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Updated: May 26, 2026
Extraction of Plant-based Capsules for Microencapsulation Applications
Published on: November 9, 2016
Microencapsulation of onion (Allium cepa L.) seed oil: influence of emulsion preparation and drying technologies
Rabeb Azaiez1,2, Abderrahmen Chargui3, Donia Chaabane4
1Laboratory of Protein Engineering and Bioactive Molecules, National Institute of Applied Sciences and Technology, University of Carthage, LR11ES24, Tunis, 1080, Tunisia.
Aim:
This study aimed to evaluate the influence of emulsification and drying techniques on the microencapsulation efficiency and stability of onion seed oil.
Methods:
Emulsions were prepared using rotor-stator homogenisation and cross-flow membrane emulsification, followed by spray drying or freeze drying. Three wall systems were tested: whey protein isolate (WPI), WPI/maltodextrin (MD), and WPI/trehalose (TRH). Encapsulation efficiency, moisture content, particle size, morphology, NIR spectroscopy, and principal component analysis were performed.
Results:
The highest encapsulation efficiency was obtained with spray-dried WPI/TRH microcapsules (83.08 ± 0.13%), followed by freeze-dried WPI/TRH (81.37 ± 0.36%). Spray-dried samples showed lower moisture and fewer fat-related NIR absorption bands. TRH formulations produced smoother, more spherical particles with reduced surface oil. PCA confirmed clustering according to drying method.
Conclusions:
The WPI/TRH system combined with spray drying significantly enhances onion seed oil protection, demonstrating strong potential for functional food applications.