New Insights in the Use of Trehalose and Modified Starches for the Encapsulation of Orange Essential Oil

Abstract

During the encapsulation of aromas by spray-drying, some volatile components may be lost; consequently, the sensory profile could be modified in the final product. Therefore, the selection of the carrier matrix for the encapsulation is crucial to obtain high aroma retention and long shelf-life stability, reduce aroma oxidation and increase physical stability of the powder. With the aim of studying the use of trehalose for the encapsulation of orange essential oil, emulsions were prepared containing mixtures of trehalose–maltodextrin (TMD) and sucrose–maltodextrin (SMD). Two modified starches were used as emulsifiers. The emulsions were spray-dried and stored at 25 and 37 °C. The aroma retention was evaluated using head space–solid phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC-MS) and by sensory evaluation. In addition, some physical properties of orange essential oil powders, such as water sorption and glass transition temperature (T g), were determined. The sensory profiles obtained for TMD and SMD were different: TMD formulations retained mainly limonene, while SMD retained mostly α-pinene and myrcene. The modified starches (Capsul and Hi Cap) used as emulsifiers also affected the retention of certain volatiles. Therefore, the selection of components in the carrier matrix is relevant to the retention of aromas in orange oil powders. Regarding the physical properties, TMD formulations presented better characteristics in comparison to SMD, particularly due to the higher T g values. The high aroma retention levels and the good physical characteristics are promising results in relation to the inclusion of the developed formulations in dehydrated citric juices.