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Vegetable-fruit storage

Storing food before marketing is very important. During storage the quality of food can deteriorate depending on the storage conditions, due to the action of external agents: air, water, heat, bacteria, pests.

The effects are very noticeable in the case of vegetables and fruits.

Food degradation can not be prevented, but it can be greatly slowed down by changing storage conditions: temperature, humidity, composition of the atmosphere in the warehouse.

Food storage under modified environmental conditions is known as controlled atmosphere storage. Storage in a controlled atmosphere can slow the loss of quality after harvesting. It is a well-known technique and an important alternative to chemical preservatives and pesticides.

It has great potential to reduce post-harvest losses and to maintain both nutritional and market values.

As in any application in the food area, the reason for using nitrogen is always the same: preventing food degradation. Nitrogen replaces the oxygen to which food is exposed and slows down the oxidation process.

Controlled atmosphere storage systems with Parker technology-Smartstock system

Reducing the oxygen content in a cold store slows down the process of degradation of stored food. Creating such an atmosphere is done by introducing high concentration nitrogen produced by a Parker nitrogen generator into the chamber.

Oxygen concentration, room temperature, humidity and RH are monitored and controlled by an automatic system. The system ensures the maintenance of the favorable atmosphere throughout the storage period.

Advantages Of SmartStock:

– Increase the shelf life of food (especially fruits and vegetables)

– Continuous monitoring of storage parameters

– Automatic control of the storage atmosphere

– The possibility of expanding the system with the growth of the warehouse

Controlled atmosphere systems maintain the organoleptic characteristics of the products and reduce losses due to pathogens. Fruits and vegetables stored in warehouses with controlled atmosphere can withstand several months without damage.

The Controlled Atmosphere systems offered by Frigother group SRL are able to meet any requirement of our customers. Their management is completely computerized, and integrated with the cooling system, allowing a total automation of the activity in the warehouse.

Controlled atmosphere cells have a number of particular characteristics that differentiate them from simple refrigerated cells. The design, construction and installation of controlled atmosphere cells requires a lot of attention and extensive experience in the field.

Panel joints

The joining of the panels must be absolutely tight, to guarantee complete sealing of the interior of the cell with controlled atmosphere, compared to the outside.

Access doors

Doors used in cold stores must be adapted for use in a controlled atmosphere warehouse. They are equipped with 4 additional locking systems and glass for inspection.

CO2 absorption systems

Carbon dioxide absorption systems can be used either as independent units that can manage one or two cells, or as centralized units that can manage a larger group of cells.

The absorption systems use special filters with Activated carbon, and aim to keep the concentration of CO2 constant inside the cells, even under the conditions of a very low percentage of oxygen. The systems are managed by a computer and an automatic cell monitoring system. It consists of CO2 and O2 analyzers that continuously monitor the interior of the cells, automatically analyzing the air and maintaining its characteristics between preset values.

CO2 absorption systems are provided with pneumatic valves that do not require any intervention and maintenance. Optionally, a nitrogen regeneration system NRS (Nitrogen Regeneration System) can be added which improves conservation in conditions of minimal presence of Hyper Low Oxygen (HLO).

Ethylene absorption systems

The use of ethylene absorption systems allows to maintain a low level of ethylene in the refrigerated cells, eliminating the negative effects that it has during the conservation of fruits and legumelor.Cu using this system can absorb other harmful gases, such as hydrocarbons and sulfur dioxide.

This absorption system is mainly used in the preservation of fruits, vegetables and flowers (especially kiwi) and in general of all products that during the preservation produce small amounts of ethylene, but which are also sensitive to the presence of this gas.

Nitrogen generation systems

They produce nitrogen with purity from 95% to 99% using the technology of separating compressed atmospheric air by means of a screw compressor. The introduction of nitrogen is done very quickly so that carbon dioxide is not formed at the same time.

Nitrogen generators are used in sectors where “ecological” nitrogen is required, without combustion residues (CO2, CO, NOx, SO2, C2H2, etc.). They are available in fixed or mobile versions. The models proposed by us can also be used for the production of enriched oxygen, for maturation cells.

Computerized control systems

Managing all systems is a complex task that requires the presence of a multitude of sensors connected to a control panel. The entire system allows the sampling and storage of all conservation parameters, such as: percentages of CO2, O2, ethylene, humidity, pressure, but also provides automatic controls to the necessary equipment, to keep these parameters within the required limits.

Refrigerated storage systems with controlled atmosphere are mainly aimed at long-term storage of vegetables and fruits, storage carried out immediately after their harvest. Refrigerated storage with controlled atmosphere is carried out within the field of industrial and commercial cold, with the modification of storage conditions, controlling the temperature, humidity and composition of the atmosphere in the refrigerated warehouse (refrigerated warehouses, production areas, storage, packaging areas, airlock areas).

Controlled atmosphere storage of fruits is a method by which their quality is preserved by maintaining an optimal level of the ratio between oxygen concentration and carbon dioxide concentration, regulating ethylene concentrations, temperature and humidity.

