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Chapter 6: Loss and waste at wholesale and retail markets • 85

Chapter 6

Loss and waste atwholesale and retailmarkets

6.0 IntroductionWholesale and retail markets varygreatly in their complexity andcapacity. Losses and wastes in thesemarkets can also vary widely. Thewholesale marketing of fruits,vegetables, meat, fish, dairy productsand canned foods operate on arelatively well-organized basis even inrural parts of developing countries.However, the same is not always truewhen trading and selling cereals, grainsand legumes. Cold storage facilities areprovided for fish, meat and dairyproducts even in the remotest areas, toensure that they are stored properlyand maintained in good condition.However, complete loss of produce canoccur when handling and marketingmeat, fish and dairy products wheresuitable storage facilities are notavailable.

If properly dried, cereal grains andlegumes can be stored for long periodsbut, unfortunately, they are not alwaysgiven the care and attention required.Drying is sometimes inadequate andresults in the product becomingmouldy during long-term storage,particularly under humid conditions.High levels of loss are typical whenhandling and marketing fruits andvegetables. Special arrangements forstorage are rarely provided atmarketing centres, even in the urbanareas of most developing countries.

Canned products are usually sold inshops or held in store where they are

kept away from excessive heat, forexample, from the direct heat of thesun. That said, in some cases cannedgoods can be found displayed in opensheds and stalls in full sunlight. It takeslittle training to provide the informationrequired of market traders or shop-keepers to explain the hazardsinvolved with the storage of cannedgoods under hot conditions, and thusto minimize the damage caused bythese practices.

6.1 Cereals and legumesWholesale markets are markets atwhich grains are collected fordistribution to retailers and others.Processing may also be undertakenwhere grain is dried (in the sun and/orin artificial driers), treated (withchemical insecticides, etc.) and storedover a period of time - usually in a siloor purpose-built grain store - and thensold. Storage and processing atwholesale level is complex and well-structured, such that losses are kept toa minimum. People working at thislevel are usually qualified and well-trained, with a basic knowledge ofgrain processing, handling and storage.In most cases, a complement ofpractical auxiliary staff will also beavailable to provide, for example,transport, materials handling,secretarial services and maintenanceand repair services.

Storage at retail level is not as well-organized or as controlled. Here,market stalls and other temporary

Losses and wastes in the food chain • 86

structures normally serve as storageareas. The length of storage may not beconsistent and may vary greatly - froma period of a few days to severalmonths. Storage is normally handledby market women and traders at retaillevel. With no formal training in grainhandling and storage, there can behigh losses and degradation of qualityand, it follows, serious consequencesfor both consumer and trader alike.

6.1.1 Losses and wastes atwholesale markets

Losses at wholesale markets are mainlydue to spillage during handling, forexample, when taking delivery orshipping the goods out-of-the-market.On arrival, bagged grain is emptiedinto a reception pit from where it maybe elevated to a pre-cleaner, a graincleaner and/or a dryer. Treatment withan insecticide is usually carried outbefore the grain is loaded into silo orstore. Losses at reception includespillage from improper handling of thebagged produce, contamination frommouldy grain due to prolonged storagein humid conditions, and insectdamage. Losses due to insect damageare normally controlled with theapplication of well-proven pest controlmeasures undertaken by well-trainedtechnicians and experienced workers.With effective management andsupervision, it is possible to keeplosses to a minimum. In most casessilos and other storage structures arecorrectly installed and monitored.Grain is normally handled and sold inbags, because the bag serves as acontainer and a unit of measure.Moreover, a sack can be handled easilyby one or two people and transportedeasily by bus, truck or bicycle. Otherlosses include:

6.1.1.1 Transfer of moisture withinbulk grain stored in metalsilos

Alternating heating and cooling of

metal silos in warm humid tropicalconditions often results in moisturetransfer from within the bulk grain,from the warmer areas to the coolerareas of the bulk load. If this persistswithout checks or correction, thenthere will be a net gain of moisture intothe cooler areas of the bulk load,resulting in damp and mouldy grain.

6.1.1.2 Condensation on metal silowalls

Sometimes the cooling of the walls ofmetal silos can be such thatcondensation will form on the insidewall of the cooler parts of the silo.Grain coming into contact with theseareas may become caked and mouldy.Proper monitoring of the condition ofproduce within the silo will preventthis happening. This includes regularturning and aeration of stored grains.

