Antioxidant activity of fruit raw material during freezing and vacuum dehydration

UDC 66.047.3.049.6

Antioxidant activity of fruit raw material during freezing and vacuum dehydration

Semenov G. V., Budantsev E.V., Krasnova I.S.


Abstract
The paper deals with the changes in the mass fraction of vitamin C and antioxidant activity of apple puree during freezing and dehydration at different vacuum levels. The greatest reduction of the parameters in question (18-20%) is shown to occur in intense evaporation at vacuum. Then the process is decreasing. A comparative evaluation of vitamin C mass fraction and the antioxidant activity of the samples dried by different variants of dehydration (freeze drying, vacuum drying and the combination of these modes) is made. In the combined process of dehydration indicator values are shown to remain approximately at the same level as those of the sample dried by freeze-drying. The experiments have confirmed that the vacuum dehydration of fruit raw material by combination of traditional freeze-drying and vacuum drying processes allows both to reduce power consumption and to obtain a high quality product.

Keywords: vacuum freeze drying, vacuum dehydration, sublimation, vitamin C, antioxidant activity, temperature-sensitive materials.


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