The fruits breathe; they absorb oxygen and remove carbon dioxide, thus continuing their natural process of ripening and ripening. Long-term fruit storage involves slowing down these ripening and ripening processes, thus preserving the flavor and quality of the products. In fact, is baking delayed by changing the atmospheric conditions in the warehouse so as to reduce the breathing process?fruits and vegetables.

By changing the atmospheric conditions and reducing the temperature, the organoleptic characteristics of the products are maintained unaltered and the losses due to pathogens are reduced.

The quality and freshness of the fruits stored in controlled atmosphere warehouses are maintained without the use of chemicals, the products can be stored up to four times more than usual.

Controlled atmosphere warehouses have a number of characteristics that differentiate them from the usual cold stores:

– the joining of the panels must be absolutely watertight to guarantee complete sealing of the interior of the cell with controlled atmosphere compared to the outside.

– the access doors must be adapted for use in a warehouse with controlled atmosphere, being equipped with 4 additional closing systems and glass for inspection.

– specific technological equipment: atmosphere control station, nitrogen generator, CO2 scrubber, ethylene converter, humidity control station.

Construction for storing vegetables and fruits:

To ensure the consumption of vegetables and fruits throughout the year, they must be stored, canned and conditioned. Horticultural products continue during the preservation of a number of metabolic processes namely:

– respiration, maturation, cornering, etc. the storage conditions vary from one product to another and the warehouses are designed with these needs in mind.

Classification of deposits for vegetables and fruits:

Deposits for vegetables and fruits are classified according to several criteria, namely:

– according to the nature of the production stored are: specialized warehouses for a single product, universal warehouses for several products and recovery complexes with storage and storage of products;

– according to the way of carrying out the storage conditions there are warehouses without the possibility of adjusting the storage conditions, warehouses with the possibility of adjusting the storage conditions, with controlled atmosphere, provided with mechanical ventilation and refrigeration installations;

– according to the type of construction adopted, the warehouses can be: pavilions and merged;

– after the temperature limits for storage, the deposits are: with positive temperatures

(0 °C – 5 °C), with negative temperatures up to -24 °C for frozen products and with temperatures close to those of the external environment, which are determinants in the realization of the indoor microclimate;

– according to the degree of equipment of the warehouse, there may be: special warehouses with mechanized installations for sorting and realization of the indoor climate, simple warehouses, without installations, intended for short-term storage;

– by capacity there are warehouses of small capacity (50 – 100 tons) and high capacity (20,000 tons).

Constructive features for vegetable and fruit warehouses:

The warehouses for vegetables and fruits are diversified in a multitude of types, according to the constructive-functional characteristics, from simple ditches and trenches to constructions with large capacity equipped with technological utility and performance. Traditional solutions use local and less demanding materials and new solutions use modern materials and execution technologies.

Small capacity warehouses:

Small capacity warehouses are used for small quantities of vegetables and for short periods of time, generally used to serve individual households and production units in rural areas.

Large capacity warehouses:

They are warehouses with structures generally made of prefabricated reinforced concrete, consisting of:

glass foundations, pillars and beams, prefabricated panels for walls, roof elements, straight or curved, lightweight heat-insulating panels for exterior closures. Large capacity warehouses are ground floor or multi-level type.

Elements of the design of vegetable and fruit warehouses:

The necessary spaces for storing vegetables and fruits are determined by the species of products and storage technology.

The microclimate necessary to be created in warehouses is especially important becauseit directly influences production. The temperature required to be achieved is important because at low temperatures the metabolic processes are reduced; the duration until the appearance of aging is prolonged; water losses are reduced (thus avoiding wilting) and the qualitative impairments due to the attacks of fungi and bacteria occur in a much smaller proportion.

Relative humidity varies between 70-90%; lower humidity causes products to wrinkle due to water loss and high humidity favors the development of fungi (mold)and bacteria. To achieve optimal microclimate conditions, the closing elements of the vegetable and fruit stores are designed to ensure efficient thermal insulation.

Plants and machinery used in vegetable and fruit warehouses:

The installations and machines provided in the vegetable and fruit warehouses are determined by the technological process adopted and allow indoor air conditioning, artificial lighting, transportation and handling of stored products and their conditioning. The indoor air conditioning systems ensure the microclimate in the refrigerated cells by maintaining the optimum temperature, humidity and air composition. Installed cooling devices are used for storage for longer periods of time and maintain optimum temperature, humidity, pressure and gas content. Aaer humidification plants have the role of maintaining the necessary humidity in the storage cells. The Controlled Atmosphere installation is designed to maintain all climate factors specific to each type of storage, namely:

– temperature

– humidity

– oxygen and carbon dioxide concentration

– etc.

Lighting installations (generally fluorescent), provided in vegetable and fruit warehouses are differentiated:

– in the sorting hall the lighting is done so that it is as close to the natural tea as possible;

– in storage cells, light is not needed because it would stimulate or intensify some unwanted processes (vegetation, wilting, etc.).);

– in the alleys and outbuildings, ordinary lighting.

The transport and stacking machines are necessary for handling the mass to be stored in good conditions and with a low cost price. These machines are:

– mobile conveyors with rubber band

– grips

– mechanical shovels

– electrocare with lifting arm

– manually or mechanically operated trolleys

– forklifts, electric forklifts, etc.