6.1.1.3 Rodents and birds inwarehouses

Rodents and birds should be preventedfrom entering the store. Not only dothey eat the produce and damage thestorage containers, but they alsocontaminate it with faeces, urine,feathers or fur. Sometimes the grainbecomes contaminated from carcassesof animals and birds that have becometrapped in the silos. Designers andbuilders of storage facilities normallygive routine attention to proofingagainst rodents and birds.

6.1.1.4 TheftTheft can be minimized by theinstallation of adequate securitymeasures. Entry points should beproperly secured and securitypersonnel posted during workinghours to ensure that no produce leavesthe store without proper recordscovering departure. Stores should belocked after working hours.

6.1.1.5 Damaged bagsRe-use of bags over long periods often


results in the deterioration of the bagsfrom wear-and-tear with consequentspillage of produce. Re-used bagsshould be regularly checked forweakness and replaced to avoid losses.

6.1.1.6 InsectsInsect damage to cereals and legumescan begin in the field and persistthrough into storage. Treatment withan appropriate insecticide and theprovision of proper storage conditionsshould ensure that losses due to insectsare kept to a minimum.

6.1.2 Guidelines for wholesalemarkets

Some appropriate guidelines havebeen already been discussed inChapter 5 for ‘Loss and Wastage duringStorage’ and are equally applicablehere. In summary, the followingprecautions should be taken tominimise losses in warehouses:1. Adequate grain drying, handling

and storage facilities should beprovided. During peak operationprolonged storage should beavoided to prevent the grain frombecoming mouldy.

2. Stored produce should be inspectedand monitored continuously, andremedial action taken whenrequired to reduce spoilage.

3. Pest control measures should beproperly followed to ensure thatspoilage of stored produce is keptto a minimum.

4. Adequate security measures shouldbe introduced to reduce theincidence of theft.

5. All silos and warehouses should beregularly checked and adequatelysealed to prevent rodents and birdsfrom gaining access to storedfoods.

6.1.3 Losses and wastes at retailmarkets

Retail markets rarely have any specialfacilities available for handling and

storing grains and legumes, and lossesat this level are comparable to thosefound in transit storage. Produce atretail markets is normally in transitfrom the producer to the consumer.

Loss and wastage at retail marketsincludes:1. Spillage from torn bags, containers

and other grain handling facilities.2. Rodent damage – including losses

due to eaten (and partially eaten)grain, contamination fromdroppings, urine, hair, etc. and thecarcasses of dead rodents.

3. Insect damage. Found where pestcontrol measures are not adequate.

4. Mouldiness - resulting fromprolonged storage of poorly driedgrain.

5. Loss of nutritive value fromprolonged storage under harsh andinappropriate conditions.

6. Losses due to theft.

6.1.4 Guidelines for retail markets1. Pest control measures are

recommended to ensure that lossesdue to pests (e.g. insects, rodentsand birds) are reduced.

2. Store rooms should be fumigated atleast once a year to control rodentsand insects.

3. Under tropical conditions, storagerooms should be well-ventilated toreduce heat accumulation and toprovide for aeration.

4. Storage at retail markets should beproperly organized and marketstalls should be designed toaccommodate the temporarystorage of unsold stock.

5. Bags should be replaced as often aspracticable to prevent re-infestationof fresh produce with pests fromrecycled bags, and to preventspillage from worn out and/ordamaged bags.

6. Standards and grading of produceshould be encouraged. Farmersand traders will normally strive for


higher standards when goodquality produce receives premiumprices.

7. Security in markets should bemaintained to prevent pilferageand loss due to theft.

6.2 Roots,Tubers, plantains andbananas

Roots, tubers and plantains are treateddifferently according to their marketvalue; whether destined for export ordomestic markets. Roots, tubers, yams,cassava, bananas and plantainsdestined for export markets are treatedwell – handled with care, screened,packaged appropriately and then keptin cold storage until shipped. However,the same commodities sold on localmarkets are not given this treatment,and are often left in the open and atthe mercy of rodents, insects and theweather (Fig. 6.1).

