Modelling shrinkage and porosity during vacuum dehydration

Krokida, MK; Zogzas, NP; Maroulis, ZB

dc.contributor.author	Krokida, MK	en
dc.contributor.author	Zogzas, NP	en
dc.contributor.author	Maroulis, ZB	en
dc.date.accessioned	2014-03-01T01:13:12Z
dc.date.available	2014-03-01T01:13:12Z
dc.date.issued	1997	en
dc.identifier.issn	0950-5423	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12355
dc.subject	apparent density	en
dc.subject	apple	en
dc.subject	banana	en
dc.subject	carrot	en
dc.subject	drying	en
dc.subject	potato	en
dc.subject.classification	Food Science & Technology	en
dc.subject.other	BULK-DENSITY	en
dc.subject.other	AIR-FLOW	en
dc.subject.other	FOODSTUFFS	en
dc.subject.other	RESISTANCE	en
dc.title	Modelling shrinkage and porosity during vacuum dehydration	en
heal.type	journalArticle	en
heal.identifier.primary	10.1111/j.1365-2621.1997.tb02119.x	en
heal.identifier.secondary	http://dx.doi.org/10.1111/j.1365-2621.1997.tb02119.x	en
heal.language	English	en
heal.publicationDate	1997	en
heal.abstract	Apparent density, true density, specific volume and internal porosity were investigated during vacuum dehydration of banana, apple, carrot and potato, at various moisture contents and pressures. The pressure was found to effect significantly the apparent density and porosity of the materials examined, while for the true density, this effect was practically negligible. In all four materials the development of porosity was favoured by the decrease of pressure. At the lowest pressure used (30 mbars) banana and apple developed the highest porosity values (similar to 75%), followed by those of carrot (similar to 50%) and potato (similar to 25%). A simple mathematical model was proposed to predict the above properties as functions of material moisture content and pressure. The parameters incorporated into the model were: the enclosed water density, the dry solids density, the apparent density of the dry material, and a transformed volume-shrinkage coefficient. Among these parameters, only the apparent density of the dry material was found to be strongly affected by the pressure and a suitable exponential equation was proposed to express this influence. The proposed model was fitted to the experimental data satisfactorily, and the required parameters were estimated through a regression analysis procedure.	en
heal.publisher	BLACKWELL SCIENCE LTD	en
heal.journalName	INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY	en
dc.identifier.doi	10.1111/j.1365-2621.1997.tb02119.x	en
dc.identifier.isi	ISI:000075338600002	en
dc.identifier.volume	32	en
dc.identifier.issue	6	en
dc.identifier.spage	445	en
dc.identifier.epage	458	en