Effect of encapsulation techniques on powder characteristics and aroma retention of Pistacia terebinthus L. fruit oil

The objective of this study is to evaluate the effect of maltodextrin: gum arabic ratio and the encapsulation techniques on powder characteristics and aroma retention of terebinth fruit oil. Different ratios of maltodextrin: gum arabic (25:75, 50:50, 75:25) were used to prepare oil-in-water emulsions. The oil and the wall material contents were kept constant at 10% and 20%, respectively. The highest emulsion stability was obtained at maltodextrin:gum arabic ratio of 25:75 with its low creaming index, uniform and small size distribution. Spray-drying (SD), spray-freeze drying (SFD) and freeze-drying (FD) were used as encapsulation techniques and encapsulation efficiency, drying yield, powder characteristics and aroma retention were compared. The encapsulation efficiency (>90%) in SD with ultrasonic and/or two fluid nozzle was significantly higher than those obtained by SFD and FD. However, the drying yield was significantly lower in SD with ultrasonic nozzle (45.27%) and two-fluid nozzle (74.27%) than those obtained by SFD (84.40%), and FD (95.39%). SD with ultrasonic nozzle resulted in higher volatile retention (73.19%) than FD (24.45%) and SFD (14.23%). The α-pinene and linalool are the most retained components with almost 100% among the other ones.