The Study of the Dissolution Process of Spherical Candy

In this research, the factors affecting the dissolution process of spherical candy in water and its activation energy were investigated. Spherical, chewy candy, whose trademark is Sugus, was used as studied sample. A simple apparatus was designed using a transparent rectangular box (fish tank). The experimental setup consisted of a candy sphere immersed near the bottom of a glass box, a digital camara placed above water level for recording photo and measuring diameter of the candy during dissolution process, and a paddle for stirring solution. The glass box was placed inside a water bath to control temperature. The variation of the activation energies for three different states of rotational speed was studied when the paddle was turned off and when the paddle was turned on at two different rotational speeds, which were 27 rpm and 46 rpm. To study the effect of the temperature on the rate of dissolution, the experiment was performed at temperature from 10 oC to 45 oC with a 5 oC interval. The study of the change in candy diameter and dissolution time found that candy diameter decreases linearly with time. The rate of dissolution (change in diameter over time) of candy was proportional to the surface area. The study of temperature effect on the rate of dissolution found that the dissolution rate increases with temperature. At the same temperature, the study of paddle’s rotational speed effect on the rate of dissolution found that the dissolution rate increases with paddle’s rotational speed, and the activation energy for the dissolution process was 27±5 kJ/mol. The experiments with and without solution stirring gave the close value of activation energy. This studied equipment can be useful for the class demonstration in the topic of dissolution process and determination of activation energy.