FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

AGNIESZKA CIURZYŃSKA, ANDRZEJ LENART

Title

Effect of blanching and method of freezing on selected properties of freeze-dried pumpkin

Abstract

In the paper, the effects are presented of blanching used as a pre-treatment method and of a method of freezing on some selected physical properties of freeze-dried pumpkin. It was shown that every type of pre-treatment favourably impacted the colour, but it caused the water activity, the shrinkage, and the porosity of dried pumpkin to increase compared to non-pre-treated samples. The application of quick freezing reduced the shrinkage and porosity of freeze-dried pumpkin compared to samples frozen using a slow method, but it caused the colour of dried material to essentially deteriorate. The combined method of freezing made it possible to produce dried pumpkins showing the lowest water activity and the lowest difference in colour.

Keywords

pumpkin, blanching, osmotic dehydration, freezing, shrinkage, porosity, colour

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