Study On Preservation Effect Of Modified Atmosphere Packaging And Shelf Life Prediction For Cichorium Intybus L. Var. Foliosum Hegi

In recent years,with the improvement of the quality of life,people have higher and higher requirements on the freshness and nutrition of fruits and vegetables.However,fresh fruits and vegetables are fresh and tender and perishable,which are easy to rot due to dehydration wilting and mechanical damage.Therefore,suitable storage and preservation technology is urgently needed.As a safe,effective and low pollution storage technology,air conditioning storage has been developed into an important technical means of fruit and vegetable storage.Cichorium intybus L.var.foliosum Hegi is a new kind of high-end health care vegetables,the application of modified atmosphere packaging and its shelf life prediction,research and analysis of its bitter substances and functional components is in line with the current research hot spot.This paper in view of Cichorium intybus L.var.foliosum Hegi not resistant to storage,improper packing problem such as the appearance quality and nutritional value,using different modified atmosphere packaging storage Cichorium intybus L.var.foliosum Hegi,explore the Cichorium intybus L.var.foliosum Hegi under different modified atmosphere packaging food quality of postharvest physiology and storage and its change rule,select suitable for the breath of Cichorium intybus L.var.foliosum Hegi packaging materials,It provides theoretical guidance and technical basis for improving storage transportation and commercial treatment of Cichorium intybus L.var.foliosum Hegi after harvest.At the same time,the shelf life prediction model was established by using dynamics equation and Arrhenius equation to provide reference for the storage shelf life of Cichorium intybus L.var.foliosum Hegi.In this paper,the special bitter substances in Cichorium intybus L.var.foliosum Hegi were preliminarily analyzed and explored.The functional components and the special bitter substances in Cichorium intybus L.var.foliosum Hegi were identified by liquid chromatography-time of flight mass spectrometry.Cichorium intybus L.var.foliosum Hegi were preliminarily explored by combining existing studies and Pub Chem database.It provides theoretical support for the storage and preservation,shelf life prediction and nutritional value of Cichorium intybus L.var.foliosum Hegi.The topic of the thesis is scientific,which comes from the industrial practice and the hot spot of scientific research,and has good reference value and theoretical significance.The main results are as follows:（1）The effects of different modified atmosphere packaging（biodegradable film,perforated film,polyethylene film）on the storage quality of Cichorium intybus L.var.foliosum Hegi were studied.The 30μm polyethylene packaging bag had the best preservation effect,and the storage quality of Cichorium intybus L.var.foliosum Hegi was still maintained after 20 days of storage.The mass loss rate of biodegradable film was the highest,and the leaf edge browning occurred at the later storage stage.（2）The shelf life prediction models were established at different storage temperatures（1℃,4℃,10℃,20℃）.The zero-order kinetic models（S_W and S_L）established with mass loss rate and leaf color difference L*value as the characteristic indexes could predict the shelf life well,and the R~2 of the two models were higher than 0.9%.The average relative error between predicted value and measured value was small,and the accuracy of prediction was high,which provided reference and technical basis for quality control,commercial treatment and shelf-life monitoring of Cichorium intybus L.var.foliosum Hegi after harvest.（3）Liquid chromatography-time-of-flight mass spectrometry was used to identify functional components in Cichorium intybus L.var.foliosum Hegi.Four compounds were identified in positive ion mode,including 11（S）,13-dihydrolactucine,8-deoxylactucine,11（S）,13-dihydro-8-deoxylactucine and lactucine.Among them,the cleavage patterns of 8-deoxyropicin,11（S）,13-dihydro-8-deoxyropicin and 11（S）,13-dihydrolactucine,were similar in the secondary mass spectrometry.The parent ion lost a molecule of water or a molecule of formic acid,while the parent ion lost a molecule of p-hydroxyphenylacetic acid to gain fragment ions.