Preparation of citral microcapsules through spray-dring and the stability of the micorcapsules

Spray-drying and layer by layer self-assembly method were employed to prepare citral microcapsule, using methylcellulose ( MC) , carboxymethyl chitosan ( CMCTS) and sodium alginate ( Alg) as the wall materials components.The effects of wall material composition on citral content, morphology, water absorption, and stability of the citral microcapsules were investigated.The optimum wall material composition and prepare conditions were as follows: MC ( in) 0.8 g/50 m L H₂O, CMC1.0 g/30 m L H₂O, Alg 6.0 g/180 m L H₂O, MC ( out) 0.8 g/50 m L H₂O, the citral content of citral microcapsule being 4.54%.Using amphiphilic MC as the inner wall materials improved the citral content by 3.12%. Using MC as the outer wall material increased the citral content of citral by 0.23%, reduced the water absorption of microcapsules by 0.42% in 90 days and improved the stability of the microcapsules during storage.