Cassava yams, plantains and bananas

are frequently packed tightly intoboxes or bags for transport fromproduction areas to marketing centres.At best, these wholesale markets aretemporary structures, where theproduce is sold on to retailers whothen distribute various quantities totheir respective retail outlets. Cassavafor processing is transported in bulk toprocessing centres where it is furtherdistributed into the appropriateprocessing/product routing. Left-overcassava in the market is frequentlyburied in the ground or immersed indrums of water as a means ofpreservation during short periods.However, these methods ofpreservation often result in rotting ofthe crop and consequent loss ofincome. Fresh cassava can only storefor a few days before physiological andmicrobial damage occurs. Cassava,plantains and bananas are sold as fastas possible to retailers and end users,to avoid excessive loss from spoilage.

Figure 6.1 Marketing of fruits and vegetables in the open air can increases the rateof food spoilage.


Yams are the only produce which canbe safely stored within the retail tradefor a number of weeks.

6.2.1 Losses and wastesLoss and wastage incurring in thestorage of roots, tubers and plantains ispredominantly due to microbial andphysiological damage, which results inthe rotting of the produce. Heat build-up within the produce due to highdensity packing and lack of adequateventilation will hasten this process.Undetected bruising on the farm,during transport or when handling inthe market results in physical damage,which accelerates microbial attack -particularly for plantains or bananas.Loss and wastage of plantains andbananas includes rotting,discolouration of the skin and theripening of the produce during transitor when in the market. The storage lifeof plantains and bananas reducesconsiderably as it ripens. Thus it is notpractical to store these goods whenthey are ripe as considerable losses willoccur. For the export market, skindiscolouration due to friction isundesirable as it lowers the marketvalue of the product. There arespecialist skills, equipment andprocedures that should be followedwhen handling and trading ripe fruit.

6.2.2 GuidelinesTo avoid loss the following precautionsshould be taken:1. Roots, tubers, plantains and

bananas should be carefullyharvested and handled to avoidbruising, and thus to avoidingrotting in store or when offered forsale.

2. Produce such as bananas andplantains should be transported inrobust paper cartons or boxes fromstore to market stalls. Wherepossible, refrigerated vehiclesshould be provided.

3. Storage structures at wholesale and

retail markets should be adequatelydesigned and properly constructedto ensure that produce can besafely stored for the time required,with minimum loss (Fig. 6.2).

4. Storage rooms should be cool andwell-ventilated.

5. Handling and packaging of goodsfor retail markets should be giventhe same attention as that given towholesale markets, in order toreduce losses.

6. Premium prices should be paid forhigher quality produce toencourage the better and moreexperience traders to gain benefitfrom their efforts/knowledge. Thisacts as an incentive for others tofollow their example.

6.3 Fruits and vegetablesFruits and vegetables are an importantpart of the diet of people in alldeveloping countries. Vegetables areparticularly important because they areeasy to grow, and have the ability tosupplement the protein intake of thepoorest communities. However, fruitsand vegetables are more perishablethan cereals and legumes, and requirespecial attention and care whenhandling. Fruits such as avocados,bananas, oranges and passion fruit arewidely sold on international market;they are valuable and handled withcare. There are food standards andinternational quality control measureswhich make it essential for traders tomaintain the highest quality standardsof care. Transportation from fields tocollection points, stores, etc.,subsequent packaging, pest controland cold storage follow well-established procedures such that theproduce reaches the final destinationsin good condition. Produce to beexported is transported in specially-designed cold storage trucks andwagons after being packaged intospecially-designed cartons. Theconsignment is received into cold


storage at point of departure within theexporting country and, in some cases,rapidly shipped by air to the finaldestination. Produce for the localmarket is normally treated differently –with none of the care given the exportcrop. Goods are transported by truckwith no provision for adequatepackaging or cold storage. The lack ofspecialised packaging, transportationand quality assurance standards forlocal markets is a major cause of highloss and waste of fruits and vegetablesin ACP countries.

To reduce the loss of fruits, damagedgoods such as oranges are frequentlyre-directed from fresh to processedoutlets, for example, for manufacturingjuices, jams and/or cordials on small-or medium-scale. A few householdsand cottage-scale industries may alsoprocess vegetables such as tomatoesinto chutneys or purees. Foodprocessing methods of this kind are to

be encouraged to preserve highlyperishable commodities during times ofglut, and to add value and to exploitdifferent markets. It is important forbusiness people, wholesalers andothers to have firm links withindomestic processing industries towhich they can sell, off-load and/or re-direct excess produce to minimise loss.Agro-industrial processors, however,may see these opportunities differently,of course, with much dependent uponthe extent of their product flow in-factory and, importantly, the extent ofthe market available for processedgoods.

