Effect of drying temperature on lycopene content of processed tomatoes

Abstract

Recently it has been increasing interest worldwide in the production of dehydrated tomato products, which are used in food industry and in pharmacy. An important indicator of the quality of products, beside the microbiological stability is health safety and lycopene content. The aim of this work was to evaluate the effect of drying temperature on changes of the content of lycopene in selected varieties of tomato. Drying was performed at 45 °C, 70 °C and 90 °C. Varieties of Darina F1, Denár, Kecskeméty, Orange, Paulína F1, Šejk F1 were used. Tomatoes were processed into dried slices with the dry matter content of 80-85%. Content of lycopene was determined spectrophotometrically. The content of lycopene in fresh tomatoes ranged from 63.378 mg 100 g^-1 of dry matter (Orange) to 302.37 mg 100 g^-1 of dry matter (Šejk F1). After drying at all temperatures, content of lycopene decreased on average of 64.48 to 68.3%. The most significant changes were found at temperature of 90 °C. Based on the results the most appropriate temperature for drying among the monitored temperatures was at 70 °C, in this case the content of lycopene in the product ranged from 12.839 mg 100 g^-1 dry matter (Orange) to 115.9 mg 100 g^-1 of dry matter.