IMPACT OF AIR TEMPERATURE ON DRYING CHARACTERISTICS AND SOME BIOACTIVE PROPERTIES OF KIWI FRUIT SLICES

Abstract

Drying kinetics, ascorbic acid content (AAC), total phenolic content (TPC), and antioxidant capacity (AC) of kiwifruits at different temperatures (60 °C, 70 °C, and 80) were investigated. The drying rate and effective moisture diffusivity of kiwifruits were the highest at 80 °C. Additionally, the Parabolic model best predicts the experimental moisture ratio at 60 °C and 70 °C, while the Page model described the drying curve at 80 °C. On the other hand, the AAC, TPC, and AC of kiwifruits were significantly influenced by temperature. Degradation of AAC increased with the increment in temperature, while TPC and AC were higher at the higher temperature. The range of the AAC, TPC, and AC of fresh and dried fruits were 165.59±12.58-462.81±11.53 mg/100 g DW, 747.66±16.09-1846.87±15.52 mg/100 g GAE DW, and 0.283±0.15-1.903±0.15 mmol TE/100 g DW, respectively. The highest AAC, TPC, and AC losses were calculated as 64.22%, 59.43%, and 85.13%, respectively.