Comparison of Physical and Bioactive Properties, Phenolic Compounds and Nutrients of Raw and Dehydrated Hawthorn (Crataegus spp.) Fruits

In this study, changes in protein content, bioactive compounds (total phenol, total flavonoid, total carotenoid), radical scavenging activity, polyphenols and minerals of raw and dehydrated hawthorn fruits were compared. The moisture content of hawthorn fruits was determined to be between 7.17% (microwave) and 69.88% (control). In addition, the crude protein content of fresh and hawthorn fruits dehydrated by both drying methods was between 11.37% (control) and 25.53% (microwave). While the total phenolic content of hawthorn fruits increased during drying treatments, the antioxidant activities of hawthorns decreased. The total phenol and total flavonoid content of hawthorn fruits that were oven dried was measured to be higher than that of hawthorn fruits dried by microwave. The L* values of hawthorn samples ranged from 65.66 (control) to 56.72 (dried in a microwave oven). The heat treatment decreased the L* values of samples. The highest a* value (3.36) was found in the sample dried in a conventional oven, while the lowest a* value (−3.27) was determined in the control sample. The highest phenolic constituent was (+)-catechin in fresh and dehydrated (dried) hawthorn fruits, followed by 1,2-dihydroxybenzene, gallic acid, caffeic acid, and syringic acid. Also, the (+)-catechin and 1,2-dihydroxybenzene content of hawthorn fruits was between 9.57 (control) and 29.9 mg/100 g (microwave) and 5.79 (oven) and 24.41 mg/100 g (microwave), respectively. K, P, Ca, and Mg were measured at the highest levels in fresh and dehydrated hawthorn fruits. The K content of fruits changed between 8443.05 (control) and 10,655.62 mg/kg (microwave).