Evaluation of drying kinetics and quality parameters of rosehip pestils dried by three different methods

Abstract

BACKGROUND: Rosehip fruits cannot be eaten as entire fruits in their fresh feature so they processed into various products including pestils. OBJECTIVE: In the current work, rosehip pestil as a new healthy snack food was developed by using hot air (HA) drying at 55, 65 and 75°C, vacuum (VC) drying at 55, 65 and 75°C with 25 kPa and microwave (MCW) drying at 90 and 180 W. METHODS: The effect of three different drying methods on drying kinetics and quality parameters i.e., total phenolic content (TPC), antioxidant capacity (AC), Hydroxymethylfurfural (HMF) formation, lycopene, β-carotene content, element composition, color, texture and sensorial properties of rosehip pestils was studied. RESULTS: Wang and Singh model was best fitted for MCW drying at 90 W, however Page and Modified Page models were best fitted for other drying conditions. The rosehip pestils dried by MCW drying method had highest drying rate, TPC, AC, lycopene and β-carotene content, element concentration, color values, whereas their HMF content and sensorial properties were not acceptable. Sensory evaluation results indicated that rosehip pestils dried with HA was rated the most acceptable. CONCLUSIONS: It was concluded that rosehip pestil with its sensorial and nutritive properties could be an alternative product for the functional food market. However, it has been seen that the drying methods used alone have some disadvantages. For this reason, it may be possible to eliminate these disadvantages if hybrid drying methods (for example MCW drying followed by HA or VC drying) are preferred in future studies.