Effects Of Hypoxia On Grain Quality And Its Inhibition On Insects And Mildew

In this paper,under laboratory conditions,using the vacuum packaging technology for the relatively low oxygen,explore the 30 ?,vacuum low oxygen conditions of wheat,corn and rice storage after one year quality change,low oxygen conditions on the main storage pests and inhibition effects of grain mildew,and remove the changes of the rice main storage index of the vacuum condition.The results showed that when the vacuum hypoxic technology was maintained at 900 pa the quality characteristics of grain could be maintained significantly,the occurrence of pests in stored grain could be inhibited significantly,and grain mildew could be inhibited significantly.The main conclusions are as follows:(1)Vacuum hypoxia can significantly delay the water loss of grain(wheat,corn and rice)(P<0.05),when the vacuum degree was 700,900 and 1100 pa,the moisture content was maintained well,and there was no significant difference among the three(P>0.05).Vacuum hypoxia can reduce the physiological metabolism of grain,reduce the change of water content,maintain the physiological stability of grain and reduce the decline of grain germination rate.Vacuum hypoxia can effectively delay the increase of wheat fall value,and the effect is most significant when the vacuum degree is 700 pa and 1100pa(P<0.05).Vacuum hypoxia could delay the decrease of wheat gluten water absorption,inhibit the hydrolysis of fat in the grain,slow down the increase of fatty acid value,and significantly delay the decrease of rice processing quality(P<0.05),and the delay effect was the best when the vacuum degree was 700 Pa.Vacuum hypoxia has the effect of delaying the decrease of Catalase(CAT)activity,and the best delaying effect is 700-1100 pa on CAT activity of wheat and maize,and there is no significant difference(P>0.05),CAT activity will decrease with the prolonging of storage time,while vacuum hypoxia can reduce the seed respiration efficiency,inhibit the accumulation of H2O2 in grain,and then delay the decrease of CAT activity of grain and prolong the storage period of grain.(2)Vacuum packing 9 months than vacuum packaging of rice scattered in 3 months after six months of rice higher peak viscosity,lower gelatinization temperature,lower retrogradation value,breakdown value higher,shows that continuous vacuum treatment than after vacuum first remove vacuum have maintained good rice quality,under the condition of vacuum before lifting the rice quality of vacuum conditions change quickly.The p H value,fatty acid value and dry matter of rice soup in continuous vacuum treatment were higher than those in the condition of first vacuum and then vacuum removal,but the water absorption of the two rice soup was similar.In terms of water absorption of rice,there was no significant difference in rice quality between continuous vacuum treatment and the condition of first vacuum and then vacuum removal(P>0.05);In terms of p H value,fatty acid value,dry matter and other indexes of rice soup,the quality of rice packaged by vacuum packaging after a period of time changes rapidly,that is,continuous vacuum treatment can effectively delay the deterioration of rice quality.It shows that vacuum hypoxic technology can effectively delay the deterioration of rice storage quality.(3)When treated with a vacuum degree of 900 pa for 30 hours,the mortality rates of Sitophilus zeamais?Sitophilus oryzae(Linnaeus)?Tribolium castaneum(Herbst)?Tribolium confusum Jac.du Val,were 100.00%,99.83%,94.16% and 98.72%,respectively,which could effectively control the occurrence of stored grain pests.When the O2 concentration was in the range of 0.3-1.3% and 0.3-1.9%,the adults of Sitophilus zeamais were completely killed after treatment for 8 days and 10 days.On this basis,the control effect on the other three pests was further explored when O2 concentration was 0.3-1.9%.The results showed that when O2 concentration was 1.0% and 1.9% for 4d,the lethality rates of the above four storage pests were all above 92.22% and 80.01%,indicating that the lower the O2 concentration,the higher the mortality of pests and the shorter the time needed.At 30?,the vacuum degree was 900 pa,and the grain sample was treated for 30 days,the total amount of bacteria in the grain sample increased slowly in 0-10 days,and the growth of mold was in the logarithmic growth period in 10-20 days,and the total amount of bacteria showed a fast increasing trend.Within 0-30 days,the total number of colonies in the sample at 900 pa increased slowly compared with that in the conventional group.This indicates that vacuum hypoxia can effectively inhibit the growth of the number of mold.