ABSTRACT
I. INTRODUCTION Deep-fat frying is a common method of food preparation that imparts desired sensory characteristics of fried food flavor, golden brown color, and crisp texture. During frying, at approximately 190C, as oils thermally and oxidatively decompose, volatile and nonvolatile products are formed that alter functional, sensory, and nutritional qualities of oils. During the past 30 years, scientists have reported extensively on the physical and chemical changes that occur during frying and on the wide variety of decomposition products formed in frying oils. This chapter will review the physical and chemical changes in oils during frying, including reactions that occur in the frying process. In addition to discussing the degradation products formed, their effects on oil stability and quality of fried food will be included. Methods to measure oil deterioration will be discussed in terms of their significance, advantages, and limitations.
