VERSENE
EDTA
Food-Grade Chelating Agents
Trace-metal control for food applications
VERSENE
EDTA
Food-Grade Chelating Agents
Do your food products exhibit the common symptoms of trace-metal reactions listed below?
Trace amounts of soluble copper, iron, or another metal could be the cause By accelerating undesirable chemical reactions, trace amounts of soluble iron, copper, and other metals can degrade the quality, shelf-life, and value of food products. Flavor, color, clarity, stability, and vitamin content can all be affected. Even though trace metals can be found in practically all processed foods, they are often overlooked as the cause of these problems. Almost any food product can be affected Because trace metals occur naturally in all plant and animal tissues, are normally found in processing water, and can also be introduced by processing equipment, the potential for undesirable metal-catalyzed reactions is widespread. In many instances, uncontrolled metal ions can affect a food's flavor, quality, nutritional content, consumer appeal, and ultimate value. Emulsified products are particularly vulnerable One major problem is the metal-catalyzed oxidation of fats and oils. Emulsified products are particularly sensitive. In products such as salad dressings, mayonnaise, sauces, and spreads, as little as 0.5 to 1.0 ppm copper or iron can oxidize fatty oils, leading to rancidity. Color changes, off-flavors, and emulsion instability can also occur. In reduced-fat and low-fat products of this type, flavor stability is particularly delicate. Seafood, pickles, canned vegetables and beverages also suffer In canned seafood, naturally high levels of copper, zinc, tin, and iron combine with organics to cause discoloration, rancidity, off-flavors, and off-odors. The formation of struvite crystals (magnesium ammonium phosphate) in canned seafoods results from high concentrations of magnesium. Trace amounts of copper and iron in pickled cucumbers can lead to problems with color, flavor, and texture. In canned beans, trace metals contribute to darkening, graying, and skin breakage during retort and storage. In potato processing, iron combines with naturally-present compounds to darken or grey the potato flesh. This problem occurs in both frozen and canned potatoes. Other canned vegetables are subject to similar effects. In beverages, 0.05 ppm copper or iron can lead to flavor loss, color fading, and degradation of formulation ingredients, especially vitamins. Ascorbic acid has been shown to degrade rapidly in the presence of trace quantities of copper.
Discoloration Rancidity Off-odors Off-flavors Color loss Precipitation Loss of clarity Vitamin degradation Crystal formation Reduced shelf-life
CaNa2EDTA Control
VERSENE * CA food-grade EDTA prevents loss of color in pickled products by controlling copper and iron.
*Trademark of The Dow Chemical Company
2
Applications which benefit from VERSENE Food-Grade EDTA products
Dressings & sauces Mayonnaise
How VERSENE food-grade EDTA products stop metal ion reactions from degrading the value of food products Chelating agents (sometimes referred to as sequestering agents) inhibit undesirable reactions in foods by complexing metal ions. The resulting structure, called a chelate, immobilizes the metal ion and prevents it from reacting with other components in the system. For the food problems described in this brochure, only EDTA chelating agents provide effective metal ion control under typical food conditions. EDTA (ethylenediaminetetraacetate) forms highly stable complexes with metal ions and is a cost-effective solution due to its effectiveness at remarkably low concentrations. Use of EDTA in food products is regulated under the US Food, Drug and Cosmetic Act. Table 1 on page 5 summarizes applications where VERSENE CA and VERSENE NA food-grade EDTA products are cleared for use in foods. EDTA locks up troublesome metal ions in a highly stable complex Soluble trace metals in the aqueous component of foods exist as positively charged ions. Each of these ions has a number of coordination sites (associated with molecular orbitals) which are referred to as "reactive sites". Copper and iron ions, the most frequent troublemakers in foods, often have either four or six reactive sites. Figure 1 illustrates how the EDTA molecule can block up to six reactive sites on a metal ion, completely deactivating the ion. Equally important, the intrinsically strong, five-sided ring structures in this complex are highly stable, even under heat and light, and over a wide pH range. In foods, this can translate into longer shelf-life even in adverse conditions. VERSENE food-grade EDTA products can help you reduce ingredient costs Because they are so efficient, VERSENE CA and VERSENE NA food-grade EDTA can provide the protection you need at low concentrations. Typical use levels are from 30 ppm in beverages, 70 ppm in sauces and dressings, and 150 to 300 ppm in canned products. VERSENE products offer greater pH and heat stability The stability of complexes formed by chelating agents and metals is a critical factor in ensuring food product quality. If the complexes are not stable, they can break down during or after processing, freeing the metals to react with
Margarine Canned vegetables Beverages Pickles Seafood
foods. The heat and pH stability of EDTA chelating agents make them highly effective metal ion control agents under typical food conditions. EDTA is stable up to 400°F, which means metals remain complexed under the temperature conditions most commonly associated with food processing operations. What's more, EDTA-metal complexes remain stable throughout the typical food pH range. EDTA-metal complexes even remain stable under combined conditions of low pH and high temperatures. VERSENE food-grade EDTA products have no equal To prevent oxidation, degradation, and trace metal catalyzed reactions in foods, an extreme level of control is required. The best measure of this is the stability constant of the complex. High stability constants mean stronger, more thorough control. In practicle terms, this higher strength is required and only EDTA can provide it.
