Correlation Analysis Of Chlorophyll Content And Quality In Different Growth Stages Of Onion

This study conducted a research on the extraction process of chlorophyll,light stability,antioxidant capacity,acid and alkali resistance and thermal stability in onion leaf.We analyzed single factor test results,using Design Expert 8.0.5.0 software and designingthe test according to the principle of Box-Behnken design,and the data were analyzed.We tried to optimize the factors which have significant influence on extractionof chlorophyll byselecting extraction time,extraction temperature,ratio of extraction liquid etc.Investigating light stability through natural light and photophobictreatment;Investigatingthe antioxidant capacity through different oxidants(H2O2)concentration;Investigating acid and alkali resistance with different pH valuesand of thermal stability under different temperature.We finally got the best extraction scheme of onion chlorophyll.The content and quality of chlorophyll in 12 different onion varieties at different periods werethen determined,and the difference and correlation were analyzed,in order to provide theoretical basis for breeding and forecasting of the yield.The results are as the follows:1.Based on single factor experiments,the extraction process of onion leaf chlorophyll was optimized by response surface method and the optimum parameters are:liquid ratio is 91.84:1,the extraction temperature is 48.7 ?,the extraction time is 6.16 h.With these parameters,the actual measured chlorophyll content of onion was 1.356mg/g,only 2.5%of the deviation compared to the model forecast value,suggestingthe Box-Behnken model is feasible,accurate and reliable.This methodprovided the basis for breeding and comprehensive development in other areas.In this study,we found the onion leaf chlorophyll was greatly affected by light and pH value,with poor thermal stability and antioxidant ability.Therefore,in the process of extraction and application of onion leaf chlorophyll,environment should be lucifugal,weak acidity,no oxidation agent and low temperature.2.According to the content and quality of chlorophyll in 12 different onion varieties at different periods,we found significant differences in chlorophyll quality,which will provide good germplasm resources for breeding.By analyzing the relationship between chlorophyll and onion quality analysis,we found the onion chlorophyll changing value has a negative correlation with the bulb;a positive relationship with soluble sugar,vitamin C content.The chlorophyllcan be used as an important index for selecting oniongermplasm.By analyzing the relationship between chlorophyll and yield,we found the content of onion chlorophyll in seedling stage,wintering,inflating stage was significantly correlated with yield,which provides theory basis for predicting yield by measuring chlorophyll content in the early period.