Machines and conditioning systems are used to prepare vegetables and fruits for storage and then delivery.

Storage of blueberries in a controlled atmosphere for a long time:

Maturity: for long-term storage, blueberries should be picked at the right time. The timing of harvesting depends on several factors:

– the color of the fruit at the time of harvesting.

– the content of sugar or antioxidant acids. Blueberry berries are harvested when they are almost ripe, because the quality of the fruits quickly decreases after harvesting.

Temperature: the storage temperature of blueberries in the refrigerated state is within the range (-0.5 / 0)°C.

Humidity: relative humidity should be maintained between 90 – 95%. If the relative humidity drops below the level of 90% blueberries will dry out and present wrinkles on the surface.

Lighting: blueberries must be stored in total and constant darkness.

Ventilation: it must be ensured at a minimum level, to avoid dehydration, but sufficient to eliminate the excess CO2 generated during storage.

STORAGE SYSTEMS:

1. Refrigerated storage:

– it is recommended that after harvesting the fruits be subjected to the process of rapid cooling (pre-cooling) at a temperature as close as possible to the storage temperature.

– considering the relatively large air currents that are involved in the rapid cooling process, it is recommended to use constant pressure chambers or a protective curtain on the surface of the upper flasks.

– during rapid cooling, two factors are mainly pursued: reducing weight loss (water loss) and extending the storage term.

– storage condition refrigerated is directly dependent on the type and mixture of the fruits during the harvest, the quantity of CO2 (15 to 20% could be prevented successfully, the extension of Botrytis and other fungi), the possibility of the removal of ethylene during the storage, and the quality of the water used to provide and maintain the humidity required.

– the storage term in pre-drying conditions, controlled temperature and humidity is about 2 – 3 weeks.

2. Refrigerated storage in CA / ULO-refrigerated storage:

– it is recommended that after harvesting the fruits go through exactly the same steps as in the case of storage under controlled temperature and humidity conditions.

– after the completion of the loading of the Fruit Warehouse, proceed to its sealing and proceed to ensure the conditions as in the storage room. Generic storage conditions are included in the parameters: 3% O2 and 10% CO2 / (-0.5 / 0)°c / 90-95% rH.

– in these conditions the storage periods increase up to 7 – 8 weeks depending on the condition of the fruits at the date of picking.

3. Refrigerated storage in CA / UA conditions-palletized system:

– fruit storage in CA / ULO cold stores is done individually under O2 and CO2 conditions determined according to the nature of the fruit.

– pallets with sant fruit covered with a gas-tight plastic system. Dimensions of the system sant 1200 x 1000 x 4500 max (Lxwxh) (mm). The system thus created is connected to the plant as / ULO there is the possibility of creating specific conditions for a variety of fruits inside the same cold storage.

– advantages: different O2 and CO2 settings, it is impossible to migrate fungi / spores and flavors from one fruit time to another, the impossibility of CO2 loss in cases of accidental decoupling.

– the system allows simultaneous use of mínimum 10 pallets and máximum 300 pallets.

For storage at home, we recommend:

– they are stored either in the refrigerator or in the freezer, but there are also options for drying and preserving them in different forms.

– if they will be kept in the refrigerator, do not wash them before and keep them in a clean and dry container, covered with a plastic wrap. Do not put in this storage place the fruits that are soft or that begin to spoil, and when it will be seen that one shows traces of damage, it will have to be removed from the storage space. Thus, the fruits will last up to two weeks, but it would be good to be eaten as quickly as possible.

– blueberries can also be put in the freezer, after they are thawed they will be as tasty and only slightly juicier than in the fresh version. they should not be washed before freezing them, but after they have been thawed.

– to be placed in a covered box, leaving a space of 1-2 centimeters from the fruit to the lid, to allow them to grow in volume. If you want to be eaten raw, to be contained in a syrup made of four cups of water and three cups of sugar, to be sealed box and put in the freezer. And if after defrosting it is thought to be crushed, add 1-1.5 cups of sugar for each liter.

– if it is desired to be dried, follow the following procedure: to be immersed for 15-30 seconds in boiling water, then immediately thrown into cold water. To be wiped from traces of juice and dried in a dehydrator or in a space where they will be put to dry – it must be well ventilated and protected from light and too strong heat. It can be considered that they have dried when pressing no more juice comes out of them.

Long-term storage of potatoes in controlled atmosphere:

Keeping potatoes is as important as producing them. The potato tuber contains about 75% water, due to this it gets very easily sick during storage from so-called storage diseases: wet rot, dry rot, rot due to potato blight, etc.

But the potato has built up, over time, and some positive traits, which ensure some resistance to preservation. Let’s see what these are.

Maturity: for long-term storage, potatoes must be picked at full maturity. Harvesting them must be done on time.

– new potatoes: they are harvested for fresh sale . They are not harvested for storage, especially long-term storage. At the time of harvest they are considered a delicacy / truffle.

– mature potatoes: most potato crops are prone to medium and long term storage. Storage conditions differ depending on the variety and final use of stored potatoes: sale as such or potato processing industry.

