Frequently asked questions

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• 1) What are the potential of food safety hazards?

Clostridium botulinum toxin formation as a result of time/temperature abuse during processing, storage and distribution, can cause consumer illness and death. When C. botulinum grows it can produces a potent toxin and spores. Though, the toxin can be destroyed by heat but processors cannot rely on this as a means of control. Although the vegetative cells of all types are easily killed by heat, the spores are very heat resistant.

Temperature abuse occurs when product is exposed to temperatures favorable for C. botulinum growth for sufficient time in toxin formation. Packaging conditions that reduce the amount of oxygen present in the package (e.g. vacuum packaging) extend the shelf life of product by inhibiting the growth of aerobic spoilage bacteria. The safety concern with these products is the increased potential for the formation of C. botulinum toxin before spoilage makes the product unacceptable to consumers.​

• 2) What is Reduced Oxygen Packaging and what are the benefits?

​Reduced Oxygen Packaging (ROP) produces an environment that contains little or no oxygen, offers unique advantages and opportunities for the food industry but also raises microbiological concerns.
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Products packaged using ROP may be produced safely if proper controls are in effect. Producing and distributing these products with a HACCP or ISO 22000 approach offer an effective, rational and systematic method of assurance for food safety.

​Benefits of ROP

1. ROP can create an important anaerobic environment that prevents the growth of aerobic spoilage organism which generally are aerobic yeast and molds. These organisms are responsible for off-odors, slime and texture changes, which are sign of spoilage.
2. ROP can be used to prevent degradation or oxidation processes in food products. Reducing the oxygen in and around a food retards the amount of oxidative rancidity in fats and oils.
3. ROP also prevents colour deterioration in raw meats caused by oxygen.
4. Another benefit in ROP is the reduction of product shrinkage by preventing water loss.

 
ROP allows an extended shelf –life for food to be distributed over a large geographic areas or for convenient ready –meals, are examples of economic and quality advantages.

• 3) What are the various methods of ROP?

​There are a number of conditions that can result in the creation of ROP environment. ROP is an inclusive term that include many options but the most significant are sous vide and vacuum packaging.
        i)   Cook-chill—a process that uses a plastic bag filled with hot cooked food from which air has been expelled. It is then closed with a plastic or metal crimp sealed.
        ii)   Controlled Atmosphere Packaging (CAP)—an active system that maintains a desired atmosphere within a package throughout the shelf-life of a product by the use of an agent to bind or scavenge oxygen.
        iii)   Modified Atmosphere Packaging (MAP)—it employs gas flushing and sealing process or reduction of oxygen through respiration of vegetables or microbial action. Gases used are Nitrogen or Carbon Dioxide or a combination of both; percentage of each type depending on the products to be packed.
        iv)   Sous vide—a special process of ROP for partially cooked ingredients alone or combined with raw foods that require refrigeration or frozen storage until the package is thoroughly heated immediately before serve. The sous vide process is a pasteurization step that reduces bacterial load but is not sufficient to make the food shelf-stable.   The process involves the following steps:

1.  Preparation of raw materials, and may include partial cooking of some or all ingredients.
2. Vacuum pack
3. Pasteurization of the product for a specified and monitored time/temperature.
4. Rapid and monitored cooling of the product at or below 3°C or frozen
5. Reheating of the packages to a specified temperature before opening and serve.

 
         v) Vacuum Packaging—reduces the amount of air from a package and hermetically seals the package so that a near perfect vacuum remains inside.
 
Our ISO 22000 cast co-extrude vacuum bags have aseptic (sterile) interior monitored by Eurofins.
All Hevel bags undergo 3-monthly LAB TEST for bacteria count and a 6-monthly LAB TEST for migration on regular basis, following the EU laws.
All LAB TESTS are strictly monitored by Eurofins.

​Reports are available upon request.

• 4) Who are the Eurofins?

