The Process of Baking and Function of Eggs in Bakery Products

Baking is an oldest technique through which not only bread making take place, it is also involve in processing of those food products that containing flour as a basic raw material and to which heat is provide from top and bottom walls of an oven by radiation. Moreover, frosting, center filling, topping also include in it. Through this process various forms of bakery products can be synthesize like cookie, crackers, cakes, muffins, bread etc. they are different in many aspects like in baking technology and baking ingredients or materials etc. Different techniques and recipe of baking are followed to increase the shelf life of product because bakery products have low shelf life. Modified atmosphere packaging also used to keep the shelf life of bakery products longer. A few aspects that influence the quality and shelf life of bakery products like environmental temperature, relative humidity of the environment, acidity, moisture, and gaseous atmosphere.

During baking four major changes occur:

• When temperature increases, gases are vaporized.
• As the temperature increases, starch become gelatinizes.
• Gas cells that present on the wall of dough change into interconnected porous structure called dough-crumb transition.
• Water vaporized due to high temperature in oven, due to this hard and dry crust formation occur in bread and in biscuits and cookies complete drying occur.

Principal of Baking

Heat is transferred through convection, conduction and radiation. As the product introduced into the oven water evaporation occur due to the heat transfer. In every baked product it is important that moisture gradient exist at the end of baking process because it is responsible for textural properties like softness of crumb and crispness of crust in high moisture bakery product. The initial water content ranges from 11-30% for biscuits & cookies. The final temperature range will be 1-5% depending on finish product.

Chickens egg is a notable food material that used in many food products and it contain variety of nutrients like protein, phospholipids, unsaturated fatty acids, antioxidant, and vitamins. Eggs are one of the most important ingredients that used in bakery products like biscuits, cakes etc. An egg is composed of three main parts egg shell, egg yolk and egg white. The yolk is composed of lipids like phospholipids, triglycerides and cholesterol. The egg white or albumin contains water and protein.

Function in Bakery Products

In baking egg play some very important roles such as it gives a proper structure to finish product because it contain protein which coagulate while heating and provide stiffness to the product. In egg yolk lecithin is present that act as an emulsifier. Lecithin has a back bone of glycerol on which 3 smaller molecules are attach, two of them are fatty acids (this end of lecithin is hydrophobic) and third one is phosphoric acid that contain an amino acid called choline (this end of lecithin is hydrophilic).

Lecithin act as an emulsifier because it has both hydrophilic and hydrophobic end and during emulsion hydrophobic end dissolve in oil droplets and hydrophilic end in water so in this way oil in water are easily protected by lecithin. The emulsifying property of yolk depends on various intrinsic factors such as protein structure, hydrophobicity and stability of yolk structure plus extrinsic factors like ph, NaCl etc. It acts as a leavening agent by trapping air cells in whipped eggs or egg white.

It also acts as a tenderizing agent because the fat in the egg shortens the strands of gluten in dough to tenderize product. Egg also used as a wash to give a glossy appearance to finish product. In baked product egg take part in the enhancement of sensory and rheological characteristics. It also improves color and flavor of product.