Diglycerides are a common food additive derived from fats and oils, scientifically known as a partial glyceride. While found in small amounts naturally in seed oils, the versions used in mass food production are manufactured. Their purpose is to improve the texture and consistency of processed foods.
The Function of Diglycerides in Food Products
The primary role of diglycerides in the food industry is to act as an emulsifier. Emulsifiers are substances that help to mix ingredients that do not normally combine, such as oil and water. By stabilizing these mixtures, they prevent separation and create a uniform consistency in the final product.
This emulsifying property directly impacts the texture, stability, and shelf life of a wide range of food items. In baked goods like bread and cakes, diglycerides improve dough texture and moisture retention, which helps to keep the products soft and fresh for longer. They also create a creamy mouthfeel in ice cream and prevent the formation of large ice crystals, while in margarine and mayonnaise, they keep the oil and water components from separating. Consumers can also find them in products like coffee creamers, whipped toppings, and nut butters.
Chemical Structure and Production
To understand diglycerides, it helps to compare them to triglycerides. Most dietary fats are composed of triglycerides, which consist of a glycerol molecule attached to three fatty acid chains. Diglycerides have a similar structure but with only two fatty acid chains attached to the glycerol backbone, while monoglycerides have just one.
Although diglycerides occur naturally in oils like soybean and palm oil, their concentration is too low for commercial use. They are produced through a process called glycerolysis, which involves heating triglycerides from vegetable oils with glycerol. This reaction breaks down and reassembles the molecules into a mixture containing monoglycerides and diglycerides, which are then purified for use as a food additive.
Safety and Health Profile
The U.S. Food and Drug Administration (FDA) classifies diglycerides as Generally Recognized as Safe (GRAS), meaning they can be used in food without a specified daily intake limit. This designation is based on the fact that the body digests and metabolizes mono- and diglycerides in the same way it processes other dietary fats. They are broken down during normal fat digestion and provide approximately nine calories per gram.
Diglycerides are chemically distinct substances from trans fats, though they are often used in the same processed foods. It is important to note that small amounts of trans fats can sometimes be formed during the manufacturing process of mono- and diglycerides. For this reason, individuals aiming to minimize their intake of processed fats may choose to limit foods containing these additives.
International bodies like the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA) have also evaluated mono- and diglycerides. They concluded these additives do not pose a safety concern at current levels of use in food.