6.3.1 Losses and wastesLosses and wastes occur when unsoldand/or surplus produce is not preparedcorrectly for storage, and the store isnot ready or not suitable for storage ofthe produce. This occurs in mostwholesale and retail markets where noprovision may be made for the

Figure 6.2 Simple air-cooled holding bins for temporary storage at trading centres arean advantage.


handling and storage of fruits andvegetables. These are exceedinglydifficult goods to store – and casualarrangements are rarely successful.Produce is usually loaded into truckseither in bulk or in bags depending onthe most convenient method availableto the trader. Loss of fruits andvegetables can be as high as 70-80%,especially should the transport vehiclebreakdown during transit - resulting inincreased transportation time, etc. Fruitis often harvested in the heat of the dayand sometimes left in the hot sun for aperiod before being transported inunventilated trucks to trading centres.

Problems encountered are typically:1. Rotting of fruit and vegetables.

Bacteria, mould, yeast and viruscontamination is a major source ofspoilage. This may be acceleratedin retail and wholesale markets as aconsequence of poor handling andpackaging, excessive heat build-upwithin the bulk and/or severeexposure to the sun whendisplayed on tables or trays in themarket.

2. Loss of nutritional value. This istypical of poor handling and over-exposure to the sun. In mostcircumstances vitamin losses ingreen vegetables will be high –thereby lowering food value.

3. Cross contamination. Microbialdamage may be passed on fromone fruit to another as goods arerarely washed before transportation– and only infrequently afterwards.

4. Physiological disorders. Resultsfrom rapid heat build up within themass of fruit and vegetables,thereby causing spoilage.

5. Rapid loss of moisture fromvegetables (e.g. leafy plants) mayresult when care is not taken toprotect them from direct exposureto the sun or from the build up ofheat.

6. Lack of proper storage facilities in

trading centres is always acontributing factor.

7. Frequent power cuts will makestorage under refrigerated conditionsineffective.

6.3.2 GuidelinesTo avoid loss of fruits and vegetablessome simply precautions arerecommended:1. Provision of adequate packaging

and handling facilities at wholesaleand retail markets to ensure thatfruit and vegetables are properlyhandled.

2. Improved storage facilities for fruitand vegetables for local marketsshould be introduced, to matchthose available for high valueexport crops.

3. Where necessary, fruit andvegetables should be treated withappropriate fungicides/insecticidesbefore storage to minimize theincidence of microbial damageand/or insect infestation.

4. Cold storage facilities should beprovided for highly perishablecrops such as leafy vegetables.

5. Correct methods of handling,packaging and/or storing should beintroduced to ensure that excessiveheat build up within stored bulkgoods does not occur.

6. Where possible, stores should beequipped with stand-by powergenerators to ensure that frequentpower cuts from external supplierswill not affect the produce in store.

7. As practical, there should be closecollaboration between retailers andprocessors to preserve excess foodproduce at times of glut.

6.4 Fish, meat and dairy produceFish, meat and dairy products areusually treated differently from otherfood products because of high valueand their highly perishable nature.Cold storage facilities of varying sizeand complexity can be found at ports


where imported produce is regularlystored. Cold storage facilities may alsobe found at various wholesale andretail market centres. Most abattoirsalso have cold storage facilities forpost-killing and pre-transport of meat.

If the produce is for export then strictfood quality assurance will bemaintained. However, few such lawsare enforced for domestic wholesale orretail markets when handling meat, fishor diary products. As with other foodcrops, standards are often compromisedand/or ignored by both traders and theauthorities. Traders at the main portsand large markets frequently haveaccess to cold stores, which provide ameans of reducing losses and wastagerather than a means of ensuring highquality food standards. Lack of foodstandard law enforcement in most ACP countries has sometimes been the cause of food poisoning andgastro-intestinal infection in localcommunities.

In many milk producing countriesinternational agencies such as theCanadian International DevelopmentAgency (CIDA), the British Departmentfor International Development (DfID)and the Australian Agency forInternational Development (AusAID)have introduced programmes fortraining milk producers, processors andretailers in good milk handling,processing and storage practices, inorder to enhance food handling andpreservation. Food poisoning resultingfrom poor handling of meat and meatproducts and poor personal hygiene ofpeople who handle these foods inmarkets can have devastatingconsequences and sometimes leads tofatalities for those eating contaminatedfoods. It is essential to ensure strictpersonal hygiene in retail andwholesale markets at all times and forall goods. This is a challenge for bothfood traders and market authorities.

