In order to study the effect of glutaraldehyde con- centration on particle size and encapsulation efficiency, thyme oil concentration was fixed at 1.2 or 1.5%, while the glutaraldehyde concentration was varied in the range from 2 to 8%. The results are presented in Table 2 and Fig. 5. Optical microscopy images of the micro- capsules are shown in Fig. 6.
According to the results presented in Fig. 5, the concentration of glutaraldehyde did not significantlly affect the degree of thyme oil encapsulation. However, an optimal glutaraldehyde concentration is required for