DETERMINATION OF THE QUALITY OF OILS AND FATS USED FOR FRYING IN FOOD ESTABLISHMENTS-EXISTING METHODS AND PROPOSAL OF A NOVEL METHOD

摘要

Frying food quality is highly determined by the quality of the oil or fat used for frying. This latter deteriorates significantly when the oil or fat is used repeatedly for frying. As a consequence, determining frying oil quality is a critical quality parameter in the production of frying products. However, the determination of frying oil quality is not a trivial task. This is because frying induces a plethora of physical and chemical changes in the oil and therefore for a proper determination of oil quality numerous properties need to be measured. This task becomes even more difficult when it must be performed in small food production units (caterers, restaurants, fast-foods) which lack quality control laboratories and personnel with appropriate expertise. On the other hand, the determination of frying oil quality in such establishments is critical for consumer health since the highest quantities of frying foods are consumed in small food production units. This work presents the existing fast methods for oil quality determination making a reference also to the limits for frying oil usage according to food laws and recommendations. The available fast methods are discussed and their advantages and disadvantages are analyzed. Furthermore, existing methods are assessed in respect to whether they can be used in small food production units such as fast foods and restaurants. Finally, a novel technique for the determination of frying oil quality is presented. The technique is under development in the Dept. of Food Technology in ATEI of Thessaloniki. The technique aims at determining in a fast, simple, safe, economic, yet reliable way the quality of frying oils. The theoretical basis of the technique is presented, the set-up used for the determination as well as some first very encouraging results. The advantages, disadvantages and further development of this novel technique are also discussed.