2022 年 13 巻 1 号 p. 26-33
The effective use of agricultural products and the development of processed foods with guaranteed safety and quality are needed in Kampong Cham Province, Cambodia. Young papaya is an important agricultural product in this area. Dried young papaya is one of the preserved foods. The main objective in this paper was to provide basic information for the optimization of drying process. Two types of young papaya, raw or fresh papaya and blanched young papaya, were used in this study to investigate the influence of drying pretreatment that is, blanching, on the changes in the moisture content during drying and water absorption. The hot air-drying characteristics of each sample were measured at three temperatures (30, 50, and 70°C), three air velocities (1, 2, and 3 m/s), and a relative humidity of 40%. The examination of the effects of temperature, air velocity, and blanching on the drying of samples resulted in the drying characteristics of the raw sample being very similar to that of the blanched sample. A linear relationship existed in the moisture content range between the initial moisture contents and 500% (d.b.). The exponential model was applied to predict the changes in the moisture contents of samples below500% (d.b.) at each drying condition. The drying rate constants in the period above or below500% (d.b.) were increased with increasing air temperature and air velocity and expressed as a linear function of both temperature and air velocity, respectively. The water absorption characteristics of the dried young papaya and the dried blanched young papaya that were dried after blanching were investigated at three temperatures (20, 30, and 40°C). Blanching before drying of the sample had the effect of slowing the water absorption rate. The water absorption rate constant tended to increase with increasing soaking temperature.
