Peptide Microencapsulation by Core-Shell Printing Technology for Edible Film Application

This paper presents a new microencapsulation methodology for incorporation of functional ingredients in edible films. Core-shell microcapsules filled with demineralized water (C) or 1 % (w/v) peptide solution (Cp) were prepared using the microencapsulation printer technology. Shell material, composed of a stearic acid/carnauba wax mixture (75:25), represented around 10 % of the capsule weight, corresponding to a shell material/peptide ratio of 13.3:1 on dry basis. C capsules were more spherical and homogeneous than Cp ones. Cp's more irregular morphology would explain the slightly higher size of d (90) (126 mu m) compared to C (122.50 mu m). Cp microcapsules were more stable at pH 5 and 7 (< 30 % peptide released in 3 h) than at pH 2 and 9.2 (40-50 % released in 3 h). A procedure for homogeneous microencapsule inclusion in hydrophilic Laminaria digitata edible films was developed, without losing microcapsule integrity either in the filmogenic solution or during the drying process. Films with added microcapsules were stronger and more deformable, more opaque, more water-soluble but less permeable to water vapour and less resistant to perforation.