The largest Food Laboratory in Europe. It is a laboratory setting Industry Standards for food safety and hygiene problems and offers coaching on quality systems and monitoring. With 23,000 staff in over 225 laboratories across 39 countries, Eurofins Scientific is the World Leader in food, environmental and pharmaceutical products testing.
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Eurofins is accredited against ISO/IEC 17025 by the Dutch Accredition Council RvA.

• 5) Why HEVEL vacuum bags bulged like a ball when the packed products are off-colour or turned slimy?

​When the products are off-colour or turned slimy it is a sign of spoilage, probably due to temperature abuse, and product decomposition releases gases. The gas barriers of Hevel (the Polyamide nylon) vacuum bags are so good that the decomposed gases cannot escape despite having a pressure much higher than the atmospheric pressure of the air and therefore the vacuum bags bulged.

• 6) Why when we vacuum packed a big chunk of beef sometimes air bubbles appear overnight?

Air bubbles on meat when vacuum packed normally shows on the bigger parts. When vacuuming the smaller parts, the vacuum reaches deeper into the meat compared to bigger parts.

The exact cause is very difficult to determine:

It started with the food of the cow; if it contains ingredients like onion, coleslaw or others which produces gas, there will be a chance of air bubbles in the meat. Also the slaughter method may be a leading cause; with a lot of stress the muscles are tensed and their water binding properties are not enough anymore. The same thing when the cow grows too fast; the meat/muscle ratio is out of balance, therefore there is too much moist.

Another option is a bacteria from, or after slaughter; if the bottom part of the cow has been processed before the more tender parts, there is a chance of bacteria migration. This may cause the air bubbles.

Please note that as far as we know, the cause of the air bubbles has never been the vacuum bags.

• 7) What is co-extruded vacuum bags?

Extrusion is a process where plastic melt at very high temperature is extruded through an annular slit die to form a thin walled tube.

Co extrusion means when 2 or more materials are extruded through 2 or more cylindrical slits and welded together because of the very high temperature to form a tube consisting of 2 materials; technically a tube with a compound of 2 materials.

Delamination is not possible because the 2 materials are welded even during high fluctuation in thermal cycle; as compared to 3-sealed or 2-side sealed bags whereby the stiff polyester nylon is glued to the inner PE.

Hevel bags used the flexible Polyamide nylon and welded bi CAST extrusion as witnessed by the longitudinal lines when viewed against the light.

The bottom seals of all Hevel vacuum bags are 3 to 4mm wide as the sealing was carried out at high pressure and low heat or temperature to avoid thinning of the gas barrier nylon at the inner edge of the seals lines.

• 8) Why Hevel uses CAST co-extrusion and not BLOWN co-extrusion for the thermoforming films?

Blown films are pre stretched by virtue of their manufacturing process and thus it is a challenge for deep drawn thermoforming films. Cast films have even thickness and more even distribution of the cast film’s structure. This makes it a better quality choice for deep drawn thermoforming applications, especially the bottom weld where the 4 corners are thinner.

When high barrier films are required to prevent the transmission of gases, moisture and aromas, co-extrude cast films effectively extend product shelf-life. Overall cast film thickness and the more evenly distributed layers of the Polyamide in cast film structures make them an optimal choice.

• 9) What are the basic steps to cooking sous vide?

1) Vacuum seal food in food-grade Hevel sous vide vacuum pouches certified suitable for vacuum cooking to eliminate migratory problems
2) Place the pouch in a water bath that has been brought to the designated cooking temperature.
3) Let food cook for at least the time specified. Longer is generally fine.
4) Remove and serve.

Note: Before serving meat dishes may benefit in searing in a hot pan, on a grill, or with a kitchen torch briefly to create a browned surface and impart a caramelised flavour.

• 10) What kind of food can you cook sous vide?

​All types of food and especially fish and seafood to prevent them from overcooking. Meat examples beef, pork, lamb and poultry are ideal for sous vide. Even eggs, fruits and almost all vegetables can be cooked sous vide with delicious results. Just about anything that requires a fixed temperature to cook can be sous vided.