Temperature: the storage temperature of the potatoes is determined by the final use of the stored potatoes.

Humidity: relative humidity should be maintained between 90 – 95%. If the relative humidity drops below the level of 90% the potatoes will dry out and show wrinkles on the surface.

Lighting: potatoes must be stored in total and constant darkness.

Ventilation: it must be ensured at a minimum level, to avoid dehydration, but sufficient to eliminate the surplus of CO2 generated by potatoes during storage.

During the storage of potatoes must be observed the 5 steps as follows:

– Stage 1 (blowing): it is a very important and delicate process at the same time. It has the role of removing excessive moisture from the tubers without dehydrating them and preventing the spread of infections in the potato mass.

Process: including mechanical ventilation with fresh air at a temperature of 2..3°C lower than the temperature of potatoes.

Duration: between 3 – 5 days.

– Stage 2 (wound healing): it is a process in which potatoes are kept for a long period of time, the period in which potatoes have the opportunity to heal surface injuries sustained during harvesting, transportation and storage. This healing is done to prepare potatoes for storage. The decrease in the number of” open wounds ” leads to a decrease in the chances of infection during storage. Of major importance is the system of maintaining the necessary humidity.

Attention: if during this period the development of “potato blight” is observed, the affected potatoes should be removed.

Process: mechanical ventilation with cold intake at a temperature 15-16°C / humidity 95%.

Duration: 15-25 days.

– stage 3 cooling : after blowing and wound healing the cooling process is very important. Cooling should be done in such a way that the potatoes do not lose weight and pre-prevent the formation of sugar in the potato. It is very important that during the cooling period the heating of potatoes is not carried out – this accidental heating can cause the beginning of the germination period which is fatal for the stored potato.

Process: mechanical ventilation (10-12 times / day), gradual cooling with 0.3-0.5°C / day with an air temperature not lower than 2°C compared to the temperature of potatoes.

Duration: 30-60 days.

– Step 4 storage: start when the potatoes have reached the final storage temperature. Temperature / humidity conditions may vary depending on the final destination of the potatoes, namely: potatoes for chips will store at +..+ 12°C / 90% rH , potatoes for frying will store at + 5… + 6°C / 90% rH , potatoes for consumption will store at +4++7°C / 90% rH, potatoes for seed will store at+3.5…+5°C / 90% rH, potatoes for starch will store at+4. + 5°C / 90% rH.

Process: mechanical ventilation with cooled air, maintaining constant temperature + humidity.

Duration: 90-180 days.

– stage 5 heating: this stage begins about 10 – 15 days before the delivery of potatoes and represents the reverse process of cooling potatoes.

This heating step is carried out with two purposes: time is given to the reducing sugars produced during cooling to turn into starch( avoid the Maillard reaction), condensation is avoided on the surface of the potatoes at the time of delivery.

Process: increase the storage temperature to a level of + 8..+ 10°C.

Duration: 10-15 days.

For storing potatoes you can choose one of the following systems:

– simple wooden boxes with the possibility of good ventilation (ventilation) stored in mechanically ventilated spaces and equipped with refrigeration / humidification systems.

– wooden boxes provided with a suction side and a pressure side stored in ventilated / refrigerated spaces provided with a logical process unit.

– bulk storage in warehouses provided with ventilation through the floor / ventilation channels and equipment for temperature / humidity control.

Long-term storage of onions in controlled atmosphere:

Onion storage

And onions can be stored both in warehouses with mechanized ventilation and in cold storage

Onion Fachir

Fachir-medium early golden onion. Vegetation-85-100 days. Variety grown annually. Green leaves with a wax coating. Onions are round, thick, large, weighing 130-170 g, leaves from the outside attractive yellow-golden color, inside – White, juicy, fatty and crispy, medium-spicy taste. Recommended for sowing directly in the soil, or by cuttings (cassette technology). Sowing rate of 4-5 kg / ha. The number of plants per hectare should be about 800,000 – 1,200,000. It is recommended to sow with a spacing of 30-45cm, and the distance between plants of 2.5 – 4.0 cm or 8.0-12.0 cm ( depending on what kind of products we want to get). With drip irrigation is recommended 8 and 6 in line (per meter should be 20-25 plants at a distance of 27 cm between rows). Proper sowing-it is essential for a high yield. With an even row of plants is facilitated mechanical treatment in the field, harvesting and drying. This allows to obtain a high-quality and uniform product. Particular attention should be paid to watering, the lack of moisture can be detrimental to the future harvest. Humidity during germination and early bulb formation should be at least 75-80%, and in the period of formation -70% of HB. The largest amount of water is consumed by onions in the intensive growth stage. Yields of Golden onions Fachir – 50-65 t / ha.

