Controlled Atmosphere (CA) Stores:
Extend the storage life of fruits and vegetables up to 12 months
Izhar Steel is the first and only company in Pakistan capable of establishing of CA store facilities in Pakistan. Technical team of Izhar Steel along with ‘Fruit Control Equipments’ staff, with over 50 year global experience in this field, is able to give advice on the products to be stored in controlled atmosphere, suggesting the best technology currently available for each product
A Controlled Atmosphere(CA) is an agricultural storage method in which the concentrations of oxygen, carbon dioxide and nitrogen as well as the temperature and humidity of a storage room are regulated. Both dry commodities and fresh fruit and vegetables can be stored in CA.
Controlled atmosphere is applied to extend the storage life of fruits and vegetables. Most of them can be stored considerably for more time compared with normal 0° cold store. In fact CA reduce drastically metabolism and respiration of the fruits. Just to give some example it’s possible to store pears and apples even for 12 months, cherries up to 90 days, cauliflowers 70 days and mangoes up to 50 days with the proper technology.
Regarding the time of storage in Controlled Atmosphere/Ultra Low Oxygen conditions a lot depends from the initial conditions of fruits (ripening level, presence of physiological disorders, etc.) and from other components during storage (quality of refrigeration system, level of humidity, etc).
Composition of Air in CA
Atmospheric air is composed of 20,8% oxygen, 78% nitrogen and about 0,03%carbon dioxide. The principle of controlled atmosphere is based upon the variation of this composition with the aim of slowing down ,as much as possible, the fruits’ respiration rate and relative maturity.
Humidity in CA
During the storage period, fruit yields humidity to the environment. More humid the environment ,lesser humidity the fruit will surrender including relative weight loss. For this reason it is important to guarantee high relative humidity (RH) inside the storage room ,essentially by means of a well designed refrigeration plant (which avoids excessive condensation on the evaporator fins) and secondly through implementation of humidifiers that increase the RH value.
Ethylene is a hormone naturally produced by fruit , able to promote and accelerate maturity, with the effect of softening the pulp and de-greening the chlorophyll. Ethylene removal is often useful, especially for the more sensitive cultivars, (for example vegetables, kiwifruit, tropical fruits etc).
Ethylene may be removed by adsorbers using potassium permanganate or by catalytic converters even within existing cold stores, in fact, impermeabilized panels are not necessary .
Controlled atmosphere is a technology based on variations of the parameters relative to atmospheric composition inside refrigerated/cold-storage rooms, consisting mainly in lowering the oxygen content and surveying the carbon dioxide value during the entire storage period of fresh produce.
Both technologies foresee a variation of the parameters relative to the atmospheric composition, but for modified atmosphere continuous monitoring during storage is no longer used (for example “bagged” products, cut-fresh etc) whereas in controlled atmosphere continuous and constant monitoring of the gaseous composition is carried out using customized analysis systems and, if necessary, correction of the values can be made.
Controlled atmosphere is to be considered “clean” technology, and absolutely does not foresee the use of chemicals, and it is for this same reason that it is considered one of the safest and most reliable technologies with regards to human health .
Particularly, in the storage of biological products, a sector that has grown considerably over the last few years, this is the only available storage me
The list of products that can benefit from being stored under controlled atmosphere is long. The main products are: apples, pears, kiwifruit, plums, blueberries, strawberries, tomatoes, mango ,avocado, pineapple, banana ,citrus fruits etc.
The main prerogative is the absolute impermeability/tightness of the storage room, therefore, during the construction phase it is necessary to provide all the necessary solutions to avoid gaseous exchanges with the outside environment once the store is destined for CA storage. In particular, the floor must be properly prepared , all refrigeration panel joints must be sealed, a suitable CA door installed, a siphon for the de-frost water discharge from the refrigeration plant must be installed, gas tightnessof all passages and piping must be carried out and to complete the work the final gas-tightness test on termination of the running tests.
ULO means Ultra Low Oxygen, an acronym introduced during the 80’s that indicates storage techniques using oxygen levels lower than 1,5% inside the store rooms/cells (nowadays the tendency is to maintain the value around 1%)
ULO is applied to guarantee even more restricted conditions with respect to traditional CA, with the aim of maintaining the qualitative characteristics of a product even longer.
It is mainly applied during the storage of apples.
ILOS means Initial Low Oxygen Stress and is based on the lowering of oxygen to extreme limits, around 0,5% inside the cell, for a brief period (+/-15 days) with the aim of avoiding the scald that some varieties of apples suffer during long-term storage, as well as maintaining optimal qualitative characteristics.
Swinglos technology represents the latest frontier in CA storage. The system is based on the principles of dynamic CA (DCA), according to which a constant and fixed value for the duration of storage is no longer foreseen, instead variable values (henceforth dynamic) are used. (LINK).
In other words the gaseous values undergo variations during the storage period according to the reply from the fruit itself ,especially the pulp, through application of repeated oxygen stress.
It is important to know what goes on inside the fruit pulp under such conditions to prevent and avoid the formation of alcohol in apples, which would render the product inedible. To this purpose, the only safe and applicable method is connected to alcohol analysis, easily detectable using an enzymic/enzymatic analyser
Certain cv are harvested early with respect to their full maturity, to allow them to be transported and handled (bananas for example). In such cases maturation is carried out during storage, using ethylene. Fruit Control Equipments markets/has a system which supervises automatic emission of the gaseous maturation mixture.
Controlled atmosphere is applied in numerous other situations as well as fresh produce storage. For example in the disinfestations sector, this method may be employed for the storage of various products such as seeds (wheat, rice, coffee ,pulses etc) nuts (walnuts, peanuts etc) dried foodstuffs (teas, herbs etc) and even beverages (oils, wine, juices etc.)
