Preliminary investigations of the gelling characteristics of the enzyme- degraded xyloglucan were carried out to define the gel region for subsequent release experiments. Fig. 2 shows the reversible sol-gel transition temperatures as a function of concentration over the concentration range of interest for the present study. The gelation temperature determined for the 2% sol is in agreement with the value reported by Shirakawa et al. [14]for a sample of galactoxyloglucan with 44% conversion. The gelation time, determined as the time at which lack of movement of the meniscus was first detected on tilting a tube containing the sol at constant temperature, decreased with increase of both the temperature and concentration. The relationship between these three parameters is shown in Fig. 3.