Cold Storage of Fruit and Vegetables

c

Cold storage reduces the rate of biochemical changes in fresh foods (known as µrespiration¶ and µsenescence¶) and also slows down the growth of contaminating micro-organisms. The reason for storing fruits and vegetables in a cold store is therefore to extend their life beyond the harvest season. This may be because they can achieve a higher sale price out of season or for food security reasons. However, cold storage is expensive - both in terms of buying the store and the operating costs. So it is essential that this is only considered where the price for the stored crop is high enough to cover these costs. The factors that control the shelf life of fresh crops in cold storage include: * The and variety or cultivar. * The (the fastest growing parts have the highest respiration rates and the shortest storage lives). * The (e.g. the presence of damage or microbial contamination, and the degree of maturity). * The . * The , which also influences weight losses due to drying out. * The (see note below).

Most crops are likely to contain contaminants, to have parts that are inedible, or to have variable shape or size. To ensure that foods have a uniformly high quality for sale in the fresh market sector, it is necessary to clean, sort and grade the crop before cooling and cold storage.

= ut is essential that fruits and vegetables are not damaged during harvest. Cut or bruised produce is susceptible to post-harvest infection and has a much shorter storage life and poor appearance after storage. Crops should be harvested carefully using a sharp stainless steel blade and should not be placed on the ground where they could pick up dirt. Crops should be handled carefully and as little as possible. The best option is to prepare crops in the field and place them carefully in the containers that are also used in the cold store. This reduces the amount of handling and keeps damage to a minimum. Dirty crops can introduce insects, pests and moulds into the cold store, which will then damage good quality produce. uf produce (e.g. root crops) is dirty it should be

cleaned before storage. The washing water has to be kept clean to prevent it from transferring fungus spores throughout the produce. Some fruit and vegetables should have their outer leaves removed before sale. However, it is usually better to leave the leaves in place during cold storage to reduce moisture loss, and then remove them before sale. Crops should be sorted to remove any that are too small or those that have defects such as insect or rodent damage, splits, cuts etc. Any damaged crops may become infected with mould during storage and these will rapidly infect good quality crops stored alongside them. Depending on the requirements of the customers, it may also be useful to grade crops so that fruits or vegetables that have similar size, maturity or colour are packed together. Cleaning removes contaminating materials from crops. The selection of a cleaning procedure depends on the type of crop and the types and amounts of contaminants that are likely to be present, but wet cleaning methods are commonly used. Examples of wet-cleaning equipment include soaking tanks, spray washers, brush washers, belt or drum washers and flotation tanks. These are effective for removing soil from root crops or dust and pesticide residues from fruits or vegetables. Different combinations of detergents and sterilants (or disinfectants) can be used at different temperatures. For example, warm water improves cleaning efficiency, especially if mineral oil is a contaminant, but this increases costs and may also damage the texture of some foods and accelerate spoilage by enzymes and micro-organisms. Wet cleaning methods also produce large volumes of waste water that may require payment for disposal or construction of water treatment facilities to avoid the risk of local pollution. To reduce costs, water is recirculated, filtered and chlorinated with 100 - 200 mg l±1 of chlorine. Soaking is used for cleaning heavily contaminated root crops to remove soil and stones. For delicate foods such as strawberries or asparagus, or products that can trap dirt internally (e.g. celery), air can be µsparged¶ through the water to increase cleaning efficiency. Spray washing using drum washers or belt washers is used for many types of crops. Larger foods are rotated so that the whole surface is sprayed, and some equipment has brushes or flexible rubber discs that gently clean the food surfaces. Flotation washing exploits the difference in the density of foods to separate contaminants. Foods that float in water (especially fruits or root crops), are separated from contaminating soil, stones or rotten crops that sink.

ð ut is important to remove µfield heat¶ from crops as quickly as possible after harvest. This reduces their metabolic activity, reduces the growth of micro-organisms and prevents other changes such as wilting, before crops are placed in cold storage. ut also reduces the load on the cold store refrigeration system. A simple method is to pick the crop either early in the morning when it is cool or late in the evening and leave it to cool overnight. On larger farms, µhydrocooling¶ is used to rapidly cool produce. Foods are sprayed with or submerged in chilled water produced by a refrigeration unit. Alternatively crushed ice can be used to make cold water. This has a lower capital cost for the equipment and may be more suitable for growers that have smaller amounts of produce, provided that there is a reliable source of ice at a reasonable cost. un hydrocooling, produce is packed into wooden crates, mesh bags or perforated metal

bins that are stacked on pallets to cause water to flow through and not around the packages. There are four different types of hydrocoolers: 1. Batch hydrocoolers have bins of produce loaded into an enclosure and chilled water is sprayed over the produce, collected, re-cooled and recycled. They are relatively inexpensive and are suitable for growers that have a limited amount of produce or a short harvest season. 2. Conveyor hydrocoolers pass containers of produce under a shower of chilled water on a conveyor belt. However, because of the higher cost, this equipment must operate for long periods in a year to be economically justified. 3. un immersion hydrocoolers, crates of produce are moved by a submerged conveyor through a large, shallow tank of recirculated chilled water. This system produces more rapid cooling than other types because the water has greater contact with food surfaces. 4. Truck hydrocooling involves loading produce onto an enclosed trailer and inserting perforated pipes above the load. These produce a shower of chilled water, which is collected, re-cooled, and recycled. After cooling, the pipes are removed and the produce is transported. Truck hydrocoolers can be constructed at a lower cost than a commercial hydrocooler, but the cooling times are longer than other designs. There is a wide range of hydrocooling equipment available commercially. However, it is designed for high production rates and is generally very expensive. To be costeffective, a hydrocooler must be used for as long as possible during the harvest season and is only affordable by growers or co-operatives with large acreages. A cheaper thermal storage immersion hydrocooler is described by Boyette, which is more suitable for growers that have smaller volumes and cannot invest in commercial hydrocooling equipment.

c ut is not advisable to attempt conversion of an existing room to make a cold store. Cold stores should be purpose-built using insulating materials to reduce the amount of heat that can enter the store through the walls and ceiling. Most cold stores are now constructed from prefabricated panels that have: * structural steel or concrete to give them strength * insulation (fibrous material such as rock wool or cellular plastics such as polyisocyanurate) * a vapour barrier to prevent movement of water vapour, and * an outer and inner facing material that is bonded to the core. The inner facing provides a hygienic, easily cleaned surface and the outer facing provides protection against the weather. The panels are erected on a concrete base. The insulated door to the cold store is close-fitting to minimise leakage of heat, and it may be fitted with plastic curtain strip or an µair curtain¶ to reduce the amount of cold air that can escape from the store when the door is opened. A refrigeration unit inside the store is fitted with fans to recirculate air (Fig. 1) to give the required temperature range, controlled by a thermostat

A packing system is required in the store so that produce can be loaded and unloaded easily and safely. This system can involve stacked crates or a more complicated system using racks and trays. For small-scale cold storage, stackable crates are the most appropriate packing system. The layout of crates in the store needs to be simple and clearly understood by operators so that produce can be loaded or removed easily and quickly. ut is important that the crates are small enough to be moved easily when full of crop; that the crop cannot be crushed by stacking crates; and that the crates are strong enough to support the weight of other crates above them without collapsing. To maintain the airflow around crates, a 60 cm gap should be left between the storeroom walls and the crates, and a 90 cm gap between the crates, the ceiling and the refrigeration unit. Fig. 2 shows a design of crate that is suitable for cold stores. These can be made locally from wood, or plastic (polypropylene) crates may be available from import agents. uf the produce can be transported to market in the same crates that they are stored in, this reduces handling and possible damage to the crop.

Cold stores are cooled by circulation of cold air produced by refrigeration units. All cold stores should lower the temperature of crops as quickly as possible through the µwarm zone¶ (50 ±> 10°C) where maximum growth of micro-organisms occurs. Not all foods can be chilled to low temperatures and some tropical, subtropical and temperate fruits suffer from µchilling injury¶ at 3 - 10°C. This causes a range of effects, including browning or discolouration, the development of off-flavours and excessive softening. The storage temperature always has to be above the minimum temperature and care is needed to set the store thermostat so that the cooling system does not produce any oscillation in temperature below the minimum temperature. ut can be seen from Table 2 that there are basically three groups of fruit and vegetables: those stored at 0 - 4°C; those stored at 4 - 8°C; and those that require a storage temperature above 8°C. For storage of mixed crops in a single cold store it is important that the crops should have similar temperature requirements. Table 2 also shows control of humidity and cooling methods needed to achieve the required storage life for different crops.

There is always some moisture loss from fruits and vegetables during cold storage but excessive moisture loss is a problem. ut is prevented by keeping the humidity of air in the store above 85%. Table 2 shows specific storage humidities for different fruits and vegetables. Moisture loss can be reduced by allowing the crop to cool to the storage temperature and then covering it in plastic, or sprinkling the crop with water before storage. ut is not advisable to sprinkle water during storage because this increases ice

formation in the refrigeration unit. ut is important to maintain an adequate circulation of air using fans, and foods are therefore stacked in ways that enable air to circulate freely around all sides and avoid the risk of spoilage by moulds if µdead-spots¶ permit localised increases in humidity.

