30℃条件下玉米自呼吸对储藏环境中气体浓度变化的影响研究

THE EFFECT OF MAIZE RESPIRATION ON GAS CONCENTRATION CHANGES UNDER HERMETIC STORAGE CONDITIONS AT30℃

通过对3种不同水分(偏低水分11.8%、安全水分13.3%和偏高水分16.3%)的玉米在30℃条件下,密闭储藏环境内N2、O2和CO2百分浓度变化的测定,研究密闭储藏环境条件下玉米粮粒周围环境气体成分浓度的变化规律。20L规模的试验室研究结果表明:不同水分玉米在密闭储藏时环境中N2浓度随时间的变化均不大;不同水分玉米在密闭储藏时环境中O2浓度与储藏时间呈负相关;不同水分玉米在密闭储藏时环境中CO2浓度与储藏时间呈正相关。在气调储藏时,对偏低水分和安全水分的玉米可充分利用粮粒的自呼吸使环境中的O2浓度在21d内迅速下降,后期可通过粮粒的自呼吸使O2浓度维持在5%左右,偏高水分的玉米在11d内即可使O2浓度迅速下降,但后期O2浓度接近0%,无氧呼吸加剧。通过对玉米密闭储藏环境中气体浓度以及耗氧量和CO2累积量随时间的变化趋势线进行回归分析,得到30℃条件下不同水分玉米密闭环境中N2、O2和CO2的回归方程以及耗氧量和CO2累积量的回归方程,利用相应回归方程,可获得玉米在密闭储藏时环境中不同储藏时间段的气体浓度,为气调储藏时玉米粮粒自呼吸的合理利用提供基础技术参数和数据模型。

The purpose of the study was to examine variation of gas composition caused by maize grain respiration by determining O2, CO2 and N2 content in percentage due to respiration depletion of O2 and entichment in CO2 under hermetic storage conditions, based on three different moisture contents of maize （low mois- ture 11.8%,safe moisture 13.3% and high moisture 16.3%） at 30℃ The results obtained from the 20L-scale experiments have demonstrated that the respiration of maize grain, under hermetic storage conditions in three different moisture, affected little on nitrogen concentration but more on oxygen concentration and CO2 concentration. There have a negative correlation relationship between storage time and oxygen concentration and positive correlation relationship between storage time and CCh concentration in self--regulated environment. Grain self--breathing could be used in low moisture and safe moisture maize grain to reduce the O2 concentration of storage environment in beginning 21 days, and could maintain the O2 concentration at 5 % at the later test. High moisture maize grain could drop the O2 concentration quickly in 11 day, but the anaerobic respiration increase when the O2 concentration is dropped close to 0%. The study was undertaken to perform regression analysis according to trends of gas concentration, O2 consumption of and CO2 cumulative amount change with time, to obtain the regression e- quations of nitrogen concentration, oxygen concentration, CO2 concentration, CO2 cumulative amount and O2 the consumption in hermetic storage conditions of maize with different moisture contents at 30℃ temperature conditions. On the basis of corresponding regression equations obtained, the prediction model can be employed to work out the gas concentrate under hermetic condition of stored maize in terms of different time and to provide basic parameters for rational utilization of maize respiration under controlled atmosphere storage environment.