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Advice for preserving vacuum packed foods
The vacuum packed preservation system is the way to preserve purchased and cooked
food. Once you have used vacuum packing preservation, it will soon become essential
in preparing food. Follow the instructions below concerning vacuum packaging and
preservation to guarantee food quality:
1. Chemical reactions of food in contact with room temperature, air, humidity and the
formation of enzymes, microorganisms or contamination from insects ruin food.
2. Oxygen in the air is the main reason for loss of nutritional substances, texture, taste
and quality. The growth of microorganisms is largely due to air, as it removes
humidity, unless food is wrapped in moisture resistant material. Frozen foods,
exposed to freezing, suffer freezer burns.
3. Vacuum packaging suctions approximately 90% of the air from the bag.
With approximately 21% oxygen in the air, removing 90% means about 2%-3% of air is
left in the vacuum packed bag. If the oxygen content is less than 5%, most
microorganisms do not multiply.
4. In general there are three types of microorganisms: moulds, yeasts and bacteria. They
are everywhere, but are dangerous only in certain circumstances.
5. In an environment with little oxygen or without humidity, moulds cannot grow. In a
moist, sugary environment and at mild temperatures, yeasts grow with or without air.
Refrigeration capability slows down the growth of yeast, while deep-frozen
preservation completely impairs growth of bacteria with or without air.
6. One of the most dangerous types of bacteria, Clostridium botulinum, in certain
conditions grows without air: at a temperature between 4˚C and 46˚C. Clostridium
botulinum is a very dangerous type of bacteria which can develop in environments
which do not contain acids, are oxygen-free and exposed to temperatures higher
than 4° C for long periods.
7. Foodstuffs frozen, dried, very acids, salted or sweeten are botulinum resistant.
Other foodstuffs with low acidity such as meat, seafood, olives, poultry, fish, eggs
and mushrooms as well as medium acidity foodstuffs like ripe tomatoes, onions,
red peppers, figs and cucumbers are all vulnerable to be attacked by Clostridium
Botulinum.
8. These foods must be preserved for a short amount of time in a cool place, whereas
for a long time if frozen, and consumed immediately after being cooked.
9. Some dry foods such as flour and cereals can contain insect larvae. If they are not
preserved vacuum packed, the larvae could contaminate food during preservation. To
prevent insects from hatching, vacuum package foods.
10. Food can be preserved at low temperatures since only a few microorganisms
thrive without air.
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