Defect Mapping Pattern Of Single Pathogenic Bacteria And Mixed Bacteria In Kulle Balsam Pear During Storage Period

Korla fragrant pear is not only loved by domestic consumers due to its unique aroma,strong aroma,crispy flesh,and abundant juice,but also a characteristic agricultural product that Xinjiang mainly exports to earn foreign exchange.In the preliminary research,it was learned that the prevention and control of black spot and penicilliosis during the storage process of pear fruits are difficult.Most of the cold storage companies visited have set an acceptable fruit loss rate of 10-20% due to disease infection,which can be controlled below 10%.Therefore,the Korla fragrant pear industry urgently needs a fast and accurate disease detection method.This study used near-infrared spectroscopy combined with evaluation indicators and images to explore the single and mixed pathogenic bacteria of Xiangli.Provide data and theoretical support for the prevention and detection of pear diseases during the later storage period,reduce the loss of Korla pear during storage,and provide safety protection for consumers.The main research content and results are as follows:(1)The changes in total bacterial count,chromaticity,and soluble solids content(SSC)of defective and healthy areas of Korla fragrant pear during different storage periods under the action of single and mixed pathogens.In the affected area,the color of mixed fungus fragrant pear is less bright,more red,and less yellow than that of single pathogen fragrant pear,with lower SSC content and faster growth in total bacterial count;In non susceptible areas,the color of mixed fungus fragrant pears is brighter,less green,and more yellow than that of single pathogen fragrant pears,with higher SSC content and faster growth in total bacterial count.(2)Analyze the image texture characteristics and spectral changes of diseased spots and healthy areas during storage under the action of single or mixed bacteria.Comparing the spectral images,Lab values,SSC values,and total bacterial count of single and mixed pathogen disease spots and healthy areas,it was found that the mixed pathogen has a stronger ability to decompose susceptible fragrant pears and a stronger ripening effect on susceptible fragrant pears than single pathogen.Mixed bacteria have stronger reproductive ability than single pathogenic bacteria.The degree of SSC and water consumption by mixed bacteria is higher than that of single pathogenic bacteria;There is a significant difference in contrast and stability between single pathogenic bacteria and mixed bacteria.(3)We have constructed a disease classification and recognition model for Korla fragrant pear,as well as a classification model for the degree of infection.Support vector machines combined with Random forest(SVM-RF)classification model was determined as the optimal model for disease classification and recognition,with a classification accuracy of 98.64%.According to the total number of bacterial colonies,the degree of infection in Korla fragrant pear is divided into mild,moderate,and severe.After being infected with a single pathogen in Xiangli,the optimal model was wavelet transform(WT),principal component analysis(PCA),and SVM-RF,with an accuracy of 97.08%.After infection with mixed bacteria in Xiangli,the optimal model was Probability Entropy Normalization(PQN),Bootstrap Soft Shrinkage Combined with Continuous Projection Algorithm(BOOS-SPA),and SVM-RF,with a accuracy of 97.07%.