Label-Friendly Meat Shelf-Life Solutions

By Donna Berry, Contributing Editor

Long-distance distribution networks and convenience-craving consumers have meat processors exploring methods to extend the shelf life of all types of proteinsfrom marinated, raw, prepackaged chicken breasts to fully cooked slabs of ribs to simple ground beef. Factor in that an increasing number of consumers seek out labels with terms such as natural" and minimally processed," and take a pass on chemical-sounding" names in the ingredient list, and this dramatically reduces the available options for ensuring product longevity.

The shelf life of meat products is limited by microbial spoilage and oxidative rancidity," says Kristen Robbins, assistant manager of research and development, Kemin Food Technologies, Des Moines, IA. Rancidity is responsible for flavor deterioration and color loss, and is also the primary mode of failure for frozen processed meats."

Artificial preservatives such as BHA, BHT and TBHQ have long been the standard to ensure an economically sensible shelf life for fully cooked and packaged meat products. But todays consumer is not interested in such alphabet soup," says Rodger Jonas, director, national sales, P.L. Thomas & Co., Morristown, NJ. They want ingredients that have a clean label and ones that they can recognize."

Plant-based solutions

Many naturally occuring shelf-life extenders can lead a double life. For example, rosemary extract, which is obtained from the bush Rosmarinus officinalis, can be labeled as simply natural flavor" or rosemary extract." It is a concentrated source of carnosic acid, a potent antioxidant that slows the development of oxidative rancidity in meat.

To determine antioxidant power rosemary extracts can be standardized by carnosic acid concentration. Available in powder and liquid form, our rosemary extracts come in a wide range of carnosic-acid concentrations, including 4%, 6%, 15%, 20%, 40% and higher," says Jonas. They can be dispersed in brine and injected into various meats, or dispersed into a solution with other flavors and topically sprayed onto meats. Another option is to dry-blend the powdered form with seasonings and apply it topically by either tumbling or through a batter. It can also be added directly to the blender, mixer or mincer."

In a shelf-life test, rosemary extract containing 20 ppm of carnosic acid extended the shelf life of ham up to five times the shelf life obtained without any added antioxidant or preservative. At the same time, there was no change of taste, odor or other organoleptic properties," says Jonas.

Green-tea extract is another natural, plant-derived ingredient that has been shown to delay the onset of oxidative rancidity in meat. Not only does dried green-tea extract contain as much as 40% of the antioxidants classified as catechins, half of which are highly effective epigallocatechin gallate (EGCG), it also contains an array of other compounds that facilitate its antioxidant activities. This includes gallic acid, carotenoids, tocopherols, ascorbic acid and minerals such as chromium, manganese, selenium and zinc.

Studies have shown that certain green-tea extracts work better than to synthetic antioxidants such as BHA. The high content of catechins in our green-tea extract maintains the fresh quality of many meat applications for longer, with no unpleasant off-flavors," says Jorgen Sorensen, global business director for natural extracts, Danisco, New Century, KS.

Heng Tsang, culinary and meat industry manager, BioActives, a division of Danisco, adds: Standardization is crucial when dealing with plant-based active ingredients. We show customers that natural extracts can be as effective and dependable as synthetic alternatives." He notes that the company fully standardizes its natural extracts, thereby guaranteeing customers a consistent product, so they get the performance they expect."

Combinations of green-tea and rosemary extracts are also viable options. Oxidative rancidity can be delayed in both raw and cooked ground pork when levels as low as 0.2% are incorporated into the product. Warmed-over flavor can also be delayed in cooked ground pork crumbles," says Robbins. Pork products treated with the green tearosemary extract maintain a desirable meaty flavor without adding unwanted herbal or tea-like flavors, as it is highly effective at levels below its flavor threshold.

Fresh, refrigerated, raw ground pork treated with 0.2% of this green tearosemary extract maintained a desirable red color for a significantly longer period of time than untreated meat or pork treated with green-tea extract alone," Robbins adds.

Color degradation is also a consequence of oxidation in poultry and is a limiting factor in the shelf life of many varieties of minimally processed poultry products, explains Tom Jones, applied technology manager, Kalsec, Kalamazoo, MI. Ground and mechanically separated poultry quickly turns from reddish-pink to a brownish-gray color. Oxidation of oxymyoglobin pigments to metmyoglobin pigments shifts the hue of fresh meat from an appetizing reddish-pink to brownish-gray," he says. This change is accelerated by exposure to light and temperatures typical of retail display conditions. Our rosemary extract extends the color life of ground poultry by way of direct addition, and whole muscle by way of marinades and injection solutions."

