| In this paper,use the XOGZ-7 kW continuous tunnel microwave drying sterilization line for common experimental pests:Tribolium castaneum,Sitophilus oryzae,Sitophilus zeamais motschulsky,Tribolium confusum,Oryzaephilus surinamensis,Rhizopertha dominica.After mixing the test pests with 1 kg of rice,they were treated with different microwave conditions,and the slow-soiling rice operation was introduced to determine the quality of rice after microwave treatment.The optimal response surface was optimized to obtain the best experimental parameters of microwave insecticides.At the same time,the infrared thermal imager and Fahrenheit micro-respiration instrument were used to test the microwave-treated test insects to investigate the temperature and respiration changes of the test insects in microwave irradiation.The main research contents are as follows:(1)A variety of microwave powers were used to microwave the 6 kinds of stored grain pests in rice,and their lethal effects were studied.The mortality of six species of insects and their four species of insects increased significantly with the increase of microwave power and microwave time.The lethal susceptibility of each of the Rhizoertha dominica and Sitophilus oryzae was adult larvae,pupa,larvae,and eggs.The lethal susceptibility of the tribolium castaneum was as follows:adults<larvae<pupa<egg;The susceptibility of the Rryzaephilus surinamensis,Tribolium confusum,Sitophilus zeamais motschulsky is:adults<pupa<egg<larvae.The hybrid microwave treatment of six test adult pests revealed that when the microwave power was 4.0 kW and the microwave duration was 40 s,the mortality rates of the six test species could exceed 50%.The order of sensitivity of the six adult insects to microwave irradiation from low to high is:Rhizopertha dominica<Tribolium castaneum<Sitophilus oryzae<Sitophilus zeamais motschulsky<Tribolium confusum<Oryzaephilus surinamensis.(2)After microwave irradiation treatment of 6 stored grain pests in rice,slow-soiling operation was to introduced to explore the lethal effects of 6 species of insects and their insect status.Treating 6 kinds of stored grain pests under different microwave heating temperature and different slowing time,prolonging the slowing time and increaseing the microwave heating temperature,which can significantly increase the mortality rate of the tested animals.Each insect species had a certain degree of resistance to heat at 40 and 45?.When the insects in the experiment were within the temperature range of 55 to 60?,the mortality rates suddenly increased,sustaining the time for slowing time can lead to complete death,this temperature range is the most effective range of pest control.In the experiment,the insects showed slightly different heat-resistance:the heat resistance of the Rhizopertha dominica and Tribolium castaneum pests varied from low to high,followed by eggs,larvae,adults larvae,and pupa;The heat-tolerance of the insects Sitophilus oiyzae,Oryzaephilus surinamensis,Tribolium confusum,Sitophilus zeamais motschulsky was ranked as follows:eggs,larvae,and adults.The eggs of all six species showed better killing effect.(3)Through microwave irradiation and slow-soiling operation of rice,microwave power,microwave heating temperature and slowing time were the three factors to study the processing quality,appearance quality,RVA spectrum characteristics and microstructure of rice samples.The experiment found that the microwave treatment had no significant effect on the roughness of the rice.The microwave heating temperature significantly affected the popping rate and the percentage of polished rice in the rice,which led to a rapid increase in the waist rate and a reduced rate of whole polished rice.However,with the prolonged slowing of time,the popping rate of rice can be significantly reduced and the rate of whole polished rice can be increased.L-value,a value,b value of the surface of polished rice increased with increasing degree of treatment varies,i.e.,such increasing the degree of processing rice to increase the apparent color of the black levels,redness,yellowness strengthened.After rice was treated with slow-wave microwave,the content of mold in rice was significantly reduced,and it had a good effect of removing mold.When the microwave heating temperature reaches 60? and above,the surface mold mortality rate can reach more than 98%,and with the prolonged slowing time,it can be completely deadly.The microwave treatment can appropriately reduce the peak viscosity,increase the attenuation value,and reduce the rejuvenation value,so that the food quality of rice is improved and the taste after cooking is enhanced.When rice particles with electron microscopic observation of cross section after microwave treatment was found,with the increase of the microwave heating temperature,cross-sectional arrangement of rice starch molecules no longer tightly and orderly,increased area faults,cracks gully section increases,disintegration phenomenon starch obviously,the amount of single-grain starch increased.Prolonging the time of slowing the soothing time and increasing the microwave power can significantly reduce the damage of the starch structure.Through data analysis,it is found that there is a certain correlation between the quality of rice after the slow-wave microwave treatment.Wherein a value and b value of the rice surface color was(r=0.836,P<0.01)large positive correlation;rice peak viscosity and attenuation values were large positive correlation(r=0.872,P<0.01);paddy rice rate and L value The peak viscosity was significantly negatively correlated(r=-0.483,P<0.01;r=-0.492,P<0.01).(4)Response surface optimization of mortality and rice quality of different microwave rice suspension cultures in response to test insects.Through the analysis of the mortality rate of test pests,the growth rate of popcorn,the taste value,fatty acid value,and the rice hardness response index to reach a comprehensive assessment of the expected degree of satisfaction of microwave rice processing on insecticide products and the combination of actual equipment conditions yielded microwave slowing time.The optimal process parameters for the operation were:microwave power 5.3 kW,microwave heating temperature 59.8?,slowing-soiling time 2.34 h,at this time the desired function value was 0.85 maximum.At the same time,after inspection,the expected value of optimization based on the actual best process parameters is not significantly different from the regression model prediction(P>0.05),and the optimization results are reliable and effective,and are in line with expectations.(5)Infrared thermal imaging of the test samples after microwave treatment and changes in the respiration of the test pests were studied using the TiX640 infrared thermal imager and the Huabo micro-respiration meter.Experiments show that in the microwave heating process,the absorption of electromagnetic energy by the test pests is much less than that of rice.With the microwave power of 4 kW,the average temperature of the test insects was not significantly different when the test insects were placed directly in the microwave equipment and when they were added to the rice microwave(P>0.05).However,after mixed with rice,sitophilus zeamais motschulsky and rhizopertha dominica were killed by microwave treatment.In the surviving insects,the respiration of sitophilus zeamais motschulsky and rhizopertha dominica was first increased,then decreased,and finally increased sharply.However,no death occurred after treatment of the test insects alone,and with the prolonged exposure time,the respiration of the two species of insects gradually increased. |
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