Vacuum Sealing, Low-Temperature Cooking & Food Safety

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How Quality Vacuum Sealing and Low- Temperature Cooking improve Food Safety  

 

food-safety

 

I am not the savviest guy when it comes to working with the internet, most of the time I get absolutely messed up, but I learn every day and  sometimes, but then also sometimes, I get  a pleasant surprise which gives me some hope for the future.

 

One way or the other I came across Google Alerts, absolutely new to me, don’t laugh, I already admitted not to be the savviest when it comes to the WWW.

 

This feature, if you are as ignorant as me, allows you to key- in a few words and Google tells you within seconds everything about the subject you are looking for that has been published recently.

 

Great! So I keyed in vacuum sealing food and an article (only one, but then I am still a beginner) popped up about meat being impounded from restaurants in Portland, Maine.

 

 Food safety and Authorities

 

All this meat, said to be meant for curing and sous-vide cooking, was embargoed by health inspectors who questioned the food safety aspects of the procedures followed, subsequently the award winning chefs of the restaurants were ordered to put all efforts to make their, highly prized  Gourmet dishes, on hold.

 

Several restaurants are ordered to stop vacuuming their meat and to stop cooking sous-vide dishes until they develop special health plans and in some cases to get formal variances of the Main food code.

 

If you live in Maine, Portland or in another part, you are free to carry on vacuuming, cooking sous –vide and curing meat as you like, so not to worry that your vacuum sealer has gone to waste by this measure, but why do these authorities target hard working entrepreneurs and chefs instead of setting desired guidelines themselves?

 

One reason is that restaurants need to develop their own HACCP plan, based on their own procedures and practices which then need to comply with the HACCP guidelines.

 

Curing meat, ‘the butcher way’ has been practiced for ages and is still practiced all over the world, without curing and smoking there is no bacon, pepperoni, Parma ham, smoked salmon, Grav Laks and many more cured delicacies we adore.

 

It is more than commendable that health inspectors are serious about the food safety aspects of food served in restaurants, but let’s see, how this concern justifies.

 

The scientific explanation 

 

Main areas of concern are the risks from foodborne pathogens like salmonella and listeria. I returned to the www and found this explanation in an article (from which I quote) in the Journal of Gastronomy and Food Science.

bacteria holly

You are most probably thought that there is a danger zone between 40 F and 140 F, these temperatures are not quite right, food pathogens can only multiply between 29.7 F and 126.1 F, while spoilage bacteria begin multiplying at 23 F. so why are we thought between 40 F and 140F.

 

Because it takes days for food pathogens to grow to a dangerous level at 40 F and it takes many hours for food to be made safe at just above 126.1 F, compared with only around 12 minutes (for meat) and 35 minutes (for poultry) to be made safe for (immune-compromised people) when the coldest part is at 140 F.

 

There are food pathogens that can multiply down to 29.7 F, (Listeria) but only once per day at 40 F and so you can hold food at below 40 F for 5-7 days.

 

At 126.1 F when the common food pathogen, C. Perfringens, stops multiplying, it takes a very long time to reduce those food pathogens we worry about, Salmonella and E-Coli strains to be reduced to a safe level, in a 1 inch thick hamburger patty.

 

Holding a hamburger patty for 2 ½ hours at 130 F is then also inconceivable with traditional cooking methods- which is why the danger zone for traditional cooking methods does not start at 130 F, but at 140 F.

 

Bit confusing? Basically this means that the rules are based on traditional cooking and sous-vide has never been taken into account.

 

Sousvide processing in the food industry is used to extend shelf-life, vacuum sealing is used. Sousvide cooked food pouches are held below 38 F (refrigerated), they remain safe and palatable for 2-3 weeks. It should be noted here that recommended guides are followed: Quality vacuum sealing and the right cooking times for the right product.

 

For cook-hold sous-vide (prolong shelf-life), the main pathogens of interest are Salmonella and E-Coli, there are of course many others, but these two species are relatively heat resistant and require very few vegetative bacteria per gram to make an immune- compromised person sick, cooking times at the right temperatures are therefore very important.

 

Precise temperature has more benefits for chefs and home cooks than vacuumed packaging does, vacuuming products for sous-vide cooking is a necessity to avoid penetration of unwanted agents while the packet with food is submerged in the water bath, temperature allows for almost perfect re-producibility and allows greater control over doneness than traditional cooking methods.

 

Food can be made safe at lower temperature considering a thorough understanding of the process.

 

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Pasteurization is a combination of temperature and time, Salmonella in a piece of ground beef cooked at 140 F does not instantly die –  it is reduced by a factor 10 every 5.48 minutes, so to eliminate Salmonella it needs to be cooked for 10 x 5.48 = 54.8 minutes at 140 F.

 

The rate at which the bacteria die depends on many factors, temperatures, meat species, muscle type, fat content, acidity, spices, salt and water, but does not mean that sous-vide cooking cannot produce a product that is safe to eat.

 

HACCP

 

Science- based food safety criteria are usually based on the HACCP system and generally considered by food safety authorities, changes do however happen and when new cooking methods are introduced (sous-vide became popular 45 years ago) food safety authorities should have followed this trend by understanding that sous- vide, curing and vacuuming is NOT necessary a critical control point when understood and performed according to scientific studies.

 

  1. When you buy your raw food it has millions of microorganisms on it, vacuuming that raw food does not reduce these microorganisms, so you must keep your vacuumed food chilled or frozen.
  2. As the food heats, microorganisms begin to multiply rapidly with most of them growing fastest between 85 F and 120 F. If you are not pasteurizing it is then also advisable not to leave your vacuumed food outside a refrigerated or freezing environment longer than one hour.
  3. You heat your vacuumed food pouches in a temperature controlled water bath. Recall that it is important your vacuumed pouches have a quality seal.
  4. If you are not heating to pasteurize, but to cook a meal that will be consumed after preparation, minimizing the pathogen growth is a critical control point.
  5. Once the temperature of the food exceeds 126.1 F, then all the known food pathogens stop growing and begin to die. Many recommend that the core of the food reach 130 F within 6 hours, many if not most sous-vide recipe time tables are based on these principals.
  6. If the cooked food is served immediately, then you do not have to worry about any additional pathogens growing.

 

Conclusion

Sous-vide cooking is a powerful tool in the modern kitchen, precise temperature control provide for superb quality products, you may expect when dining in a top class establishment.

 

Vacuum sealing improves heat flow, extends shelf-life of food by eliminating re-contamination, vacuuming reduces off-flavors from oxidation and reduces the loss of nutrients to the cooking medium (for example, water)

 

I sincerely hope that the Portland chefs are able to draw up the necessary, able to comply with the requirements and you can enjoy delicious safe to eat sous-vide meals again.

 

If the warning from the Maine authorities made you hesitate to cook sous-vide at home, read the full article here: http://www.sciencedirect.com/science/article/pii/S1878450X11000035?np=y

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Be ensured that you can make food perfectly safe at low temperatures, provided you follow the right procedures and use the right vacuum sealing equipment, which you can find here:

 

www.vacupack.com  for USA and www.vacupack.ca for Canada.

 

By Marinus Hoogendoorn

 

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