Extending Shelf Life Of Fresh Meat And Poultry Products
By Lynn Petrak, Special Projects Editor
Beyond packaging, ingredient technology enables processors to extend the shelf life of fresh meat and poultry products.
Everyone wants the secrets to a long life. Even meat and poultry processors.
The quest is not the fountain of youth, but rather the drive for safe, fresh products, satisfied retail and foodservice customers and the ability to offer an array of value-added items. As with other perishables like dairy and produce, advances in extended shelf life (ESL) technology for fresh meat and poultry are allowing meatpackers to increasingly push back “sell by” dates.
Preserving meat is a concept that has been around for centuries. Legend has it that the hamburger can trace its history back Genghis Khan’s 13th century army of Mongols, who carried meat in their saddles during long journeys and discovered that it had softened into a palatable dish. In more recent times, the refrigeration revolution of the early and mid-20th century and improvements in packaging in subsequent years lengthened the time it took from the slaughterhouse to the butcher to the American kitchen table.
During the past decade — even in the past two or three years alone — fresh meat and poultry products with a longer shelf life have become more available and diverse in scope. Today, “ESL” is a term that refers to products that have been manufactured using a certain process or packaged in a specific way that allows them to be bought and stored for a longer period of time than traditional perishable items.
Industry observers agree that there is a concerted effort to offer products that can stay in the meat case and in an end user’s refrigerator for several days and at times weeks more without spoilage due to oxidation or microbe growth. “For fresh meats, it is a steadily growing and dynamic market,” reports Rene Monderen, market development specialist for ingredient supplier PURAC America, Lincolnshire, IL.
Major processing companies, too, say that this is an area to watch. “Demand for extended shelf life is increasing – it is among the top five considerations we give to every new product we develop, along with taste, appearance, packaging graphics and convenience,” reports Jim Herlihy, vice president of communications for Greeley, CO-based Swift & Company.
Interest in ESL fresh meats comes from various points within the food chain. Herlihy cites the changing and often more demanding distribution channel, including supermarket customers. “Retailers are leading the demand for extended shelf life,” he reports.
Juan L. Silva, Ph.D., food science and technology professor at Mississippi State University and an expert on antimicrobials and ingredient technology, agrees. “Of course, retailers want longer time in the shelf, thus less turnover of product and reduced labor costs,” he observes, adding that consumers also have an important role in such product development. “The consumer wants fresh products.”
The why behind the sell-by
In addition to the matter of who is driving interest in ESL fresh meats, there is discussion over why the shift is happening now. Several converging factors have contributed to the trend toward greater shelf life of fresh meat.
For one thing, consumers continue to clamor for convenience, which encompasses shelf life. “Life has become more fast-paced, as many people are working longer hours and facing longer commute times, and evening family or social activities remain a priority. These trends have increased the popularity of convenience foods, yet consumers still desire to consume food that is fresh tasting, home-cooked, and natural,” points out Kristen Robbins, associate scientist at Kemin Food Ingredients, Inc., Des Moines, IA, which supplies natural preservatives for meat and poultry applications.
Within the food industry, consolidations within the respective meat, retail and foodservice sectors have translated to more centralized decisions in how products are to be distributed and sold. Larger supermarket chains have a defined set of expectations and demands for the meat case, and their ever-shrinking roster of meat and poultry suppliers tend to respond with products with longer “sell by” and “use by” dates.
Related to the consolidation trend is the shift toward more branded fresh meat products. Indeed, another impact of the branded case ready evolution has been the greater number of products sold in vacuum packaging or barrier packaging.
Innovations in the value-added category have also helped spur ESL offerings at the fresh meat case, since value-added products are often tenderized or pre-marinated using methods like injection and tumbling that can enhance shelf life properties. “Certain seasoned and marinated products are well suited to ESL, as well as products like our LaHerencia chorizo,” says Herlihy. “Also, some value-added products, like those that are pre-sliced by the processor, reduce the need for cutting and slicing by retailer, and limit exposure to light and bacteria that will shorten shelf life.”
Color is a feature linked to oxidation that affects shelf life as well. “Color is a main driver of sales — people throw cases of pork away because the meat is gray,” points out Monderen, adding that although the use of carbon dioxide has helped extend the desired color of meat product, shelf life hasn’t always keep up. “We have proven extensively that lactates stabilize the color of fresh meat products and in the meantime, they also control shelf life.”
Of course, not to be overlooked in any discussion of shelf life is food safety. “If you have an antimicrobial that is able to increase food safety by controlling pathogens, in the meantime you control spoilage bacteria, too,” points out Monderen.