Oat opportunity

Oxidation isnt the only problem some natural ingredients tackle in meats. An all-natural, oat-derived flavor modifier extends the shelf life of meat and poultry products while promoting moisture and flavor retention. It is a cost-effective, value-added antioxidant flavor potentiator," says Ron Ratz, director of protein development, Wixon, Inc., St. Francis, WI. An alternative to other meat extenders, such as soy or starch, this flavor modifier intensifies inherit savory notes without adding any visual distractions or off flavors that could negatively impact product taste.

It also adds the benefits of fiber, while reducing the warmed-over flavor often found in pre-cooked meats," adds Ratz. It has been shown to increase moisture retention up to 15 times of the inclusion rate of up to 1.5%, allowing for greater yields in a variety of meat applications." Applications include fresh, frozen, precooked and further-processed meats.

The product is highly effective in conjunction with ground, emulsified and internal addition uses, regardless of species, with minimal impact to pH," says Ratz. This dry ingredient is labeled as: isolated oat product, natural flavor, carrier (customer-specific).

Vitamin E for life

Vitamin E is not only a critical dietary nutrient, it also exerts powerful antioxidative properties when added to select foods, including meat products. There are eight classes of vitamin E, each with different physiological activity and functionality. The side-chain structure determines if it is a tocopherol or tocotrienol. Within each of these groups, the number and position of methyl groups in the chromanol ring determines if it is alpha, beta, gamma or delta. For function as a shelf-life extender, meat processors will often use a mixture of tocopherols, appropriately referred to as mixed tocopherols."

When it comes to retarding development of rancidity in meat products, research suggests that the delta and gamma forms are slightly stronger antioxidants in food systems than the alpha and beta forms. However, in the human body, the alpha-tocopherols have the highest bioavailability. Thus, mixed tocopherols high in non-alpha or beta tocopherols are typically used to prevent lipid oxidation.

Surprise, surprise

Some unexpected ingredients have confirmed shelf-life-extension properties in various proteins.

For example, the naturally occurring organic acids in dried plums, primarily malic acid at 1.5% to 2.0%, combined with the high antioxidant power from an array of phytochemicals, have been linked to the suppression of microbial development in raw and cooked red meats and poultry. In raw meats, the addition of dried plums can provide an extra margin of safety from pathogens associated with food contamination. In precooked meats, the ability of dried plums to minimize the effects of warmed-over flavor is on par with BHA and BHT, explains Jim Degen, spokesperson, California Dried Plum Board, Sacramento, CA.

Dried plums also contain sorbitol, which can act as a humectant to keep meat products, such as ground sausage, moist and palatable. Pastes, purées, butters, powders and juice concentrates give processors a variety of forms to consider in wet and dry batch systems.

A new patent-pending, dairy-based antioxidant and yield-enhancement system offers a cost-effective way to improve flavor, texture, color and shelf life in meat and poultry applications. Labeled as dehydrated whey, this all-natural ingredient is active at usage levels of 0.3% to 0.5% in most applications," says Tim Harried, business development manager, Glanbia Nutritionals, Inc., Monroe, WI. It has application in all meat and poultry proteins. We have seen positive results in cooked applications such as meat patties, sausages, deli meats and loaves. We have also seen excellent performance in raw applications, including sausage and ground-meat patties."

Food scientists long believed the preservative effect of lactic-acid bacteria during the manufacture and subsequent storage of fermented foods was due solely to the acidic conditions created during fermentation, which converts carbohydrates into organic acids. However, researchers have discovered there is more to the preservation process than simply a pH drop. Lactic-acid bacteria produce and excrete a variety of inhibitory substances other than lactic and acetic acids, including ethanol, hydrogen peroxide, diacetyl, free fatty acids, benzoate, antibiotics and bacteriocins. In addition, some beneficial microorganisms inhibit pathogen growth by consuming the resources that pathogens need to survive and proliferate.

A new range of natural shelf life extenders for meat products is based on corn- or cane-sugar fermentations. With customer-friendly ingredient statements such as cultured corn sugar or cultured sugar, vinegar, these products provide excellent microbial control properties," says Robin Peterson, business development manager, Purac America, Lincolnshire, IL. The ingredient is able to extend color stability and shelf life of fresh meat and poultry, as well as enhance juiciness and flavor.

We have developed an ingredient specifically for control of Listeria in select cured and uncured meat items," Peterson adds. In research studies, it was able to prevent two-log Listeria growth up to 120 days."

The bioactive milk protein lactoferrin plays an important role in immune-system response and helps protect the body against infections. It is an ingredient in infant formula, dairy products and chewing gums. In Jan. 2002, USDA approved activated lactoferrin for use on fresh beef, providing beef processors with a potentially powerful technology to protect consumers from pathogenic bacteria.

