Chemical reactions involved in the deep fat frying of foods. I. A laboratory apparatus for frying under simulated restaurant conditions

A laboratory apparatus has been designed which can be used to quantitatively collect the volatile decomposition products produced during deep fat frying under simulated restaurant conditions. In order to study the chemical reactions of frying fat without any inter-reaction with the food fried, moist cotton balls were fried in corn oil. The oil used for frying was shown to differ considerably from oil which was continuously heated. The latter had a darker color and higher viscosity. It foamed significantly while the oil used for frying did not. Furthermore, the continuously heated oil had a much lower free fatty acid content than did the oil used for frying under simulated restaurant conditions. The volatile decomposition products collected during frying of cotton balls in corn oil were separated into acidic and nonacidic compounds. Each group exhibited a definite gas chromatographic pattern after only a short period of frying. Part of the degradation products, particularly those of higher boiling points, were found to remain in the frying oil. Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers. The State University of New Jersey, Department of Food Science, New Brunswick.