Not only has the coronavirus (COVID-19) pandemic changed the way consumers shop, cook and eat at home, it’s completely overhauled grab-and-go and institutional foodservice, putting increased demands on food integrity. This includes fully cooked meat and poultry products, such as the slices in the pre-made packaged sandwich, the strips in ready-to-eat salads and the cubes in snack packs.
It is acceptable, in fact to some consumers it’s inviting, to see fully cooked packaged meat and poultry sold at retail having some juice on the surface. This visually communicates the product is moist and tender. Sitting in juices is not appealing, especially in partitioned salad bowls or in a multi-package salad kit.
The same is true with the growing number of varied meat-containing snack packs in the market. Excess liquid may be associated with product breakdown, even spoilage.
Packaged sandwiches have always been challenged, as it is paramount that the meat does not make the bread soggy through moisture migration. At the same time, the meat should not easily dry out, particularly around the edges that are on display at time of purchase. The demand for such sandwiches has skyrocketed, especially in the convenience-store channel and coffee shops. Hospital cafeterias and university dining halls that previously had build-a-sandwich bars have turned to pre-made options, complete with meat, cheese, lettuce, tomato and condiments.
Food manufacturers and commissaries are responding with increased options of all types of packaged convenience meat-containing products. Vacuum refrigerated packaging may assist with ensuring product integrity, possibly even extending shelf life a few days. In some instances, including a moisture absorber in the package is helpful; however, this must be done carefully so that it is clearly labeled as being inedible.
One of the first places to start with managing moisture in such packaged products is during the preparation and cooking of the meat and poultry component. Moisture binders enhance the ability of protein fibers to bond with water. This tenderizes the meat and increases its weight, thus improving yield and contributing to positive economics for the processor.
With fully cooked products, bound moisture may improve ease-of-use. That is because moisture binders improve sliceability in deli meats by increasing firmness, which enables faster slicing and a higher percentage of intact slices. The same is true with cubing or dicing meat for finger-food in snack packs and salads.
There are many moisture-enhancing ingredients in the marketplace. Use, including forms and addition levels, is regulated by the US Department of Agriculture (USDA). Before selecting an ingredient system, a product developer should determine if there are any labeling restrictions, e.g., organic, natural, uncured, etc., as well as the target finished product moisture content after cooking and over shelf life. This includes knowing the intended use of the meat. If it’s going in a sandwich or on a pre-made salad or snack pack, that moisture needs to be bound tightly.
Phosphates have long been used as cost-effective tools to bind moisture in meat processing, in particular with whole muscle intended for fully cooked deli-style meats and comminuted products. Phosphates are “generally recognized as safe” (GRAS) by the US Food and Drug Administration (FDA), which shares responsibility with the Food Safety and Inspection Service (FSIS) of USDA when it comes to ingredients intended for meat and poultry. It is the latter that regulates usage of the ingredients in specific applications. Such GRAS ingredients include substances considered harmless under prescribed conditions.
Phosphates have been embraced by meat and poultry processors for years and will continue to be used for their powerful and economical functional properties. Many processors, however, are eliminating such chemical-sounding ingredients from product formulations. It is possible, but with some shortcomings, namely higher prices and reduced shelf life.
Label-reading consumers may find this surprising, but phosphates are naturally derived ingredients. They are obtained from mined phosphate rock, which is the element phosphorus combined with metal cations, such as potassium and sodium. They are one of the building blocks of all life, with every living cell – plant and human – requiring it. Most fertilizers include phosphorus, even those certified organic. Some phosphates, albeit not those typically used in meat and poultry, are included on the list of the 5% of nonorganic ingredients allowed in organic certified foods.
Processors rely on an array of phosphates for different functions. They differ in solubility and their impact on finished product pH, which influences selection in an application. Limited solubility, for example, may result in phosphate precipitation in processed meats after cooking and chilling. This may produce gritty texture.
Phosphates basically work by raising the pH of meat, which causes protein fibers to unfold, opening up the protein structure. Once opened, phosphates and water bind with protein molecules.
The pH of phosphates can range from about 5 to more than 10, but most are at neutral pH 7 or higher. Neutral and acidic phosphates may enhance desirable cured color. The more acidic the phosphate, the lower its water-binding capacity. More alkaline phosphates will raise the pH of the meat, which increases the muscle’s water-holding capacity.
As mentioned, there are many forms of phosphates, each possessing unique functionalities. Most are linear molecules and contain a single phosphate (ortho), two phosphates (pyro) or three or more phosphates (poly). There are also metaphosphates, which are composed of several phosphates in a ring-shape structure. Processors will often use blends of phosphates to achieve specific finished product attributes.