Onion Emir

Emir – medium early white onion. The growth period of 110-120 days allows harvesting and drying before the rains begin. Annual crop. Emir onions are strong and have economic growth potential. Onions of spherical shapes, compact, large in size, weighing 120-200 g, on the outside perfectly white. Inside – white, thick, juicy and crispy. Suitable for storage (up to 4-6 months). Recommended Emir for all regions, sown directly in the field, or by cuttings. The average sowing rate – 4-5 kg / ha. The number of plants per hectare should be about 600.000 -800.000 . Harvest is better carried out, 80-90%, with drip irrigation. It is recommended to sow in rows of 6 and 8 (the distance between rows 27 cm). Proper planting is essential for a high yield. With an even row of plants, mechanical treatment in the field, harvesting and drying are facilitated. This allows to obtain a high-quality product. Great attention should be paid to watering, the onions are very demanding to moisture. The largest amount of water is consumed by onions during the period of intensive growth. The yield is-50-80 t / ha.

Onion Pharaoh

Pharaoh-medium white onion variety. The growth period of 110-120 days after germination. Bulbs of medium quality Pharaoh grow in a year. Plants with leaves of dark green color, covered with a layer of wax. Onions are rounded, large in size, weighing 160-220 g perfectly white external color. with the inside – white, thick and juicy. Arw a strong taste, suitable for drying, and universal use. Productivity is 60-70 t / ha. Suitable for long-term storage (up to 6 months). Varieties of onions that can be grown in all regions from seeds directly in the field or by cuttings. Sowing rate of 4-5 kg / ha. The number of plants per hectare should be about 800,000-1,200,000. If large bulbs are desired, rare drilling is used, with 600,000-800,000 plants per hectare. Recommended sowing with row spacing of 30-45 cm and a distance of 2.5 – 4.0 cm, between plants, or 8.0-12.0 cm (depending on the type of products to be obtained). With drip irrigation is recommended 8 and 6 seeds per line (the distance between rows – 27 cm). Proper planting is essential for the success of the crop. With an even row of plants is facilitated mechanical treatment in the field, harvesting and drying. This allows you to get a high-quality product. Onions –it is moisture-loving, so it should be watered regularly. The largest amount of water consumed by onions is at the stage of intensive growth.

Onion Timur

Timur-early middle class, red onion. Growth period of 80-100 days. Plants with leaves of dark green color, covered with a layer of wax. Onions have an elongated rounded shape, large in size, weighing 140-200 g, with purple-red sheets in color. Interior of purple-pink color, juicy with medium-spicy taste. Recommended growth in all regions, with sowing directly in the field or by cuttings.For seedlings it is best to be sown in boxes, or in the drawer. These seedlings can tolerate transplantation and easily settle. Optimal sowing is done with an average of 4-5 kg / ha. The number of plants per hectare should be about 800,000 – 1,200,000, if large onions are desired, drilling is done rarely, with results of 600,000 – 800,000 plants per hectare. Harvest is better carried out, 80-90%, with drip irrigation. It is recommended to sow in rows of 6 and 8 (the distance between rows 27 cm). Correct planting is essential for a high yield. With an even row of plants, mechanical treatment in the field, harvesting and drying are facilitated. This allows to obtain a high-quality product. Great attention should be paid to watering, the onions are very demanding to moisture. The largest amount of water is consumed by onions during the period of intensive growth. The yield is – 50-70 t / ha. Shelf life of onions is 6-7 months.

Storage of onions for a shorter period of time in an artificial space

Harvesting:

– if the leaves of the onion begin to turn yellow and wither, it means that the plant has reached maturity and the time of harvesting is approaching. The ripening process can be accelerated by laying the leaves on the ground. After 10-15 days can harvest;

– onion harvesting is preferably done on a sunny day, but in no case when the Earth is very wet;

– remove the onion from the ground with a fork, but carefully not to hurt the bulbs;

Preparation for winter

– dry the onions for several days, exposing them to the sun with all the leaves and turning them frequently;

– while they are still wet, onions are not allowed to touch, because a touch how small makes them sprout and rot;

– if you can dry the onions in the sun, you can do this in a warm, dry and well-ventilated place;

Winter storage

– before winter storage, cut the tail of the onion, keeping only a few millimeters of the leaves. After drying and cutting, onions are prepared for wintering, they can be placed in crates;

– keep for the winter only perfectly healthy onions;

– the best storage conditions for onions are in well-ventilated places with low humidity and positive temperatures, but not exceeding 15°C.

Storage of apples in a controlled atmosphere:

Storage of apples

The preservation of apples is done in refrigerated warehouses with normal or controlled atmosphere, as well as in warehouses with natural ventilation.

The storage of apples begins as soon as possible after harvesting and is stored in batches of the same variety.

The apples are stored in boxes that are stacked on 8-9 levels, up to 5-7 m high, the space between the ceiling and the last box is 80 cm. Also leave spaces of about 20-30 cm between the walls and the rows of stacks so that the air can circulate.

Filling a cell should not take more than 2 weeks, during this period ventilation is provided.

The storage temperature depends on the variety. Thus the apples of the Golden and Red delicious variety are stored at temperatures between 0 and +1°C. The Apples of the Ionathan and the Ioared variety, which are more sensitive to cold, are stored at temperatures between +3 and +4°C. the relative humidity of the air is 90-95%.

In refrigerated warehouses with controlled atmosphere (2-3% O2 and 1-3% CO2) the storage temperatures will be higher by 0.5-1°C, depending on the variety.

