Effect of different drying processes on functional properties of industrial lemon byproduct

摘要

The aim of this work was to investigate the effects of different drying processes on drying kinetics, physico-chemical properties and antioxidants of industrial lemon by-product. Lemon byproduct was submitted to infrared drying (50-75 degrees C), convective drying (50-75 degrees C), microwave drying (90-350 W) and combined air-microwave drying (90 W/50 degrees C; 90 W/75 degrees C). Lemon byproduct is rich in water (3.18 +/- 0.12 g water/g d.b), but also in phenols (5.52 +/- 0.08 g GAE/100 g d.b), with a radical scavenging activity of 8.381 +/- 0.400 mg Trolox Equivalent/g of extract. The drying time of industrial lemon byproduct varies between 27 min (350 W) and 480 min (infrared drying at 50 degrees C). Combined-air microwave drying (590 W/75 degrees C) and convective air drying at 75 degrees C allow better retention of phenols and flavonoids (more than 60%). Infrared drying of lemon byproduct at 75 degrees C was in favour of maximal water and oil retention capacities and radical scavenging activity; whereas color preservation is achieved after microwave drying (90 W) and convective drying (50 degrees C). (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.