G Aeducing the level of oxygen in the atmosphere of a cold store (either with or without increasing the level of carbon dioxide) can extend the life of the crop. ut slows down spoilage, destroys insects and prevents mould growth without the need for treatment with toxic fumigants. However, different types of crop, and even different cultivars of the same species, require different atmospheres for successful storage, and each therefore needs to be independently assessed. uf the oxygen concentration is too low, it can produce off-flavours or discolouration in some types of fruits and vegetables. But the main disadvantages of controlling the cold store atmosphere are economic: the costs of setting up a controlled-atmosphere store and the cost of monitoring the gas composition are both high (twice those of normal cold storage); unless high-value, short-season crops are stored, which substantially increase in price out of season, it may be difficult to justify the additional costs. Also the store has to be fully used by a single crop, because of the different gas compositions required by different crops, and there may be competition from other producing areas that have different harvest seasons. For these reasons, it is unlikely that controlled-atmosphere cold stores will be suitable for producers in developing countries. When operated at the correct temperature and optimum conditions for a particular crop, cold storage causes little change to the quality or nutritional value. However, over-long storage times, incorrect temperatures and damage to crops can cause significant changes, including browning, wilting and weight loss due to evaporation of water from crops. Losses of vitamin C in fruits and vegetables depend on temperature management after harvest. Losses are accelerated by higher storage temperatures and longer storage times, and conditions that cause moisture loss after harvest, especially in leafy vegetables. Losses are also accelerated by bruising and other injuries and by excessive trimming.

X !"# $%&'% 'respiration' and 'senescence') and also slows down the growth of contaminating ϢγΎΑ ΔϓϭήόϤϟ΍) ΔΟίΎτϟ΍ ΔϳάϏϷ΍ ϲϓ ΔϳϮϴΤϟ΍ Ε΍ήϴϐΘϟ΍ ϝΪόϣ Ϧϣ ϞϠϘϳ ΩήΒϤϟ΍ ϦϳΰΨΘϟ΍ micro-organisms. The reason for storing fruits .ΔϘϴϗΪϟ΍ ΔϴΤϟ΍ ΕΎϨ΋ΎϜϟ΍ ΚϳϮϠΗ ϮϤϧ ΊτΒϳ Ύπϳ΃ϭ ('ΔΧϮΨϴθϟ΍' ϭ ' βϔϨΘϟ΍' and vegetables in a cold store is therefore to extend their life beyond the harvest This .ΩΎμΤϟ΍ ϢγϮϣ ΪόΑ ϢϬΗΎϴΣ ΪϳΪϤΗ ϲϟΎΘϟΎΑϭ ΩέΎΑ ϥΰΨϣ ϲϓ Ε΍ϭήπΨϟ΍ϭ Ϫϛ΍Ϯϔϟ΍ ϦϳΰΨΗ ΐΒγ season. may be because they can achieve a higher sale price out of season or for food security .ϲ΋΍άϐϟ΍ ϦϣϷ΍ ΏΎΒγϷ ϭ΃ ϢγϮϤϟ΍ Ϧϣ ΝϭήΨϠϟ ϊϴΑ ήόγ ϰϠϋ΃ ϖϘΤϳ ϥ΃ ϦϜϤϳ ΎϬϧϷ ΍άϫ ϥϮϜϳ Ϊϗ reasons. However, cold storage is expensive - both in terms of buying the store and the So it .ϞϴϐθΘϟ΍ ϒϴϟΎϜΗϭ ήΠΘϤϟ΍ ˯΍ήη ΚϴΣ Ϧϣ ˯΍Ϯγ -- ϒϠϜϣ ΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ ˬ ϚϟΫ ϊϣϭ operating costs. is essential that this is only considered where the price for the stored crop is high ΔϴϟΎϋ ϦϳΰΨΗ ϝϮμΤϤϟ΍ ϦϤΛ ΚϴΣ ςϘϓ ΍άϫ ήΒΘόϳ ϥ΃ ϱέϭήπϟ΍ ϦϤϓ Ϛϟάϟϭ enough to cover these costs. .ϒϴϟΎϜΘϟ΍ ϩάϫ ΔϴτϐΘϟ ϲϔϜϳ ΎϤΑ ϲΘϟ΍ Ϟϣ΍Ϯόϟ΍ The factors that control the shelf life of fresh crops in cold storage include: : ϲϠϳ Ύϣ ΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ ϲϓ ΓΪϳΪΟ ϞϴλΎΤϤϠϟ ϲο΍ήΘϓϻ΍ ήϤόϟ΍ ϲϓ ϢϜΤΘΗ .ΔϋϮϨΘϣϭ ϒϨλ ϭ΃ ()*!%+ * * The and variety or cultivar. * The (the fastest growing parts have the highest respiration ϰϠϋ΃ ΎϬϳΪϟ ˯΍ΰΟ΃ ΍ϮϤϧ ωήγϷ΍ ) &,-. ,-!%/#0 * rates and the shortest storage lives). .(ήμϗ΃ ΓΎϴΣ ϦϳΰΨΗϭ βϔϨΘϟ΍ ΕϻΪόϣ * The (eg the presence of damage or microbial έήπϟ΍ ΩϮΟϭ ϞΜϣ) ,&12()*!%345 * contamination, and the degree of maturity). .(ΞπϨϟ΍ ΔΟέΩϭ ˬ ϲΑϭήϜϴϤϟ΍ ΙϮϠΘϟ΍ ϭ΃ ; ,67%.89:4,$0 * * The . * The , which also influences weight ή΋ΎδΧ Ύπϳ΃ ήΛΆϳ ϱάϟ΍ ήϣϷ΍ ˬ !"# < =8>$? @1$A 4 * losses due to drying out. .ϑΎϔΠϟ΍ ΐΒδΑ ϥίϮϟ΍ < =8>!" * * The (see note below). .(ϩΎϧΩ΃ ΔϴηΎΤϟ΍ ήψϧ΍ ) !"# This Technical Brief gives an outline of the storage requirements of different crops Δπϳήόϟ΍ ρϮτΨϟ΍ ϲτόϳ ϲϨϔϟ΍ ΰΟϮϣ ΍άϫ and the construction and operation of cold stores. .ΪϳήΒΘϟ΍ ϥίΎΨϣ ϞϴϐθΗϭ ˯ΎϨΑϭ ΔϔϠΘΨϤϟ΍ ϞϴλΎΤϤϠϟ ϦϳΰΨΘϟ΍ ΕΎΒϠτΘϤϠϟ

: B?C,-!"# &2D Most crops are likely to contain contaminants, to have parts that are inedible, or to ήϴϏ ϥϮϜϳ ϥ΃ ˬ ΕΎΛϮϠϤϟ΍ ϰϠϋ ϱϮΘΤΗ ϥ΃ ΢ΟήϤϟ΍ Ϧϣ ϞϴλΎΤϤϟ΍ Ϣψόϣ have variable shape or size. To ensure that foods have a .ήϴϐΘϣ ϢΠΣ ϭ΃ ϞϜη ϥϮϜϳ ϥ΃ ϭ΃ ˬ ϲϫ ϲΘϟ΍ ˯΍ΰΟ΃ Ϟϛϸϟ ΢ϟΎλ uniformly high quality for sale in the fresh market sector, it is necessary to clean, sort ϊϴΒϠϟ ΪΣϮϣ ΔϴϟΎϋ ΓΩϮΟϭ ΔϳάϏϷ΍ ϥ΃ ϥΎϤπϟ and grade the crop before cooling and cold storage. .ΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ϭ ΪϳήΒΘϟ΍ ϞΒϗ ϞϴλΎΤϤϟ΍ ϒμϟ΍ϭ ίήϓϭ ϒϴψϨΘϟ ϱέϭήπ ϟ΍ ϦϤϓ ˬ ΓΪϳΪΟ ωΎτϘϟ΍ ϕϮγ ϲϓ

