Effects of Heating and Storage Conditions on Growth Properties of Mould in Rice

The effects of low intensity of heating treatments and storage conditions on growth properties of mould in rice were investigated and a model was obtained to describe the growth properties of mould. The parameters of growth properties of rice mould were obtained in order to provide the information for the control of rice mould. The rice samples were treated with traditional heating and microwave radiation, then were stored in the conditions of 20-35°C and 75%~97% (Relative Humidity) for 30 days. Rice mould counts were enumerated periodically. There were lag phases for the rice mould during storage. The growth properties of rice mould were fitted to Gompertz equation precisely. The growth rate constant was between 0.015~0.6 d
^-1
and was influenced by heating methods and storage conditions. The growth rate constant of rice mould treated by the two heating methods was lower than that of the control, whereas the amplitude difference between the treatments and control was reduced as the temperature risen, and the value of the mould treated by microwave radiation was bigger than that of traditional heating. The equivalent mould counts increased as the temperature risen, the values of mould treated with heating are higher in comparison with the control and the difference was more obvious when the treated mould were stored in low temperature and low relative humidity.