FATS AND OIL

Fats and oils make up 95% of food lipids and phospholipids, and sterols make up the other 5%. Traditionally, fats were considered to be solid at room temperature, and oils were considered to be liquid. However, this designation is often used to distinguish between fats and oils from animals and plants, respectively. Animal fats are found in meats (beef, chicken, lamb, pork, and veal), milk products, eggs, and seafood (fish oil). Plant (vegetable) oils come from nuts (peanuts), olives, and seeds (soybean, canola, safflower, and corn). We use lipids for flavor (butter and olive oil), to cook foods (oils and shortening), to increase the palatability of foods by improving the texture or “mouthfeel” (cakes, creamy ice cream), and in food processing (emulsifiers).

Fatty acids are generally long, straight chains of carbon atoms with hydrogen atoms attached (hydrocarbons) with a carboxylic acid group (COOH) at one end and a methyl group (CH3) at the other end. These long, straight chains combine with the glycerol molecule to form lipids (glycerol lipids).