Mono- and diglycerides (of fatty acids) are the most common emulsifiers used in food manufacturing. Mono- and diglycerides can attach to both oil and water and are used to combine them in products, such as margarine, ice cream, mayonnaise, salad dressings, and low-cost cooking spray.

Many other products that use both oil and water, that would separate without the addition of an emulsifier, can use mono- and diglycerides. A classic example is peanut butter. Natural peanut butter does not contain an emulsifier, so the peanut oil naturally rises to the top. By adding an emulsifier, as is done with most peanut butter, the oil remains fully incorporated in the peanut butter.

Another popular use is in baked goods; the mono- and diglycerides improve the gluten bond in the dough so it can rise higher and increase the volume and softness. Another advantage is that the combinations of mono- and diglycerides with the starch in the food slows the natural hardening of the starch, extending the freshness and the softness of the product.

Vegetable oils and animal fats both have the same chemical makeup, with triglycerides as the main component. The name itself describes the makeup. The backbone is glycerin and there are three chains of fatty acids attached to the glycerin. As the name suggests, monoglycerides have one fatty chain and diglycerides have two. The mono- and diglycerides are both naturally present in different oils, but in low levels that are not sufficient for industrial production.

The triglycerides are reacted with glycerin and a catalyst in a reactor at high temperature (over 200℃/392℉) to break and reform the fatty acid chain from triglycerides into mono and diglycerides with the desired characteristics. The outcome of this process is a mixture of mono-, di- and triglycerides.

The mono- and diglycerides are separated and purified through distillation and then further processed according to the desired texture and end-use application.

Mono- and diglycerides are a highly kosher sensitive ingredient, because the main ingredients, triglycerides and glycerin1, can be derived from animal fat or processed, stored, or transported on the same equipment as animal fat. Any product containing mono- and diglycerides should only be purchased with reliable kosher certification.

  1. See more about the kashrus of glycerin in the Fall 2015 issue of the Kosher Spirit.