25℃条件下不同水分玉米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 AT25℃

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25℃条件下,储藏密闭环境内N2、O2和CO2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规模的实验室研究结果表明: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,偏低水分和安全水分玉米储藏环境中O2浓度随时间变化趋势基本无差异,偏高水分玉米储藏环境中O2浓度在各时间段均明显低于偏低水分和安全水分玉米,并且这种差异达极显著水平;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,其中储藏环境中CO2浓度在各时间段的大小为:偏低水分玉米<安全水分玉米<偏高水分玉米,且偏低水分和安全水分、安全水分和偏高水分间的差异达到显著水平,偏低水分和偏高水分间的差异达极显著水平;不同水分玉米密闭储藏环境中CO2的累积量在有氧呼吸阶段随耗O2量增加而增加,在无氧呼吸阶段CO2累积量和耗O2量无关。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25℃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 respiration by determining O2, CO2 and N2 content under hermetic storage conditions with three different moisture contents of maize （low moisture 11.8%,safe moisture 13.3%and high moisture 16.3%） stored in it at 25℃. The results obtained from the 20L-scale experiments have demonstrated that the respiration of maize under hermetic storage conditions in three different moisture, had little effect 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 CO2 concentration in self--regulated environment the difference of oxygen concentration in the hermetic storage conditions between the maize of low moisture and safe moister is little, but they are both signifi- cant higher to the oxygen concentration of high moisture maize. The CO2 concentration of three moisture content maize under hermetic storage conditions changed as follow： low moisture〈 safe moisture〈high moisture, and the difference of CO2 concentration between the maize of low moisture and the maize of safe moisture is significant,, the difference between safe moisture and high moisture is extremely significant. The relation between cumulative amount of CO2 and the consumption of O2 are different from aerobic resipiration and anaerobic respiration, At aerobic resipiration phase the cumulative amount of CO2 go up with the consumption of O2, but when anaerobic respiration there were no relationship between the cumulative amount of CO2 and the consumption of O2. 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 equations 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 25 ℃ 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.