Partial dehydration of cherry tomato at different temperature, and nutritional quality of the products

This study concerns the partial dehydration of cherry tomatoes (Lycopersicon esculentum, var. Shiren) to obtain a product with 25% initial water content. Two kinds of dried tomatoes were obtained using a forced air oven at 40, 60 and 80 degrees C for different lengths of treatment. The first type was dehydrated after immersion of the fresh tomatoes in an aqueous Solution of citric acid, sodium and Calcium chloride (10:10:24 g/1); the second was obtained with no pre-treatment. The products were characterised by measuring their CIE L*a*b* colour parameters and levels Of L-ascorbic acid, lycopene and beta-carotene to evaluate thermal damage during processing under the different conditions. Moreover, water activity and the formation of 5-hydroxymethylfurfural were also determined as an index of sugar heat degradation. Treatment with a dipping solution protected both the nutritional and chemical qualities of the partially dried cherry tomatoes. Temperature was directly related to browning, ascorbic acid loss and HMF formation, while no clear influence could be found for carotenoid degradation. (c) 2008 Elsevier Ltd. All rights reserved.