Changes in the bioactive compounds, antioxidant activity and phenolic profiles of dried peach fruits

In this study, the effect of drying process on the bioactive properties and some polyphenols of peach fruits dried in oven, microwave and air was investigated. The moisture contents of dried peaches varied between 5.86 (microwave) and 16.35% (air). The moisture contents of dried peach fruits were significantly decreased compared to the control (86.80%). The total carotenoid and flavonoid amounts of dried peaches were reported between 5.59 (air) and 35.47 µg/g (microwave) to 1371.04 ((oven) and 2928.23 mg/100 g (microwave), respectively. While total phenolic contents of dried peaches vary between 579.19 (air) and 994.67 mgGAE/100 g (microwave), the antioxidant activity values of dehydrated peaches were diagnosed between 8.86 (microwave) and 11.86 mmol TE/kg (air). In general, the carotenoid, total phenol and total flavonoid amounts of the peach samples dried in microwave were found higher compared to the results of both control and other types of drying (oven and air). On the other hand, the antioxidant activities of the peaches dried in microwave were low according to the control and other types of drying. The abundant phenolic compounds of peaches were 3,4-dihydroxybenzoic acid, catechin, caffeic acid, syringic acid and rutin. While 3,4-dihydroxybenzoic acid amounts of dehydrated-peaches are determined between 55.36 (air) and 96.919 mg/100 g (microwave), catechin amounts of the peach samples were diagnosed between 149.98 (air) and 369.968 mg/100 g (microwave). The most increasing phenolic compounds with dehydration were caffeic acid, syringic acid, rutin, p-coumaric acid, ferulic acid, resveratrol and quercetin. Depending on the types of dehydration, the contents of phenolic constituents of peaches showed fluctuations.