Controlled atmosphere in its’ wider term is used in other fields such as the transformation of plastics, the archiving and disinfestation of works of art, the neutralization/sterilization of premises and storage areas using technical gases and many other applications
Fruit Control Equipments, a leader and standard bearer of “made in Italy” around the world/worldwide leader and standard bearer of “Made in Italy”, produces entirely in Italy.
The production site is in Locate Triulzi, in the milanese outer-metropolitan area, within easy reach of three international airports.
The technical, commercial and administrative offices are housed in the same premises
Fruit Control Equipments’ customers are spread worldwide in over 45 nations . The company is able to manage all problems related to controlled atmosphere application with a staff composed of agronomists, technicians and engineers and can give complete service, from the design stage up to plant supervision.
Our collaboration with leading national and international research institutes has always been very close, in order to enable us to study and apply innovative technologies in the field of fresh horticultural produce storage, as demonstrated by various international publications.
There are also a wide number of research institutesworldwide with FCE signature plants.
GAC 5000 Computerized Analysis Group
The GAC 5000 system consists of CO2 and O2 analysis groups and management software using PLC logics and a supervising PC.
The apparatus is connected via the network with the CA machines and the sensors inside the storage cells. This system permits surveillance, data storage and print-off of all storage parameters (CO2/O2/ethylene/temperature/humidity/pressure etc) as well as control of the various appliances.
It is possible to plot and print the graphs illustrating all the parameters measured in addition to memorizing all measured values.
The apparatus has been entirely designed, developed and realized by Fruit Control Equipments for both the hardware and software components. This guarantees greater flexibility during realization enabling us to embrace the wide range of needs and preferences of the final user as well as competent and efficient support to the customer .
By connecting the apparatus to an existing Internet connection immediate long-distance support is available as well as complete remote management of the entire system, modification or control of the set parameters and training and information for the refrigeration technicians.
It is also possible to use the system to manage additional warehouses from a single station.
With dedicated software cell tightness tests may be carried out and the results memorized.
This apparatus may also be connected to a gas chromatograph for highly accurate analyses especially with regard to ethylene concentrations.
Catalytic converter for removal of ethylene and volatile odorous products against decomposition
The SWINGTHERM-BS are catalytic reactors studied for reducing the concentration of ethylene and volatile odorous products inside normal and controlled atmosphere storage cells.
Using SWINGTHERM-BS converters you can economically maintain the following ethylene concentrations:
in refrigerated & C.A. cells for apples : < 1 ÷ 5 ppm
in citrus, pear and vegetable cells: 0,05 ÷ 0,1 ppm
in kiwi cells: < 0,02 ppm The SWINGTHERM-BS catalytic converters will also help you to:
obtain the best prevention against undesired ripening of fruit and vegetables and against the physio-pathologic effects of ethylene.
maintain a very low level of spore and bacteria due to the thermal-shock in the reactor
Avoid disturbing the thermal balance of the cells due to particular work cycles and solutions that will limit heating of the processed air
The INTELLIGEM® IG adsorbers represent the most avante-garde system for CO2 adsorption in DCA ( Dynamic Controlled Atmosphere-patented by Fruit Control Equipments) “SwinglosTM” stores. The “state-of-the-art” apparatus consists of two tanks filled with active carbons which give continuous adsorption on the room. This apparatus has been designed, realized and perfected to offer top performance during use employing the most recent storage technologies in Controlled Atmosphere at low CO2 concentrations.
Energy saving using a patented system, for the optimal application of the regeneration and adsorption cycles.
INTELLIGEM® IG are the apparatus with the best performance/installed power ratio presently available on the market. Reduced consumption doesn’t mean only a reduction in running costs, but also greater environmental responsibility.
You don’t need a nitrogen generator to maintain dynamic atmospheres at low levels because the performance of INTELLIGEM® IG allow limited CO2 concentrations to be reached without needing nitrogen emission. The apparatus has been perfected to reduce to a minimum undesired oxygen emission.
System for Nitrogen Production
The FIGHTER, BRAVO and SWAN generators produce nitrogen with 95% to 99% purity using molecular dimension separation of atmospheric air compressed by a screw compressor..
Fighter, Bravo and Swan are used for rapid pull-down in controlled atmosphere cells avoiding the contemporary formation of CO2 and for re-establishing storage conditions (even ULO) in those cells opened for partial sale of the stored goods.
These nitrogen generators are used in those sectors where “ecological” nitrogen is required, free from combustion residuals (CO2, CO, NOx, SO2, C2H4, etc.), and are available as fixed or mobile units (aboard ships, containers, or for pull-down on several plants etc.).
Fighter, Bravo, Swan may also be employed for the production of oxygen-enriched air (up to 40%) for ripening cells.
The Fruit Control membrane generators use a totally clean operating principle ( the only “waste” product is a mixture of air and oxygen) and can reach a significantly higher flow-rate.
The apparatus is based on the principal of molecular separation of oxygen from air by using molecular sieves allowing rapid pull-down in CA cells at low working costs.
The apparatus is regulated by an electronic control panel that automatically manages the absorption and regeneration phases of the sieves.
The system is able to function either alone, using the oxygen sensor included on the control panel, or connected to the centralized analysis system (GAC 3000 or 5000)
Oxygen Scrubber, ripening System control panel, and Adiabatic Humidifiers are also provided with the system
Mr. Luca Buglia from Fruit Control Equipment Italy, visiting
Izhar Steel during execution of a CA Store