Presentation 3.2

Presentation 3.2

Presentation 3.2

Product quality at harvesting

Presentation 3.2

Product quality after improper mechanical

grading process.

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• Product quality maintenance Product quality maintenance (reduce loses)(reduce loses)

• Generate product added value Generate product added value

• Generate market opportunit iesGenerate market opportunit ies

Presentation 3.2

Product loses. Product loses. (Quality decay/physical loses).(Quality decay/physical loses).

High costs and low profits.High costs and low profits.

Loss of market opportunities.Loss of market opportunities.

Low competitiveness.Low competitiveness.

Presentation 3.2

Key processes during the

post-harvest- life :

• Respiration .

• Transpiration .

• Ethylene production.

• Maturity process.

Presentation 3.2

Factors affecting the respiration rate of FFV:

Internal:Internal:

Type of tissue or organ: Leaves > fruits> roots. Product size: bigger size< respiration rate. Stages of development: young leaves >respiration. In fruits will depend on their classification as climacteric or non-climacteric.

Presentation 3.2

Respiración Climatérica

time

Res

pi r

ati o

n (

mg

CO

2/K

g./ H

r)

180160140120100 80 60 40 20 0

Cherimoya

Mango

Tomate

Prickly pear

StrawberryGrape

Cherry

Lemon

Time

30

20

10

0Res

pi r

atio

n (

mg

CO

2/K

g./H

r)

CLIMACTERIC

AvocadoMangoGuava

PlantainBananaPapayaApple

NO-CLIMACTERIC

CarambolaEgg-Plant

LemonOrange

Watermelon Pineapple

Respirat ion rate

Low

Moderate

High

Very High

Rep. Rep. RhythmRhythm ..Mg COMg CO 22 /Kg./Hr/Kg./Hr

5 - 10 mg

10 - 20 mg

20 - 40 mg

40 - 60 mg

PRODUCTPRODUCT

Sugar beet, garlic, onion, watermelon, citrus.

Cabbage, carrot, cucumber, mango, tomato.

Avocado, cauliflower, lettuce, strawberry.

Artichoke, broccoli, spinach, parsley, sweet Corn.

PERISHABILITYINDEX

Very high

High

Moderate

Low

Very low

POTENTIAL LIFEPOTENTIAL LIFE(WEEKS)(WEEKS)

< 2 weeks

2 - 4 weeks

4 - 8 weeks

8 - 16 weeks

> 16 weeks

PRODUCTSPRODUCTS

broccoli, cauliflower,blackberry, strawberryavocado, pineapple,celery, tomatolemon, watermelonmango, potato,onion, apple,garlic, pear

nuts, dried fruits.

Presentation 3.2

Factors affecting the respiration rates:Factors affecting the respiration rates:

External:External:

mechanical damage and product’s sanitary condition. temperature. atmosphere composition (< Oxygen and CO2< respiration; > ethylene > respiration). physical barriers (waxes, plastic films, etc.)

• the temperature - affects the degree of response/severity of mechanical damage.

• Compromise natural barriers -increasing water loses and pathogenic infections.

Impact

Respiration

Time

Ethylene

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• At temperatures above the optimum, the rate of deterioration increases 2 to 3 fold for every 10ºC rise in temperature.

• High temperature-increases the transpiration rate.

Res

pira

tory

rhy

thm

Time

10ºC

20ºC

30ºC

Presentation 3.2

Loss of water, as vapor, from the product’s area exposed to the air, throughout the cuticle, lenticels, stomas, etc. It depends on:

Internal factors:Internal factors:

species and variety. type of tissue. integrity and sanitary product condition.

Presentation 3.2

External factors:External factors:

Relative Humidity (<RH> transpiration). Temperature (> temperature> transpiration) Air movement (increase the transpiration rate). Altitude (higher altitude< transpiration). Physical barriers (avoid air contact with the product-reduce transpiration rate).

Presentation 3.2

Climacteric fruits are sensitive to ethylene-produce larger quantities of ethylene in association with their ripening- (auto catalysis). No climacteric fruits produce very small quantities of ethylene. At high concentration produce degreening and increase the metabolism. Leafy vegetables are highly sensitive to Ethylene (withering and yellowing )

Presentation 3.2

Physiological process that occur at the cellular level. After finishing the anabolic process, a series of catalytic reactions start –degradation of: chlorophyll, aromas, organelles and finally causing cellular collapse/death.

Post-harvest technology: to delayPost-harvest technology: to delayas long as possible, the tissue as long as possible, the tissue

disintegration/senescence phasedisintegration/senescence phase

STRAWBERRY –EXTERNAL COLOUR CHANGES. STRAWBERRY –EXTERNAL COLOUR CHANGES.

MANGO-INTERNAL COLOUR CHANGES

• Loss of chlorophyll (undesirable in veg.)• Production of carotenoids and

antocianines. • Starches conversion into sugars. • Changes in organic acids, proteins and

fats. • Reduction in tannins and fungistatic

compounds.

UnripeUnripe Ripened InteriorInterior

100%

0%

ExteriorExterior

100%

0%

Presentation 3.2

Avoid the negative Avoid the negative effect of effect of external external

factorsfactors

To reduce and delay the action of the internal internal

factorsfactors that are responsible for product deterioration

Presentation 3.2

Temperature control.Temperature control.

• Product protection from sun heat (full sunlight) after harvesting.

• Pre-cooling treatments to remove field heat.

• Refrigeration.

• Maintaining the cold chain.

Presentation 3.2

• Key factor affecting product deterioration rate.

• is the most effective tool for extending the shelf life of fresh horticultural commodities.

