
The measured values to be determined by these methods have frequently proven to be unreliable, usually require a comparison oil or a comparison fat, and are complex in terms of apparatus used and amount of time-consumed.
The German journal "Deutsche Lebensmittel-Rundschau", volume 69, part 12, 1973, pages 461 to 466 discloses a method for determining the degree of deterioration of oils and fats for frying, in which the content of oxidized fats is used as a criterion.
The German journal "Deutsche Lebensmittel-Rundschau", volume 70, part 2, 1974, pages 57 to 65 and EP 0,501,682 A2 disclose determining the keeping quality or stability to oxidation of oils or fats by means of conductometric measurement cells.