Indicatori di trattamento termico di oli sottoposti a frittura prolungata e discontinua

During deep-frying various deteriorative chemical processes, such as hydrolysis, oxidation,and polymerization, and polymerization, take place and oils decompose to form degradation products both for the product and the consumer. The aims of this study were to evaluate the stability of fats with a difefrent degree of unsaturation in heat-treated in batch and identify a possible marker of oxisation correlated with the official method of total polar compounds (TPC) The frying process was carried out with 3 fats (sunflower and olive oils and lard) at T=180°C ± 4°C and the frozen potatoes was dep fried. The indexes were: acidity, peroxid value, fatty acids composition (HRGC FID) and TPC. In olive oil the methyl octanoate showed an interesting trend. In lard fatty acids showed a very good correlation with TPC. In sunflower oil the palmitic acid and the ratio between linoleic and palmitic acids should be proposed as an alternative to the TPC.