Gac Fruit Oils Encapsulated by Palm Oil-based Monoacylglycerols: The Effect of Drying Methods.

ABSTRACT

Lyotropic liquid crystals (LLCs) are interesting wall-materials for encapsulation technology, in which monoacylglycerols (MAGs) are considered as potential ingredient for LLC formulation. This study, therefore, applied palm oil-based MAGs to encapsulate Gac fruit oils and compared the effect of two drying methods (freeze-drying and spray-drying) on the quality of products during storage. Wall-materials were prepared by ultrasound dispersing MAGs/water mixtures (40/60, w/w) into Pluronic solution (2%, w/w) to formulate LLC dispersions. Then, Gac fruit oils were encapsulated by freeze-drying and spray-drying. Various technologies were applied to characterize the properties of dispersions, the encapsulated powder morphology and the loading capacity. Obtained results showed that LLC dispersions made of palm oilbased MAG were micro- and nano-emulsions which were very convenient for encapsulating Gac fruit oils. For both drying methods, ß-carotene of Gac fruit oils was successfully entrapped by MAGs with a high loading capacity (200 µg ß-carotene/g powder). The degradation of encapsulated ß-carotene after four storage weeks was 10 - 40% and freeze-dried samples showed a better protection effect in comparison to spray-dried samples.