Food Frying

6Chemistry of Interactions in Frying

6.1 Introduction

Frying has two important components: the frying medium and the food. These components are classified further into several biomolecules, as described in Chapters 4 and 5 and elsewhere (Perkins and Erickson 1996; Stier 2000; Velisek 2014). These biomolecules interact with one another or transform alone to form new products. None is exempted from the interactions and transformation. Since temperature is an essential component of frying, it is not considered a limiting factor. Applied pressure and frying time also affect interactions during frying. However, all physical and chemical reactions are the result of either the food or the frying medium. The interactions may be either physical or chemical in nature (Figure 6.1). Thus, the interactions occurring during food frying may be classified on the basis of their components as follows:

1. Food–Food Interactions: Interactions producing chemical reactions within the food components are called food–food interactions or homogenous interactions. These include the formation of 5‐hydroxymethyl‐2‐furfural (HMF), acrylamide, heterocyclic aromatic amines (HAAs), and polycyclic aromatic hydrocarbons (PAHs). Such interactions do not involve the frying medium, but are rather caused by the heat supplied.
2. Food–Oil Interactions: Interactions involving the transformation of food components or their interaction with the oil components are called food–oil interactions or heterogeneous interactions. They ...