Experimental Values and Correlations for Characteristic Variables and Thermophysical Properties of Osmotically Dehydrated Stone Fruits

RODRIGUEZ ANABEL; RODRIGUEZ M. MARCELA; PAGANO ANA MARÍA; MASCHERONI RODOLFO H.

Stellenbosch

Congreso; 2012 CIGR Section VI International Technical Symposium on “Innovating the Food Value Chain” Postharvest Technology and Agri-Food Processing; 2012

Osmotic dehydration (OD) of foods, especially of fruits and vegetables, is often used as a pretreatment to further conservation procedures. It is important to develop general relations between variables relevant to the dehydration process (water content WC, soluble solids content SS) independent of product characteristics and process conditions. It is also of technical value to develop general equations to predict the variation of heat capacity and enthalpy with temperature and water content and initial freezing point with water content independent of the fruit and vegetable used. Based on own experimental data and information from literature, in this work we developed: - A linear correlation between WC and SS for stone fruits dehydrated in sugar or alcohol solutions that allows to characterize both properties with only one rapid determination (of any of both); - General correlations between heat capacity and enthalpy with water content and temperature for fresh and osmotically dehydrated stone fruits; - A general correlation for initial freezing temperature of fresh and osmotically dehydrated stone fruits as a function of water content.