• 11) Do I need to season food like traditional methods for sous vide cooking?

​The sous vide cooking temperature is low, certain raw seasoning may not develop flavours in the same way as they do at higher temperatures. Also the sous vide process locks in a food natural favours and prevent their loss, so seasoning can be lighter.

Note: certain items, like Garlic and alcohol, need to precook before adding to the food to be sous vided. When sous vide raw garlic will remain raw and alcohol will evaporate in the sous vide process.

• 12) All Hevel vacuum pouches are produced with an aseptic interior. What do you mean by ‘aseptic’ and what is the process to achieve this?

Aseptic means sterile or almost bacteria free. This can only happen when the bags are co-extruded into a tube. Absolutely cleaned air that has been cleansed through several layers of micro-filters is directed through the tubes.

This process not only cleaned the bag interior but also assist the bag to open with ease when loading the products. To ensure our bag interior are aseptic, we send them to Eurofins Food Lab for bacteria count every 3-monthly interval. Latest bacteria Certificate is available upon request.

• 13) Your GLX has revolutionised the concept of vacuum packaging. How did you do it, as you claimed there is no added chemical like sodium sulphite, etc, etc.

We do not add any chemical into the bag and the bags are manufactured under the guided principles and regulations of ISO 22000 for Food Hygiene and Food Safety. We used a combination of several raw materials to produce the bags. GLX pouches are strictly for red meat, like beef and veal, and for fish, like tunas and yellow tail.

Please note that GLX bags ONLY work when the 3 following conditions are strictly adhered to:
       i) The vacuum must be 99% to 100% and the machine seal must not be easily opened with ease by hands.
       ii) Once vacuum placed the bag in the chiller for 3 days until the redness appears and it can remain red in the chiller for 3 to 4 weeks in the case of beef or in the freezer for 1 year.
       iii) Kindly note that for GLX to work effectively the bag size should preferably not be too large, e.g, no more than 50% of the product.

• 14) What are PP and PET? Are they considered as Nylon PA?

PP or Polypropylene film is a transparent film, which can withstand higher temperature. The barrier is low as compared to Polyamide nylon, PA. It is a stiff and rigid film with no stretch. It can only sealed to PP material only, therefore it is mainly used as top film for PP trays. In order to get a barrier, an EVOH layer is added as a sandwich between 2 PP materials, PP/EVOH/PP.

Some Companies claim that PP bags are a perfect replacement for PA/PE cooking bags because it can stand temperature up to 120°C, but they did not mention that it hardly had any barrier. At high temperature the EVOH vaporises when heated, so this is not an option. Most PP bags have 3 seals so they cannot be aseptic. It is stiff so not stretchable and a lot of leakages.

PET is a very stiff material with half the barrier of our Polyamide, PA. It is used as a laminated layer in the 3-sealed or 2-side sealed vacuum bags and totally not stretchable. It is usually not very transparent and many vendors believe that PET/PE bags are as good as PA/PE vacuum bags. Instead of PET/PE they claim to be PA/PE but did not mention that they require twice the thickness of Pet to have the same barrier as PA, example: for our 80microns bag with 20microns of nylon (PA/PE=20/60) you need 40microns of PET to have the same barrier as 20microns of Polyamide nylon, ie, PET/PE=40/60.

They are much cheaper and can delaminate during thermal cycle. Cannot produce co-extrude therefore they are not aseptic.

Please note that we do not use PP or PET as they do not meet the quality standard of our vacuum packaging.

• 15) What is Migration Testing and Compliance Testing?

​Almost all packed food are sold in some kind of packaging, especially plastic. The packaging has to achieve several objectives:
i) the packaging must be able to sell
ii) it must carry all the necessary information about the product
iii) it shall be stable and fit for its purpose
iv) it must be safe and protect against microbial deterioration.

Material that come into contact with food are object of serious public concern.

Plastics and Polymers are regulated under EU REGULATION that packaging material shall neither transfer their ingredients into food in quantities that may impair human health, or deteriorate aroma or taste.