Food Additives - Leavening Agents

Doughs and batters if not of the required texture can lead to making and baking of worse breads. Must have observed at home how chapathi dough when too hard produces a dry rough chapathi and when too soft it is a sticky mass of mess. So, for these doughs and batters to rise and form a required texture, a leavening agent is required. In the presence of moisture, heat, acidity, or other triggers the leavening agent reacts to produce gas (often carbon dioxide) that becomes trapped as bubbles within the dough. When a dough or batter is baked, it “sets” and the holes left by the gas bubbles remain. This is what gives breads, cakes, and other baked goods their soft, sponge-like textures.

The alternative or supplement to leavening agents is mechanical leavening by which air is incorporated by mechanical means. Remember? the proper mixing of cake batters and kneading of dough. Most leavening agents are synthetic chemical compounds, but carbon dioxide can also be produced by biological agents. 

Biological Agents	Chemical Agents	Other Leaveners
Saccharomyces cerevisiae producing Carbon dioxide found in: Baker’s yeast Beer (unpasteurized – live yeast) Buttermilk Ginger bread Sourdough Starter Clostridium perfringens producing hydrogen found in salt-rising bread	Chemical leaveners are mixtures or compounds that release gases (usually carbon dioxide) when they react with each other, with moisture, or with heat. Most are based on a combination of acid and a salt of bicarbonate. After they act, these compounds leave behind a chemical salt. Chemical leaveners are used in quick breads and cakes, as well as cookies and numerous other applications where a long biological fermentation is impractical or undesirable.	Steam and air are used as leavening agents when they expand upon heating. To take advantage of this style of leavening, the baking must be done at high enough temperatures to flash the water to steam, with a batter that is capable of holding the steam in until set.

Creaming is the process of beating sugar crystals and solid fat (typically butter) together in a mixer. This integrates tiny air bubbles into the mixture, since the sugar crystals physically cut through the structure of the fat. Creamed mixtures are usually further leavened by a chemical leavener like baking soda. This is often used in cookies.

Using a whisk on certain liquids, notably cream or egg whites can also create foams through mechanical action. This is the method employed in the making of sponge cakes, where an egg protein matrix produced by vigorous whipping provides almost all the structure of the finished product.

 Below are leavening agents found in a variety of foods:

There are foods or ingredients not leavened, although they are mistaken for leavening or leavened food:

Puffed cereals:  Some food products are “puffed up” by mechanical means.  They are just puffed up by air and are not chemically leavened.  They include: popcorn, beaten eggs, and air puffed cereal like puffed rice or wheat. 

Brewer’s yeast (Saccharomyces cerevisiae): is inactive yeast, meaning the yeasts have been killed and have no leavening power. It is the yeast remaining after beer making. It is used as a nutrient supplement to increase the intake of B vitamins.

Yeast extract, autolyzed yeast extract: When yeast cells die, they automatically break up, a process called autolysis in which the yeasts’ digestive enzymes break their proteins down into simpler compounds. What remains is a collection of protein, fats, vitamins, minerals, and monosodium glutamate (MSG), a flavor enhancer.

Post by Faiz Lahori