E?F1GHI,H = ϱέϭήπϟ΍ Ϧϣϭ ut is essential that fruits and vegetables are not damaged during harvest. Cut or bruised produce is susceptible to .ΩΎμΤϟ΍ ϢγϮϣ ϝϼΧ Ε΍ϭήπΨϟ΍ϭ Ϫϛ΍Ϯϔϟ΍ ϒϠΗ ϢΘϳ ϻ ϥ΃ post-harvest infection and has a much shorter storage life and poor appearance after ˬ ήϴΜϜΑ ϚϟΫ Ϧϣ ήμϗ΃ ΓΎϴΤϟ΍ ΎϬϳΪϟ ϦϳΰΨΘϟ΍ϭ ΩΎμΤϟ΍ ΪόΑ Ύϣ ϯϭΪόϠϟ Δοήϋ νϮοέ ϭ΃ ΝΎΘϧ· ξϔΧ storage. Crops should be harvested carefully using a sharp stainless .ϦϳΰΨΘϟ΍ ˯΍ήϘϔϟ΍ έϮϬχ ΪόΑϭ steel blade and should not be placed on the ground where they could pick up dirt. νέϷ΍ ϰϠϋ ϊοϮϳ ϻ΃ ϲϐΒϨϳϭ ˬ ΃ΪμϠϟ ϡϭΎϘϤϟ΍ ΫϻϮϔϟ΍ ΓΩΎΣ Γήϔη ϡ΍ΪΨΘγΎΑ ΔϳΎϨόΑ ϞϴλΎΤϤϟ΍ ΩΎμΣ ϥ΃ ϲϐΒϨϳϭ Crops should be handled carefully and as little as possible. .ΥΎγϭϷ΍ ςϘΘϠΗ ϥ΃ ϦϜϤϳ ΚϴΣ The best option is to prepare crops in the .ϦϜϤϣ έΪϗ Ϟϗ΃ϭ ΔϳΎϨόΑ ϞϴλΎΤϤϟ΍ ϊϣ ϞϣΎόΘϟ΍ ϲϐΒϨϳϭ field and place them carefully in the containers that are also used in the cold store. ϥΰΨϣ ϲϓ Ύπϳ΃ ϡΪΨΘδΗ ϲΘϟ΍ ΕΎϳϭΎΤϟ΍ ϲϓ ΔϳΎϨόΑ ΎϬόοϭϭ ϞϴλΎΤϤϟ΍ ϝΎΠϣ ϲ ϓ ήϴπΤΘϟ΍ Ϯϫ ϞπϓϷ΍ έΎϴΨϟ΍ Ϧϣ ϞϠϘϳ ΍άϫ This reduces the amount of handling and keeps damage to a minimum. .ΩέΎΑ .ϦϜϤϣ ΪΣ ϰϧΩ΃ ϰϟ· έήπϟ΍ ϰϘΒϳϭ ϝϭ΍ΪΘϟ΍ ΔϴϤϛ Dirty crops can introduce insects, pests and moulds into the cold store, which will ϰϟ· ΐϟ΍Ϯϗϭ ΕΎϓϵ΍ϭ Ε΍ήθΤϟ΍ ΓέάϘϟ΍ ϞϴλΎΤϤϟ΍ ϝΎΧΩ· ϦϜϤϳ then damage good quality produce. uf produce (eg root crops) is dirty it .ΓΪϴΟ ΔϴϋϮϧ ΞΘϨΗ ϢΛ έήπϟ΍ ϑϮγ ϲΘϟ΍ϭ ˬ ΓΩέΎΒϟ΍ ϥΰΨϣ ΐΠϳ Γέάϗ ϲϫ (ϝΎΜϤϟ΍ ϞϴΒγ ϰϠϋ ΔϳέάΠϟ΍ Ϟϴλ ΎΤϤϟ΍) ΝΎΘϧ· ϥΎϛ ΍Ϋ· should be cleaned before storage. The washing water has to be kept clean to prevent it from transferring .ϦϳΰΨΘϟ΍ ϞΒϗ ΎϬϔϴψϨΗ ήτϔϟ΍ ϢϴΛ΍ήΟ ϞϘϧ Ϧϣ ΎϬόϨϤϟ Δϔϴψϧ ϞψΗ ϥ΃ ΐΠϳ Ϟϴδϐϟ΍ ϩΎϴϣ fungus spores throughout the produce. Some fruit and vegetables should have their outer leaves removed .ΝΎΘϧ· ˯ΎΤϧ΃ ϊϴϤΟ ϲϓ However, it is .ϊϴΑ ϞΒϗ ΎϬΘϟ΍ί· ϲΟέΎΨϟ΍ ΎϬϗ΍έϭ΃ϭ Ε΍ϭήπΨϟ΍ϭ Ϫϛ΍Ϯϔϟ΍ ξόΑ ϥ΃ ϲϐΒϨϳϭ before sale. usually better to leave the leaves in place during cold storage to reduce moisture loss, ˯ΎϨΛ΃ ϥΎϜϣ ϲϓ ϙήΘϳ ϙήΗ ϰϟ· ΓΩΎϋ ϞπϓϷ΍ ϦϤϓ ˬ ϚϟΫ ϊϣϭ and then remove them before sale. .ϊϴΑ ϞΒϗ ΎϬΘϟ΍ί· ϢΛ Ϧϣϭ ˬ ΔΑϮσήϟ΍ ϥ΍ΪϘϓ Ϧϣ ΪΤϠϟ ΓΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ Crops should be sorted to remove any that are too small or those that have defects such as insect or rodent damage, splits, cuts etc. Any damaged crops may become infected with mould during storage and these will rapidly infect good quality crops ΎϬϳΪϟ ϲΘϟ΍ ϚϠΗ ϭ΃ ΍ΪΟ Γήϴϐλ ϲϫ ϲΘϟ΍ ϱ΃ Δϟ΍ίϹ ϞϴλΎΤϤϟ΍ ίήϓ ϥϮϜϳ ϥ΃ ΐΠϳ stored alongside them. ϱ΃ ΢ΒμΗ Ϊϗ ΕΎπϴϔΨΘϟ΍ ϚϟΫ ϰϟ· Ύϣϭ ˬ ϱ΃ήϟ΍ ϲϓ ϑϼΘΧϻ΍ ˬ έήπϟ΍ νέ΍ϮϘϟ΍ ϭ΃ Ε΍ήθΤϟ΍ ϞΜϣ ΏϮϴϋ ϦϳΰΨΗ ΓΪϴΟ ΔϴϋϮϧ Ε΍Ϋ ϞϴλΎΤϤϟ΍ ΔϋήδΑ ϝΎτΗ ϑϮγ ϩάϫϭ ˬ ϦϳΰΨΘϟ΍ ˯ΎϨΛ΃ Ϧϔόϟ΍ έ΍ήο΄Α ϦϴΑΎμϤϟ΍ ϞϴλΎΤϣ Depending on the requirements of the customers, it may also be useful to grade .ϢϬΒϧΎΠΑ crops so that fruits or vegetables that have similar size, maturity or colour are packed ϭ΃ Ϫϛ΍Ϯϔϟ΍ Γ΄Βόϣ ΚϴΤΑ ϒμϟ΍ ϞϴλΎΤϤϠϟ Ύπϳ΃ ΪϴϔϤϟ΍ Ϧϣ ϥϮϜϳ Ϊϗ ˬ ˯ϼϤόϟ΍ ΕΎΟΎϴΘΣ΍ ϰϠϋ ΍ΩΎϤΘϋ΍ together. .Ύόϣ ϥϮϠϟ΍ ϭ΃ ΞπϨϟ΍ϭ ϢΠΤϟ΍ ΔϠΛΎϤϣ ϲΘϟ΍ έΎπΨϟ΍ Ϧϣ Ω΍ϮϤϟ΍ ΙϮϠΗ Ϟϳΰϳ ϒϴψϨΘϟ΍ Cleaning removes contaminating materials from crops. The selection of a cleaning procedure depends on the type of crop and the .ϞϴλΎΤϤϟ΍ types and amounts of contaminants that are likely to be present, but wet cleaning ΕΎϴϤϛϭ ω΍Ϯϧ΃ϭ ϞϴλΎΤϤϟ΍ Ϧϣ ωϮϧ ϰϠϋ ΪϤΘ όϳ ϒϴψϨΗ ˯΍ήΟ· έΎϴΘΧ΍ methods are commonly used. Examples of wet- .ΐσήϟ΍ ϒϴψϨΘϟ΍ ΐϴϟΎγ΃ ϡΪΨΘδΗ Ύϣ ΓΩΎϋ ϦϜϟϭ ˬ ΓΩϮΟϮϣ ϥϮϜΗ ϥ΃ ϞϤΘΤϳ ϲΘϟ΍ ΕΎΛϮϠϤϟ΍ cleaning equipment include soaking tanks, spray washers, brush washers, belt or drum ˬ Ϋ΍Ϋέ ΕϻΎδϏ ˬ ύήϤΗ ΕΎΑΎΑΪϟ΍ ϞϤθΗϭ ΐσήϟ΍ ϒϴψϨΘϟ΍ Ε΍Ϊόϣ Ϧϣ ΔϠΜϣ΃ washers and flotation tanks. These are effective for removing soil .ϢϳϮόΘϟ΍ ΕΎϧ΍ΰΧϭ ΕϻΎδϏ ϞΒσ ϭ΃ ϡ΍ΰΣ ˬ ΓΎηήϓ ΕϻΎδϏ ΔϟΎόϓ ϲϫ ϩάϫ from root crops or dust and pesticide residues from fruits or vegetables. Different .έΎπΨϟ΍ ϭ΃ Ϫϛ΍Ϯϔϟ΍ Ϧϣ Ε΍ΪϴΒϤϟ΍ ΎϳΎϘΑϭ έΎΒϐϟ΍ ϭ΃ ΔϳέάΠϟ΍ Ϟ ϴλΎΤϤϟ΍ Ϧϣ ΔΑήΘϟ΍ Δϟ΍ίϹ combinations of detergents and sterilants (or disinfectants) can be used at different Γέ΍ήΣ ΕΎΟέΩ ΪϨϋ (Ε΍ήϬτϤϟ΍ ϭ΃) ΕΎϤϘόϤϟ΍ϭ ΕΎϔψϨϤϟ΍ Ϧϣ ΔϔϠΘΨϣ ΕΎΒϴϛήΗ ϡ΍ΪΨΘγ΍ ϦϜϤϳϭ temperatures. For example, warm water improves cleaning efficiency, especially if mineral .ΔϔϠΘΨϣ oil is a contaminant, but this increases costs and may also damage the texture of some

