Effect of freeze-drying conditions on shrinkage and porosity of dehydrated agricultural products

Krokida, MK; Karathanos, VT; Maroulis, ZB

dc.contributor.author	Krokida, MK	en
dc.contributor.author	Karathanos, VT	en
dc.contributor.author	Maroulis, ZB	en
dc.date.accessioned	2014-03-01T01:13:42Z
dc.date.available	2014-03-01T01:13:42Z
dc.date.issued	1998	en
dc.identifier.issn	0260-8774	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12672
dc.subject	Agricultural Production	en
dc.subject	Bulk Density	en
dc.subject	Glass Transition Temperature	en
dc.subject	Potato	en
dc.subject	Structural Properties	en
dc.subject	Freeze Dried	en
dc.subject.classification	Engineering, Chemical	en
dc.subject.classification	Food Science & Technology	en
dc.subject.other	Agricultural products	en
dc.subject.other	Dehydration	en
dc.subject.other	Density (specific gravity)	en
dc.subject.other	Drying	en
dc.subject.other	Freezing	en
dc.subject.other	Mathematical models	en
dc.subject.other	Porosity	en
dc.subject.other	Pressure effects	en
dc.subject.other	Shrinkage	en
dc.subject.other	Thermal effects	en
dc.subject.other	Viscosity	en
dc.subject.other	Bulk density	en
dc.subject.other	Exponential equation	en
dc.subject.other	Freeze drying	en
dc.subject.other	Particle density	en
dc.subject.other	Food processing	en
dc.title	Effect of freeze-drying conditions on shrinkage and porosity of dehydrated agricultural products	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0260-8774(98)00031-4	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0260-8774(98)00031-4	en
heal.language	English	en
heal.publicationDate	1998	en
heal.abstract	Structural proper ties such as particle density bulk (or apparent ent) density and porosity of apple, banana, carrot and potato were investigated after freeze-drying under various drying conditions. The materials were freeze-dried at various pressures, to achieve sample temperature ranging between -50 and -5 degrees C. Fbr temperatures above the glass transition temperature of the concentrated amorphous solution (T'(g)= -45 degrees C), the freeze-dried materials decreased in size. The bulk density of the freeze-dried materials was increased with temperature and an exponential equation was used to express this influence. The final porosity decreased as the sample temperature increased for all the materials examined, ranging between 70 and 95%. The final porosity was related to the complex viscosity of frozen apple and potato which decreased linearly as the temperature increased in the temperature range examined. (C) 1998 Elsevier Science Limited. All rights reserved.	en
heal.publisher	ELSEVIER SCI LTD	en
heal.journalName	Journal of Food Engineering	en
dc.identifier.doi	10.1016/S0260-8774(98)00031-4	en
dc.identifier.isi	ISI:000074808300001	en
dc.identifier.volume	35	en
dc.identifier.issue	4	en
dc.identifier.spage	369	en
dc.identifier.epage	380	en