Moisture in food:
Due to the balance of grain moisture, the air humidity in the warehouse and in the pores of the grain pile has a great influence on the grain moisture. The air humidity affects the humidity in the warehouse, the humidity in the warehouse affects the humidity of the grain pile, and the humidity, warehouse humidity, grain humidity and grain water content determine the change of grain moisture. The moisture change after the grain enters the warehouse is caused by the change of air humidity except for the reasons such as the leakage of the warehouse, the leakage of the warehouse wall and the floor.
The annual change of grain moisture is mainly due to the annual change of air relative humidity and presents a certain law. The annual change of relative air humidity varies from region to region: the northern region is low in summer and high in winter; the coastal region is low in autumn and high in spring. From the perspective of moisture changes in the entire stored grain, the moisture changes in the surface layer and peripheral parts are mainly affected by external humidity and warehouse humidity, while the internal moisture changes in stored grains are more complicated. In addition to the obvious changes in the moisture content of the upper layer throughout the year, the changes in the middle and lower layers are not significant, and the range is within 1%. According to this rule, when the external humidity is high, the warehouse should be sealed to prevent moisture absorption. Ventilation can be carried out when the external humidity is low and the temperature is low. For grains that have absorbed moisture on the grain surface or have high moisture in the upper surface layer, you can turn the grain surface to loosen the moisture.
In the general composition analysis of grain and oilseeds, protein, lipid, carbohydrate and ash are the approximation of the basic composition
Analysis, and moisture analysis is very clear water molecule H2O. Therefore, a method that can accurately, simply and quickly measure the precise content of moisture is expected by people. Over the years, people have continuously applied new technologies to develop and research fast and accurate determination methods suitable for various grain oils from various aspects. However, it is not easy to accurately measure the water content of grain and oil, and there are still many problems to be solved.
