As the industry seeks natural ingredient alternatives to combat pathogens, shelf life takes a positive turn.

A lot of pressure has been put on the meat industry for the last 20 years to solve the problem of Listeria. As a result, new technologies have been developed and implemented, which experts say are very effective in controlling this hardy pathogen.

Proof of this is a notable decline in Listeria outbreaks. In a November 2006 report, the Centers for Disease Control reported 54 cases in 2002, compared with 105 in 1998.

Consequently, the improved sanitation practices for controlling Listeria have had a positive effect on the shelf life of meat and poultry.

Still, much of the industry’s focus has been on compounds that can be incorporated into formulas that inhibit bacterial growth and not on shelf-life extension, says Jim Marsden, Regents Distinguished Professor at Kansas State University. “This has a shelf-life effect, but the primary focus is on food safety,” he says. “The main challenge the industry has is that Listeria grows under refrigeration, even at miniscule levels.”

According to Robert Brooks, applications specialist at World Technology Ingredients (WTI), based in Athens, Ga., “Almost all meat products today incorporate some form of shelf-life extender. Some of these may have originally been intended for pathogen control. However, most ingredients in this segment are not bacteria specific, so there is a corresponding increase in shelf life.

“In addition, with nationwide marketing of meat products, it is imperative to increase shelf life to accommodate [additional] time in the distribution channels.”

Most shelf-life extenders serve to interrupt or delay the natural growth process of bacteria.

“By slowing the bacterial growth, you increase the time it takes to reach spoilage,” Brooks adds.

The three types of shelf-life extenders are chemical preservatives, natural preservatives and processes. Most shelf-life extenders are labeled by their common names, such as vinegar or sodium lactate. However, a few ingredients have been deemed as secondary direct additives by USDA, and can be used without addition to the label.

Marcy Epstein, director of research and development at First Spice Mixing Co., says there are many types of shelf-life extenders for meat products, including food-grade substances added to the meat, food-grade substances added to the meat packaging and methods that treat the meat to kill spoilage organisms.

“Several common food additives include starter cultures, smoke, salt, sugar and dextrose,” she explains. “These ingredients make the environment less suitable for spoilage organism growth either through friendly organism competition or by decreasing the products water activity.”

Steve Campano, vice president of Trumark, based in Linden, N.J., says one of the most popular types, organic acid salts, includes lactates, acetates and blends of both.

“These are primarily used in [ready-to-eat] products because they assist manufacturers in complying with the USDA 430.4 regulation on Listeria control,” he explains. Whether these products affect meat flavor and quality “depends on who you ask,” Campano adds.

“Lactates were originally approved for use as flavoring ingredients at levels of two percent or less. Most processors know how to deal with lactates at the higher levels required for antimicrobial effectiveness. If there is any flavor [with these ingredients], it’s a little salty note, especially with the use of sodium-based lactates. But this is easy to compensate for and not difficult to deal with.”

Because lactates are so common and naturally a part of most meat products, experts agree that consumers are not concerned with this ingredient. In fact, these additives are commonly used in natural and organic products. In addition, says Rodney Schaffer, director of technical services at Con Yeager Spice Co., based in Zelienople, Pa., the added shelf life provided by lactates can be quite significant.

“If you look at meat products with no lactate and those with lactate added, the lactate product has a shelf life that’s two to three times higher,” he explains.

Hayley Walls, product marketing manager at Lincolnshire, Ill.-based PURAC, has seen significant shelf-life increases for fresh meat products using lactates.

“For cooked cured products, it’s between 30 and 50 percent and for cooked uncured meats the shelf life is between 50 and 100 percent,” she says.

PURAC provides sodium and potassium lactates as well as blends with both ingredients. Walls says originally these ingredients were geared for shelf-life extension.

“However, with the continued focus on pathogen control and food safety, now processors [primarily] use them to help control pathogens in meat and poultry products,” she says.

Because these products offer a relatively inexpensive way to extend shelf life, with no additional cost or capital equipment needed for processing, lactates continue to be popular. Other benefits are improved yield of meat and poultry due to added moisture retention and versatility in terms of product usage.

“This ingredient can be used in virtually any meat product, including fresh sausage, enhanced pork or beef, frankfurters, ham or turkey breast,” Walls says.

Fruit and vegetable juices and purees also have been noted to inhibit microbial growth in meats to help extend shelf life. In his report, Fruit and Vegetable Juices and Purees: Nature’s Multi-functional Ingredients for Meat Marinades, Romeo T. Toledo, Ph.D., who is a professor and the director of the Food Processing Research and Development Laboratory, Department of Food Science & Technology at the University of Georgia, discusses how these phyto-ingredients, which were mainly used as flavoring ingredients in the past, are now performing multifunctional roles in foods. One of these functions is microbial growth inhibition.

One of the most notable developments in this segment is the focus on natural ingredients, says Marsden.

“There are many additives now labeled as natural ingredients that do the same thing as chemical additives, but rely on natural ingredients like vinegar or citrus fruit derivatives or extracts,” he says.

