Changes Of Active Substances In Strawberry During Storage

This research aims to create different storage environments and study the influence of the storage environment on the beneficial substances and harmful substances in the storage process!What is the relationship between the low O₂and high CO₂atmosphere composition?Poly（lactic acid）（PLLA）was used as the substrate and poly（butylene succinate）,glycol ester（PBS）,poly（caprolactone）（PCL）,and poly（butylene adipate terephthalate）（PBAT）were added to prepare blended films.During storage,the atmosphere concentration in the packaging,sensory evaluation,weight loss rate of strawberries,soluble solids,total phenols and flavonoids content were measured to evaluate the spontaneous modified atmosphere preservation effect of the film on strawberries.The polyphenols in strawberry extract were analyzed by UPLC-Q-TOF-MS,To explore the relationship between the changes in the storage process and the composition of the atmosphere.The results indicated that:（1）In the package composed of PBAT/PLLA/PBS/PCL+0.1%chain extender and 0.25%hydrophobic Si O₂,the concentration of CO₂and O₂entered equilibrium from the third day,and their volume fractions were maintained in the ranges of 5 to 7%and 3 to 5%.The quality of strawberry samples were acceptable within 24 days,therefore,this blend film can inhibit the respiration of strawberries and prolong their freshness.However,during the storage of strawberries,the content of gallic acid,rutin,caffeic acid,chlorogenic acid,trans-cinnamic acid,epicatechin,isoquercetin,coumarin,and p-hydroxybenzoic acid gradually decreases,CK group because there is no protective measures,the content of 9 substances decreased most obviously,and the decrease was less than 50%on the 3rd day.Because of serious condensation in the bag,microorganisms multiply rapidly,leading to decay and deterioration.The PE group began to decrease its content on the 6th day of storage.The content of polyphenols in the two groups of PBAT2 and PBAT3 has been higher than that of the other groups.The atmosphere in the bag is more suitable for the storage and packaging of strawberries.The composition of the atmosphere can be adjusted to induce the activity of antioxidant enzymes in fruits and vegetables,weaken the peroxidation of membrane lipids,and maintain better The high content of VC reduces the accumulation of membrane lipid peroxidation products and reduces oxidative stress,which can reduce the content of polyphenol flavonoids.（3）The UPLC-Q-TOF-MS was used to analyze the changes of active substances in Strawberry during storage and the detected substances were organic acids and anthocyanins.Anthocyanins are unstable and mainly exist in fruits and vegetables in the form of glycosides.As the fruit matures,the content of anthocyanins gradually increases,accumulates in a large amount during the mature period,and decreases in the senescence process.Compared with other groups,the PBAT2 and PBAT3 groups can effectively inhibit the consumption and degradation of organic acids at low temperatures,maintain the content of organic acids,delay the occurrence of enzymatic browning,and inhibit the aging and softening process of fruits and vegetables.Strawberry produces quinone substances during storage,which is harmful to human body.Compared with other groups,the PBAT2 and PBAT3 groups can effectively inhibit the production of quinone substances.