6.4.1 Losses and wastesSome simple factors for controllingwastes normally apply and can besummarised:1. Fish, meat and dairy products are

highly prone to bacterial spoilage.High temperatures favour the rapidgrowth of dangerous bacteria andthis results in loss of flavour,texture, taste and smell. Foodpoisoning in local communities canfollow.

2. Lack of appropriate packagingmaterials and handling facilitiessometimes results in storedproduce being subjected to badhandling. Produce may be exposedto adverse storage conditions witha consequent loss of value.

3. Frequent cuts are a feature ofpower supplies in most developingcountries. These can result in thefailure of cold storage facilities withthe consequent loss of produce.

4. Once deterioration has begun, highprotein foods such as milk, meatand meat products cannot beprocessed because of the dangerthat may arise from food poisoning.This is in contrast to food cropssuch as cassava or plantain, whichcan be processed into other foodsto reduce wastage. Spoiled meatand dairy products normally haveto be discarded in bulk.

5. Processed foods such as cannedfish and meat are highly prone tospoilage when stored at hightemperatures or exposed toadverse weather conditions.

6.4.2 GuidelinesTo minimize loss and wastage of fish,meat and dairy products some simpleguidelines should be followed:1. Storage facilities at wholesale and

retail markets should be well-designed and capable of handlingthe produce to be stored (Fig. 6.3).

2. Appropriate packaging andhandling facilities should be


provided to ensure that theproduce, once in store, is notsubsequently exposed to badstorage conditions.

3. Where possible, large stores shouldhave stand-by generators to ensurethat power cuts do not adverselyaffect storage of the produce.

4. Storage should be for as short aperiod as possible to avoid loss ofnutritive value.

5. Produce should not be exposed toinsects, vermin, etc. and heat,which can accelerate spoilage.

6.5 Canned and processed foodsCanned and other processed foods arebecoming increasingly important indeveloping countries and especially inurban centres. Canned foods such asfruits, fruit cocktails, salads, vegetables,milk, meat and fish can all be found onall market shelves. They are popularfoods. Conditions under which theproduce are stored affect the quality of

the product during the period of store.Canned produce should be handledwith care and stored under appropriateconditions – as recommended by themanufacturer. Containers can be easilydamaged by poor handling and thismay result in spoilage of the produce.Packing and stacking in wholesale andretail markets should be off the floor -on pallets - and should be stacked suchas to ensure adequate ventilation andto minimize heat build-up within thestack.

6.5.1 Losses and wastesLoss and wastage is usually associatedwith poor practices when handling andstoring canned and processed foods.Consider:1. Storage and sale beyond the

manufacturer’s recommended sell-by date. This occurs whenmanufacturers do not labelpackages clearly, or irresponsibleor ill-informed shop-keepers do

Figure 6.3 Spacious facilities for storing perishable goods at trading centres help improvethe keeping quality of foods.


not remove expired goods from theshelves. Sometimes out-of-dategoods are discounted and soldmore cheaply, but this raises risksto the consumer.

2. Storage under hot and dampconditions results in rapiddeterioration of the containers and,it follows, of the produce inside thecontainer or can.

3. Exposure to sunlight and heat insheds and retail market stalls isrisky.

4. Exposure to adverse weather suchas rain and frost will causedeterioration of goods.

5. Improper handling of the produceat loading and off-loading stagesresults in split bags, broken bottlesand damage to paper packaging.Again, this results in losses andwastes.

6.5.2 GuidelinesSome simple guidelines apply to safe

storage and handling:1. Traders at wholesale and retail

markets need to be aware that allitems of manufactured producehave an expiry date. Produce notsold by the expiry date should notbe used.

2. Loading and off-loading of produceshould be done with the use of aforklift truck and one, moreover,which is operated by anexperienced driver (Fig. 6.4). Thiswill prevent damage to goods,packets, cans, etc. as the result ofmishandling.

3. Storage should always beundertaken in cool and dryconditions. Warm and humidconditions can lead to a rapiddeterioration of packagingmaterials.

4. Processed foods should be keptaway from direct sunlight toprevent deterioration of theproduce.

Figure 6.4 The use of mechanical handling equipment is recommended for loading andunloading materials on and off trucks.

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