HPP technology, a guarantee for food safety in meat products

550 million people worldwide contract a foodborne infection (FI) every year, despite efforts made by governments, farms, industries and consumers to ensure food safety in products such as meat. High hydrostatic pressure (APH) or high pressure processing (HPP) is presented as a real strategic option for the fight against E. coli, Salmonella spp. and Listeria monocytogenes in this type of fresh or processed products.

Food Safety in meat products

According to the World Health Organization (WHO), despite the efforts made to ensure the safety of the food we eat, every year 550 million people worldwide contract a Foodborne Infections (FI). From those, 220 million are children under 5 years old.

We speak of a growing public health problem since food can be contaminated at any point in the agricultural and food production, distribution or handling chain and spread quickly and with relative ease from one country to another.

Although there are numerous guides to good practices and comprehensive controls, the number of annual outbreaks of certain pathogens does not decrease, putting in check all food safety measures adopted.

Foodborne pathogens in raw meats

Escherichia coli (E. coli)

According to the scientific article “Meat products: main pathogens and non-thermal control strategies” published by the Autonomous University of Nuevo León in Nacameh, E. coli has been listed as the most dangerous food contaminant for human health due to Severe complications that can cause. Thus, raw meat is one of the most common vehicles of poisoning.

In the US so far this year, there have been two E. coli outbreaks associated with the consumption of raw meats. One in July for consumption of undercooked bison burgers and another in June (figure 1) for consumption of contaminated minced beef. The total number of patients is 230, of which 37 have needed to be hospitalized.

Figure 1. People infected for lack of food safety in meat products by eating minced beef contaminated with E. coli. Source: USA Center for Disease Control and Prevention (CDC).

Figure 1. People infected by eating minced beef contaminated with E. coli. Source: USA Center for Disease Control and Prevention (CDC).

Behind these outbreaks, there are a greater number of recalled products that have not caused infection or food poisoning, but could have done so if all control measures had not been quickly implemented. Since there are no cases of FI associated with them, they do not transcend public opinion like the previous ones. Still, they represent an important economic and a big loss for the industries that process them and for those that commercialize these products.

It is important to have good manufacturing procedures (GMP) to guarantee food safety in these meat products and avoid recent recall examples such as that of Aurora Packing Company, Inc. In March and May they have recalled about 32,000 kg of beef from the market contaminated with E. coli. Another example like the rejection on the Spanish border on August 8, of beef from Argentina with the presence of Shiga toxin produced by E. coli, which does not transcend the name of the marketer.

Campylobacter

According to the United States Department of Agriculture (USDA), Campylobacter bacteria is the second most frequently reported cause of foodborne illness. In the period from 2010 to 2015, the Center for Disease Control and Prevention (CDC) reported 209 foodborne Campylobacter outbreaks, with a total of 2,234 cases (Figure 2).

According to the European Food Safety Agency (EFSA), in Europe almost 246,000 people a year are treated in the health services by campylobacteriosis, but it is believed that the actual number of cases is much higher, around 9 million.

Figure 2. Incidence of cases of campilobacterioris by food category in the period 2010–2015. Source: USA Center for Disease Control and Prevention (CDC)

Figure 2. Incidence of cases of campilobacterioris by food category in the period 2010–2015. Source: USA Center for Disease Control and Prevention (CDC)

The reasons why these huge differences exist between the notified and the real cases and, for which no food alerts are issued are several, but the most important are:

  1. That outbreaks are identified when there is an increase in the number of cases reported in a specific place or period of time and the statistics remain fairly stable.
  2. That the symptoms are perceived by the population as something mild without medical assistance in many cases.

There are no food alerts for this pathogen so far this year, in fact the last outbreak in the US was notified in 2002.

Salmonella spp.

The first outbreak of salmonellosis was described in Germany in 1888, among 50 people who had ingested raw minced meat from a dying cow. Since then, every year there are several outbreaks worldwide, some of them of considerable importance.

In the European Union about 91,000 cases of salmonellosis are reported annually. The most recent, notified in the month of August, are a contamination by Salmonella Enteritidis in chilled chicken meat from Poland and that has affected other 3 Member Countries, a contamination by the same pathogen in chilled chicken thighs that they have been marketed by a Belgian company in the Netherlands and the United Kingdom and a contamination by Salmonella Typhimurium in frozen raw chicken fillets from the Netherlands that has affected Sweden and Norway. All of them only during the month of August. In July, an outbreak of Salmonella Bredeney in chilled cooked pork from Romania was also reported to RASFF.

