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Fats and Oils

Chapter 21

Functions of Fats and Oils in Food

Functions in Foods

Heat Transfer Satiety

Shor teni ng Po wer Emul si fi cat ion

Melting Point Plasticity

Solubility Flavor

Texture Appearance

Functions of Fats in Food

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Types of Fats and Oils in Foods

Food Fats and Oils

Fats Oils

Animal Plant Plant Animal

Butter

Lard

Tallow

Margarine

Shortening

Cocoa butter

Vegetable oil s

Specialty oilsFish

Types of Processing of Fats

Hydrogenation

Superglycerination

Winterizing

Interesterification

Frying types

Saut / Stir-fryCooking a food relatively quickly in a small

amount of fat

Pan fryingUses a shallow layer of fat visible during

cooking but is not necessarily cookedquickly

Deep-fat fryingFood is entirely submerged in fat

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Movement of Fat and Water in Frying

Functions of Fats in Food

Fats melting point is determined by the

following four characteristics of the fatty acid:

Degree of saturation

Length of fatty acid structure

Cis-trans configuration

Crystalline structure

Cooking wi th Fat

Selection of a fat used in frying must be

carefully chosen as not every fat is

suitable for the high temperatures ofdeep-fat frying.

Safety concerns

Smoke point

Temperature at which thin bluish smoke is

given off forming Acrolein

Fat is decomposing

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Factors Influencing Smoke

Point

Crumbs

Water

Temperature

Overuse

Smoke Points of Fats and Oils

Fat Replacers

Substitutes physically resemble fats, are

often lipid based, and usually replace the fat

in foods on a one-to-one basis to duplicate

the functional properties of fat.

Fat mimetics are water-soluble, often

protein or carbohydrate based, and imitate

the mouthfeel of fat.

Fat-soluble substitutes and extenders

replace the weight added by fat .

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Food Preparation with Fats

Lower-Fat Preparation Techniques

Reducing the consumption of dietary fat may be

accomplished by following the dietary guidelines

recommending:

Meal patterns that are lower in fat.

Especially lower in saturated fat.

Rely on lower-fat or nonfat cooking methods.

Reduce the fat in recipes.

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Other ways to lower fat

Friut purees

Non- fat dairy products

Egg whites

Fat replacers/ low fat version of products

Substituting equal portions of yogurt for oil

Reducing fat up to 50%

Not using butter or marg. on breads, etc.

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Storage of Fats

Storage of fat depends on its ty pe.

Fats such as butter and margarine are best storedin the refrigerator.

Shortenings and most oils are usually stored at

room temperature and should be kept tightly

covered in a dark spot on the cupboard shelf.

They will keep longer if refrigerated.

Olive oil has a shorter shelf life than most vegetable

oils and should be refrigerated fairly soon after

opening.

Storage of Fats

Rancidity: the chemical deterioration of fats,

which occurs when the triglyceride molecule

and/or the fatty acids attached to the glycerol

molecule are broken down into smaller units

that yield off-flavors and odors.

There are two basic types of rancidity:

Hydrolytic rancidity

Oxidative rancidity