| At present,Northeast in China bulk grain containers transport nearly 60 million tons of grain to the south every year,which is the main mode of grain transportation.In the process of long-distance transportation,bulk grain transportation often has the risk of pest breeding,which threatens the safety of grain transportation.In this paper,the changes of the volatile compounds from wheat which infected by Cryptolestes ferrugineus(Stephens),Sitophilu oyzae Motschulsky,Tribolium castaneum(Herbst)were studied by Head space solid phase microextraction(HS-SPME)and Direct immersion solid phase microextraction(DI-SPME).There are significant differences in the composition of wheat volatile compounds extracted by HS-SPME and DI-SPME.HS-SPME was mainly used to extract the high-volatile compounds from wheat,which are aldehydes,alcohols and hydrocarbons.but acids are not detected.DI-SPME mainly extracted the low-volatile and non-volatile compounds from wheat,which are hydrocarbons,acids and ketones.Aldehydes,alcohols and esters were not detected.The combination of the two analysis methods provides more comprehensive and complete information for the identification of wheat volatile components.There were significant distinction in compounds of the wheat infected by different grain insects.Gamma-linolenic acid was only detected in the wheat infected by C.ferrugineus;3-ethyltetracosane,9-octyl-heptadecane and 11-butyldocosane were only detected in the wheat infected by T.castaneum,and lead to the number of 1-pentadecene increased significantly.The increased about 4 times in 5pests/80 g wheat about one week.Heptadecyl pentafluoropropionate,triacetate acetate,octacosanol and octadecyl acetate were only detected in the wheat infected by S.oyzae.and lead to a significant increase in dodecane and tridecane.The increased about 112% and 127% in 80 gram wheat infected by 10 pests about one week respectively.The above research results shows that the variation of the contents of r-linolenic acid,1-pentadecene,11-butyldocosane and octacosanol are the characteristics of on the wheat infected by three stored grain pests.In the paper,We uesd the teniques of SPME-GCMS to analysis volatile compounds of wheat infested T.castaneum,C.ferrugineus and S.oyzae respectively.According to the changes of volatile compounds under different infection conditions,the characteristic compounds of wheat infected by three stored grain pests were identified,to provides a theoretical basis for further study about the establishment of rapid detection technology of pests in wheats during the transportation process. |
