By improving texture and flavor characteristics, ingredient has promise in low-fat applications
Mono-diglycerides are used in many food items including meat products. They can be used as either an efficient binder or as a basic or incidental product for a variety of ingredient blends.
Illertissen, Germany-based The Gruenau Corp. specializes in manufacturing different chain length mono-diglycerides. These ingredients used in combination with phosphates, protein and herbs can lead to synergistic effects including improving water binding and inhibiting bacterial growth, according to the company.
C.G. Stabilizer, for example, is a product which controls water activity in protein cells and tackles bacterial growth as well as many types of microbiological hazards successfully.
The results are good water binding capability and less risk in processing.
Meat and sausage products
The purpose for using mono-diglycerides in meat products is to improve texture and flavor characteristics, water holding capacity, emulsifying capacity and emulsion stability.
Mono-diglycerides hold particular promise in creating new low-fat and low-salt meat products.
Emulsifiers such as mono-diglycerides are surface-active substances. The characteristic feature of these compounds is their ambiphilic (fat soluble) molecular structure. The emulsifier molecule consists of a lipophilic and a hydrophilic (water soluble) part. In a fat-water system, emulsifiers interact with both substances.
With mono-diglycerides, a film is formed at the interface between fat and water as a result of the solubility of the lipophilic fatty acid and the orientation of the hydrated glycerin part to water.
The Gruenau Corp. has developed a range of emulsifiers which differ in content of mono-diglycerides and in the level of esterification (i.e., change to an ester-an organic compound, comparable to an inorganic salt) with lactic and citric acids.
These improvements are because of the fundamental surface-active properties, such as wetting, emulsification and solvent dispersing.
There are also specific effects in meats-the most important of which are the interactions with the lipids and proteins of meat and other recipe components.
Fundamentals of binding
Water and fat stabilization are the decisive factors in producing a firm, elastic and heat-stable product. The manufacture of the finely comminuted meats is as follows:
-- Work in and fix the moisture native to the meat and the added water in the lean meat.
-- Emulsify the free fat constituents into this hydrophilic lean meat mixture with high water content.
-- The fat is liquid throughout most of the cooking process and should be protected from coalescence. During heat treatment, the protein denatures, and the fat particles will melt and move to the surface if there is no sufficient stabilization and/or emulsification.
A microscopic view shows different structures of stabilization. Either fat particles are immobilized in a swollen protein network or sometimes a protein film holds the fat globules together.
With mono-diglycerides, the protein cell is finely organized and the movement of water is efficiently reduced. Jelly formation is thus avoided.
Because of the extremely fine dispersion, the fat content can be reduced by more than 50 percent without a reduction of sensory advantages. The 3-D protein network is filled with small fat particles instead of coarse fat globules.
When working with a reduced-salt content, the formation of a protein membrane surrounding the fat globules is not sufficient. In this case, a mono-molecular layer of mono-diglycerides around the fat particles is supporting the stabilization in finely comminuted meat.
Sodium chloride (NaC1) has been utilized in the production of finely comminuted sausages for centuries because it imparts desirable flavor and texture characteristics to meat products. Fat, traditionally an important part of frankfurter-type products, has also been linked to heart disease and atherosclerosis. Although the relationship between fat and salt and hypertension and heart disease is not a simple one, meat processors are faced with growing demand for low-salt and low-fat meat products.
The trend to leaner meat is very welcome, however, it bears the dangerous situation of unstable products with the risk of water separation because of regular release and various types of processing.
The results of these conditions are the separating of minerals, meat juice, fat and protein into an unwelcome bacterial flora.
Retaining valuable meat juice not only makes economic sense, but even more important it reduces purge to a minimum, which automatically gives a better product and extended shelf life. The economic loss is money, the health risk is dangerous.
It is a risky run against a time bomb. A Hazard Analysis and Critical Control Point program is unmatched worldwide and leads in the right direction, but even the best control system can not replace quality, stability and safety if the product is not technically safe.
Natural companions
Mono-diglycerides are natural companions to triglycerides. They are also formed during the enzymatic splitting of triglycerides in the digestive system, with 75 percent of the nutrient fat being absorbed as 2-monoglycerides and thus returned to the metabolism.
Mono-diglycerides are fully digestible and have no toxicological effects.
They are safe and also technically necessary. The physiological and toxicological assessment and classification of emulsifiers are confirmed by FDA and a Joint World Health Organization and Food and Agricultural Organization Expert Committee on Food Additives.
Mono-diglycerides are generally recognized as safe and have been used for more than 40 years in many food systems.
All about mono-diglycerides
The following Q&A was conducted between MM&T and a spokesperson for Illertissen, Germany-based Gruenau GMbH.
Q: It has been said that an increasing number of meat companies are looking into using mono-diglycerides as a binder and shelf-life extender. What are the major features of using mono-diglycerides over competitive ingredients both in terms of binding and shelf-life extension?
A: The role of mono-diglycerides in stabilizing emulsions is well documented and applied extensively. However, attention has focused on the beneficial role of mono-diglycerides in other food application areas.
Mono-diglycerides, in addition to their emulsifying properties, play various significant roles in different ways as multi-functional ingredients (starch complexing, protein complexing, lubrication, control of crystallization, antibacterial agent and improved freeze/thaw stability.)
From this overview, it can be seen that in the future the major influence of mono-diglycerides in the red meat industry will be achieved by using them in combination with other additives like starches, proteins, phosphates and hydrocolloids.
Consequently, optimum synergistic effects with excellent results are obtained. In fact, the combination of phosphate, meat protein and mono-diglycerides in meat systems-used for many years in Germany and other countries-is the cornerstone for safety, stability and shelf life.
Mono-diglycerides are new in the [U.S.] meat industry. However, several companies are utilizing them as incidental additives. We just recently obtained USDA approval for use in low-fat and low-salt systems covered by Memo No. 123.
Q: Technically speaking, how do mono-diglycerides work?
A: Because of the supporting effect of mono-diglycerides, a better dispersion and fat crystallization can be achieved.
It is possible to establish a fine protein matrix structure with finely dispersed fat and thus considerably improve the product texture.
Q: When are mono-diglycerides incorporated into a meat product during processing? How is it incorporated into the product?
A: The method of incorporation depends on the manufacturing technique and the recipe chosen. In most cases, the powder form is best suitable to develop the desired properties in the final product.
When producing sausages, for example, the emulsifier is added in powder form together with salt and phosphate.
Q: What predictions do you have for future mono-diglycerides use in the U.S. meat industry?
A: Those who are involved in selling food ingredients are well advised not only to have well-prepared arguments with regard to price and technological advantages, but also arguments related to their safety (non-toxicity) and the legal situation.
Developing new ingredients is a long and expensive process. With the current lead time required for scientific development and FDA approval, it may take 10 years or more.
Mono-diglycerides are an approved product range and are generally recognized as safe. It is possible to introduce fairly new emulsifier-types without any legislation problems, especially by using a combination of different mono-diglycerides.
At this time, mono-diglycerides are only approved for Memo 123 products. However, this will be an important consideration for tailor-made products in the near future.
Such a new generation of emulsifiers could be the key to new food markets and product ranges.
Another important fact is that mono-diglycerides are based on naturally renewable raw material sources that have been used for more than 40 years in many food systems. They are proven safe and perfect where stability, shelf life and firm texture is required.