˯ΎϤϟ΍ ˬ ϝΎΜϤϟ΍ ϞϴΒγ ϰϠϋ foods and accelerate spoilage by enzymes and micro-organisms. έήπϟ΍ϭ ϒϴϟΎϜΘϟ΍ Ϊϳΰϳ Ϊϗ ΍άϫ ϦϜϟϭ ˬ ΕΎΛϮϠϤϟ΍ Ϧϣ Ϯϫ ϲϧΪόϤϟ΍ Ζϳΰϟ΍ ΍Ϋ· ΔλΎΧϭ ˬ ϒϴψϨΘϟ΍ Γ˯Ύϔϛ ϦδΤϳ Ίϓ΍Ϊϟ΍ Wet cleaning methods .ΔϘϴϗΪϟ΍ ΔϴΤϟ΍ ΕΎϨ΋ΎϜϟ΍ϭ ΕΎϤϳΰϧϻ΍ Ϧϣ ϒϠΗ ϊϳήδΗϭ ΔϤόσϷ΍ ξόΑ Ϧϣ Ξϴδϧ Ύπϳ΃ also produce large volumes of waste water that may require payment for disposal or ϕήσ construction of water treatment facilities to avoid the risk of local pollution. ˯ΎϨΑ ϭ΃ ΎϬϨϣ κϠΨΘϠϟ ϊϓΪϟ΍ ΐϠτΘΗ Ϊϗ ϲΘϟ΍ ϲΤμϟ΍ ϑήμϟ΍ ϩΎϴϣ Ϧϣ ΓήϴΒϛ ΕΎϴϤϛ ΝΎΘϧ· Ύπϳ΃ ΐσήϟ΍ ϒϴψϨΘϟ΍ To reduce costs, water is recirculated, filtered .ϲϠΤϤϟ΍ ΙϮϠΘϟ΍ ήσΎΨϣ ΐϨΠΘϟ ϩΎϴϤϟ΍ ΔΠϟΎόϤϟ Ε΂θϨϣ ΎϬΘϴϔμΗϭ ϩΎϴϤϟ΍ ΎϬϤϴϤόΗϭ ˬ ϒϴϟΎϜΘϟ΍ ξϔΨϟ and chlorinated with 100 - 200 mg l±1 of chlorine. .έϮϠϜϟ΍ ΓΩΎϣ Ϧϣ ώϠϣ 1 - ήΘϟ 200 ϲΘΣ 100 ϊϣ έϮϠϜϟΎΑ ΔΠϟΎόϤϟ΍ϭ Soaking is used for cleaning heavily contaminated root crops to remove soil and For delicate foods .ΓέΎΠΤϟ΍ϭ ΔΑήΘϟ΍ Δϟ΍ίϹ ΓΪθΑ ΔΛϮϠϤϟ΍ ΔϳέάΠϟ΍ ϞϴλΎΤϤϟ΍ ϒϴψϨΘϟ ϊϘϨϟ΍ ϡΪΨΘδϳ stones. such as strawberries or asparagus, or products that can trap dirt internally (eg celery), ϞΜϣ ΔγΎδΤϟ΍ ΔϳάϏϷ΍ air can be 'sparged' through the water to increase cleaning efficiency. ˯΍ϮϬϟ΍ ϦϜϤϳ ˬ (ϝΎΜϤϟ΍ ϞϴΒγ ϰϠϋ βϓήϜϟ΍ ) ΎϴϠΧ΍Ω Φϓ ΥΎγϭϷ΍ ϥ΃ ϦϜϤϳ ϲΘϟ΍ ΕΎΠΘϨϤϟ΍ ϭ΃ ˬ ϥϮϴϠϬϟ΍ ϭ΃ Δϟϭ΍ήϔϟ΍ Spray washing using drum washers or belt .ϒϴψϨΘϟ΍ Γ˯Ύϔϛ ΓΩΎϳΰϟ ϩΎϴϤϟ΍ ϝϼΧ Ϧϣ sparged' ϡ΍ΰΣ ΕϻΎδϏ ΕϻΎδϏ ϭ΃ ϞΒσ ϡ΍ΪΨΘγΎΑ Ϟϴδϐϟ΍ Ϋ΍Ϋέ washers is used for many types of crops. Larger foods are rotated so that the whole surface is .ϞϴλΎΤϤϟ΍ ω΍Ϯϧ΃ Ϧϣ ΪϳΪόϠϟ ϡΪΨΘδϳ sprayed, and some equipment has brushes or flexible rubber discs that gently clean the ι΍ήϗ΃ ϭ΃ εήϔϟ΍ϭ Ε΍ΪόϤϟ΍ ξόΑϭ ˬ ϪϠϛ ΢τδϟ΍ εέ ϢΘϳ ΚϴΤΑ Γέ΍ΪΘγ΍ ϢΘϳ ήΒϛ΃ ΔϤόσϷ΍ food surfaces. Flotation washing exploits the difference in the .˯΍άϐϟ΍ ΡϮτδϟ΍ ϒτϠΑ Δϔϴψϧ ΔϴσΎτϣ Δϧήϣ ΔϤόσϷ΍ Ϧϣ ΔϓΎΜϜϟ΍ ϲϓ ϑϼΘΧϻ΍ ϞϐΘδϳ ϞδϏ ϢϳϮόΗ density of foods to separate contaminants. Foods that float in water (especially fruits or root crops), are separated .ΕΎΛϮϠϤϟ΍ Ϟμϔϟ ˯ΎϤϟ΍ ϲϓ ϮϔτΗ ϲΘϟ΍ ΔϤόσϷ΍ Ϟμϓ ϢΘϳ from contaminating soil, stones or rotten crops that sink. .ϕήϐΗ ϲΘϟ΍ ΓΪγΎϔϟ΍ ϞϴλΎΤϤϟ΍ ϭ΃ ΓέΎΠΤϟ΍ϭ ΔΑήΘϟ΍ ΚϳϮϠΗ Ϧϣ ˬ (ΔϳέάΠϟ΍ ϞϴλΎΤϤϟ΍ϭ Ϫϛ΍Ϯϔϟ΍ ΎλϮμΧϭ )

&"4 GHB J%ð ut is important to remove 'field heat' from crops as quickly as possible after harvest. This reduces their .ΩΎμΤϟ΍ ΪόΑ ϦϜϤϣ Ζϗϭ ωήγ΃ ϲϓ ϞϴλΎΤϤϟ΍ Ϧϣ Δϴϧ΍ΪϴϤϟ΍ Γέ΍ήΤϟ΍ ' Δϟ΍ί· ϢϬϤϟ΍ Ϧϣϭ metabolic activity, reduces the growth of micro-organisms and prevents other changes Ϧϣ ϞϠϘϳϭ ˬ ξϳϷ΍ ϢϬσΎθϧ ϞϠϘϳ ΍άϫϭ such as wilting, before crops are placed in cold storage. ut .ΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ ϞϴλΎΤϤϟ΍ ϲϓ ϊοϮΗ ϥ΃ ϞΒϗ ˬ ϝ ϮΑάϟ΍ ϞΜϣ ϯήΧϷ΍ Ε΍ήϴϐΘϟ΍ ϊϨϤϳϭ ˬ ΔϘϴϗΪϟ΍ ΕΎϨ΋ΎϜϟ΍ ϮϤϧ ϡΎψϧ ϰϠϋ ϞϤΤϟ΍ Ϧϣ ϞϠϘϳ Ϫϧ΃ ΎϤϛ also reduces the load on the cold store refrigeration system. A simple method is to pick the crop either early in the morning .ΓΩέΎΒϟ΍ ΪϳήΒΘϟ΍ ϦϳΰΨΗ ΔτϴδΑ ΔϘϳήσ ϙΎϨϫϭ when it is cool or late in the evening and leave it to cool overnight. ΩήΒΘϟ ϙήΘΗϭ ˬ ˯ΎδϤϟ΍ Ϧϣ ήΧ΄Θϣ Ζϗϭ ϲϓ ϭ΃ ΍ΩέΎΑ ϥϮϜϳ ΎϣΪϨϋ ΡΎΒμϟ΍ ϲϓ Ύϣ· ήϜΒϣ Ζϗϭ ϲϓ ϞϴλΎΤϤϟ΍ έΎϴΘΧϻ ϲϓ On larger farms, 'hydrocooling' is used to rapidly cool produce. .ΎϫΎΤοϭ Δϴθϋ ϦϴΑ Foods are sprayed with or .ΝΎΘϧ· ΔϋήδΑ ΩήΒΘϟ 'hydrocooling' ϡΪΨΘδϳ ˬ ΓήϴΒ Ϝϟ΍ ωέ΍ΰϤϟ΍ ΓέϮϤϐϤϟ΍ ϭ΃ ΔϤόσϷ΍ ϊϣ εέ ϢΘϳ submerged in chilled water produced by a refrigeration unit. Alternatively crushed ice can be used to make cold .ΪϳήΒΘϟ΍ ΓΪΣϭ ΎϬΠΘϨΗ ϲΘϟ΍ ΓΩήΒϤϟ΍ ϩΎϴϤϟ΍ ϲϓ This has a lower capital cost .ΩέΎΒϟ΍ ˯ΎϤϟ΍ ϞόΠϟ εϭήΠϤϟ΍ ΞϠΜϟ΍ ϡ΍ΪΨΘγ΍ ϦϜϤϳ ϚϟΫ Ϧϣ ϻΪΑ water. for the equipment and may be more suitable for growers that have smaller amounts of Ϫϟ ΍άϫϭ produce, provided that there is a reliable source of ice at a reasonable cost. ˬ Ϧϣ Γήϴϐλ ΕΎϴϤϛ ΞΘϨΗ ϲΘϟ΍ Ϧϴϋέ΍ΰϤϠϟ Δϣ˯ϼϣ ήΜϛ΃ ϥϮϜϳ ΎϤΑέϭ Ε΍ΪόϤϠϟ ΔΒδϨϟΎΑ ϝΎϤϟ΍ α΃έ ΔϔϠϜΗ νΎϔΨϧ΍ .ΔϟϮϘόϣ ΔϔϠϜΘΑ ΪϴϠΠϟ΍ Ϧϣ ϕϮΛϮϣ έΪμϣ ϙΎϨϫ ϥϮϜϳ ϥ΃ ρήθΑ un hydrocooling, produce is packed into wooden crates, mesh bags or perforated metal bins that are stacked on pallets to cause water to flow through and not around the ΔΒϘΜϣ ΔϴϧΪόϣ ϖϳΩΎϨλ ΔϴϜΒη αΎϴϛ΃ ϭ΃ ˬ ΔϴΒθΧ ϖϳΩΎϨλ ϲϓ Γ΄Βόϣ ϲϫ ΞΘϨΗ ˬ hydrocooling ϲϓ packages.