The shelf life also differs depending on the Variety, the apples of the Golden and Red delicious groups can be kept 5-6 months in refrigerated warehouses with normal atmosphere and 7-8 months in refrigerated warehouses with controlled atmosphere.

Root storage in controlled atmosphere:

Root crops (carrot, parsley, parsnip, celery, beetroot, radish) are stored in cold stores. Within a maximum of two days after harvesting, storage must be done.

Before Storage, The Roots will go through the conditioning stage, which consists in the qualitative sorting and shaping of the roots (cleaning them of leaves).

Storage of Roots is done in wooden or plastic jars. Vegetables are not washed and must be stored in warehouses without a light source. The optimum storage temperature is around 0°c and relative humidity 90-95%. The shelf life is between 5 and 6 months.

Depozitarea strugurilor in atmosfera controlata pe termen lung:

Aproape toate aceste fructe sunt preracite si Multi dintre ele sunt depozitate pentru perioade diferite de timp inainte de consum. Pe de alta parte, pentru consumul in stare proaspata, fructele din speciile Vitis sunt in mare masura limitare la distribuzione pe piata locala.

Strugurii cresc greu si trebuie sa fie la maturitate deplina in momentul culesului deoarece intreaga perioada de coacere trebuie ca acestia sa fie pe butuc. “Matur” sono aici semnificatie psihologica, adica este starea in care fructul arata placut ochiului si poate fi mancat cu satisfactie. Totusi strugurii nu trebuie sa fie trecuti din copto, deoarece aceasta ii predispune la probleme serioase dupa recoltare: slabirea tulpinii / coditei ciorchinelui pentru alcune zone varietati , cum este varietatea Thompson fara seminte, cura devenir (desprinderea boabelor si probabilitatea marita de a fi atacati de microorganismele de descompunere. Pericolul descompunerii fructului creste in cazul expunerii la ploaie SAU vreme umeda excesiva inainte de recoltare (conditii favorevole pentru infectarea in camp cu Botrytis cinerea.

Racire si depozitare:

Strugurii sunt vulnerabili la efectul de uscare al aerului datorita raportului relativ mare intre suprafata si volum, in special cei cu codita. Starea coditei este un factor important de calitate si un indicator excelent al tratamentului care s-a aplicat asupra fructului. Codita trebuie mentinuta in stare proaspata, verde, nu numai CA aspect, dar si pentru ca devine frágila prin uscare si se poate rupe. Codita unui ciorchine de strugure, spre deosebire de Alte fructe, este partea de care se tine la manipulare; daca aceasta se rupe fructul este pierdut pentru orice scop practic, chiar daca boabele sunt in stare excelenta. Asadar trebuie sa se acorde o atentie deosebita operatiilor cura minimizeaza pierderea de umiditate.

Rata pierderii apei este mare in special inainte si in timpul preracirii, deoarece strugurii sunt culesi in mod normal in conditii de temperatura ridicata si aer uscat. Caldura din camp trebuie repede eliminata dupa culegere pentru a minimiza expunerea strugurilor la conditii de presiune joasa de vapori. Volumul si temperatura aerului de preracire, viteza cu care trece peste / printre containere si accessibilitatea fructului la acest AER sunt fattori semnificativi in rata de eliminare a caldurii. Acesti fattori sunt influentati drastic de localizarea si ventilarea containerelor, alinierea acestora (canale de aer) si materialele de ambalare.

Strugurii de masa sunt Initial raciti cu un sistem de racire fortata cu aer. Un gradient de presiune este astfel dat incat se creeaza un debit Pozitiv de aer rece printre fructe de la un capat ventilat al containerului la celalalt capat . Il Containerele sunt aranjate astfel incat aerul trebuie sa treaca prin container inainte de se intoarce la suprafata de racire. Timpul de preracire este de obicei de 3-6 h, in functie de sistemul de ambalare si de debitul de aer.

Temperatura de depozitare recomandata pentru strugurii Vitis vinifera (tipul European SAU Californian) este de -1°C. Umiditatea relativa trebuie sa fie de 90-95 %. Desi temperaturile de – 1.7 °C nu au afectat bine fructele coapte ale unor varietati, alte varietati de struguri cu un continut mai mic de zahar au fost deteriorarsi prin expunere la – 0,5 °C. Depozitele de struguri trebuie sa asigure o circulatie uniforma un aerului in containere. Fructele trebuie racite fortat cu jet de aer La mai putin de 4°c inainte de depozitare. In timpul depozitarii initiale, un debit de aer bine distrubuit de 52 l / s La tona de struguri este necesar pentru finalizarea racirii. Dupa ce fructele au fost preracite, viteza aerului trebuie redusa la o valoare CE permite mentinerea uniforme a temperaturilor in toata camera (nu mai mult de 0.05 la 0.1 m/s in canalele dintre picioarele stivei).

Cea mai mare modificare ce intervine la strugurii depozitati este pierderea umiditatii. Primul efect notabil este uscarea si inmaronirea coditei si a tulpinei ciorchinelui. Aceasta devine evidenta chiar si la o pierdere de numai 1 pana la 2% din masa fructului. Cand pierderea este de 3% pana la 5 % fructele pierd turgescenta si catifelarea.

