Mono and diglycerides (EU) are used in a diverse variety of food categories. This category of emulsifiers offers the food industry many solutions for optimal product formulation and processing. I will highlight a few below.
Understanding the Basics
Chemically, fats are composed of esters formed from glycerol and fatty acids. Fats and oils are most commonly termed triglycerides and have three fatty acids, while monoglycerides have one fatty acid, and as the name suggests, diglycerides have two fatty acids.
When manufactured, mono and diglycerides may use animal fats or vegetable oils (soybean, canola or rapeseed, sunflower, cottonseed, coconut or palm oil) as the starting material. An alkaline catalyst is used with high temperatures to create a blend of mono-, di-, and triglycerides, and a small amount of glycerol. Monoglycerides can be separated from this mix using distillation methods, then processed further to give the ingredient additional functionality in a formula.
Further refinement of monoglycerides include:
- Distilled Monoglycerides (or DMG/Glycerol Monostearate) (EU)
- Ethoxylated Monoglycerides (EU)
- Citric Acid Esters of Monoglycerides (EU)
- Lactic Acid Esters of Monoglycerides (EU)
- Acetic Acid Ester of Monoglycerides (EU)
- Diacetyl Tartaric Esters of Mono- and Diglycerides (DATEM) (EU)
Functional properties of mono- and diglycerides are determined by:
- Percent of Monoglycerides.
- How well the blend stabilizes an emulsion of two unmixable substances (water-in-oil or oil-in water emulsions). This is referred to as the hydrophilic-lipophilic balance – more on this later.
- Type of fat used as the base ingredient.
- If the original fat is saturated or unsaturated.
- Crystal form – Like fats, mono- and diglycerides have three major crystalline forms. These are referred to as alpha-, beta’- (beta prime-), or beta-crystals, with alpha- form being the most highly functional, but over time some have a tendency to convert to the more stable beta forms, which are still moderately functional.
Hydrophilic – Lipophilic Balance
Within the monoglyceride molecule, the glycerol “head” is hydrophilic, meaning it favors water and the fatty acid chain – or “tail”- is lipophilic, meaning it favors oil. The hydrophilic-lipophilic balance (HLB) number is an indication of solubility of an emulsifier, and the scale is a value between 0 and 20. Keep in mind that this value doesn’t provide a whole picture of how it will behave in a formula, as most food products are made up of more than just water and oil, but it can give you indications of potential uses.
- Low HLB values are more soluble in oil, and promote water-in-oil emulsions.
- Higher HLB values are more soluble in water, and promote oil-in-water emulsions.
Key Functions of Mono- and Diglycerides
Aeration, Agglomeration and Emulsification:
- Mono- and diglycerides are effective at stabilizing foods where a visible separation would occur over time without its use, such as peanut butter, coffee creamers, margarine or mayonnaise.
- Air-in-liquid emulsions, like cake batter or ice cream, quickly produce and stabilize air pockets when a mono- or diglyceride is added to the formula. In cakes using cake shortening containing monoglycerides, air and fat are dispersed into finer particles in the batter, giving the baked cake a higher volume and a fine, even grain. In ice creams, incorporating emulsifiers into the formula will yield a more stable foam structure, with smoother body and texture.
Starch Complexing and Protein Interaction:
- Mono-and diglycerides slow the retrogradation of starch, seen during the staling of baked goods like bread and cakes. This is the tendency for starch granules to recrystallize and force water out of the baked gelatinized matrix. The addition of mono- and diglycerides also improves the shelf life of baked products, improves the softness and makes the crumb softness last longer.
- Mono- and diglycerides have an effect on gluten protein in baked products. When bread dough is formed, the gluten forms an elastic network to trap leavening gases, causing the dough to rise. With a weak network, gases may be lost, causing losses in bread volume. Using DATEM or sometimes ethoxylated monoglycerides in your formulation will aid in improving this network, no matter if caused by annual wheat crop variation or mixing tolerance.
Fat Interaction and Crystal Modification:
- Since mono- and diglycerides are created using fat, they can influence the fat content of a formula in many ways. Mono- and diglycerides are added in margarines and spreads to emulsify ingredients and provide crystal modification. In meats and sausages, citric acid esters of monoglycerides can aid in better fat distribution and improved emulsification.
- Mono- and diglycerides can be added to your formulation to aid in the prevention of sticking during processing. It is effective when drum drying, as well as when extruding starch based products.
Additional Formulation Insights:
- Use levels will be very low in comparison to other ingredients in your formula. Refer to country’s regulatory information to determine if limits are in place.
- Sometimes a blend of multiple types of mono- and diglycerides, as well as other emulsifiers, will be needed to give the best performance in your final product.
- Mono- and diglycerides may aid in reduction of fat from your formulation, or allow you to switch to liquid oil, with little impact on your product texture or shelf life.
- Developers can work with emulsifier vendors to identify a mono-and diglyceride blend to achieve the desired finished product attributes. Also, consult your supplier to learn of any pre-processing that must occur – such as heating – to get the most benefit out of your mono- and diglyceride blend.
- With the consumer push for clean-labeled products, be aware of how your consumer feels about mono- and diglycerides in a product – alternatives, like soy lecithin may be perceived differently. Vegetarians and vegans may express concern over the fat source, and if it is animal or vegetable based. GMO oils for the base material may also be a concern that your consumer may bring up as a potential concern.
This only briefly begins to cover the subject of mono- and diglycerides in formulating. Your supplier may be able to assist in finding the ideal product to fit your formula needs.
Product Resources – North America
Loders Croklaan – Durlac™ 100 W
Loders Croklaan – Durem™ 114
Loders Croklaan – Durem™ 300
DuPont Danisco – Dimodan® HP K-A
DuPont Danisco – Grindsted® Mono-Di HV 52 K-A
DuPont Danisco – Panodan® 205 K
Product Resources – Europe
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