Partial removal of water before freezing: cultivar and pre-treatments as quality factors of frozen muskmelon (Cucumis melo, cv reticulatus Naud.)

The influence of both the cultivar and the dehydration method, applied befo re freezing, on quality characteristics of dehydro-frozen muskmelon spheres has been studied. Water was removed from muskmelon cultivar Mirado and Ron y, prior to freezing, by Dewatering-Impregnation-Soaking in concentrated so lution (DIS) for 1 h, air dehydration and combined DIS-air dehydration to a final 50% weight reduction. The results of the analysis of exudate loss, t exture, colour, aroma composition and sensory characteristics ascertained t he crucial importance of the cultivar which had a great influence on the qu ality of the end products. Moisture reduction prior to freezing reduced exu date loss and improved texture at thawing. All the pre-treatments caused th e loss of ethyl esters, namely "positive" aroma compounds, while the alcoho ls, "negative" aroma compounds, increased in air dehydrated fruits and rema ined stable in the DIS-treated ones. This finding could explain the higher sensory acceptability of the DIS-treated fruit when compared with those pre -air dehydrated. (C) 2001 Elsevier Science Ltd. All rights reserved.