Figure 1: EDTA surrounds and immobilizes problem ions with a stable ring structure
Complex between metal ion and EDTA--This illustration shows how the EDTA molecule can block up to six reactive sites on a metal ion, deactivating the ion. The highly stable ring structures contribute excellent pH, heat, and light stability to these complexes.
3
VERSENE
EDTA
Food-Grade Chelating Agents less, and tasteless at recommended use levels. And both products are certified by the Orthodox Union as Kosher and Pareve for Passover use. VERSENE CA food-grade EDTA is highly purified calcium disodium EDTA which meets all requirements for Calcium Disodium EDTA as specified in the Food Chemicals Codex and for Edetate Calcium Disodium as specified in the U.S. Pharmacopoeia. VERSENE NA food-grade EDTA is highly purified disodium EDTA which meets all requirements for Disodium EDTA as specified in the Food Chemicals Codex and for Edetate Disodium as specified in the U.S. Pharmacopoeia.
Although citric acid, phosphates, and lactates are sometimes promoted as metal ion control agents in food applications, Figures 2 and 3 show that these materials are nowhere near as strong as EDTA in the typical food pH range and are particularly ineffective for copper and iron--the metals which can cause most degradation problems. The data show why EDTA is clearly the only effective solution to metals problems. VERSENE products are also used in indirect food applications In addition to the direct uses for VERSENE food-grade EDTA products, a number of indirect food uses for other VERSENE chelating agents are allowed by the FDA and USDA . For example, VERSENE products are used for scale removal in food processing lines. This technique is widely practiced in the brewing industry to remove calcium-derived precipitates (beer stone). Unlike acid cleaning, flushing with a VERSENE chelating agent removes the scale without attacking system components. Dairy, meat, sugar, and other food processing facilities also use cleaning solutions that incorporate VERSENE chelating agents to clean processing equipment. Other indirect food applications include food packaging materials; cleaning, sanitizing, and laundering formulations; lubricants; and a number of others. For more information and a complete listing of indirect food uses for VERSENE products, call the phone number for your region listed on the back of this brochure. Where to use VERSENE CA and VERSENE NA chelating agents Listed on the next page are specific US FDA-allowed uses as well as a number of uses in which EDTA has demonstrated utility but which are not currently allowed by the FDA. Several applications are allowed in Europe by EU regulations. These are noted in Table 1. Clearances for food-grade EDTA exist in Canada, Japan, and many other countries. Contact Dow at the numbers in the back of this brochure for more information. New product applications require that a petition be filed with the FDA. If you are interested in developing an application for EDTA in food, our Technical Service and Development team for VERSENE products will be happy to assist you in your developmental work. Two versatile food-grade products to meet your needs The availability of two VERSENE food-grade EDTA products gives you excellent formulating flexibility. Both products are white crystalline powders which dissolve readily in water. Both are essentially odorless, color-
Figure 2: Conditional stability constants versus pH for iron complexes with EDTA, citrate, and pyrophosphate.
Fe (Iron) 16 14 12 10 8 6 4 2 2 Citrate Pyrophosphate 3 4 5 6 7 8 EDTA
