About Vacuum Packing; How To Preserve Food In Bags - Flama 1905 FL Manual De Instrucciones

The deterioration of food is caused by chemical reactions that
occur in food which is exposed to the air, temperature,
moisture, the action of enzymes, the growth of micro-organisms
or contamination by insects.
Vacuum packing reduces the absolute pressure of the air inside
the package or container, by removing the oxygen and
eliminating volatile compounds. The oxygen in the air causes
food to deteriorate, firstly through a process of oxidation,
causing the loss of nutritional values, flavour and all the food's
qualities. Air also promotes the growth of most micro-organisms
and causes the frost burns which occur on frozen food.
Vacuum packing extends the shelf life of many fresh foods, by
reducing oxidation and preventing the proliferation of microbes
(bacteria and mould). However, many fresh foods contain
sufficient moisture to encourage the growth of micro-organisms
that can grow with or without air. To prevent the deterioration
of such foods, they must be preserved at low temperatures.
Micro-organisms like mould, yeast and bacteria are present
everywhere, but they can cause problems only in certain
conditions.
For example, mould will not grow in environments with a low
oxygen content, or in the absence of moisture or humidity. To
grow, yeast requires moisture, sugar and a moderate
temperature, but it can grow in the presence or absence of
air. Refrigeration slows the growth of yeast and freezing blocks
it completely. Bacteria can multiply with or without air, depending
on their type.
Clostridium Botulinum is a very dangerous type of bacteria
which can develop in environments which do not contain
acids, are without oxygen and are exposed to temperatures
in excess of 4°C for long periods of time.
Foodstuffs vulnerable to attack by Clostridium Botulinum are
those with low acidity (like red meat, poultry, fish, seafood,
olives in brine, eggs, mushrooms and vegetables) and medium
acidity foods like virtually all vegetables and many fruits (ripe
tomatoes, onions, red pepper, figs and cucumbers). To prevent
Vacuum packing for the freezer
First of all, use the freshest possible food. The system will allow
you to retain all the freshness of the food only if it is properly
preserved.
Some foods have a soft consistency which could be damaged
by vacuum packing the product when fresh. To prepare delicate
foods like meat, fish, berries, bread, etc., it is advisable to pre-
freeze them first. In the first twenty-four hours there is no risk
of freezer burns, so you can vacuum pack the products frozen
the previous day in bags, and then keep them in the freezer
for long periods so as to preserve all the nutritional values
and flavour of the product you have packed.
When vacuum packing soups, stews or other liquid food, pre-
freeze it in a pan or high-strength dish. When the food becomes
solid, vacuum pack it, add a label and replace in your freezer.
To vacuum pack vegetables, peel them and then blanche them
briefly in boiling water or a microwave oven until they are
warm but still firm.

ABOUT VACUUM PACKING

HOW TO PRESERVE FOOD IN BAGS

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contamination by this bacterium, it is essential to observe the
basic rules of hygiene and, to prevent its harmful proliferation
in preserved foods, they must be refrigerated for short periods
and/or frozen for long-life preservation. However, such foods
must be eaten immediately after heating.
Important: you must consume immediately any food
which has been heated while still sealed in bags. Leaving
the food to cool slowly at room temperature in the sealed
vacuum bag may cause several harmful micro-organisms
to multiply, in just a few hours, to values that are health-
threatening.
Several enzymes found in foods cause increasingly noticeable
changes in colour, structure and flavour; such changes depend
on the preservation time, temperature and, above all, the
presence of air. To halt the action of enzymes, vegetables must
be blanched briefly using steam or a microwave oven. Food
which contains a high percentage of acidity, like most fruits,
do not require blanching. The absence of air created by the
vacuum will in any case slow down or prevent the action of
these enzymes.
Insect larvae are frequently found in many low water content
or dried foods which have not been vacuum packed or frozen,
and they can develop during preservation and thus contaminate
the food. Some products like flour and grain might contain
larvae, but using vacuum packing will stop them developing
into insects.
Then vacuum pack them in convenient portions.
If the food is not pre-frozen, leave an extra 5 cm in the length
of the bag to allow for expansion due to freezing.
With regard to meat and fish, it is advisable to place the food
on a paper towel and vacuum pack it with the towel in the
bag. This will absorb any moisture in the food.
To preserve food like focaccia, crêpes and small hamburgers,
stack them on top of each other, placing greaseproof paper
or film between each piece. This will make it easier to remove
some of the food, repackage the rest and replace it immediately
in the freezer.
Vacuum packing for the fridge
For busy households, food can be prepared in advance, then
vacuum packed and kept in the fridge for use at different
times, ready to be heated as and when necessary.