There are four different types .ϡΰΣ ϝϮΣ βϴϟϭ ϝϼΧ Ϧϣ ϖϓΪΘΘϟ ϩΎϴϤϟ΍ ΔϴπϘϟ ΕΎμϨϣ ϰϠϋ ΔγΪϜϣ ϥ΃ : hydrocoolers Ϧϣ ΔϔϠΘΨϣ ω΍Ϯϧ΃ ΔόΑέ΃ ϙΎϨϫϭ of hydrocoolers: Batch hydrocoolers have bins of produce loaded into an enclosure and chilled .1 1. ΔόϓΩ hydrocoolers water is sprayed over the produce, collected, re-cooled and recycled. ΓΩΎϋ·ϭ ΓΩήΒϤϟ΍ ΓΩΎϋ·ϭ ΎϬόϤΟϭ ΝΎΘϧ· ϝϼΧ ΓΩήΒϤϟ΍ ϩΎϴϤϟ΍ εέ ϢΘϳϭ ΔόϗϮϘϟ΍ ϰϟ· ΎϬϠϴϤΤΗ ΝΎΘ ϧ΍ Ϧϣ ϖϳΩΎϨλϭ They are relatively inexpensive and are suitable for growers that have a limited .ΎϫήϳϭΪΗ ΎϬϳΪϟ ϲΘϟ΍ Ϧϴϋέ΍ΰϤϠϟ ΔΒγΎϨϣϭ ΎϴΒδϧ ΔμϴΧέ ΎϬϧ΃ amount of produce or a short harvest season. .ήϴμϘϟ΍ ΩΎμΤϟ΍ ϢγϮϣ ϭ΃ ΕΎΠΘϨϤϟ΍ Ϧϣ ΓΩϭΪΤϣ ΔϴϤϛ Conveyor hydrocoolers pass containers of produce under a shower of chilled .2 2. ϰϠϋ ΓΩήΒϤϟ΍ ϩΎϴϤϟ΍ Ϧϣ ϞΑ΍ϭ ΖΤΗ ΝΎΘϧ· Ϧϣ ήϤΗ ΕΎϳϭΎΣ ΔϠϗΎϧ hydrocoolers water on a conveyor belt. However, because of the higher cost, this equipment must operate for long .ϞϗΎϨϟ΍ ϡ΍ΰΤϟ΍ ϞϤόΗ ϥ΃ ΐΠϳϭ ˬ ΔϔϠϜΘϟ΍ ωΎϔΗέ΍ ΐΒδΑ ˬ ϚϟΫ ϊϣϭ periods in a year to be economically justified. .ΎϳΩΎμΘϗ΍ ΍έήΒϣ ϥϮϜϴϟ ΔϨδϟ΍ ϲϓ ΔϠϳϮσ Ε΍ήΘϔϟ Ε΍ΪόϤϟ΍ ϩάϫ un immersion hydrocoolers, crates of produce are moved by a submerged .3 3. hydrocoolers ϲϓ conveyor through a large, shallow tank of recirculated chilled water. ΓΩήΒϤϟ΍ ϩΎϴϤϟ΍ Ϧϣ ΔϠΤο ΓήϴΒϛ ΔΑΎΑΩ ϝϼΧ Ϧϣ ΓέϮϤϐϤϟ΍ ϞϗΎϨϟ΍ ϞΒϗ Ϧϣ ΕΎΠΘϨϤϟ΍ Ϧϣ ϖϳΩΎϨλ ϞϘϧ ϢΘϳϭ ˬ ήϤϐϟ΍ This system produces more rapid cooling than other types because the water .ΎϬϤϴϤόΗ ϯήΧϷ΍ ω΍ϮϧϷ΍ Ϧϣ ϊϳήδϟ΍ ΪϳήΒΘϟ΍ Ϧϣ Ϊϳΰϣ ΞΘϨϳ ϡΎψϨϟ΍ ΍άϫ has greater contact with food surfaces. .˯΍άϐϟ΍ ΡϮτδϟ΍ ϊϣ ϝΎμΗϻ΍ ΓΩΎϳίϭ ˯ΎϤϟ΍ ϥϷ Truck hydrocooling involves loading produce onto an enclosed trailer and .4 4. ϞϴϤΤΗ ΝΎΘϧ· ϰϠϋ ϱϮτϨϳ hydrocooling ΔϨΣΎη inserting perforated pipes above the load. These produce a shower of chilled water, .ϞϴϤΤΗ ϕϮϓ ΔΑϮϘΜϣ ΐϴΑΎϧ΃ ϝΎΧΩ·ϭ ΔϘϠϐϤϟ΍ ΓέϮτϘϣ ˬ ΎϬόϤΟ ϢΘϳ ϲΘϟ΍ϭ ˬ ΩήΒϤϟ΍ ˯ ΎϤϟ΍ Ϧϣ εΩ ϩάϫ ΞΘϨΗ which is collected, re-cooled, and recycled. After cooling, the pipes are removed and the produce is .ΎϫήϳϭΪΗ ΓΩΎϋ·ϭ ˬ ϩΪϳήΒΗ ΓΩΎϋ·ϭ Truck hydrocoolers can be .ΝΎΘϧ· ϞϘϧ ϢΘϳϭ ΐϴΑΎϧϷ΍ Δϟ΍ί· ϢΘϳϭ ˬ ΪϳήΒΘϟ΍ ΪόΑ transported. constructed at a lower cost than a commercial hydrocooler, but the cooling times are ΔϳέΎΠΘϟ΍ hydrocooler Ϧϣ Ϟϗ΃ ΔϔϠϜΘΑ ΔϨΣΎη hydrocoolers Ύϫ΅ΎϨΑ ϦϜϤϳ longer than other designs. .ϯήΧ΃ ϢϴϣΎμΗ Ϧϣ ϝϮσ΃ ϥϮϜΗ ΪϳήΒΘϟ΍ Ε΍ήϣ ϦϜϟϭ ˬ ΔϋϮϤΠϣ ϙΎϨϫ There is a wide range of hydrocooling equipment available commercially. However, it is designed for high production .ΎϳέΎΠΗ ΔΣΎΘϣ hydrocooling Ε΍ΪόϤϟ΍ Ϧϣ Δόγ΍ϭ ΔϔϠϜϣ ΓΩΎϋϭ ΔϴϟΎϋ ΝΎΘϧ· ΕϻΪόϤϟ ΔϤϤμϣ ϲϫϭ ˬ ϚϟΫ ϊϣϭ rates and is generally very expensive. To be cost-effective, a hydrocooler must be used for as long as possible during .ΔϳΎϐϠϟ the harvest season and is only affordable by growers or co-operatives with large ϢγϮϣ ϝϼΧ ϦϜϤϣ ΔϠϳϮσ ΓήΘϔϟ hydrocooler ϡ΍ΪΨΘγ΍ ΐΠϳ ˬ ΔϔϠϜΘϟ΍ ΚϴΣ Ϧϣ ΔϟΎόϓ ϥϮϜΗ ϥ΃ acreages. A cheaper .ΓήϴΒϛ ΔϋϭέΰϤϟ΍ ϰο΍έϷ΍ ϊϣ ΕΎϴϧϭΎόΘϟ΍ ϭ΃ Ϧϴϋέ ΍ΰϤϟ΍ ϞΒϗ Ϧϣ ςϘϓ ΔϟϮϘόϣ έΎόγ΄Αϭ ΩΎμΤϟ΍ thermal storage immersion hydrocooler is described by Boyette, which is more suitable for growers that have smaller volumes and cannot invest in commercial ˬ hydrocooler Boyette ϲΘϟ΍ ϱέ΍ήΤϟ΍ Ϧϳΰ ΨΘϟ΍ ήϤϐϟ΍ κΧέ΃ ϒλϮϳ hydrocooling equipment. Ε΍ΪόϤϟ΍ ϲϓ ήϤΜΘδΗ ϻ ϥ΃ ϦϜϤϳϭ ˬ ϦϳΰΨΘϟ΍ Ε΍ΪΣϭ ήϐλ΃ ϲΘϟ΍ Ϧϴϋέ΍ΰϤϠϟ Δϣ˯ϼϣ ήΜϛ΃ Ϯϫ ϱάϟ΍ .ΔϳέΎΠΘϟ΍ hydrocooling