Mentinerea unei umiditati de 90 la 95% in depozitele de struguri este adesea o problema, in special la inceputul sezonului de depozitare cand ambalajele sunt uscate. Fiecare ambalaj absoarbe 0.15 pana la 0.3 kg apa intr-o luna si cu cat mai putina umiditate este introduzione in camera cu atat mai multa este extra din fruct. Umidificarea prin pulverizare este eficienta pentru minimizarea contractiei. Cu un echilibru adecvat al apei si presiunii aerului, tipul de duza ales corect, se poate obtine o pulverizare fina chiar si la – 0.5 °C.

Afumare / fumigare:

Strugurii Vinifera trebuie fumigati cu dióxid de sulf dupa ambalare pentru a preveni sau intarzia raspandirea microorganismelor de descompunere. Tratamentul de suprafata sterilizeaza fructul, si in particolare leziunile produse in timpul manipularii.

Fumigarea cu SO2 in depozit previne infectiile noi dar nu le controleaza pe cele care au fost contactate in camp. De cele mai multi ori ele nu sunt dezvoltate suficient de mult pentru a fi identify la recoltare si ca urmare sunt cauza primara a descompunerii in depozit. Harvey descrie o metoda de masurare un infectiei in campo per prevedea descompunerea in timpul depozitarii ; previziunea indica loturile care sunt sigure si pot fi depozitate in siguranta si cele care au probabilitate de descompunere mai mare si trebuie comercializate mai devreme.

Practica comuna la racirea initiala este de a se fumiga fructele seara. In acest fel preracirea nu este intarziata si fumigarea se poate face dupa plecarea personalului. Acest tratament intra iniziale in responsabilitatea personalului frigotehnic.

Cantitatea de SO2:

Alte produse n-ar trebui tratate impreuna cu strugurii sau nici macar in apropiere astfel incat gazul sa le atinga, deoarece cele mai multi pot fi foarte usor afectate de acesta. Deoarece si strugurii pot fi afectati, ei trebuiesc expusi la cantitatea minima de SO2 ceruta, ce depinde de :

– potentialul de descompunere si starea fructelor .

– cantitatea de fructe de tratat .

– tipul containerelor si materialele de ambalat .

– viteza aerului si uniformitatea distributiei aerului .

– dimensiunea camerei .

– pierderile prin neetanseitatile si absortia peretilor .

Cantitatea de SO2 necessesara pentru controlul eficient al Botrytis variaza cu durata de timp de expunere a strugurilor la contactul cu gazul. Dozarea SO2 pentru distrugerea sporilor / miceliului de Botrytis este de 100 mg/kg?h.

Fumigation methods:

Traditional fumigation can be used for initial treatment when the grapes are received at the warehouse or for weekly fumigation during long-term storage. Relatively high concentrations of SO2 are added for 20 to 30 min. and then the remaining gas is vented from the room.

Initial traditional fumigation can use either circulating air or forced air fumigation. Each is used either in combination with initial cooling or as a separate operation. In circulating air fumigation, the Air jet passes over, but not among box-pallets. The penetration of SO2 as deep as possible in the boxes depends on the speed of the air passing over the pallets , the type of the box and the packaging materials. For maximum penetration a minimum speed of 0.7 m / s is required.

Air flow systems for forced air fumigation are the same as systems for forced air cooling. SO2 is introduced into the air in the chamber and is forced through the boxes, resulting in rapid penetration, regardless of the package.

The airflow for many forced air fumigation Chambers is typical for forced circulation exchangers ( around 0.5 l / s per kg of stored product); however a good penetration of SO2 was observed even with a lower air flow (0.25 l/s per kg) and slower cooling.

The maximum concentration of SO2 allowed for initial fumigation is 10000 mg / kg. Although few operators regularly use this level in small circulating air fumigation rooms, many operators use 5000 mg/kg for initial fumigation. The levels for a particular location should be determined using SO2 dosimetric tubes.

According to the new regulations it is forbidden to release any amount of SO2 into the atmosphere, so water is used to remove SO2 from the room without ventilation. The most effective systems pass chilled air through a nozzle with water. Water can absorb SO2 at a rate of 0.86 kg SO2 per 1000 L water, if the water is at 0 °c and becomes completely saturated with fumigant. At 21 °C water will absorb only half the amount of SO2. This water cannot be reused and must be disposed of. To increase the amount of SO2 absorbed in the water, sodium / potassium hydroxide can be added.

In total fumigation, the amount of SO2 introduced is balanced with that absorbed by the fruit, the boxes and the chamber itself. This method is used only associated with preraciation. For complete gas absorption , the gas will be kept in contact for at least a few hours. Without preraciation the grapes will be exposed to hot air which can lead to dehydration of the cod. By the simultaneous use of fumigation and pre-drying the fruits will be cooled quickly and fumigated effectively.

Frequency of fumigation in warehouses:

Deposits should be fumigated regularly and frequently so as to prevent the spread of mycelium from the affected grains to adjacent ones. The speed of development of mycelium varies with temperature. The temperature of the grain during storage should be as close as possible to -0.5 °C. Industrial Experience and test results show that 7 days is the appropriate interval for preventing the spread of Botrytis.

