| Korla fragrant pear is Xinjiang’s unique famous fruit.The current harvest maturity and postharvest quality grading are mainly based on the farmers’ experience and the quality of single fruit,rather than the Korla fragrant pear’s physical parameters and nutritional quality.Then,the best picking time and postharvest grading priced can not be determined.There are adverse effects on farmers’ income.Guidance is lack on the rational allocation of Korla fragrant pear industry resources.In this paper,the experimental study on maturity law and maturity evaluation of Korla fragrant Pear is carried out.Firstly,the changes law of physical and chemical indexes were studied for Korla fragrant pear during maturity.To obtain a quantifying method for the maturity of Korla fragrant pear is based on multi-index comprehensive analysis.Based on mature accumulated temperature of fragrant pear,to select the fragrant pear firmness,soluble solids content,pericarp chlorophyll content and vitamin C content as the basic parameters are described fragrant pear ripening characteristics by surveying Korla fragrant pear industry in southern Xinjiang and analyzing related literature.Change datas of basic parameters are gathered during Korla fragrant pear ripening.The differences and commonalities of the physical and chemical indexes changed were described through analyzing and processed the data.The mature characteristics of the Korla fragrant pear were revealed and the mature model of the Korla fragrant pear was established.To put forward maturity evaluation and prediction methods of fragrant pear is based on the physical and chemical index variation characteristics.Secondly,the changes law of the electrical characteristics were studied for Korla fragrant pear in ripening stage.The relationship between maturity and electrical characteristics was clarified.The detection of electrical properties in the process of Korla fragrant pear ripening is studied by self-designed equipment non-destructive testing fruit electrical properties.The optimum test conditions for electrical characteristics of Korla fragrant pear are determined through a large number of experiments,and the further change law of electrical parameters is analyzed,such as capacitance,inductance,resistance,during Korla fragrant pear ripening.The data was processed with principal component analysis.To select electrical variables can characterize the mature law of Korla fragrant pear.At one point of accumulated temperature axis for maturity model,the relationship between electrical characteristic variables and Korla fragrant pear maturity is studied.The pears mature process parameters are taken as the transmission medium.The transforming of maturity models and evaluation method from basic parameters to the electrical characteristics isachieved.A forecasting method on the maturity feature and maturity evaluation of fragrant pear was based on the electrical properties.Finally,validation research on the maturity evaluation method by Korla fragrant pear storage test is carried out,and optimize testing device structure and function with electrical properties.Postharvest storage of fragrant pear was seen maturity application example.Through ice tempreture storage test for different maturity Korla fragrant pear,to verify the guiding function of maturity evaluation method for fragrant pear harvesting.Based on the optimal test condition of electrical characteristics and maturity electrical model,the structure and function of electrical characteristics detection device are optimized,and Korla fragrant pear maturity tester based on the electrical characteristics is designd.The main conclusions were as follows:(1)Within the experimental parameters,the change range of physical and chemical parameters of Korla fragrant pear were shown respectively.fruit firmness was 4.23-8.51 kg/cm~2,fruit chlorophyll content was 3.17-6.54mg/100 g,soluble solids content was 11.02%-14.91%,vitamin C content was 0.36-0.6mg/100 g.The fruit firmness gradually reduced,chlorophyll content gradually decreased,the soluble solids content gradually increased,vitamin C content gradually increased with the ripe of Korla fragrant pear.The mean value of each index was significantly correlated at 0.01 level.The errors were 1.4%,2.47% and 2.99% respectively when the soluble solids content,chlorophyll content and vitamin C content were forecasted by the fruit firmness in Korla fragrant pear.The errors were 1.4%,2.47% and 3.21%,respectively while the fruit hardness,chlorophyll content and vitamin C content were forecasted by the content of soluble solids in Korla fragrant pear.(2)Fruit firmness,soluble solids content,pericarp chlorophyll content and vitamin C content showed a common pattern of Sigmoidal model in the process of Korla fragrant pear ripening.Basic parameters could be precisely expressed by corrected the model coefficients.Based on this analysis of the change law of basic parameters,Korla fragrant pear maturity evaluation method were established.The maturity can be quantified of Korla fragrant pear.To complete the mutual prediction between accumulated temperature,maturity and physical and chemical indicator(3)Within the experimental parameters,the experimental of electrical characteristics of fragrant pear showed that the test voltage has no significant effect,and the test frequency has a significant effect on the electrical parameters of Korla fragrant pear.The optimum test frequency was 1000 Hz for Korla fragrant pear.The correlation was poor between the single electrical parameters and the physical and chemical indexes during the ripening process.Under the 0.1V and1000 Hz test conditions,the correlation was better between the characteristic electrical variables,which based on the variation rules of the multiple electrical parameters and the basic parameters.To formulate the related equation of characteristics electrical variables and basic parameter.The minimum value of R2 was 0.88,which can predict the electrical characteristics and basic parameters in Korla fragrant pear ripening process.(4)The storage experiment of room temperature and ice temperature with different maturefragrant pear,illuminated the effect rule of maturity on the storage.It can provide reference for short-term storage and ice temperature storage in pond after picking.There were the same trend for the ripening rule of different maturity Korla fragrant pear and the after-ripening rule in postharvest storage.For the storage after harvest Korla fragrant pear,50% maturity was more suitable.(5)According to the analysis of physical and chemical properties and electrical properties into the mature period of of fragrant pear,a mature characteristic detector that can realize the mutual test and analysis of accumulated temperature,maturity and basic parameters for Korla fragrant pear ripening is designed.Changing the different embedding model and calculation method,the detector could achieve the fruit maturity test.In this paper,maturity was pointcut that was the basis of Korla fragrant pear industry chain.Mature character expression and evaluation method of Korla fragrant pear are studied.The research results can assess and predict fragrant pear picking time according to the actual production requirement,and provide reference for the rational allocation of resources in fragrant pear industry chain.The research method can provide reference for fruit maturity and quality non-destructive testing based on electrical properties.It is great importance for the promotion of Korla fragrant pear industry development and improving the income of practitioners. |
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