The aroma of freshly baked goods is irresistible to most people. The wide range of products that yield the delicious smells and tastes of freshly baked goods is the result of a complex interaction of various ingredients and physical processes.

Along with flour, egg is a crucial component of many baked goods due to its unique functional properties and the significant contribution it makes to structure, appearance, texture and taste. Exquisitely simple, yet enormously complex, the egg is one of Nature’s marvels. It is a vital baking ingredient for a large number of products, such as cakes, pastries, meringues, macaroons, custard fillings, quiches and pancakes.

This paper discusses the structure and properties of egg used as a baking ingredient, and considers the resulting changes that arise within the product throughout the baking process.

Introduction

Eggs consist of a clear white substance called albumen, which is derived from albus, the Latin word for ‘white’. Four alternating layers of thick and thin albumen contain approximately 40 different proteins, which are the main components of the egg white in addition to water (1).

The yolk contains less water and more protein than the albumen, some fat, and most of the vitamins and minerals of the egg. These include iron, vitamin A, vitamin D, phosphorus, calcium, thiamine, riboflavin and lecithin. Yolk colours range from just a hint of yellow to a magnificent deep orange, according to the feed and breed of the hen (1).

An examination of the functional properties of eggs is useful to understand how much they contribute to the baked goods we know and love today.

Binding

Whole eggs are used as a binder many baked goods, such as cakes, muffins, cookies, pancakes, waffles and doughs. Eggs are natural binders and help to hold all other baking ingredients together, while increasing the viscosity of batters and doughs. Egg white has the capability to gel and is frequently used as a binding agent in many different prepared foods. Using more whites in a cake mixture will help to create a fluffy, light baked product with a good volume and texture, while using more yolks will create a denser baked good with a deeper, richer flavour.