Storage time:

The normal storage time can vary from Variety to Variety and is most affected by the attention given to the selection and preparation of fruits. Grapes should be harvested at the optimal time of maturity for storage. The tail and pedicle (stem of the bunch) should be well developed and the fruit should be firm and mature.

Soft and insufficiently developed fruits do not store.

Cooling to a temperature of 4 to 7 °C is recommended for fruits that are in transit to the warehouse.

Materials and practice of refrigeration systems:

SO2 is corrosive so the following actions are required to ensure the durability of the equipment and economic operation :

Evaporators:

– heat exchanger battery made of SO2-resistant aluminum alloy; can be covered with a material to prevent chemical attack; aluminum sheet housing with fasteners made of food grade stainless steel.

– fan protection grille made of soft steel treated and covered in electrostatic field; fan motors capsulated with cast iron or cast steel housing with high quality paint coating; fan motor shaft made of a nickel-based material.

– pipes for vaporizers: aluminum or stainless steel pipes are used; the fixing rods will also be made of stainless steel.

Place manual and control valves outside the warehouse to minimize corrosion and for easy maintenance

Place the vaporizers as close as possible to the outer walls to minimize the length of the pipes between the control valves and the vaporizers.

Long-term storage of strawberries in controlled atmosphere:

Storage conditions strawberries:

Maturity: strawberries are harvested at different stages of development, depending on the variety and market preference. The maturity of strawberries is best indexed by the color of the outer surface and the firmness of the fruit. Fruits of most varieties intended for consumption should be harvested whenthe surface of the fruit is completely red, but fruits of less hard varieties should be harvested when they have a lighter color. Less hard varieties include Senga Sengana, Polka and Honoeye.Stronger varieties, such as Selva and Camarosa, should be harvested when they have a deep red color. The Aroma of all varieties of strawberries is more sought after and sweeter if the fruits are allowed to ripen entirely on the plant. Strawberry fruits no longer ripen after harvest.

Temperature: the storage temperature of strawberries in the refrigerated state is within the range (0 / +1)°C.

Humidity: relative humidity should be maintained between 90 – 98%. If the relative humidity drops below the level of 90% the strawberries will dry out and present wrinkles on the surface.

Lighting: strawberries must be stored in total and constant darkness.

Ventilation: it must be ensured at a minimum level, to avoid dehydration, but sufficient to eliminate the excess CO2 generated during storage.

STORAGE SYSTEMS:

1. Refrigerated storage:

– it is recommended that after harvesting the fruit be subjected to the rapid cooling process (pre – cooling) at a temperature as close as possible to the storage temperature (0 / +1)°C.

– considering the relatively large air currents that are involved in the rapid cooling process, it is recommended to use constant pressure chambers or a protective curtain on the surface of the upper flasks.

– during rapid cooling, two factors are mainly pursued: reducing weight loss (water loss) and extending the storage term.

– storage condition refrigerated is directly dependent on the type and mixture of the fruits during the harvest , the quantity of CO2 (15 to 20% could be prevented successfully, the extension of Botrytis and other fungi), the possibility of the removal of ethylene during the storage, and the quality of the water used to provide and maintain the humidity required.

– the storage term in pre-drying conditions, controlled temperature and humidity is about 2 weeks.

2. Refrigerated storage in CA / UA conditions-refrigerated warehouses.

– it is recommended that after harvesting the fruits go through exactly the same steps as in the case of storage under controlled temperature and humidity conditions.

– after the completion of the loading of the Fruit Warehouse, proceed to its sealing and proceed to ensure the conditions as in the storage room. Generic storage conditions are included in the parameters: 3% O2 and 10% CO2 / (-0.5 / 0)°c / 90-95% rH.

– in these conditions the storage periods increase up to 7 – 8 weeks depending on the condition of the fruits at the date of picking.

3. Refrigerated storage in CA / UA conditions – palletized system.

– fruit storage in CA / ULO cold stores is done individually under O2 and CO2 conditions determined according to the nature of the fruit.

– pallets with sant fruit covered with a gas-tight plastic system. Dimensions of the system sant 1200 x 1000 x 4500 max (Lxwxh) (mm). The system thus created is connected to the plant as / ULO there is the possibility of creating specific conditions for a variety of fruits inside the same cold storage.

– advantages: different O2 and CO2 settings, it is impossible to migrate fungi / spores and flavors from one fruit time to another, the impossibility of CO2 loss in cases of accidental decoupling.

– the system allows simultaneous use of mínimum 10 pallets and máximum 300 pallets.

Post-harvest diseases:

Post-harvest degradation is a major cause of the existence of poor quality, unsold fruits. Several different fungal diseases are responsible for the vast majority of post-harvest decay problems. The main disease after harvesting strawberries is gray rot – Botrytis. Diseases of lesser importance are soft rot and Rhizopus skin rot.

Strawberry diseases involve complex interactions between the causative agents, the host plant and the environment. The development of a disease is influenced by the strawberry variety, the stage of maturity of the fruit, physical degradation, when the fruit is infected, post-harvest temperature and surface humidity.

 

 

 

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