The effect of thermal treatment on antioxidant activity and changes in bioactive and phenolic compounds of three pear (Pyrus spp.) varieties slices

In this research, the effect of dehydration on total phenolic amounts, total flavonoid, total carotenoid, antioxidant activity values of pear cultivars (Santamaria, Margerit, and Deveci) dried by hot-air (oven) at 50 and 90 °C temperatures was investigated. The moisture contents of control groups of pear fruits were found between 79.12% (Deveci) and 83.39% (Santamaria). The moisture contents of pear samples dehydrated at 50 and 90°C changed between 8.39 (Santamaria) and 12.11% (Deveci) to 8.27 (Santamaria) and 14.17% (Deveci), respectively. The phenolic results of pear varieties for control groups were determined between 3.33 (Deveci and 38.43 GAE/100 g (Margarit). Total phenolic contents of pear fruits dried at 50 and 90 °C varied between 73.98 mgGAE/ 100 g Deveci) and 114.81 mgGAE/100 g (Santamaria) to 148.89 mg/100 g (Deveci) and 176.48 mgGAE/ 100 g (Margarit), respectively. In addition, total flavonoid contents of pear samples dried at 50 and 90 °C changed between 99.56 mg/100 g (Deveci) and 229.56 mg/100 g (Santamaria) to 254.00 (Deveci) and 392.89 mg/100 g (Santamaria), respectively. While antioxidant activities of pears dried at 50 °C change between 30.44% (Deveci) and 44.90% (Santamaria), the antioxidant activities of pears dried at 90 °C were determined between 60.52% (Deveci) and 67.47% (Santamaria). Results obtained exhibited some fluctuations depending on drying temperatures compared to the control.