Functional metabolic disturbances, which are irreversible and occur in particular in vegetable products, are not a consequence of freezing of tissue but rather arise when fruit is exposed to low temperatures which are nevertheless above the freezing point of the product. This leads to chilling damage, which is visually manifested by discoloration and with regard to taste by an inability to ripen. For these reasons, the specified refrigeration temperatures must be complied with exactly.
Refrigeration must only bring about a reduction in metabolic processes and not interrupt them completely. The fruit adopts a dormant state resulting in only slight losses in weight, nutrients and vitamins due to the reduction in respiration.
It should not be assumed that the lower the temperature at which fruit is stored, the longer it will keep. Each type of fruit has a specific "dormancy temperature", which has to be complied with exactly. At this temperature, the fruit does not suffer spoilage, nor is the subsequent ripening process influenced unfavorably. The temperatures to be maintained in the hold or container are often far above freezing point. Abnormal metabolic processes occur between freezing point and the optimum travel temperature, which lead to chilling damage.
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