Processors need to be aware that most phosphates are sodium based; thus, if reducing sodium content is a concern, it might make sense to opt for potassium phosphates, when available. However, because potassium often contributes bitter notes, there may be an impact on flavor. Regardless of type, phosphates tend to be self-limiting, as too much negatively impacts flavor and quality. Nevertheless, USDA limits the amount of phosphate that can be used in meat and poultry to 8 oz per 100 lbs of product.
Phosphates are permitted in whole muscle bone-in and boneless products. The application of phosphates for whole-muscle products is by injection, vacuum or static marination. For ground and comminuted systems such as sausages, hot dogs, bologna and meatballs, phosphates are applied in a dry or in solution form.
Carrageenan, a seaweed extract, is also a traditional water binder in fully cooked meat products, most notably ham and poultry. There are three types of carrageenan classified by seaweed source, which influences its performance. Kappa carrageenan, for example, is the form typically used in meat processing, as it forms a strong, brittle-like gel that improves sliceability, lowers cook loss, decreases purge loss and enhances texture.
Two years ago, Applegate, Bridgewater, NJ, started removing carrageenan from its poultry deli meat varieties because of growing consumer concerns regarding its safety. Some studies suggest it is highly inflammatory and toxic to the digestive tract.
Nothing has changed in the regulatory world in terms of its safety and use in foods. In fact, being plant derived, it’s allowed in vegan foods, and in the United States, it can be included in organic foods, too.
The company switched to organic potato starch as a clean label water-binding ingredient. Potato starch has a low gelatinization temperature and it swells fast. This, combined with its bland flavor and neutral color, make it very adaptable to fully cooked meat applications.
Potato starch is one of many hydrocolloids that offer simpler labeling. Native waxy rice starch is another. It improves yields in both phosphate and phosphate-free products.
In a phosphate-free system for chicken, for example, rice starch increased yield seven percentage points higher than the control. In a phosphate-containing system, there was even greater impact, as much as 18 percentage points over the control.
These benefits are due to the structure of amylopectin and its ratio to amylose in rice starch. The configuration ensures that there is very low retrogradation, enabling water retention to be maintained after the poultry has been packed.
Citrus fiber ingredients are another option. Derived from various citrus plants, the ingredient contains both insoluble and soluble fiber, which contains natural intact pectin. This contributes to its high water-binding and emulsification properties. Fine grades are made for injections while coarser ingredients are more suited for ground and comminuted meat products.
Other fruit-derived ingredients have water-binding properties, too. Ingredients made of prune plums, for example, accomplish this because of their high sorbitol and pectin content. Sorbitol is a slow-metabolizing sugar alcohol that is also hygroscopic, which means it attracts moisture. Fresh plum concentrate can be added to a brine or marinade and then injected into or vacuum-tumbled with whole-muscle meat. Dried plum powder can be massaged on the exterior of whole-muscle meat to reduce purge. The same powder, as well as dried plum puree, can be added to sausages for moisture binding.
Honey may also assist with binding water, while contributing a desirable sweet flavor, and depending on the honey, some color. There are important considerations when working with honey in product development, as honey contains enzymes that can break down other ingredients in a formulation, impacting the finished product. Honey varies in color, flavor and even consistency, based on the flower from which worker bees extract nectar that eventually becomes honey. The colors of honey form a continuous range from water white to dark amber. Light-colored honey typically has a mild flavor, while a darker color is more intense. This can be used to provide signature color and flavor to meat and poultry products.
Honey is also about as clean label as an ingredient gets. But if clean label is not a priority, modified starches are an option, with or without phosphates. They bind moisture, provide heat and shear stability, extend shelf life and improve freeze/thaw stability and texture.
Like carrageenan, other gums may be used to immobilize water. Gums react with the polar part of protein, forming hydrogen bonds with free water and creating a gel. Xanthan gum, for example, is a hydrocolloid produced through bacterial fermentation. It binds water and emulsifies fully cooked meats, while also stabilizing color and flavor.
Most moisture-enhancing ingredients are multi-functional, which is why it’s not a one-size-fits-all product development platform. Knowing your end-product goals is critical for success. When adding any type of water binder to meat and poultry, it is best to start at a low-use level and then slowly increase addition, as needed, to the maximum allowed. If levels are too high in a product, it may develop a soft, gummy texture or even a slimy surface. This is highly undesirable in packaged convenience meats, even more so than being wet.