
14
The advantage of storing deep frozen food is in
preserving its essence – vitamins, minerals and
taste. Besides, at temperatures between -30° C
and -40° C the texture of raw food changes only to a
minimum extent (e.g. meat). Freeze food as quickly as
possible.
Reason: When you are freezing food slowly, big ice
crystals are formed on the surface. They overgrow
food cells and subsequently damage their structure.
When you are freezing food quickly, small ice crystals
are formed, which do not damage the food to such an
extent. If possible, freeze food at constant temperature
(–18 °C at the most). Only food of the highest quali-
ty should be frozen. Some foods have to be blanched
(scalded) in order to avoid unwanted changes when
freezing or deeply refrigerating (enzyme activation,
ceased germination). Blanched or in any other way heat
treated foods must be chilled before freezing. Otherwi-
se, already stored food can start thawing and become
damaged or vacuum can be lost when storing food in
vacuum containers. To ensure better quality of stored
fruit, use sugar as additive. This also preserves aroma
and colours. In the freezer, containers should be kept
together as close as possible. The rest of them can be
kept in the refrigerator.
8.2. WHAT IS FREEZER BURN?
Signs of freezer burn are rancid meat, rotten vegeta-
bles and tasteless fruit. Freezer burn appears, when the
packaging is permeable to air (common 1 ply PE bags)
and frozen food comes into contact with oxygen. Con-
sequently, water evaporates and the surface of frozen
food dries out. Oxygen penetrates through the porous
cracks and initiates oxidation. As a consequence, food
loses its aroma and fresh taste. We can recognize free-
zer burn by the white and dun stains on the food.
8.3. DEEP FROZEN OR CHILLED
Thawing should be a slow (the most suitable way of
thawing is in the refrigerator) and natural process. It
should not be forced (as it is when putting a bag into
hot water or thawing food in the microwave). Once the
food is defrosted, it should not be refrozen. When refre-
ezing, mechanical damages occur and food can perish
more quickly. Taste, colour and aroma are decompo-
sed. Micro-organisms (bacteria, mould) multiply much
faster. These consequences cannot be eliminated by
refreezing. It is therefore recommended that once the
foods are thawed, they should be used as soon as pos-
sible.
8.4. THAWING
Vacuum packing is also suitable for picnics, sailing and
camping. Food, equipment and documents stay dry and
protected. Batteries, mobile phones and cameras can
also be vacuum packaged to keep them from getting
wet. Vacuum packing prevents mixing of odours and
keeps food from perishing due to moisture. This is
particularly important in small spaces.
8.5. SAILING, CAMPING AND PICNICKING
8.1. WHAT IS VACUUM?
Vacuum or negative pressure is removal of oxygen from
a closed space, in our case from a bag or vacuum cani-
ster.Reducingtheoxygenlevelinthepackaginglowers
the risk of harmful oxidation reactions. Oxygen is an
important factor in the formation of moulds and
bacteria. Oxygen pumping (vacuuming) from a closed
canister or bag prevents or slows down spoilage of food.