Cooking Oils

The available vegetable oils are derived primarily from soybeans, rapeseed (canola oil), sunflower seed, corn, cottonseed, and safflower seed. Fruit oil sources include the avocado, coconut, palm kernel, palm, and olive. Oil differ dramatically in their taste, color, and texture, depending on their source and method of extraction. Read more »

What exactly are shortenings?

Shortenings are plant oils that have been hydrogenated to make them more solid and pliable. Soybean oil is the major source of hydrogenated shortening and serves as a common frying oil. In the manufacture of shortenings, the soybean oil is hydrogenated until it reaches a solid consistency and then whipped or pumped with air to improve plasticity and give it a white color. Read more »

The desirability of fat’s presence in foods and its multiple roles in food preparation have led to many different types of fats being obtained from both animal and plant sources through the years. At first, people probably used the fat rendered from animal carcasses. Butter was probably not far behind once milk from domesticated animals became available. Read more »

About Butter

Butter is made from the cream of milk, with 10 cups (2.5 quarts) of milk required to generate one stick (1/4 pound) of butter. Butter contains about 80 percent milk fat, no more than 16 percent water, and 4 percent milk solids. Salt and coloring additives such as extract of annatto seed or carotene may or may not be added. Read more »

Plasticity of Fats

The plasticity of fat is its ability to hold its shape but still be molded or shaped under light pressure. Plasticity determines a fat’s spreadability. It is an important characteristic to consider when choosing which fat to use in the preparation of confections, icings, pastries, and other baked products. Although most fats look solid at room temperature, they are actually composed of liquid oil with a network of solid fat crystals holding it in place. Read more »

The Melting Point of Fats

Fatty acids are single molecules, each with a distinct melting point. Because triglycerides contain different fatty acids, food fats have a range of melting temperatures. Ultimately, four factors determine a fat’s melting point:

• The fatty acid’s degree of saturation
• The length of its carbon chain
• Its cis-trans configuration
• Its crystalline structure

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Types of Emulsions

Emulsions can be temporary, semipermanent, or permanent and differ in their degree of viscosity and stability. Stability is defined by the degree to which the liquids stay in emulsion regardless of gravity, agitation, long storage times, extreme temperatures, surface drying, or added salt. Read more »

Emulsifiers

There are three parts to an emulsion:

• The dispersed or discontinuous phase, usually oil
• The dispersion or continuous phase, most like water-based
• An emulsifier, which is a stabilizing compound that helps keep one phase dispersed in the other

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Emulsions

Fats play an important role in the formation of emulsions. All foods containing some liquid, and if fats or oils are present, then the combination is some type of emulsion. Emulsions are continuous blends described as either oil-in-water, in which oil droplets are dispersed throughout the water, or water-in-oil, in which water droplets are dispersed throughout the oil. Read more »

The shortening power of certain fats make them essential in the preparation of pastries, pie crusts, biscuits, and cakes. The more highly saturated fats tend to have greater shortening power. Incorporated into a flour mixture, fat separates the flour’s starch and protein and, when heated, melts into the dough, leavening the air spaces that give the finished product its characteristic delicate texture. A fine grain is created from certain cake and cookie batters with the use of shortenings that gently encase the numerous air bubbles, serving as a starting point for the air to expand and increase overall volume. Baked goods also become more tender, up to a point, as fat concentration increases.