Studies on the Deterioration of Frying Oils. III.

Influence of the Temperature for the Deterioration

Abstract

The higher the temperature reises the more the deterioration of oil by oxidation become active, hence a proper temperature is necessary for frying.
This paper reports that the deterioration of oil was more accelerated at higher frying temperature.
Potato chips and wheat flour doughs were fried in corn oil containing no antioxidants or synergists.
Frying has been carried out at exact temperature of 170 or 200°C to investigate deterioration and AOM stability of the fried oils by measuring color, viscosity, refractor, peroxide value, iodine value, carbonyl value and conjugated dienoic acid contents.
Deterioration indicated by the above value has not changed so markedly in the frying test made at lower temperature, but a considerable change was observed at higher temperature.
The degree of deterioration after 3hr's frying at 200°C corresponded closely with that of 5hr at 170°C.
As a result, higher temperature in the frying had a great influence upon the deterioration of oil.
Regarding the oxidation stability of fried oil under AOM condition, the fried oil at 200°C proved to be more stable than that at 170°C. A complicate relationship exists between frying and AOM test.