Study On The Flash Heat Treatment Technology For Control Pests In Stored Wheat

In this paper, Flash heat treatment technology was used to prevent and control of pests instored wheat. Directly lethal effect of Flash heat treatment on different stages of Cryptolestesferrugineus (Stephens),Tribolium castaneum (Herbst),Oryzaephilus surinamensis (Linnaeus),Rhyzopertha dominica (Fabricius),Sitophilus Oryzae (Linnaeus),and Sitophilus ZeamaisMotschulsky were studied respectively. Then used rapid heating uniformity of wheat heap andinsulation flash heat treatment technology for a short period of time by self-made heatpreservation warehouse, the lethal effect of flash heat treatment on each stage of6kinds ofinsect pests in different moisture content wheat heap was studied. Temperature/timecombination that can completely killed larva and adult of6kinds of pests were researched,finally the effect of Flash heat treatment on quality indicators of3kinds of moisture contentwheat were also researched, such as germination rate, the water absorption of gluten andstarch gelatinization characteristics etc. The main results were as follows:Correction mortality of3kinds of powder feeding of insect pests increased significantlywhen directly treated at55℃. Fully lethal time of all stages of3kinds of powder feedingpests is15min when processed at55℃.Heat resistance of different stages of the same speciepest are difference, different stages of3kinds of powder feeding pests have different heatresistance, to Oryzaephilus surinamensis (L.): pupa>egg>adult>larvae, to Cryptolestesferrugineus (S.) and Tribolium castaneum (H.): pupa> larvae> adult> eggs. Different pestsof the same stage have different heat resistance, the results show that the egg and the adult ofTribolium castaneum (H.) have the strongest heat resistance of the3kinds of powder feedingpests, completely kill the egg and the adult needs combination of temperature/time are55℃/10min; Larvae and pupa stage heat resistance to Oryzaephilus surinamensis (L.) is strongest,completely lethal combination of temperature/time respectively55℃/55℃/10min and15min.Mortality of3kinds of boring pests was positively correlate to the temperature and timewhen directly treated by Flash heat, Fully lethal time of all stages of3kinds of boring pests is15min when processed at60℃. Different stages of the same specie pest have different heatresistance, different heat resistance of all stages of3kinds of boring pest respectively is to Sitophilus Zeamais M.: pupa> adult> larvae> eggs; to Sitophilus Oryzae (L.): pupa> adult>larvae> eggs; to Rhyzopertha dominica (F.): larvae> adult> pupa. The same stage ofdifferent kinds of pests also have different heat resistance: in3kinds of boring pests, the adultof Rhyzopertha dominica (F.) has strongest heat resistance, completely kill the adult needscombination of temperature/time is55℃/15min, the pupa and the larvae of SitophilusZeamais M.and Rhyzopertha dominica (F.) have strongest heat resistance, completely killthe pupa and the larvae all needs combination of temperature/time is60℃/10min. Heatresistance of the egg stage between3kinds of boring pests was not significantly different.The corrected mortality of the larva and the adult of6kinds of pests at3kinds ofmoisture content of wheat were greater than50%when treated by flash heat at55/10min, thelethal effect is remarkable. Fully lethal time of all stages of6kinds of insect pests is20minwhen processed at60℃.Result suggested the boring pests have stronger heat resistance thanthe powder feeding pests, the temperature that can kill all stage of the boring pests whenprocessed at10min higher than the powder feeding pests. With the increase of wheat moisturecontent, completely kill all stage pests at the same time the required temperature is higheror at the same temperature the required time is longer when treated by flash heat, suggestedthat the moisture content of wheat can significantly affect the insecticidal effect of flash heattreatment.Flash heat treatment effect on several quality indexes of3kinds of moisture wheat all notsignificant, such as gluten water absorption, germination rate and amylase activity. Qualityindex of12%of moisture content of wheat and14%all have insignificant change after flashheat treatment, while gluten water absorption and germination rate of16%moisture contentwheat have decreased slightly when treated at60℃, so the temperature should not more than60℃when process high moisture content wheat, to ensure the safety of wheat quality. Inconclusion, according to the wheat moisture to choose the appropriate temperature/timecombination, for flash heating uniformity of wheat heap and keep the flash heat insecticidaltreatment for a short period of time for wheat quality is safe.