Introduction to Eco Atmosphere Freshness Storage
Atmosphere storage and preervaion is a modem preervaion technolgy developed onthe basis of tradional refigeration presanaon, and is considered to be a storage metod for fnuits ir
the world today the most efecive storage mehod for fnuit. Commercial controled atmosphere storage has a histoy of over 80 years inforein counlies, and vanous producs from developed countres
especially apples. The long-term storage ofuis and vegetables such as pears, kiwis, citrus fruits, gfapes,and jujubes mostly uses controled atmosphere storage for presenaon.in nomal ai t generalcontains oxygenGas 21%, carbon dioxide 0.03%, the rest is nitrogen and some trace gases. Fruits are living organisms that undergo internal processes before and after harvestingMetabolic activity dominated by respiration. The characteristics of aerobic respiraion afer fruit harvesting are: breaking down sugars stored in fruit tissue celsCarbohydrates such as fruit acids produce carbon dioxide, water yapor.heat and some aromatic compounds, which consume the fruit body durina this processThe stronger the respratory funcion,the fasterthe consumption, the earer the ripening penod comes,and the shoter the storage time. 0xvgen,carbon dioxide, and temperalure afectrespiratory intensity.
The oxygen contentin the storage space is high,the respiratony intensilyis high, and vice versais low. High carbon dioxide gas contentin storage space can inhibit respration and delalPectin substances decompose and chlorophyll degrades, and can inhibit microorganisms.The temperature in the storage space decreases, resulting in a decrease in respiratory intensity, andvice versa, an increase.
In adition, a cereain concenteation of low oxven and high carbon dioxide in the envronmenthas the efect of inhibing the growth and expansion offungal diseases
The basic principle of controlled atmosphere preservation technology is:
On the basis of sealed storage and renigeration,air conditioning parameters are set acording to the physiologital characteristics of diferentfruits. Through speciaized testing andcontrolequipment the oxygen concentrationin the storage spac is manualy reduced and the carbon dioxide gas concentration is increased tothe set airconditioning parameters, andthis parameter is accrately maintained throughouthe storage perod therebyinhibting the respiraton offutsand keepingthem ina nomaland ow coasumption metabolic stateachieving the purpose of fruit preservation.
Composition of Eco Atmosphere Storage
1. Eco Atmosphere Storage room
Airtightness is one of the main characteristics that distinguishesThe controlled atmosphereoooutside world, but also requires strict sealing aroundwarehouse requires that the enclosure structure not only has insulation and moisture res1 the qas composition inside thethe warehouse wals doorsand all inlet and outet pieline.Due to the strict requirements for the airtightness of thevarehouse be artiticialy adlusted to reduce or avoid intererence trom externa aasesenclosure structure in the controlled atmosphere warehouse, during the cooling and air conditioning processthe temperature and pressure inside the warehouse change, a pressuredifference will be generated on both sides of the enclosure structure, which wil damage the airtight laver andor collapse of the enclosure structure. In order to balanceand reduce the pressure dilference inside and outside the warehouse,the controled atmosphere warehouse mustbe ecuipped with safety valves and air condionina bas, and posivepressure nitrogen filling and oxygen reduction devices should be selected as much as possible2 Refrigeration equipmentThe modem desian ofcontroled atmosphere siorage aimsto conro temperare fucuatons within t 0.5'co achieve this,in addtionto requlno the encosure sirucure to have a hiohhermal resistance o reduce extema inuences, the design ofthe evaporaiorin the storage should also adopt a large-area lowtemperalure diference cold ar fan scheme. The design of theentire refigeraton systemin a controled atmosphere warehouse can be based on diferent silaons,using cenrazed cooing from large units or seoareaie coling from smallunisin a sinalswarehouse
Cold. the ater has qreater exiblly.in orderto ensure the economical operaion ofthe refigeration un during he controled aimosphere proces,the inslalon laver of the encosure strucureof the controlled atmosphere warehouse should be thicker than that of a typical high-temperature warehouse3 Air Conditioning Equipment(1)Nitrogen generatorThe oxygen reduction in controlled atmosphere storage generally adopts the positive pressure inflation replacement method, which means that nitrogen with a higher concentration (nitrogencontent>98%) is taken through the nitrogen reduction mechanism and injected into thethrough the oxygen reduction equipment system. At the same time, the gaswith a higher oxygen content in the storage is vented through a pipeine.This proces is repeated to reduce the oxygen contentin the storageto about3% -5%, and thenthe oxygen cantentinthe sioraeis uthereduced and the capon dioxide cocanralon is inceasad throuoh the respralion ofthe fnuitisea in onder to achieve the pumose of reoeilathe gas comoasian in thestorage
(2) Co2 absorber
During onlroled atmosphere storage of fnus and vegetables,the release ofcarbon dioxide due to respraion wllgradualy increasethe concenraion ofcarton dioxide in the storage. Whenthe concentraion of carbon dioxide reaches a cetain vale,itwilcause caron dioxde damage and produce a seres of dverse symptoms,ulimately leading to decay and deterioraon. At thispoint, itis necesaryto use a C02 removal machine to remove the exces C02 in the warehouse, achievina the opimal range reouired bythe gas reaulaion paramelers
(3) Ethylene absorber
Ethyene is a plhant hormone that can promoie respiaion and accelerate ripening and aging ofruits and vegelabes. Some people also alit "ipemninghomone".ltis a product of the metaboismof fnuits themsewves, Smoke emited from chimevs in the exeal envronment carexhaust and some facioy exhaustaso coniain a carain amount of eivene Fnuits that are hiohy sensieto ethvlene must be eauipped with ethvlene removal devices to reduce the ethvlene concentratiostorage conditions to helow a thresholc
(4)Automatic controleauipment
The controled atmosphere storage must accurately measure and control he oas composion of each comparment throughouthe enire storage perod.in order to improvethe auomaion leveofthe peration and management of the controled atmosphere storage,domesic and foreion controled aimosphere equiomen manufaclrers have designed and manufactured corespondingautomaic control equipment,which has achieved automaion in most ofthe above work. A control system can be used to control around 20 air condtoning rooms,each ofwhich can set is owrair conditionina parameters accordina to the variety of fruit and perform automatic patrol detectio
(5)Humidifier and ozone generator
Due to the long storage period of fnuits in the ontroled atmsphere warehouse, the mitogen gas fled inis also very dry, and the water content of thefnuis evaporates more.ln order to reduc
the storage environment
The patial pressure diference of water vapor between fuis and vegetables inhibis water evaporation, mailtains high relalive humidity in the conroed atmosphere storage, and reduesthe
water loss rate and dry consumption of fruits and vegetables-
General, sealed ultrasonic humidifers should be instaled in controled atmosphere warehouses. 0zone disinfecion is a safe and enronmentaly fiendly technology that can be controled in
warehouses