Activated lactoferrin" describes a unique combination of natural ingredients that mimic the optimum environment necessary for lactoferrins maximum antimicrobial activity. Activation biases lactoferrin to its iron-free and immobilized forms, in effect returning lactoferrin to its most-natural and functional state. A multiple-function ingredient, activated lactoferrin protects meat in three key ways: It detaches pathogens already attached to meat, prevents other pathogens from adhering to meat and inhibits pathogen growth. It does all this without impacting the meats taste, appearance or nutritional qualities. Activated lactoferrin has a U.S. patent.

Nothing added

A non-ingredient option that a growing number of processors are turning to utilizes high-pressure processing, which exposes food to pressures up to 87,000 psi. This inactivates foodborne pathogens and does not affect the organoleptic qualities of the food.

More than ever, consumers are demanding natural, ready-to-eat (RTE) meat products that have fresh, just-prepared characteristics without preservatives," says Glenn Hewson, vice president, global marketing, Avure Technologies Inc., Kent, WA. Processors want to meet consumer demand for these clean-label products, but cant sacrifice shelf life or food safety. Many companies are turning to our commercially proven, high-pressure processing technology, which made its North American debut in the refrigerated guacamole category more than a decade ago.

When RTE meat products, including cold cuts and hams, are subjected to very high pressures, the levels of spoilage organisms are reduced significantly and pathogens are inactivated," continues Hewson. The high-pressure-treated meats retain their original sensory qualities, such as texture, color and nutritional content, throughout their shelf life. This quality extension reduces product spoilage and returns. It can actually extend shelf life to a minimum of twice as long as when traditional chemical preservation methods are used and, depending upon product, shelf life can be extended as much as four times longer."

With high-pressure processing, RTE meat products are prepared and packaged as usual. It is a noninvasive processing aid, and use does not require disclosure.

Products are processed in the final consumer package, eliminating the potential for recontamination," says Hewson. Most existing plastic food packages are already suitable for high-pressure processing, including vacuum and gas-flushed."

What makes the technology especially attractive is that it is not merely a surface treatment. It is effective throughout the product, whatever its size or shape," says Hewson. This is important to those meat processors producing sliced deli meats, where the risk of recontamination with harmful pathogens, particularly Listeria monocytogenes, may be greatest."

The use of high-pressure processing or any of the natural" ingredient systems for shelf-life extension will continue to drive innovation in the meat and poultry industries. Expect to see meat and poultry products travel further and longer, and still taste like they are fresh from the farm.

Donna Berry, president of Chicago-based Dairy & Food Communications, Inc., a network of professionals in business-to-business technical and trade communications, has been writing about product development and marketing for 13 years. Prior to that, she worked for Kraft Foods in the natural-cheese division. She has a B.S. in food science from the University of Illinois in Urbana-Champaign. She can be reached at [email protected].

A Natural Labeling Dilemma

Using naturally-derived ingredients does not always mean the finished product can be called natural. While under consideration for changes per a USDA Food Safety and Inspection Service Advance Notice of Proposed Rulemaking (Federal Register, Sept. 14, 2009, Vol. 74, No. 176), the current USDA definition of the claim natural" in meat and poultry products is outlined in the 2005 Food Standards and Labeling Policy Book (For the full rule, go to fsis.usda.gov/OPPDE/larc/Policies/Labeling_Policy_Book_082005.pdf).

The term natural" may be used on labeling for meat products and poultry products, provided the applicant for such labeling demonstrates that:

(1) the product does not contain any artificial flavor or flavoring, coloring ingredient, or chemical preservative (as defined in Title 21 of the Code of Federal Regulations, Part 101.22), or any other artificial or synthetic ingredient; and (2) the product and its ingredients are not more than minimally processed. Minimal processing may include: (a) those traditional processes used to make food edible or to preserve it or to make it safe for human consumption, e.g., smoking, roasting, freezing, drying, and fermenting, or (b) those physical processes which do not fundamentally alter the raw product and/or which only separate a whole, intact food into component parts, e.g., grinding meat, separating eggs into albumen and yolk, and pressing fruits to produce juices the presence of an ingredient which has been more than minimally processed would not necessarily preclude the product from being promoted as natural. Exceptions of this type may be granted on a case-by-case basis if it can be demonstrated that the use of such an ingredient would not significantly change the character of the product to the point that it could no longer be considered a natural product. In such cases, the natural claim must be qualified to clearly and conspicuously identify the ingredient, e.g., .all natural or all natural ingredients except dextrose, modified food starch, etc."