THE INFLUENCE OF SUGAR COMPOSITION ON THE COLOR STABILITY OF OSMODEHYDROFROZEN INTERMEDIATE MOISTURE APRICOTS

Osmodehydrofreezing is a 'combined' process consisting of osmotic dehy dration followed by air dehydration and then freezing. This process ha s been proposed to obtain intermediate moisture (a(w)=0.86) apricot in gredients without sulphur dioxide, having a natural and agreable colou r, which could be suitable for different applications. The influence o f the syrup composition [sucrose, maltose and sorbitol syrups with the addition of 1% (w/v) ascorbic acid and 0.1% (w/v) sodium chloride as antioxidant] on the chemical-physical properties of osmodehydrofrozen apricot cubes (10 mm) was studied. The effect of the modification of t he glass transition temperature (Tg) through the osmotic pretreatment on the ascorbic acid retention and on the colour stability during stor age at -20 degrees C was also analysed. The incorporation of different sugars into the apricot cubes modified the percentage distribution of the sugars and their low-temperature phase transitions. The sugar com position of the syrup affected the ascorbic acid retention during air- drying and the colour stability during the frozen storage, with maltos e showing the highest protective effect. (C) 1997 Canadian Institute o f Food Science and Technology. Published by Elsevier Science Ltd.