Food Frying

9Nutrition and Metabolism of Fried Foods

9.1 Introduction

The frying medium and fried foods provide several important nutrients that are considered vital for human survival and a balanced healthy life. Dietary fat contains important lipids, which are essential for maintaining several biological functions. It provides more energy than its counterpart biomolecules, such as carbohydrates and proteins. Triacylglycerols (TAGs) in the fat are hydrolysed by lipase enzymes, releasing fatty acids (FAs) and glycerol. Upon reaching cells, the FAs enter their mitochondria through the carnitine transport system and combine with carnitine to form acylcarnitine. Acylcarnitine is then transported to the mitochondrial matrix, where it is converted back to acyl CoA and carnitine. The acyl CoA is metabolized to produce acetyl CoA by several metabolic processes, in a process called β‐oxidation. The acetyl CoA is then metabolized in the citric acid cycle to produce reducing equivalents or adenosine triphosphate (ATP) at the substrate level. Heat is released when an ATP is hydrolysed. Acetyl CoA produced by the oxidation of FAs may serve as a precursor for several other lipid metabolites, such as cholesterol.

Carbohydrates are absorbed in the body in the form of monosaccharides such as glucose and fructose. Glucose is oxidized to form pyruvate, and finally acetyl CoA via a glycolytic process. Pyruvate is transported to the cell and metabolized to form acetyl CoA. Condensation of acetyl CoA and oxaloacetate ...