Study On The Change Rules Of Chemical Compositions And Color Protection Technology Of Fresh Longya Lilium During Storage

At present,there are few reports about fresh Lilium like to the chemical composition analysis,the change rule of nutrition and active ingredients,the technology of keeping fresh and protecting color in the process of storage after harvest.This paper aims to provide help for the effective utilization and further development of Longya Lilium resources from the following three points: 1.Through chemical composition analysis and preliminary activity evaluation,Longya Lily can be opened To provide theoretical basis for development and utilization;2.To reveal the browning mechanism and optimize the storage and transportation conditions of fresh lily through the research on the change rule of nutrition and active ingredients under different storage conditions;3.To provide technical support for anti-browning and extending shelf life of fresh Lilium through the research on color protection technology.In view of this,the main research results are as follows:1.The contents of four nutritional components(polysaccharide(404.32(±7.76)mg/g),free amino acid(23.34(±0.71)mg/g),protein(23.21(±0.19)mg/g),reducing sugar(10.15(±0.69)mg/g)and two active components(total polyphenol 1.60(± 0.09)mg/g and total saponin21.60(±1.12)mg/g)in fresh Longya Lilium were determined by UV spectrophotometry.2.By using UPLC-MS and GC-MS techniques,the secondary metabolites of fresh Longya Lilium were identified,including 12 phenolic acids(phenylpropanoids),6 steroidal saponins and 1 lignan,nine of them were identified firstly from Longya Lilium;37 volatile components,of which n-hexanol(25.87%)and n-hexanal(18.80%)were the highest.3.The anti-oxidation experiment in vitro and the evaluation experiment of anti-inflammatory activity of cells were used,the results showed that,the compounds with antioxidant and anti-inflammatory activities were mainly concentrated in the water saturated n-butanol extraction site and chloroform extraction site.The antioxidant activity of the water saturated n-butanol extraction site was stronger than that of chloroform extraction site,and the anti-inflammatory activity of chloroform extraction site was stronger than that of n-butanol extraction site.4.The change rules of nutrients in fresh Lilium under different storage conditions were studied,the results showed that the content of nutrients in fresh Lilium decreased in the storage process,which was accelerated by the influence of light and high temperature.And it showed that the change rules of nutrients did not fit the mechanism of non-enzymatic browning.5.The change rules of active ingredients in fresh Lilium under different storage conditions were studied,the results showed that:(1)after Lilium harvesting,the lipid peroxidation of cell membrane increased,phenolics accumulated in adverse circumstances,PPO and POD activities continued to rise,and browning degree would reach a high level finally.Light and temperature had a significant effect on the above indexes.The contents change rules of the above indexes were in accordance with the mechanism of enzymatic browning,which was the main factor of browning during storage.(2)The browning degree and phenols contents of Lilium could not be changed and PPO and POD activities could be inhibited by freezing storage,but MDA content would rise sharply,and fresh Lilium would rot when they returned to normal temperature.(3)The storage will lead to the browning of fresh Lilium,but also lead to the accumulation of phenolic compounds,which can be extracted from rotten and browning Lilium for waste utilization.6.The effects of citric acid,VC,phytic acid and ultrasonic treatment on browning degree of lily were studied: Based on the response surface method,the best color protecting formula was optimized by the way of fresh Lilium and color protecting liquid homogenate,under the conditions of citric acid concentration 2.4%,VC concentration 1.2% and phytic acid concentration 0.8%,the inhibition rate of browning of fresh Lilium was 85%;due to the color protecting liquid could not directly play an effective role in the whole lily,the composite color protecting liquid was used as the medium of ultrasonic to soak and combine with 20% The inhibition rate of browning and PPO activity of fresh Lilium was 76% and 88%,respectively.The total polyphenol content would increase about 23%.