Countermeasures of Grain Loss Caused by Life Activities of Grain

Respiration consumes nutrients in grains and oilseeds. The more active the respiration, the greater the dry matter loss. The moisture from respiration increases the water content of grains and oilseeds, resulting in a decrease in their storage stability. Part of the energy generated in the respiration process is released in the form of heat, causing a higher temperature or even heating of grain piles. Carbon dioxide accumulation from respiration will lead to anaerobic respiration in the grain piles, and intermediate metabolites like alcohol can reduce grain and oilseed vitality, leading to quality deterioration. Meanwhile, respiration accelerates the after-ripening of wheat and other grain varieties, thus improving their processing and process quality. Therefore, in order to mitigate the adverse effects of respiration, grain should be dried before storage.

During the after-ripening period, due to vigorous physiological activities and respiration, grain will emit a considerable amount of water vapor and heat. When it cools in the air, water vapor condenses, forming water droplets or “sweat” on the grain surface. At this point, the grain may easily heat up or even go moldy if ventilation, dehumidification or cooling is not timely applied. In order to promote after-ripening and improve grain quality, newly harvested grain should be dried to the extent possible before storage, and adequate ventilation should be ensured during storage.

Aging is a process of biodeterioration of stored grain caused by its physiological and biochemical changes, and represents a kind of intangible grain loss. The key determinant of aging is the length of storage period. Aging occurs after a certain period of storage and becomes worse over time. There is a time limit on how long grain can be stored, which varies depending on grain variety. It is necessary to replace stored grain regularly, accelerate grain circulation and avoid excessive periods of storage.

Conditions for germination: Sufficient moisture, appropriate temperature and sufficient oxygen. Germination will not occur if any of the three conditions cannot be met. Among them, moisture is the primary condition for germination. During germination, seeds generally absorb moisture about 25% to 50% or more of their own weight.

Germination inhibition: Measures can be taken to control one or two of the three conditions to make the seed dormant. For example, moisture can be controlled to inhibit germination. For high moisture grains and oilseeds that cannot be dried in time, they can be stored at lower temperatures and oxygen concentrations.