Because these natural ingredients have antimicrobial properties, the industry now has the option of labeling products as natural, Marsden says. Also new is the development of physical processes of chemical inhibitors.

“This includes high-pressure pasteurization, in which Hormel is a leader,” Marsden says. This involves packaging a product like prosciutto and then subjecting it to high pressure that kills bacteria without affecting product quality.

Another process, PPP or post-packaging pasteurization, uses heat energy to kill potential pathogens. With this system, packaged product is subjected to high temperatures that help kill surface bacteria. The packaged product is then chilled or repasteurized. In addition to killing bacteria, this process also helps increase product shelf life, Marsden says.

“There is a lot of controversy now at the USDA, because processing is not supposed to affect product shelf life. Yet, any time you have an antimicrobial treatment, it affects a product’s shelf life,” he explains. “There is currently a debate over whether processors can use antimicrobials in natural products, since this food category prohibits the use of chemical preservatives. Because these ingredients have a dual function, [serving as an antimicrobial and shelf-life extender,] everyone is struggling with this question.”

According to Jerry Hall, CEO of Excalibur Seasonings in Pekin, Ill., the U.S. government still hasn’t moved to solidify a list of natural ingredients.

“Basically, anything that’s further processed is not considered natural,” he says.

In terms of natural shelf-life enhancers, Hall says wild oregano helps control rancidity, warmed-over flavors and bacteria, while rosemary oil works well to also control warmed-over flavors while it acts as an antioxidant.

“Liquid seasonings also can enhance shelf life and help prevent spoilage because they have a pH of 3.7 to 4,” Hall adds.

Brooks concurs that the main trend in shelf-life extenders is a move toward consumer-friendly, natural preservatives, such as salt, sugar or vinegar. “Consumers are becoming more health conscious. They read labels more closely and are concerned about the effects of consuming chemical preservatives,” he says.

Recently, topical shelf-life extenders have been introduced, with some more effective than others, according to Campano.

“Some of these require special equipment to use, but if you discount the capital expense, the per-pound cost basis is typically less than traditional shelf-life extender ingredients,” he says.

In addition, both lactates and blended lactates have undergone flavor improvements over the last six to seven years, according to Schaffer.

“Both had flavors that stood out in the beginning, and manufacturers had to clean these up,” he says, adding that lactates can still sometimes be detectable in products that don’t have seasoning profiles. In these cases, masking agents help inhibit the taste of these ingredients.

Another change is that smaller and mid-sized meat processors can now more affordably incorporate shelf-life extender technology that was formerly utilized only by large plants. “We have small plants using lactates and blended lactates that are achieving wonderful shelf life beyond the numbers they had before,” Schaffer says. “We’re seeing a trend toward more potassium-based products, such as potassium lactate and potassium diacetate. This is because these ingredients don’t increase the sodium content on the nutritional statement, and they don’t have the expected metallic flavor associated with potassium chloride.”

For cured meat products, Campano notes that the most effective combination of organic acid salts evaluated to date is a mixture of sodium lactate and sodium diacetate.

In this vein, First Spice recently created an organic acid inclusion product for meat emulsions called Meatol. Epstein says this is an effective pathogen inhibitor that does not cause a flavor change.

Another new product is Nisen, which Excalibur Seasonings began importing from China late last year. “It is very expensive, but the use level is very low and it does a great job of controlling a broad range of bacteria,” Hall says.

Looking ahead, Campano says as long as there is a regulation in place that indicates ready-to-eat product is adulterated if it contains Listeria, the use of antimicrobials will continue.

“Everyone is looking for the magical ingredient, and, to my knowledge, there is none,” he says. “There have been numerous ingredients evaluated, and some work better than others. There also is a whole range of natural products that do a fair job.

“I would stress that perhaps the most important shelf-life control strategies are good manufacturing practices, effective sanitation operating procedures, time and temperature controls, and the prevention of environmental and cross contamination.”

Initially, incorporating shelf-life extenders was a big adjustment for many processors, especially the small and medium-sized plants, but Schaffer says the industry is now embracing these ingredients. “Flavor inhibitors have greatly improved,” he says.

For the future, Brooks at WTI predicts more natural preservatives will become available in this category.

“Consumers will continue to drive this segment. In addition, I feel that there will be fewer labeling exemptions for these ingredients,” he says. • Sodium lactate
C₃H₅O₃Na
Prepared commercially by the  neutralization of lactic acid with sodium hydroxide

• Potassium lactate
C₃H₅O₃K
Prepared commercially by the  neutralization of lactic acid with potassium hydroxide

• Sodium diacetate
C₄H₇O₄Na·xH₂O  
Produced by reacting equimolar amounts of anhydrous sodium acetate and acetic acid. In solution, this is split off into its constituents, and liberates 39 to 41 percent acetic acid and 58 to 60 percent sodium acetate.

• Sodium or potassium acetate
CH₃COONa/K  
Prepared by the neutralization of acetic acid by either sodium or potassium hydroxide

Source: Steve Campano, Trumark