The effect of fluctuating temperature on the quality of fruits and vegetables during low temperature storage

Abstract

It is an important problem for the cold-storage industry of fruits and vegetables to know the tolerance of the fluctuating temperature which fluctuates cyclically within a certain range while the mean temperature is not changed. In this paper, the changes in internal temperature of several kinds of fruits and vegetables, such as eggplant, pepper, cabbage, spinach, citrus (Amanatsu) and apple under the fluctuations in temperature were measured.The rate of change in temperature at internal parts varied; the required time in which the temperature at central part of fruits and vegetables attained to the refrigerator temperature was about 3 hrs for eggplant fruit, about 2 hrs for pepper fruit, about 7. 5 hrs for cabbage, about 20 min for spinach, about 5 hrs for citrus (Amanatsu) and about 3. 5 hrs for apple. The rate of change in internal temperature seemed to depend on the state of internal air of fruits and vegetables. Though the materials used in this study contained a high level of internal air, further research must be conducted in the temperature change of fruits composed of non-porous tissues.In the case of polyethylene package, the time to be equal with temperature in the refrigerator was required longer than that of non-package; about 30 min for spinach and several hours for apple. The change in internal temperature was restrained to some degree in the polyethylene package.