Animal fat

Animal fats constitute a broad category of lipid compounds derived from the tissues and secretions of animals. These substances fulfil essential physiological functions in animals—from thermoregulation to energy storage—and have long served numerous culinary, sanitary and industrial purposes for humans. Structurally composed of triglycerides, animal fats exist in either solid or liquid form depending on temperature and fatty acid composition and remain fundamental to both biological systems and traditional manufacturing practices.

Chemical Structure

Animal fats are primarily formed of triglycerides, a class of esters in which a glycerol backbone is bonded to three fatty acid chains. The nature of these fatty acids—whether identical or varied—determines the complexity and characteristics of the triglyceride molecule. Simple triglycerides contain three identical fatty acids, though most animal fats are mixtures of complex triglycerides with differing chains, producing a wide range of physical properties.
Fatty acids within animal fats fall into two broad categories:

• Saturated fatty acids, most prevalent in animal fats, generally producing solid fats at room temperature.
• Unsaturated fatty acids, less common but present in varying proportions depending on the species and tissue type.

The relative proportion of these fatty acids influences melting point, firmness and oxidative stability.

Functions of Fat in Animals

Fat serves several crucial roles in animal physiology:

• Thermal insulation: Many mammals, particularly those inhabiting cold terrestrial or aquatic environments, possess a dense subcutaneous layer known as blubber. This layer reduces heat loss, owing to fat’s low thermal conductivity, and allows animals such as whales, seals and polar bears to maintain body temperature efficiently.
• Energy storage: Fat stored in adipose tissue acts as a long-term energy reserve. Adipocytes contain large triglyceride stores that can be mobilised during periods of food scarcity. Animals preparing for hibernation, for example, build substantial fat deposits to sustain metabolic activity throughout prolonged dormancy.
• Mechanical protection: Pads of fatty tissue located in the feet of many species—from cats and dogs to horses and elephants—absorb impact forces during movement, protecting bones and joints and contributing to locomotor efficiency.

Human Usage

Culinary UsesAnimal fats have historically been key components of human diets. Depending on the animal and processing method, they may appear as:

• Butter, produced from dairy fat
• Lard, rendered from pork fat
• Schmaltz, derived from poultry fat
• Dripping, from roasted meats

These fats serve various culinary functions, including:

• Shortening: creating crumbly textures in pastry
• Binding: reducing adhesion between ingredients
• Flavouring: imparting distinctive tastes
• Cooking medium: providing a heated fat for frying or sautéing, though with generally lower smoke points than many vegetable oils

Animal fats also appear as fillers or stabilisers in processed foods, particularly in factory-produced meats and fast foods.
Other UsesTallow—rendered beef or mutton fat—has been especially significant beyond the kitchen. Key applications include:

• Soap making: Through saponification, tallow is boiled with lye to produce soap and glycerol. After purification, the resulting soap forms the basis of many traditional sanitary products.
• Cosmetics and skincare: Tallow is used in creams, balms and lotions. It contains vitamins A, D, E and K, as well as conjugated linoleic acid, which is believed to support skin health and repair.

Broader Uses and Processing

Rendering is the primary industrial method for extracting oils from animal tissues. By heating raw fatty tissues from livestock such as pigs, cattle and poultry, producers separate liquid fats from connective tissue. Dairy production contributes additional fats such as butterfat, which undergoes separate processing.
Animal fats also serve as raw materials in areas including candle making, lubricants, biodiesel production and traditional craft industries, demonstrating their versatility.