Technical Abstract: The formulation of a starch-lipid composite containing cinnamaldehyde as antimicrobial agent has been studied. Cinnamaldehyde was incorporated as an emulsion using Acetem 90-50K as a carrier and Tween 60 as the emulsifier. Oil in water emulsions were prepared by direct emulsification using a high shear mixer or a high pressure homogenizer (Microfluidizer). Oil in water emulsions containing cinnamaldehyde were further used to prepare starch-oil composites by mixing the emulsions with a completely gelatinized starch solution (waxy starch, native corn dent starch and high amylose corn starch). Results demonstrated that in the presence of the emulsifier Tween 60, stable composites could be obtained when sufficient amount of amylose was present in the sample. Finally, stable composites were tested for their biocidal activity against Listeria monocitogenes; no survivors remained after 1 day of incubation with 0.25 % cinnamaldehyde or after 7 days with 0.025% cinnamaldehyde.