c : 4 %B?>5/5 D

Ϧϣϭ ut is not advisable to attempt conversion of an existing room to make a cold store. Cold stores should be purpose-built .ΓΩέΎΒϟ΍ ήΠΘϣ ϞόΠϟ ΔϤ΋ΎϘϟ΍ ΔϓήϏ ϞϳϮΤΗ ΔϟϭΎΤϣ ϦδΤΘδϤϟ΍ ήϴϏ using insulating materials to reduce the amount of heat that can enter the store through ΔϴϤϛ ϞϴϠϘΘϟ ΔϟίΎϋ Ω΍Ϯϣ ϡ΍ΪΨΘγΎΑ νήϐϟ΍ ΍άϬϟ ΖϴϨΑ ΪϳήΒΘϟ΍ ϥίΎΨϣ ϥϮϜΗ ϥ΃ ϲϐΒϨϳϭ the walls and ceiling. Most cold stores are now .ϒϘδϟ΍ϭ ϥ΍έΪΠϟ΍ ϝϼΧ Ϧϣ ϥΰΨϤϟ΍ ϞΧΪΗ ϥ΃ ϦϜϤϳ ϲΘϟ΍ Γέ΍ήΤϟ΍ Ϧϣ ΓΩέΎΒϟ΍ ήΟΎΘϤϟ΍ Ϣψόϣ ΕΪϴη ϲΘϟ΍ ϲϫ ϥϵ΍ constructed from prefabricated panels that have: : ΎϬϳΪϟ ϲΘϟ΍ ΓΰϫΎΠϟ΍ Ρ΍ϮϟϷ΍ ΓϮϘϟ΍ ϢϬΤϨϤϟ ΔγϮϤϠϣ ϭ΃ ϲϠϜϴϬϟ΍ ΫϻϮϔϟ΍ * * structural steel or concrete to give them strength * insulation (fibrous material such as rock wool or cellular plastics such as ϞΜϣ ΔϳϮϠΨϟ΍ Ϧ΋΍ΪϠϟ΍ ϭ΃ ϱήΨμϟ΍ ϑϮμϟ΍ ϞΜϣ Δϴϔϴϟ ΓΩΎϣ ) ϝΰϋ * polyisocyanurate) (polyisocyanurate Ϧϣ ΔϛήΤϟ΍ ϊϨϤϟ έΎΨΑ ΰΟΎΣ * * a vapour barrier to prevent movement of water vapour, and ϭ ˬ ˯ΎϤϟ΍ έΎΨΑ ϲΘϟ΍ ΔϴϠΧ΍Ϊϟ΍ϭ ΔϴΟέΎΨϟ΍ϭ * * an outer and inner facing material that is bonded to the core. The inner facing provides a hygienic, easily cleaned .ϢϴϤμϟ΍ ϲϓ ϦϳΪΒόΘδϤϟ΍ ϲΘϟ΍ Ω΍ϮϤϟ΍ ϪΟ΍ϮΗ ϪΟ΍ϮΗ ϲΘϟ΍ ΔϴϠΧ΍Ϊϟ΍ surface and the outer facing provides protection against the weather. .βϘτϟ΍ Ϊο ΔϳΎϤΤϟ΍ ήϓϮϳ ϪΟ΍ϮΗϭ ϲΟέΎΨϟ΍ ΢τδϟ΍ ΔϟϮϬδΑ ΎϬϔϴψϨΗϭ ˬ ΔϓΎψϨϟ΍ ήϓϮΗ The .ΔγϮϤϠϣ ΓΪϋΎϗ ϰϠϋ ΖϤϴϗ΍ ϲΘϟ΍ϭ ΕΎΣϮϟ The panels are erected on a concrete base. insulated door to the cold store is close-fitting to minimise leakage of heat, and it may be fitted with plastic curtain strip or an 'air curtain' to reduce the amount of cold air Ϧϣ ΔΒϳήϗ ΓΩέΎΒϟ΍ ϦϳΰΨΘϟ ϝϭΰόϣ ΏΎΒϟ΍ that can escape from the store when the door is opened. ΔϴϤϛ ϞϴϠϘΘϟ ˯΍ϮϬϟ΍ ΓέΎΘγ ' ϭ΃ ΔϴϜϴΘγϼΑ ΓέΎΘγ ωΎτϗ ΓΩϭΰϣ ϥϮϜΗ Ϊϗ ΎϬϧ΃ϭ ˬ Γέ΍ήΤϟ΍ ΏήδΗ Ϧϣ ΪΤϠϟ ΐγΎϨϤϟ΍ A refrigeration unit inside the store . ΏΎΒϟ΍ ΢Θϓ ϢΘϳ ΎϣΪϨϋ ϥΰΨϣ Ϧϣ ΏϭήϬϟ΍ ϦϜϤϳ ϲΘϟ΍ ΩέΎΒϟ΍ ˯΍ϮϬϟ΍ is fitted with fans to recirculate air (Fig. 1) to give the required temperature range, (1 ϞϜθϟ΍) ˯΍ϮϬϟ΍ ϊϳίϮΗ ΓΩΎϋ· ϦϴόΠθϤϟ΍ ΓΩϭΰϣ ϞΤϤϟ΍ ϞΧ΍Ω ΪϳήΒΘϟ΍ ΓΪΣϭ controlled by a thermostat. .Γέ΍ήΤϟ΍ ΎϬϴϠϋ ήτϴδ ϳ ϲΘϟ΍ϭ ˬ ΔΑϮϠτϤϟ΍ Γέ΍ήΤϟ΍ ΕΎΟέΩ ϕΎτϧ ˯ΎτϋϹ

$K )$-F A packing system is required in the store so that produce can be loaded and unloaded This .ϥΎϣ΃ϭ ΔϟϮϬδΑ ΞΘϨΗ ώϳήϔΗϭ ϞϴϤΤΗ ϦϜϤϳ ΚϴΤΑ ϥΰΨϤϟ΍ ϲϓ ΔΌΒόΘϟ΍ ϡΎψϧ ΏϮϠτϣ easily and safely. system can involve stacked crates or a more complicated system using racks and For small- .Ν΍έΩϷ΍ϭ ϑϮϓήϟ΍ ϡ΍ΪΨΘγΎΑ ΍ΪϴϘόΗ ήΜϛ΃ ϡΎψϧ ϭ΃ ΔγΪϜϣ ϖϳΩΎϨλ ϞϤθΗ ϡΎψϨϟ΍ ΍άϫ ϦϜϤϳ trays. ΩέΎΑ ϦϳΰΨΘϟ scale cold storage, stackable crates are the most appropriate packing system. The layout of crates in the store needs .ΔΌΒόΘϟ΍ ϡΎψϧ ΐδϧ΃ ϲϫ ϖϳΩΎϨμϟ΍ ϢϳϮϜΗ ˬ ήϴϐλ ϕΎτϧ ϰϠϋ to be simple and clearly understood by operators so that produce can be loaded or ΢ο΍ϭ ϞϜθΑ ΎϣϮϬϔϣϭ ΎτϴδΑ ϥϮϜϳ ϥ΃ ΐΠϳ ϥΰΨϣ ϲϓ ϖϳΩΎϨμϟ΍ ςϴτΨΗ removed easily and quickly. ut is important that the crates .ΔϋήδΑϭ ΔϟϮϬδΑ ΎϬΘϟ΍ί· ϭ΃ ΎϬϠϴϤΤΗ ϦϜϤϳ ΞΘϨΗ ΚϴΤΑ ϦϴϠϐθϤϟ ΍ ϞΒϗ Ϧϣ are small enough to be moved easily when full of crop; that the crop cannot be crushed by stacking crates; and that the crates are strong enough to support the weight ϲϔϜϳ ΎϤΑ Γήϴϐλ ϲϫ ϖϳΩΎϨμϟ΍ ϩάϫ ϥ΃ ϢϬϤϟ΍ Ϧϣϭ of other crates above them without collapsing. ϲΘϟ΍ ϖϳΩΎϨμϟ΍ϭ ˬ ϖϳΩΎϨμϟ΍ ι΍ήΘϟ΍ ϪϘΤδΘγ ϝϮμΤϤϟ΍ ϥ΃ ϦϜϤϳ ϻ ΍άϫϭ ˬ ϞϴλΎΤϤϠϟ ϞϣΎϛ ΎϣΪϨϋ ΔϟϮϬδΑ ΎϬϠϘϨϟ To maintain the airflow around .έΎϴϬϧϻ΍ ϥϭΩ ΎϬϗϮϓ ϯήΧ΃ ϖϳΩΎϨλ Ϧϣ ϥίϮϟ΍ ϢϋΪϟ ϲϔϜϳ ΎϤΑ ΔϳϮϗ ϲϫ crates, a 60 cm gap should be left between the storeroom walls and the crates, and a ˯΍ϮϬϟ΍ ϖϓΪΗ ϰϠϋ υΎϔΤϠϟ 90 cm gap between the crates, the ceiling and the refrigeration unit. ϦϴΑ Ϣγ 90 ΓϮΠϓ ϙΎϨϫϭ ˬ ϖϳΩΎϨλϭ ϥΰΨϣ ϥ΍ έΪΠϟ΍ ϦϴΑ Ϣγ 60 ΓϮΠϓ ϙήΘΗ ϥ΃ ϲϐΒϨϳ ˬ ϖϳΩΎϨμϟ΍ ϝϮΣ 2 shows a design of crate that is suitable for cold .ϦϴΘϟ΍ Fig. .ΪϳήΒΘϟ΍ ΓΪΣϭ ϒϘγϭ ˬ ϖϳΩΎϨμϟ΍ These can be made locally from .ΪϳήΒΘϟ΍ ϥίΎΨϤϟ ΔΒγΎϨϣ ϲϫ ϲΘϟ΍ κϔϗ ϢϴϤμΗ ήϬψϳ 2 stores. ϦϜϤϳϭ wood, or plastic (polypropylene) crates may be available from import agents.

uf .Ω΍ήϴΘγϻ΍ ˯ϼϛϭ Ϧϣ ΔΣΎΘϣ ϥϮϜΗ Ϊϗ ϖϳΩΎϨμϟ΍ (ϦϴϠΑϭήΑ ϲϟϮΒϟ΍ ) ϚϴΘγϼΒϟ΍ ϭ΃ ΐθΨϟ΍ Ϧϣ ΎϴϠΤϣ ϩάϫ ˯΍ήΟ· the produce can be transported to market in the same crates that they are stored in, this ϲϓ ϕϮδϟ΍ ϰϟ· ΕΎΠΘϨϤϟ΍ ϞϘϧ ϦϜϤϳ ϥΎϛ ΍Ϋ· reduces handling and possible damage to the crop. .ϞϴλΎΤϤϟ΍ ϰϠϋ ΔϠϤΘΤϤϟ΍ έ΍ήοϷ΍ Ϧϣ ϞϠϘϳ ΍άϫϭ ΔϟϭΎϨϤϟ΍ϭ ϲϓ ΎϬϨϳΰΨΗ ϢΘϳ ϲΘϟ΍ ϖϳΩΎϨμϟ΍ βϔϧ ΩέΎΒϟ΍ ϦϳΰΨΘϠϟ ΔϣΪΨΘδϤϟ΍ κϔϗ ϲΟΫϮϤϧ MLB5 LM Typical crate used for cold storage ΓΩϭΪΤϤϟ΍ ϱΩ΍ϭ ΔγΪϨϬϠϟ ΔϠϣΎΠϣ Courtesy of Valley Engineering Ltd.