In Canada so far this year, 24 cases of salmonellosis have been reported that are under investigation for consumption of raw chicken and turkey meat that is undercooked or improperly cooked.

The incidence of this pathogen in the US It is not less, affecting at an economic and reputation level brands such as Butterball LLC which, in March this year, has removed 35,500kg of products made from turkey from the market, due to possible contamination with Salmonella Schwarzengrund.

Foodborne pathogens in processed meats

Listeria monocytogenes

Processed foods can be contaminated through raw materials, improper treatment and handling or cross contamination, so that all pathogenic microorganisms present in raw meat are susceptible to survival and grow in processed meat products if they are not eliminated. Adequate hygiene, processing and control measures are ways to mitigate risk.

The stages of greatest risk are during the time of packaging and the thermal or curing treatment where the product is handled to adapt it to a specific format and in this type of processes, Listeria monocytogenes is the microorganism with the highest incidence.

Unlike many other foodborne bacteria, Listeria tolerates saline environments and can even multiply at cooling temperatures (between 2 ° C and 4 ° C). Its resistance together with the high rates of hospitalization (99%) and mortality (13%) makes it essential to guarantee the food safety of processed meat products against this pathogen.

The references of listerioris outbreaks in North America in the last two years for sliced meat products, are numerous and the last one, from April of this year and still under investigation, has taken 8 people to the hospital, of which 1 has died. It is believed that the contamination has its origin in the use of improperly sanitized cutters and in the absence of a subsequent process of pasteurization or elimination of pathogens.

In the latest report of the European Center for Disease Prevention and Control (ECDC), 2,480 cases of listeriosis are collected among the Member States, with Germany (726 cases), France (370 cases) and Spain (284 cases) having the highest incidence of this FI.

Figure 3. Confirmed cases of listeriosis in 2017 for lack of food safety in meat products. Source: European Centre for Disease Prevention and Control (ECDC).

Figure 3. Confirmed cases of listeriosis in 2017. Source: European Centre for Disease Prevention and Control (ECDC).

The last outbreak of Listeria monocytogenes reported by the Rapid Alert System for Food and Feed (RASFF) is from August this year and corresponds to a batch of sliced cured pork loin, from Spain and marketed in France.

However, the data that unfortunately best reference the health hazards of this pathogen, are those associated with the listeriosis outbreak that South Africa suffered between 2017 and 2018 due to consumption of contaminated processed meat. Listed by the World Health Organization as the most serious in history worldwide, it claimed the lives of more than 200 people and affected almost a thousand, making an impact on the food safety programs of 157 meat processing factories throughout the country.

At the level of reputation and economic loss, the most recent alert in the US corresponds to Monogram Meat Snacks, LLC which in March of this year has removed 87,000kg of pork sausages marketed under the Conagra Brand and Duke’s Meats brands, due to a possible contamination considered to be of high health risk and suspected of being be Listeria monocytogenes. However, October 2018 was undoubtedly the month of the last two years with a higher incidence of listerioris in the country, many of them due to cross contamination with other foods and that affected Bakkavor Foods USA, Inc. (Trader Joe’s), SK Food Group, Johnston County Hams and Ukrop’s Homestyle Foods.

Foodborne pathogens in meat-based animal food

If we take into account other markets such as pet food, in which the consumption of raw foods is a trend, we also find examples of outbreaks of pathogenic microorganisms, mainly Salmonella. It is necessary to control the presence of pathogens in pet food, not only because of the risk inherent in their handling, but also because pets are vectors of transmission of several FIs to humans, what we know as zoonosis.

The most recent alert has been given in the USA. July 31 127 cases of people with salmonellosis have been reported, 26 hospitalized, of which 24 were children under 5 years (population at risk). This outbreak is associated with pig-ear chews of the Pet Supplies Plus brand marketed by Lennox Intl Inc.

Figure 4. Incidence of the Salmonella outbreak due to pig ear chews for dogs. Source: USA Center for Disease Control and Prevention (CDC)

Figure 4. Incidence of the Salmonella outbreak due to pig ear chews for dogs. Source: USA Center for Disease Control and Prevention (CDC)

The last case reported by RASFF in Europe was on July 5 of this year and is also associated with dog treats. This outbreak is being analyzed because the origin of the raw material is multiple, however it is known to affect the MultiFit brand of Fressnapf, who is already recalling several lots of some of its products.

As is the case with these two companies, there are numerous product withdrawals that the Control Bodies make per year, without transcending an FI and which entail a significant economic and image loss.

