The US food supply is one of the safest in the world. However, increased globalization of the food industry coupled with consumers’ demands for convenience can create vulnerabilities in the food-safety supply chain. Because the risk of contamination cannot be prevented completely, it is imperative that processors do their part to eliminate the presence of potentially deadly pathogens or prevent their growth.
The Food Safety Modernization Act requires food processors to shift their focus from reaction to prevention. In the meat and poultry industries, prevention focuses on protection from pathogens such as Listeria monocytogenes, Escherichia coli and Salmonella.
“There are pathogenic bacteria that are inherent in the processing of meat and poultry products and they must be controlled to ensure product is safe to consume,” says John Wyatt, regional product manager-health division of DuPont Nutrition & Health in New Century, Kan.
Tom Rourke, senior business development manager, for Corbion Purac, Lenexa, Kan., adds, “Listeria is ubiquitous in the environment, so even the best meat processors could have issues.”
What makes Listeria such an issue with meat and poultry is that this pathogen resists historical microbial growth inhibitors such as salt and acidity. It also readily grows at refrigerated temperatures. And though freezing temperatures will stop its growth, this hearty bacterium remains viable.
Proper cooking and reheating of foods effectively controls Listeria. However, certain refrigerated foods such as ready-to-eat (RTE) meat and poultry products, in particular, those purchased through the deli or in a hand-prepared sandwich, are susceptible to contamination, as these products are repeatedly exposed to microorganisms in the environment. Because these products do not require further cooking prior to consumption, they can be carriers of this deadly pathogen. Because the presence of Listeria does not change the taste or smell of the food, it easily goes undetected. This makes it imperative that manufacturers of these products take all possible precautions to ensure safety, including inclusion of food safety ingredients.
“Food safety ingredients help to extend the shelf-life of meat and poultry products by protecting the product from microbial spoilage and foodborne pathogens, as well as delay color and flavor loss,” says Courtney Schwartz, marketing manager of Kemin in Des Moines, Iowa.
By themselves, food safety ingredients may not give the level of safety required in the food, according to Wyatt. “As part of a comprehensive system, they can play an important part in achieving and maintaining food safety objectives,” he said. “They should be used as part of a multi-hurdle approach that includes consideration of processing temperatures, salt content and pH.”
Hurdle technology combines treatments and ingredients to enhance shelf stability, safety and quality of foods. Antimicrobials, such as organic acids, bacteriocins, antimycotics and essential oils, can eliminate or inhibit the growth of microorganisms, including pathogens.
It is important to distinguish between technologies that ensure quality throughout shelf-life, e.g., prevent spoilage, off flavors, discoloration, etc., and those that keep a food safe to eat. Some technologies will do both, but the fact is that most reported cases of food-borne illness result from the consumption of perfectly palatable food. Invisible pathogens invade the body and wreak havoc. Because the end result can be fatal, the product is typically recalled when pathogens are detected in food.
Schwartz explains, “Microbial spoilage is more of a concern in fresh applications, whereas Listeria is often the main concern in the RTE products.”
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There are several considerations when choosing food safety ingredients. This includes regulatory approval through the US Dept. of Agriculture Food Safety and Inspection Service (FSIS).
“But even if FSIS approves an ingredient, the consuming public may not consider the ingredient to be acceptable,” Wyatt says. “Chemical preservatives are slowly losing favor by the industry due to consumer objections, so the use of natural or clean-label alternatives continues to grow.”
In addition to regulatory and labeling considerations, when working with food safety ingredients, processors should consider ease of use, efficacy against target microorganisms, impact of processing on the ingredient, interaction with other components of the protein matrix, organoleptic effects and, of course, economics. Formulators should also determine the target shelf-life and factor in packaging conditions.
“Once these parameters are understood, the most effective food safety ingredient can be chosen, whether it be liquid or dry or maybe even a combination of multiple ingredients,” Schwartz says. For example, a naturally cured hot dog would have different food safety parameters than a frozen beef patty.
Understanding organic acids
Organic acids and their salts are the drivers behind many food safety ingredients, in particular those used to control for product adulteration from Listeria.
The level of effectiveness of organic acids is determined by the amount of undissociated acid that penetrates the bacteria cell wall and disrupts its physiology. Research shows that organic acids vary in effectiveness, with propionates being much more effective than lactates. Effectiveness further varies by pH and bacterial strain.
“Lactic acid is widely used to control pathogens on raw meat carcasses before processing,” Rourke says.
For RTE meat and poultry, lactates and diacetates have historically been considered the industry standard. Recognizing that propionic acid is a time-tested antimicrobial ingredient used in various Food & Drug Administration (FDA)-regulated food products, Kemin petitioned FSIS to amend the Code of Federal Regulations to list liquid sodium propionate as an acceptable antimicrobial agent for use in RTE meat and poultry products in 2010. The regulations were amended and now processors have another food safety ingredient option.
Prior to this amendment, lactates and diacetates were the only approved antimicrobials for RTE meat and poultry. While studies have verified that these additives are useful, consistent performance and effectiveness varies by product and interaction with other ingredients. Further, lactates and diacetates have been shown to sometimes negatively impact sensory attributes, while propionates have little or no sensory impact, according to Schwartz.
“The benefit of having sodium propionate approved is large,” she says. “Not only does it give RTE meat manufacturers an alternative to lactates, it performs more consistently, has a lower application rate and contributes much less sodium to the final formulation.”
Some suppliers offer blends of organic acid salts, including acetate, diacetate, lactate and propionate to create the most effective antimicrobial system for a particular application. It’s important to note, however that propionates are only approved for use in RTE products.
“Meat products with a ‘natural’ label are severely limited regarding antimicrobial ingredients,” Rourke says. “Antimicrobials are not allowed in natural meats, so flavors such as vinegar, lemon juice or lime juice are added to provide some antimicrobial effect.
“Vinegar is very effective against Listeria and therefore is commonly used in natural and clean-label processed meats,” Rourke says.
Schwartz agrees that buffered vinegar ingredients help meet consumer demand for clean labels. “These products are labeled as vinegar or vinegar powder and are approved for use in RTE and fresh meat and poultry products,” she says. The active component in vinegar-based antimicrobials is acetic acid.
Corbion Purac recently developed two new natural ingredients that have multi-functional capabilities, according to Rourke. “One solution is a combination of unique ingredients that provides food safety to RTE meat products while enhancing cook yield, improving sliceability and firming the product’s texture. The other solution provides a full-freshness package to raw and RTE processed meats. It provides food safety while maintaining raw meat color and fresh flavor.”
Rourke says today’s meat and poultry processors want solutions that deliver food safety that also serve to improve other production parameters.