The National Yogurt Association cites research that tout benefits of yogurt beyond providing significant sources of calcium and protein. They point out that yogurt aids in digestion, decreases the risk of yeast infections and shows promise in helping stave off certain cancers. The ingredients in yogurt vary with manufacturer, flavor and style.
Cornell University's Department of Food Science notes that milk is yogurt's main ingredient. Full-fat, low-fat and non-fat yogurt are made with whole milk, low-fat milk and skim milk respectively. Cornell explains that other dairy products are sometimes used in yogurt, such as cream to adjust fat content and non-fat dry milk to alter solidity. Some companies, such as Whole Soy Company, use soy milk in place of cow's milk in their yogurt. In these cases, water and ground soybeans are combined to form soy milk.
By definition, according to Cornell, yogurt is fermented milk. The fermentation process, driven by starter cultures Lactobacillus bulgaricus and Streptococcus thermophilus (both required by law), helps give yogurt its consistency. Other bacteria cultures, including Lactobacillus acidophilus, Lactobacillus subsp. casei, and Bifido-bacteria, are often used in yogurt as probiotics. According to Mayo Clinic gastroenterologist Michael Picco, M.D., probiotics are good bacteria that can help with digestive problems, such as gas, bloating and abdominal pain. Some yogurt makers, including Strauss Family Creamery, claim to use only milk and live cultures in their plain yogurt products.
Sweeteners and Fruit
Some yogurt companies include sweeteners in their products. These include sugar and sugar substitutes, such as fructose as well as sucralose and asparatame, which are both low-calorie sweeteners. Some yogurt manufacturers, particularly makers of organic and soy yogurt, use evaporated cane juice as a sweetener.
Fruit is often added to yogurt. Cornell points out that "set-style yogurt" is when the product is packaged with the fruit on the bottom, while "Swiss-style" is yogurt in which the fruit is blended throughout.
Some yogurt companies include additional additives in their yogurt. For example, Dannon says it uses sodium citrate to balance acidity and improve flavor. Malic acid is used control yogurt's natural tartness. Dannon says it is a fruit acid that comes from apples. Cornstarch, gelatin, pectin and several phosphates are added as well to enhance texture and consistency. Soy yogurt may contain lactic acid, which is naturally produced during dairy yogurt production.