Such gourmet convenience meals started rolling out during the recession, when many consumers traded down from dining out and take-out. Today, many of these retail prepared foods, which simply require heating prior to eating, have earned a strong customer base. So long as they continue to deliver on quality, sales will likely grow.

According to a consumer study by Packaged Facts, a division of Marketresearch.com, Rockville, Md., since the recession began, 49% of adults surveyed said that they had eaten less at fast-food restaurants and 50% said they’d eaten less fast-food takeout, while 61% said they’d eaten less at sit-down restaurants.

In recent months, though all types of restaurants are reporting improved sales, eating at home has become much more attractive thanks to convenience meals sold at the supermarket. The key to growing this category of foods is quality. The meals must resemble foods served at restaurants in terms of appearance, flavor and overall eating experience.

Phosphates are key ingredients in most of the protein components of these meals, as phosphates can aid processing and improve the eating quality of meat, poultry and fish. Food-grade phosphates are typically available as salts and produced by neutralization of phosphoric acid (one phosphorus atom with four oxygen atoms) with a metal element such as potassium and sodium.

Phosphate ingredients can be very simple and contain only one phosphate unit. There are also pyrophosphates with two phosphate units, tripolyphosphates with three units and polyphosphates containing more than three phosphate units. For labeling purposes, USDA allows all approved phosphates to be collectively labeled as potassium phosphates or sodium phosphates, instead of using complex chemicals names.

Though labeled similarly, these compounds have different functionalities, which is why it is important to work closely with your supplier to identify the right phosphate(s) for the application. It is quite common that a customized blend of phosphates will perform the best.

In processed proteins such as luncheon meat, sausages and chicken nuggets, phosphates are used for moisture retention (retaining marinade and cook juices), which improves yield, as well as flavor protection (reducing oxidation and chelating metals). The proteins being incorporated into premium frozen meals rely on phosphates for additional reasons, including preserving color and providing freeze/thaw stability.

The quality and cut of the animal proteins intended for these frozen meals influences the finished product’s premium positioning. Most use whole protein pieces, such as slices of steak or cubes of chicken. Phosphates are added to these whole pieces through the addition of an industrial marinade, which is added by a protein packer by either injection or tumbling.

USDA limits the amount of phosphate that can go into animal proteins, with the maximum usage level resulting in 0.5% in the finished product. Most industrial marinades will contain 1% to 3% phosphate, which provides enough of the desired benefits without producing any off flavors, which is possible near the 0.5% maximum.

Some protein pieces that go into these meals, as well as processed meats, are formed products. In other words, whole-muscle protein is chopped and ground. Spices, binders and other ingredients, such as phosphates, are added to help the protein emulsion hold up during cooking and processing.

Phosphates help extract proteins from meat, whether chopped or whole-muscle. Phosphate type is critical for optimal performance and varies by application. Alkaline phosphates increase pH about 0.1 to 0.6 units, depending upon the phosphate, with pyrophosphates having the greatest effect, while hexametaphosphates having little impact. Acid pyrophosphates can decrease protein pH. Increasing or decreasing the pH away from the protein’s isoelectric point increases its water-holding capacity.

Another important consideration when choosing a phosphate ingredient is its solubility, which varies by application and other ingredients in the formulation. Not only is the protein not reaping the benefits of the phosphate if it does not dissolve in solution, phosphate particles will be visible on the protein, and this is distracting and unappealing to the consumer.

Phosphates are also frequently added to curing solutions and cured product formulations, as in addition to the benefits already identified, the water-retention attribute reduces shrinkage (moisture loss) and purge (cook-out) of fermented and cured comminuted products during further-processing. Phosphates also improve the stability and uniformity of the cure color.

Protein packers selling protein ingredients to manufacturers who assemble frozen meals will want to make sure that phosphates, with all of their many functionalities, are part of their process.