Research On Evaluation Quality Safety Of Kiwi Fruit And Analysision Mold ITS With The Biological Characteristics In Storage Period

In this study, Shaanxi province kiwi fruit were the research objects. The two parts research consisted of evaluation quality safety of Kiwi fruit and the main mold strains which were identified by ITS sequences analysis.And the main pathogenic mold were studied the biological characteristics and the ability of poison which main pathogenic of Penicillium were analyzed.The first part of content included the quality safety of kiwi fruit. The Cu,Zn,Mn,Pb and Cd were detected by Atomic absorption spectrometric method in shaanxi province kiwi fruit.And the forch lorfenuron was detected by HPLC. Analyzing their contents conformed the state standards of limition.So it could provide the theory basis for the analysis of the quality fresh research in Shaanxi province kiwi fruit.The second part of content included mold separation,ITS analysis and biological characteristics in the storage period of kiwi fruit. By morphological and ITS sequences analysis, mold strains were identified and their phylogenetic relationships were also known in their phylogenetic tree. And the main pathogenic mold strains were studied with biological characteristics and the ability of poison which main pathogenic of Penicillium were analyzed.So it could provide the theory basis for the next Shaanxi province kiwi fruit storage.The main research findings are as follows:(1) The kiwi fruit of shaanxi province were analysised of metal ions and forch lorfenuron.The detection rate were100%including Cu,Zn and Mn,Pb was13.64%.And Cd was not detectd.The only Zn exceeded standard in all the samples. The other elements were lower than the national standard of set limit to fruit pollutants. The detection rate of forch lorfenuron were higherr than the national standard in QinMei,but their contents conformed the state standards of limition.(2)30mold strains were isolated from storage of kiwi fruit in shaanxi province. By morphological characteristics concluded30strains mold, e.g. Penicillium,Trichoderma,Alternaria,Mucor and Simplicillium. Penicillium was the dominant species which had19strains, accounted for63.3%in the tested strains. And Trichoderma was the second species which had8strains, accounted for26.7%.(3) By ITS sequences analysis,30mold strains were identificated through cloning sequencing after than Genebank blast,eventually identificated to the kind.The main Penicillium were Penicillium sp., Penicillium purpurogenum,Penicillium chrysogenum,Penicillium paneum and Penicillium commune. The main Trichoderma was Trichoderma longibrachiatum, Alternanthera was Alternanthera sp. MG1, Mucor was Mucor racemosus f. racemosus, Simplicillium was Simplicillium sp. KYK00011. By the use of the method of system development construction MJ trees can be found, species of ITS sequence had obvious difference. However, there were little differences of ITS sequences among intra-species. There were little differences of ITS sequences among Trichoderm, approval ratings were99%. But The differences of ITS sequences between the Penicillium were significant,and was classificated four groups.(4) The biological characteristics of mould were screened and investigated.Bean Sprouts Medium was the most favorable medium for the spore.It could produced high spore for the continuous light conditions and the temperature of30℃.The optimal pH was6.0-7.0.The lethal temperature was80℃and UV capability was from72.73%to92.45%. At the same time, selected natamycin antibacterial agent from the body experiment.The results showed that, the bacteriostatic effect was obvious, and with200mg/L concentration were the most ideal bacteriostatic effect.(5) The ability of poison which main pathogenic of Penicillium were analyzed, The results showed that the19Penicillium stains could produce Patulin.All of them belowed national limit to standard range and won't cause harm to human body. From strong to weak sequence for Production poison ability of19Penicillium strains: Penicillium sp.> Penicillium chrysogenum> Penicillium commune> Penicillium purpurogenum> Penicillium paneum. Their poison capacity were very small, all contents conformed the state standards of limition.They won't caused pollution of penicillin and harmed to human body.