Δϳ΅ήϟ ϞϣΎϜϟ΍ ϲΒόθϟ΍ έ΍ΪλϹ΍ ϞϴϤΤΗ Download the full PDF version to see this photograph. .ΓέϮμϟ΍ ϩάϫ

NO:4,$0 !"# ϢΘϳ Cold stores are cooled by circulation of cold air produced by refrigeration units. All cold stores should .ΪϳήΒΘϟ΍ Ε΍ΪΣϭ ΎϬΠΘϨΗ ϲΘϟ΍ ΓΩέΎΒϟ΍ ˯΍ϮϬϟ΍ ϥ΍έϭΩ Δτγ΍ϮΑ ΪϳήΒΘϟ΍ ϥίΎΨϣ ΪϳήΒΗ lower the temperature of crops as quickly as possible through the 'warm zone' (50 ±> ΪϳήΒΘϟ΍ ϥίΎΨϣ ϊϴϤΠϟ ϲϐΒϨϳϭ 10°C) where maximum growth of micro-organisms occurs. (ΔϳϮΌϣ ΔΟέΩ 10 <-- 50) 'ΓέΎΤϟ΍ ΔϘτϨϣ ' ϝϼΧ Ϧϣ ϦϜϤϣ Ζϗϭ ωήγ΃ ϲϓ ϞϴλΎΤϤϟ΍ Ϧϣ Γέ΍ήΤϟ΍ ΔΟέΩ ξϔΧ Not all foods can be chilled to low temperatures .ΙΪΤϳ ΔϘϴϗΪϟ΍ ΕΎϨ΋ΎϜϟ΍ ϮϤϨϟ ϰμϗϷ΍ ΪΤϟ΍ ΚϴΣ and some tropical, subtropical and temperate fruits suffer from 'chilling injury' at 3 Δϴ΋΍ϮΘγϻ΍ ϪΒηϭ Δϴ΋΍ϮΘγϻ΍ Ϫϛ΍Ϯϔϟ΍ ξόΑϭ ΔπϔΨϨϣ Γέ΍ήΣ ΕΎΟέΪϟ ΔϤόσϷ΍ Ϟϛ Ζδϴϟ ΓΩήΒϣ ϦϜϤϳϭ 10°C. This causes a range of effects, .ΔϳϮΌϣ ΔΟέΩ 10 ϲΘΣ 3 ϲϓ Ϧϣ ' ΪϳήΒΘϟ΍ έ΍ήο΃' ϥϮϧΎόϳ ΔϟΪΘόϤϟ΍ϭ including browning or discolouration, the development of off-flavours and excessive ήϴϏ ΔϬϜϧ ϊοϭϭ ˬ ϥϮϠϟ΍ ήϴϴϐΗ ϭ΃ έ΍ήϤΣϻ΍ ϚϟΫ ϲϓ ΎϤΑ ˬ έΎΛϵ΍ Ϧϣ ΔϋϮϤΠϣ ϰϟ· ϱΩΆϳ ΍άϫ softening. The storage temperature always has to be above the minimum .ΔσήϔϤϟ΍ ϦϴϴϠΗϭ ΔΑϮϏήϣ temperature and care is needed to set the store thermostat so that the cooling system ΔΟέΩ does not produce any oscillation in temperature below the minimum temperature. Γέ΍ήΤϟ΍ ςΒπϟ ΔΟΎΣ ϙΎϨϫϭ ΔϳΎϋήϟ΍ Ϧϣ ϰϧΩϷ΍ ΪΤϟ΍ Ϧϣ ϰϠϋ΃ Γέ΍ήΤϟ΍ ΔΟέΩ ϥϮϜΗ ϥ΃ ΎϤ΋΍Ω ϦϳΰΨΘϟ΍ Γέ΍ήΣ ut can be seen .ΎϴϧΪϟ΍ Γέ΍ήΤϟ΍ Ϧϣ ϰϧΩ΃ Γέ΍ήΤϟ΍ ΕΎΟέΩ ϲϓ ΏάΑάΘϟ΍ ϱ΃ ΞΘϨΗ ϻ ΪϳήΒΘϟ΍ ϡΎψϧ ϦϳΰΨΗ ΚϴΤΑ from Table 2 that there are basically three groups of fruit and vegetables: those stored at 0 - 4°C; those stored at 4 - 8°C; and those that require a storage temperature above ϲϓ ΔϧΰΨϤϟ΍ ϚϠΗ : Ε΍ϭήπΨϟ΍ϭ Ϫϛ΍Ϯϔϟ΍ Ϧϣ ΕΎϋϮϤΠϣ ΙϼΛ ΎγΎγ΃ ϙΎϨϫ ϥ΃ 2 ϝϭΪΠϟ΍ Ϧϣ ϯήϳ ϥ΃ ϦϜϤϳϭ 8°C. 8 ϩϼϋ΃ ϦϳΰΨΘϟ΍ Γέ΍ήΣ ΔΟέΩ ΐϠτΘΗ ϲΘϟ΍ ϚϠΗϭ ˬ ΔϳϮΌϣ ΔΟέΩ 8 ϲΘΣ 4 ϲϓ ΔϧΰΨϤϟ΍ ϚϠΗϭ ˬ ΔϳϮΌϣ ΔΟέΩ 4-0 For storage of mixed crops in a single cold store it is important that the .ΔϳϮΌϣ ΔΟέΩ ϦϳΰΨΗ ϲϓ ΔτϠΘΨϤϟ΍ ϞϴλΎΤϤϟ΍ ϦϳΰΨΘϟ crops should have similar temperature requirements. Table 2 also shows .ΔϠΛΎϤϣ Γέ΍ήΣ ΔΟέΩ ΕΎΒϠτΘϣ ϥϮϜϳ ϥ΃ ϲϐΒϨϳ ϞϴλΎΤϤϟ΍ ϥ΃ ϢϬϤϟ΍ Ϧϣ ΓΪΣ΍ϭ ΓΩέΎΑ control of humidity and cooling methods needed to achieve the required storage life ΓΎϴΤϟ΍ ϖϴϘΤΘϟ Δϣίϼϟ΍ ΪϳήΒΘϟ΍ ϕήσϭ ΔΑϮσήϟ΍ ϰϠϋ Γήτϴδϟ΍ Ύπϳ΃ 2 ϝϭΪΠϟ΍ ϦϴΒϳϭ for different crops. .ΔϔϠΘΨϤϟ΍ ϞϴλΎΤϤϠϟ ΔΑϮϠτϤϟ΍ ϦϳΰΨΘϟ΍

!"# $A There is always some moisture loss from fruits and vegetables during cold storage but ˯ΎϨΛ΃ Ε΍ϭήπΨϟ΍ϭ Ϫϛ΍Ϯϔϟ΍ Ϧϣ ΔΑϮσήϟ΍ ϥ΍ΪϘϓ ξόΑ ΎϤ΋΍Ω ϙΎϨϫ excessive moisture loss is a problem.

ut is prevented by keeping the humidity of .ΔϠϜθϣ ΔΑϮσήϟ΍ ϥ΍ΪϘϓ ϲϓ ρ΍ήϓϹ΍ ϦϜϟϭ ΓΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ .̃ 85 ϕϮϓ ϥΰΨϣ ϲϓ ˯΍ϮϬϟ΍ Ϧϣ ΔΑϮσήϟ΍ ϰϠϋ υΎϔΤϟ΍ ϖϳήσ Ϧϋ ΖόϨϣϭ air in the store above 85%. ϦϴΒϳϭ Table 2 shows specific storage humidities for different fruits and vegetables. Moisture loss can be reduced by .Ε΍ϭήπΨϟ΍ϭ Ϫϛ΍Ϯϔϟ΍ ϒϠΘΨϤϟ ΓΩΪΤϣ ϦϳΰΨΗ ΔΑϮσήϟ΍ 2 ϝϭΪΠϟ΍ allowing the crop to cool to the storage temperature and then covering it in plastic, or ΡΎϤδϟ΍ ϝϼΧ Ϧϣ ΔΑϮσήϟ΍ ϥ΍ΪϘϓ ϞϴϠϘΗ ϦϜϤϳϭ sprinkling the crop with water before storage. ut .ϦϳΰΨΘϟ΍ ϞΒϗ ˯ΎϤϟΎΑ ϞϴλΎΤϤϟ΍ εέ ϭ΃ ˬ ϚϴΘγϼΒϟΎΑ ΎϬΘϴτϐΗ ϢΛ Ϧϣϭ ϦϳΰΨΘϟ΍ Γέ΍ήΣ ΔΟέΪϟ ΪϳήΒΘϟ ϝϮμΤϤϠϟ is not advisable to sprinkle water during storage because this increases ice formation ΪϴϠΠϟ΍ ϦϳϮϜΗ Ϧϣ Ϊϳΰϳ ΍άϫ ϥϷ ϦϳΰΨΘϟ΍ ˯ΎϨΛ΃ ˯ΎϤϟ΍ εήϳ ϥ΃ ϦδΤΘδϤϟ΍ Ϧϣ βϴϟ in the refrigeration unit. ut is important to maintain an adequate circulation of air using fans, and .ΪϳήΒΘϟ΍ ΓΪΣϭ ϲϓ foods are therefore stacked in ways that enable air to circulate freely around all sides and avoid the risk of spoilage by moulds if 'dead-spots' permit localised increases in ϲϓ ΔγΪϜϣ ΔϤόσϷ΍ ϲϟΎΘϟΎΑϭ ˬ Ρϭ΍ήϤϟ΍ ϡ΍ΪΨΘγΎΑ ˯΍ϮϬϟ΍ Ϧϣ ΔϴϓΎϛ ϝ ϭ΍ΪΗ ϰϠϋ υΎϔΤϠϟ ϢϬϤϟ΍ ϦϤϓ humidity. 'ϊϘΒϟ΍ ΎΘϴϣ ' ΍Ϋ· ΐϟ΍Ϯϗ Δτγ΍ϮΑ ϒϠΘϟ΍ ήτΧ ΐϨΠΗϭ ϑ΍ήσϻ΍ Ϟϛ ϝϮΣ ΔϳήΤΑ ϢϴϤόΘϟ ˯΍ϮϬϟ΍ ϦϜϤΗ ϲΘϟ΍ ϕήτϟ΍ .ΔΑϮσήϟ΍ ΔΒδϧ ϲϓ Ε΍ΩΎϳί ΔϤΟήΘϤϟ΍ ΢ϳήμΗ