Since the beginning of 2018, the U.S. Food and Drug Administration (FDA) He has made 21 recalls of food or treats for dogs or cats on suspicion of Salmonella and most have been with raw food. For this reason, it is having an exhaustive impact on the controls on the feeding of pets based on raw raw materials, recommending not only a correct hygiene of the food and the manipulator, but also the use of adequate measures of elimination and control of pathogens.

HPP technology, a strategy for food safety in meat products

The most important critical points to control in the process line of any food industry, whether for human or animal consumption, are the handling of raw material, those of inactivation of pathogenic microorganisms and, the phases after inactivation and prior to packaging (for example slicing).

The actions in the field of food safety in meat products for the first of the critical points are usually aimed at ensuring the adequate storage conditions of the raw material (temperature, humidity, light, etc.), as well as the maximum hygiene of facilities, equipment and manipulators. With these actions the control of pathogens is guaranteed, but never 100% because there are many human and environmental factors that influence and it is not always possible to control them properly.

Figure 5. Hamburger packaging line

Figure 5. Hamburger packaging line

With regard to the inactivation of pathogens, the most common is the use of thermal treatments capable of minimizing or even eliminating these microorganisms but, despite their benefits, it is not always interesting to apply because:

  1. Entail alteration of color change, flavor, texture
  2. Is not always effective
  3. Not available in raw materials (figure 5).

Finally, to avoid re-contamination in post-treatment and pre-packaging stages, hygienic measures and microbial load control processes with active packaging, refrigeration, etc. are used again. The truth is that, if the hygienic measures fail, those of microbial control are usually not enough in foods with a wide expiration, leaving in the hands of the final consumer the detection of a possible infection or intoxication.

As an alternative to all these measures and their disadvantages, non-thermal technologies arise, among which the high hydrostatic pressures (HHP) stand out due to their incursion in the market and wide range of application: infant feeding, animal feeding, fruits, drinks, fish , meats, etc. Its use, alone or in combination with other processes and media (natural additives, active packaging, curing or marinating processes, etc.) guarantees safer, natural and long-lasting products.

In the processed by high pressures or conventional HPP, the packaged food is subjected to pressures between 400 and 600 MPa, achieving the inactivation of pathogenic and altering food microorganisms, while preserving the quality and organoleptic properties thereof. It is an isostatic process in which the pressure is transmitted uniformly, at the same time and adiabatically, regardless of the shape or size of the processed product.

Figure 6. Advantages of high pressure processing (HPP) a guarantee for food safety in meat products

Figure 6. Advantages of high pressure processing (HPP)

It has been shown that without heat, the application of a pressure of 400 to 600 MPa for 2–10 min is effective to achieve the inactivation of the most important microorganisms that cause FIs (Simonin et al., 2012), which is also why know this process as hyperbaric or cold pasteurization. Likewise, it has been shown that, as it is a post-packaging technology, it avoids possible re-contamination after microbial inactivation treatments, contributing to prolong the shelf life of the food during refrigeration storage (Bajovic et al., 2012) .

Finally, the possibility of treating products that cannot be subjected to thermal treatments for their conservation, such as fresh meats or cured products, makes HPP the best possible alternative to guarantee food safety and its shelf life in products such as hams, mortadelas, bacon, salami, sausages or some pre-cooked meals for both human and animal consumption (pet food). In fact, Hugas et al. as early as 2002, they demonstrated that the shelf life of cooked ham, cured ham and marinated meat loins treated by high pressures could increase their shelf life up to 120 days.

While it is true that this technology applied to raw meat products has a drawback and is that, as it is collected in HPP: Putting a New Squeeze on Meat, it modifies the coloration and some sensory attributes such as texture. For this reason, the use of high hydrostatic pressures in fresh meats is ideal for minced products intended for restoration in which they will be cooked regardless of their appearance or texture but the fact that it maintains aromas and nutritional properties.

Figure 7. Mixing phase in the meat processing line.

Figure 7. Mixing phase in the meat processing line.

For all the above, to guarantee food safety in meat products, it is recommended to follow the good hygiene, process and handling practices offered by all national Food Safety agencies and, of course, contact Hiperbaric to learn how HPP technology can help you strategically in your fight to ensure the food safety of meat products.

2 thoughts on “HPP technology, a guarantee for food safety in meat products

    • Hi Arturo! Actually both HHP and HPP mean exactly the same. High Hydrostatic Pressure (HHP) and High Pressure Processing (HPP) are two different ways to refer to the non-thermal processing technology used to preserve food by means of water-generated hydrostatic pressure on already packed products. You can find some clarification on more confusing concepts here: http://blog.hiperbaric.com/en/clarification-of-hpp-concepts

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