Silva also emphasizes the connection between safety and shelf life. “There are two primary forces moving the use of antimicrobials and other intervention strategies in meats — the need to decrease and/or eliminate pathogens on meat and poultry, and the demand for ‘fresh’ products by consumers,” he says. “Thus, meat is now ‘fresh’ for longer periods of time.”
At the processor level, tools that have been implemented to halt the spread of microbes have had the ancillary benefit of extending shelf life. “At Swift, extended shelf life is enhanced by our ability at our Greeley processing plant to take product from the initial processing directly to value-added processing, which reduces handling time and exposure to microbial organisms. By packaging and shipping product quickly, it adds days to shelf life for the customer,” notes Herlihy.
Whatever the driving force, the greater preponderance of ESL products is evident across the protein spectrum. “Fresh pork with an extended shelf life has been in hand for several years,” notes Monderen, citing products like case ready pork tenderloins. “Now, fresh beef is a main growth area and so is fresh pork sausage.”
Now taking applications
When it comes to the processing of fresh meat and poultry, there are several options for extending shelf life.
On one end of the process, advances in barrier and vacuum packaging, along with barrier tray technology, have helped lock in freshness and extend shelf life of fresh meats.
Beyond packaging, another common method of preserving fresh meat and poultry is through ingredient technology. Processors use both natural and synthetic ingredients to inhibit spoilage bacteria.
According to Silva, the supplier marketplace is full of ingredients for such purposes. “One can use acidulants like lactic, citric, erythorbic and ascorbic acids and lactic acid bacteria like probiotics or prebiotics in the animal, like in poultry to reduce Salmonella and maybe prolong the shelf life. There are also bacteriosins, some mold inhibitors and others,” he explains.
Antioxidants also function as shelf life extenders, Silva notes. “As far as antioxidants, other than the artificially made, we have now tocopherols and others like citric acid and phosphates,” he says.
In these categories, processors can turn to a variety of ingredient suppliers. PURAC, for example, offers a line of lactate-based products, including its PURASAL series of sodium lactate and potassium lactate that work to inhibit the growth of both spoilage bacteria and pathogenic bacteria. Purasal is a hygroscopic salt that is added in brine through injection and tumbling or in a cutter or mixer in the final stage of grinding. “The main thing is to make sure the product is distributed throughout the meat block or emulsion,” says Monderen, adding that usage levels depend on the purpose.
First Spice Mixing Co, Long Island City, NY, is another supplier that has focused on the use of certain acids. Last year, the company developed a series of ingredients called Meatol and Meatol-P (for poultry). “They are based on a proprietary blend of organic acids that, when used as directed, has minimal flavor carryover in the final product and produces a one log reduction of pathogens as set forth by the USDA in the Federal Register,” explains Marcy Epstein, director of research and development. Like other ingredients for ESL purposes, Meatol can be injected or tumbled or mixed into a grind.
Meanwhile, there has been a growing interest in natural shelf life extenders, including those made from spices, herbs and even fruits. “Spices like garlic, onion, turmeric, and many others contain both natural antimicrobials and antioxidants,” remarks Silva.
In addition to its Meatol line, First Spice offers a natural antioxidant made from spice extractives called Savorlok and chemical antioxidant blends with BHA and BHT. “They are used to reduce fat rancidity and lengthen shelf life in meats that are frozen or used in long-term storage,” says Epstein.
Kemin, too, has concentrated R&D work in on the natural side of the business. Among other products, Kemin offers rosemary extract to help processors combat challenges caused by oxidation. “Naturally-occurring compounds in Fortium® brand natural rosemary extracts are effective at delaying the onset of lipid oxidation and the oxidation of myoglobin at levels well below their flavor threshold,” explains Robbins, adding that the company is currently working on alternative natural ingredients to traditional lactates and diacetates.
Other natural ingredients have shown ESL promise as well. Daniel Fung, Ph.D., professor of food science at Kansas State University, has worked on several projects testing the effects of natural ingredients on safety and shelf life, including seasonings like garlic and cinnamon, and herbs like oregano and sage. One of his most recent laboratory studies involved the application of a particular fruit-based substance. “You can put dried plum extract into ground beef or ground turkey and it will inhibit the growth of pathogens and extend the shelf life,” Fung explains.
Another benefit of using ingredients like dried plums in ESL applications comes in the labeling of the final package. “It is good for labeling, because these are natural products,” Fung points out.
Even with the promise of new natural and synthetic additives, Silva emphasizes the fact that many factors can affect shelf life throughout the production and distribution chain, and that it is a good idea to have a broad range of tools to ensure freshness and quality. “The best method is to have a combination of technologies based on good production and manufacturing practices, temperature management and control, intervention strategy and packaging and good, reliable distribution and retail systems,” he remarks. NP
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