3.5. Stability of the encapsulated material
As shown in Fig. 3, AA in its free form in solution was completely degraded after 15 and 30 days of storage at the temperatures of 37 °C and 20 °C, respectively. These results highlight the instability of this compound in solution during storage. According to Fennema et al. (2010), AA is highly susceptible to oxidation, and the process is accelerated
by the presence of oxygen, high Aw and neutral pH values. Degradation of the encapsulated AA was also observed, but at a slower rate (Table 4). After 30 days at 20 °C, the microcapsules still maintained 57 to 80% of the initial concentration of AA. At the higher temperature of 37 °C, the microcapsules maintained 32 to 44% of the initial concentration of AA, thus proving the deleterious effect of temperature on the encapsulated material.