This study aimed to determine effect of different drying methods HAD (Hot air drying), Freeze drying (FD), vacuum drying (VD) and ultrasound assisted vacuum drying (UAVD) on drying kinetic, total bioactive compounds, lycopene and β-carotene, phenolic composition and color quality of rosehip. Drying times of the rosehips for USVD, VD and HAD were 180, 300 and 1140 min respectively. Total phenolic (TPC) and flavonoid (TFC) were significantly affected from drying methods. FD showed highest TPC and TFC followed by VD, UAVD and HAD. DPPH and CUPRAC methods were carried out to determine antioxidant activity of the fresh and dried samples. DPPH and CUPRAC values showed similar trend with TPC and CUPRAC values showed high positive correlation with TPC contents (R<0.95). Lycopene and β-carotene content were significantly affected from drying methods and VD showed highest lycopene and β-carotene content. Catechin and rutin were determined as most abundant phenolic compounds and their highest content were obtained from FD and VD treated samples. The effect of drying method on the color quality of the samples was found to be significant (p<0.05). UAVD and FD exhibited a lower E value than HAD and VD, indicating that they had similar color properties to the fresh sample. The results of this study showed that UAVD significant decreased drying time compared to VD while UAVD showed lower bioactive compounds retention than VD. This study suggested that ultrasound treatment with vacuum could showed negative effect on bioactive compounds despite its lower drying time.
Anahtar Kelimeler: Ultrasound Assisted Vacuum Drying, Phenolic Profile, Carotenoids.