Effect Of Ozone Pretreatment Assisting Controlled Atmosphere Storage On Wheat Quality

In order to maximize the preservation of the quality and nutrition of grains during storage,the urgent need to adopt a green and residue-free grain storage technology is put on the agenda,high guality cereal storage are becoming more and more popular with consumers,while the traditional grain storage method mainly uses aluminum phosphide and the influence of circulation fumigation on grain quality cannot be ignored.The active ozone(O3)application grain storage is an environmentally friendly and economical grain storage technology.Nitrogen(N2),carbon dioxide(CO2)and other inert gases can reduce or eliminate the use of chemical agents to achieve killing insects,mildew,and delaying the deterioration of grain quality and with safe green as main advantage.In this paper,the wheat "Gaoyou 2018" mainly recommended by Heibei province was chosen asrearch project.The effects of ozone treatment and various inert gas storage treatment on wheat quality were studied,which would provides a certain theory and foundation for the green storage of cereal.1.Taking Gaoyou 2018 harvested in 2018 as the research subject,the effects of different ozone concentration and treatment time on the physiological and biochemical indexes,processing quality,gelatinization characteristics and storage quality of wheat grains and wheat flour were studied.The results showed that O3 can effectively inhibit the growth of the total number of colonies.The O3 concentration had no significant difference on the germination rate,but the extension of O3 treatment time reduced the germination rate of wheat grains.It had no significant effect on wheat grain conductivity and pH value,and slightly increased the whiteness value of wheat flour.There was no significant difference in the color difference values L*and b*,and the a*value increased slightly.The falling numbers had an increased trend.The Maximum viscosity and End viscosity had a tendency to decrease first and then increase,and there was no significant difference in Breekdown and Setback.Treatment with O3 at a concentration of 2400 mg/kg for 75 min maintained the storage quality of wheat(flour)to the greatest extent.2.Taking Gaoyou 2018 harvested in 2019 as the research subject,the effects of different concentrations of N2,CO2 on the lethality and storage loss rate of sitophilus zeamais were studied.The results showed that in the environment of 25～30℃,The storage loss rate of wheat was negatively correlated with N2 and CO2 concentrations.N2 concentration of less than 90%for 21 days could make the adult sitophilus zeamais achieve 100%lethality.A concentration of 90%N2 for 14 days could make the adult sitophilus zeamais reach 100%lethality.Under low temperature or quasi-low temperature storage conditions.97%N2 concentration can reach half lethality within 21 days,and lethality rate for sitophilus zeamais within 28 days can reach 100%.The higher the CO2 concentration at 15～30℃,the shorter the survival time of sitophilus zeamais adults.The 100%concentration of N2 and the 65%concentration of CO2 had a significant lethal effect on the sitophilus zeamais,a typical pest in grain storage,reached 100%lethality within 9 and 6 days,respectively.3.Taking Gaoyou 2018 harvested in 2019 as the research subject,the effect of low-concentration CO2 combined with high-concentration N2 on the lethality of sitophilus zeamais,the main pest in grain storage was studied.The results showed that with the increasing of CO2 concentration and the decreasing of N2 concentration,the mortality rate of sitophilus zeamais in grain storage did not show linear change.Low concentration of CO2(15%～20%)combined with high concentration of N2(85%～80%)The controlled atmosphere grain storage method achieved low cost and good effect.4.Taking Gaoyou 2018 harvested in 2019 as the research subject,we studied the O3 pretreatment combined with the best single concentration of N2 and CO2,the best combination concentration of CO2,N2 and the control group gas.The above defferent Atmospherestorage treatments on the physical and chemical indexes,processing quality and storage quality of wheat had been determined for 105d.The results showed that the controlled atmosphere treatment group significantly inhibited the increasing in electrical conductivity and the decreased of pH value during storage.The combined controlled atmosphere group had the least influence on the germination rate of wheat grains during storage,which was 15.67%higher than that of the control group.The controlled atmosphere treatment inhibited the decrease of the whiteness value and L*value of wheat flour,and had no significant effect on the wet gluten content,gluten water holding capacity,protein content and falling numbers,while the combined controlled Atmospherestorage wheat sedimentation value decreased slightly.The Maximum viscosity,the End viscosity,Breakdown and Setback increased significantly.Modified Atmospherestorage significantly inhibited the increasing in fatty acid value and reducing sugar content of wheat during storage.The wheat storage quality characteristics were well preserved during the storage in the closed ozone treatment of 2400 mg/kg wheat combined with 15%CO2 and 85%N2.