P?Q24*?@R/0S !2:4%G &"4 GHTU %NO Aeducing the level of oxygen in the atmosphere of a cold store (either with or without Ϧϣ ΪΤϟ΍ ϦϜϤϳ increasing the level of carbon dioxide) can extend the life of the crop. ΔϟΎσ· (ϥϮΑήϜϟ΍ Ϊϴδϛ΃ ϲϧΎΛ ϯϮΘδϣ ΓΩΎϳί ϥϭΪΑ ϭ΃ ϊϣ Ύϣ· ) ΩέΎΒϟ΍ ϦϳΰΨΘϟ ϱϮΠϟ΍ ϑϼϐϟ΍ ϲϓ ϦϴΠδϛϷ΍ ϯϮΘδϣ ut slows down spoilage, destroys insects and prevents mould growth .ϝϮμΤϤϟ΍ ήϤϋ ϊϨϤϳϭ Ε΍ήθΤϟ΍ ήϣΪϳϭ ˬ ϒϠΘϟ΍ ΊτΒϳ Ϫϧ΃ without the need for treatment with toxic fumigants. However, different types of crop, and even .ΔϣΎδϟ΍ Ε΍ήϬ τϣ ϊϣ ΝϼόϠϟ ΔΟΎΤϟ΍ ϥϭΩ Ϧϔόϟ΍ ϮϤϧ different cultivars of the same species, require different atmospheres for successful Ϧϣ ΔϔϠΘΨϣ ω΍Ϯϧ΃ ˬ ϚϟΫ ϊϣϭ storage, and each therefore needs to be independently assessed. Ϟϛ ϲϟΎΘϟΎΑϭ ˬ ΔΤΟΎϧ ϦϳΰΨΘϟ ΔϔϠΘΨϣ ˯΍ϮΟ΍ ΐϠτΘΗ ˬ ωϮϨϟ΍ βϔϧ Ϧϣ ϰΘΣ ΔϔϠΘΨϣ ϑΎϨλ΃ϭ ˬ ϞϴλΎΤϤϟ΍ uf the oxygen concentration is too low, it can .ϞϘΘδϣ ϞϜθΑ ΎϬϤϴϴϘΗ ϢΘϴγ ϲΘϟ΍ ΕΎΟΎϴΘΣϻ΍ ϥΎϛ ΍Ϋ· produce off-flavours or discolouration in some types of fruits and vegetables. Ϫϛ΍Ϯϔϟ΍ ω΍Ϯϧ΃ ξόΑ ϲϓ ϥϮϠϟ΍ ήϴϴϐΗ ϭ΃ ΕΎϬϜϨϟ΍ ΝέΎΧ ΞΘϨΗ ϥ΃ ϦϜϤϳϭ ˬ ΍ΪΟ ΔπϔΨϨϣ ϦϴΠδϛϭϷ΍ ΰϴϛήΗ But the main disadvantages of controlling the cold store atmosphere are .Ε΍ϭήπΨϟ΍ϭ economic: the costs of setting up a controlled-atmosphere store and the cost of monitoring the gas composition are both high (twice those of normal cold storage); unless high-value, short-season crops are stored, which substantially increase in price ϰϠϋ Γήτϴδϟ΍ ΏϮϴϋ Ϣϫ΃ ϦϜϟ out of season, it may be difficult to justify the additional costs. ϰϠϋ ίΎϐϟ΍ ϦϳϮϜΗ Ϊλήϟ΍ ϒϴϟΎϜΗϭ ϱϮΠϟ΍ ϑϼϐϟ΍ϭ ΔΑΎϗήϠϟ ϥΰΨϣ ˯Ύθϧ· ϒϴϟΎϜΗ : ΔϳΩΎμΘϗϻ΍ ϦϳΰΨΗϭ ΩέΎ Βϟ΍ ϮΠϟ΍ ϞϴλΎΤϤϟ΍ ϦϳΰΨΗ ϢΘϳ Γήϴμϗ ˬ ΔϤϴϘϟ΍ ΔϴϟΎϋ Ϣϟ Ύϣ ˬ (ϱΩΎόϟ΍ ΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ ϚϠΗ Ϧϣ ϦϴΗήϣ ) ΔϴϟΎϋ ˯΍Ϯγ ΪΣ Also the .ΔϴϓΎο· ϒϴϟΎϜΗ ήϳήΒΗ ΐό μϟ΍ Ϧϣ ϥϮϜϳ Ϊϗ ˬ ϢγϮϤϟ΍ Ϧϣ ήόδϟ΍ ϲϓ ήϴΒϛ ϞϜθΑ Ϊϳΰϳ ΎϤϣ ˬ ϢγϮϤϟ΍ store has to be fully used by a single crop, because of the different gas compositions required by different crops, and there may be competition from other producing areas ϚϟΫϭ ˬ ΪΣ΍ϭ ϝϮμΤϣ ϞΒϗ Ϧϣ ϞϣΎϜϟΎΑ ΎϬϣ΍ΪΨΘγ ϻϭ ϦϳΰΨΗ Ύπϳ΃ that have different harvest seasons. ΔΠΘϨϤϟ΍ ϖσΎϨϤϟ΍ Ϧϣ ΔδϓΎϨϤϟ΍ ϥϮϜΗ Ϊϗ ϙΎϨϫϭ ˬ ΔϔϠΘΨϤϟ΍ ϞϴλΎΤϤϟ΍ ΎϬΒϠτΘΗ ϲΘϟ΍ ΔϔϠΘΨϤϟ΍ ίΎϐϟ΍ ΔΒϴϛήΗ ΐΒδΑ For these reasons, it is unlikely that controlled- .ΩΎμΤϟ΍ Ϣγ΍Ϯϣ ϒϠΘΨΗ ϲΘϟ΍ ϯήΧϷ΍ ϩάϬϟ atmosphere cold stores will be suitable for producers in developing countries. ϥ΍ΪϠΒϟ΍ ϲϓ ϦϴΠΘϨϤϠϟ ΔΒγΎϨϣ ϥϮϜΗ ϑϮγϭ ΪϳήΒΘϟ΍ ϥίΎΨϣ ˯΍ϮΟ΃ ΎϬϴϠϋ ήτϴδΗ ϥ΃ ΢ΟήϤϟ΍ ήϴϏ ϦϤϓ ˬ ΏΎΒγϷ΍ .ΔϴϣΎϨϟ΍ When operated at the correct temperature and optimum conditions for a particular ϞϤόΗ ΖϧΎϛ ΎϣΪϨϋ crop, cold storage causes little change to the quality or nutritional value. ϭ΃ ΔϴϋϮϧ ϲϓ ήϛάϳ ήϴϴϐΗ ΐΒδϳ ΩέΎΒϟ΍ ϦϳΰΨΘϟ΍ ˬ Ϧϴόϣ ϝϮμΤϤϟ ϰϠΜϤϟ΍ ϑϭήψϟ΍ϭ ΔΤϴΤμϟ΍ Γέ΍ήΤϟ΍ ΔΟέΩ ϲϓ

However, over-long storage times, incorrect temperatures and damage to .Δϴ΋΍άϏ ΔϤϴϗ crops can cause significant changes, including browning, wilting and weight loss due ΕΎΟέΩϭ ΔϠϳϮτϟ΍ ΕΎϗϭϷ΍ Ϧϣ ήΜϛ΃ ϦϳΰΨΗ ϦϜϤϳ ˬ ϚϟΫ ϊϣϭ to evaporation of water from crops. ΞϨϧϭ΍ήΑ ˬ ϝϮΑάϟ΍ ϚϟΫ ϲϓ ΎϤΑ ˬ ΓήϴΒϛ Ε΍ήϴϐΗ ΐΒδΗ ϞϴλΎΤϤϟΎΑ ΖϘΤϟ ϲΘϟ΍ έ΍ήοϷ΍ϭ ΔΤϴΤλ ήϴϏ Γέ΍ήΤϟ΍ Losses of vitamin C in fruits and vegetables .ϞϴλΎΤϤϟ΍ Ϧϣ ˯ΎϤϟ΍ ήΨΒΗ ΐΒδΑ ϥίϮϟ΍ ϥ΍ΪϘϓϭ Ϫϛ΍Ϯϔϟ΍ ϲϓ (Ν) ϦϴϣΎΘϴϓ Ϧϣ ή΋ΎδΧ depend on temperature management after harvest. Losses are accelerated by higher storage .ΩΎμΤϟ΍ ΪόΑ Γέ΍ήΤϟ΍ ΔΟέΩ Γέ΍Ω· ϰϠϋ ΪϤΘόΗ Ε΍ϭήπΨϟ΍ϭ temperatures and longer storage times, and conditions that cause moisture loss after ϦϳΰΨΘϟ΍ϭ Γέ΍ήΤϟ΍ ΕΎΟέΩ ωΎϔΗέ΍ ϲΘϟ΍ ή΋ΎδΨϟ΍ ωέΎδΗϭ harvest, especially in leafy vegetables. .ΔϴϗέϮϟ΍ έΎπΨϟ΍ ϲϓ ΔλΎΧϭ ˬ ΩΎμ Τϟ΍ ΪόΑ ΔΑϮσήϟ΍ ϥ΍ΪϘϓ ϲϓ ΐΒδΘΗ ϲΘϟ΍ ϑϭήψϟ΍ϭ ˬ ϝϮσ΃ ΕΎϗϭ΃ ϦϳΰΨΗ Losses are also accelerated by bruising and other injuries and by excessive trimming. .ρήϔϤϟ΍ ΐϳάθΘϟ΍ϭ ΕΎϣΪϛ Ϧϣ ΎϫήϴϏϭ ΕΎΑΎλϻ΍ Ϧϣ ή΋ΎδΧ Ύπϳ΃ ΖϋέΎδΗϭ

Cold Storage of Fruit and Vegetables

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