7. Frozen, dried or acid rich foods or foods with a high salt or sugar content, cannot
contain the bacterium Botulinum.
The following foods can be lightly infected with Botulinum:
– Foods without acid e.g. meat, seafood, poultry, fish, eggs, mushrooms and
olives in brine
– Foods with little acid like most vegetable
– Foods with moderate acid content such as tomatoes, onions, chilli-peppers,
figs and cucumbers.
8. To store the above at-risk foods, you should keep them in the refrigerator for
short term storage or in the freezer, for long term storage, and after heating
they need to be eaten straight away.
9. Some enzymes in foods can change the colour, texture and flavour of foods,
which depends on storage time, storage temperature and oxygen. To prevent
this enzyme reaction, vegetable should be blanched or steam cooked for a short
time, or cooked in the microwave. Foods with a high acid content such as most
fruits, must not be blanched. In this case, vacuum packing is enough to slow or
inhibit the enzyme reaction.
10. Some dry foods, such as flour and cereals, contain insect larvae. If the food
isn’t vacuum packed, these can hatch during storage, making the food inedible.
To prevent this these foods should be vacuumed.
11. Generally, foods should be stored at low temperatures since most micro-organ-
isms can also spread without air.
12. If the temperature in your fridge is above 4°C then this can, most of all during
long-term storage, support the growth of dangerous micro-organisms. Therefore
the temperature setting in your fridge should be max. 4°C or less.
13. If the temperature in your freezer is −17 °C or less, it is ideal for storing food, but
remember: freezing does not kill micro-organisms, it only slows their growth.
14. The shelf life of vacuum packed dried foods is also longer, the cooler the storage
temperature is: For every 10°C cooler the storage temperature, the shelf life
extends by 3 – 4 times.
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FURTHER TIPS FOR SUCCESSFUL VACUUMING:
1. Always wash your hands before preparing and vacuuming, equally the materials
and appliance which you use, should be absolutely clean.
2. As soon as the foods have been vacuumed, put them in the fridge or freezer,
do not leave them to sit at room temperature. Make sure that the temperature
in the refrigerator does not increase.
3. Vacuum packing extends the shelf life of dried foods, foods with high fat con-
tent quickly become rancid in warm temperatures and oxygen. Vacuum packing
extends the shelf life of nuts, coconuts or cereals. Store these in a cool, dark
place.
4. Vacuum packing does not extend the shelf life of fruit and vegetables such as
apples, bananas, potatoes and root vegetables, unless they are peeled first!
5. Cabbage vegetables such as broccoli, cauliflower or cabbage give off gas when
vacuum packed fresh for refrigeration. To preserve them, they must be first
blanched, then frozen before packing.
WHAT YOU SHOULD GENERALLY KNOW
WHEN PROCESSING FOOD:
The following food safety instructions are based on scientific findings and experi-
ence and are important for your health and optimal storage of foods:
1. As soon as you thaw, or remove foods from the fridge, consume them immedi-
ately.
2. Canned or ready vacuum packed foods can be vacuum packed again after
opening. Follow the instructions, storing foods in a cool place once opened (not
at room temperature!) and treating vacuumed foods just as carefully as fresh
foods. Take note of the use by date printed on the original packaging.
3. Never defrost foods in warm water or with the help of other heat sources (f.e.
microwave), regardless of whether they are vacuum packed or not. Foods are
most gently defrosted in the fridge.
4. Do not consume highly perishable foods that have been stored for hours at room
temperature. This is especially dangerous if they are in a thick sauce, if they are
vacuum packed, or if they are kept in a low oxygen environment.
5. Distribute vacuum bags evenly in the freezer so that they freeze as quickly as
possible.
