Evaluation of quality during storage of apple leather

Abstract

Fruit leathers, a dehydrated snack, have the potential to increase fruit solids consumption especially in the young. Two apple puree formulations containing sugar and citric acid and one containing potassium metabisulphite (100 mg SO2/kg final product) were prepared by hot-air drying at 60 C to a water activity of 0.7 (moisture content ¼ 25 kg water/100 kg of final product). The fruit leathers were then subjected to a storage trial and remained stable for a period of 7 months at 20 C. Changes in organoleptic and nutritional parameters such as Browning Index (BI) and antioxidant activity (AA), respectively, were evaluated. The effect of temperature was studied by accelerated storage tests at 30 C. Using the kinetic constants at both temperatures, a Q10 coefficient was calculated as 2.55 for BI and 16.26 for AA, leading to estimated activation energies of 68.9 and 206.1 kJ mol1 , respectively