ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Entrapment of ethyl vanillin in calcium alginate and calcium alginate/poly(vinyl alcohol) beads

Steva Levic, Verica Djordjevic, Nevenka Rajic, Milan Milivojevic, Branko Bugarski, and Viktor Nedovic

Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11081, Belgrade-Zemun, Serbia

E-mail: vnedovic@agrif.bg.ac.rs

Abstract: Electrostatic extrusion was applied to the encapsulation of 3-ethoxy-4-hydroxybenzaldehyde (ethyl vanillin) in calcium alginate and calcium alginate/poly(vinyl alcohol) beads. The calcium alginate/poly(vinyl alcohol) hydrogel spheres were formed after contact with the cross-linker solution of calcium chloride, followed by the freeze-thaw method for poly(vinyl alcohol) gel formation. The entrapment of aroma in beads was investigated by FTIR and thermal analysis (thermogravimetry/differential thermal gravimetry; TGA/DTG). The mass loss in the temperature range of 150–300°C is related to degradation of the matrix and the release of ethyl vanillin. According to the DTG curve, the release of ethyl vanillin occurs at about 260°C. TGA measurements of the stored samples confirmed that formulations were stable for a period of one month. FTIR analysis provides no evidence for chemical interactions between flavour and alginate that would alter the nature of the functional groups in the flavour compound.

Keywords: calcium alginate – poly(vinyl alcohol) – ethyl vanillin – encapsulation

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0260-1

Chemical Papers 67 (2) 221–228 (2013)