Substrate influence on the frying process

The substrate affects frying oil in different ways during the frying. Water is released from the substrate, which is converted into steam and participates in hydrolytical processes of frying fats. The transfer of fat into the substrate and from the substrate into frying fat depends on the fat content in the substrate and on the frying conditions. Other, more polar substances than triacylglycerols, including pigments and their precursors, pass in frying oil. Oxidation processes in frying oil are inhibited by the substrate, especially by proteins, starch or phenolic substances. Mutagenic polycyclic aromatic heterocycles are produced during the interaction of frying fat and protein. Oxidation products are bound to proteins and other components of the substrate. Flavour substances are produced by reactions of oxidized frying oil with proteins and other sulphur and nitrogen substances in the substrate.