• Key effect on spores germination and pathogenic growth.

Presentation 3.2

Temperature (°C)

Assumed Q10*Relative

velocity of deterioration

Relative post-harvest life

Loss per day (%)

0 1 100 110 3 3 33 320 2.5 7.5 13 830 2 15 7 1440 1.5 22.5 4 25

Source: Kader & Rolle (2003)

Effect of temperature on deterioration rate of a non-chilling sensitive commodity

Presentation 3.2

Temperatures above or below theoptimal range, can cause productdeterioration due to:

• Freezing.• Chilling injury.• Heat injury.

Presentation 3.2

• Freezing point of perishable commodities is relatively high (ranging from -0.3 ºC y -0.5 º C).

• Freezing produces an immediate collapse of tissues and total loss of cellular integrity.

• A result of inadequate design of refrigerator or failure of thermostats.

Presentation 3.2

Chilling InjuryChilling Injury: :

Some commodities (mainly tropical and sub-tropical) respond unfavorably to storage atlow temperatures well above their freezingpoints, temperatures called the chillingthreshold temperature or lowest safetemperature.

Presentation 3.2

Lowest safe temperature

(°C)Commodities

3 Asparagus, cranberry, jujube4 Cantaloupe, certain apple cultivars (such as McIntosh and Yellow Newton), certain avocado

cultivars (such as Booth and Lula), lychee, potato, tamarillo5 Cactus pear, cowpeas, durian, feijoa, guava, kumquat, lima bean, longan, mandarin,

orange, pepino7 Certain avocado cultivars (such as Fuerte and Hass), chayote, okra, olive, pepper,

pineapple, pomegranate, snap bean10 Carambola, cucumber, eggplant, grapefruit, lime, mango (ripe), melons (casaba, crenshaw,

honeydew, persian), papaya, passion fruit, plantain, rambutan, squash (soft rind), taro, tomato (ripe), watermelon

13 Banana, breadfruit, cherimoya, ginger, jackfruits, jicama, lemon, mango (mature-green), mangosteen, pumpkin and hard-rind squash, sapotes, sweet potato, tomato (mature-green), yam

Source: Kader & Rolle (2003)

Classification of chilling-sensitive fruits and vegetables according to their lowest safe temperature for transport and storage

Presentation 3.2

Heat injury:

Direct sources of heat can rapidly heat

tissues to above the thermal death point of

their cells, leading to localized bleaching or

necrosis or general collapse.

Presentation 3.2

Objective:Objective: to remove the f ield heat. to remove the f ield heat.

Movement of the caloric energy from the product to the cooling substance.

Presentation 3.2

Variable Ice Hydro VacuumForced-

airRoom

Cooling times (h) 0.1-0.3 0.1-1.0 0.3-2.0 1.0-10.0 20-100Water contact with the product yes yes no no noProduct moisture loss (%) 0-0.5 0-0.5 2.0-4.0 0.1-2.0 0.1-2.0Capital cost high low medium low low

Energy efficiency low high high low low

Cooling method

Comparison among cooling methods

Source: Kader & Rolle (2003)

Presentation 3.2

• Commercial cooling reaches up to 7/8 the final temperature.

• First hours are crucial.

• Additive effect of low temperatures.

Time

Tem

p.

Presentation 3.2

• well designed and adequately equipped.

• resistant floors.

• perfectly insulated.

• with adequate and well-positioned doors for loading and unloading.

• allow effective distribution of refrigerated air.

• allow monitoring and temperature control.

Cooling rooms and refrigerated vehicles….

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• refrigerated coils surfaces designed to adequately minimize differences between the coil and air temperatures.

• proper air spaces between pallets and room walls to ensure proper air circulation.

• monitoring temperature (product rather than air temperature).

Presentation 3.2

• transit vehicles must be cooled before loading the commodity.

• avoid delays.

• when mixing several products: product’s ethylene and chilling injury sensibility must be considered.

• appropriate packing (air circulation and reducing mechanical damage)

Presentation 3.2

Presentation 3.2

Relative humidity management.Relative humidity management.

Is the moisture content (as water vapor) of theatmosphere, expressed as a percentage of the amount

ofmoisture that can be retained by the atmosphere at agiven temperature and pressure without condensation.

RH can influence water loss, decay development,incidence of physiological disorders, and uniformity offruit ripening.

Presentation 3.2

• Fruits: 85-95% of RH.

• Dry products: onion and pumpkin. 70-75% de RH.

• Root vegetables: carrot, radish. 95-100% RH.

Presentation 3.2

• Adding moisture (sprays, steam) • Regulating air movement and ventilation in

relation to the produce load in the cold storage room.

• Maintaining temperature of the refrigeration Maintaining temperature of the refrigeration coils within about 1coils within about 1ºC of the air temperature. ºC of the air temperature.

• Providing moisture barriers that insulate walls of storage room and transit vehicles.

• Adding polyethylene liners in containers and using perforated polymeric films for packaging.

Presentation 3.2

• Curing.

• Waxes and others surface coatings .

• Polymeric films for packing.

• Avoiding physical injuries.

• Adding water to those commodities that tolerate misting with water.

Air in the internal Cavity

Wax layer restricts the gases interchange.

Presentation 3.2

• Wetting floors in storage rooms.

• Adding crushed ice in shipping containers.

• Sprinkling produce with sanitized, clean water during retail marketing of the product.

Presentation 3.2

• avoiding sources of ethylene close to the product storage areas.

• applications of 1-Methylcyclopropene (1-MCP)- ethylene action inhibitor, commercially approved on July 2002 in apples, apricots, avocados, kiwifruit, mangoes, nectarine, papayas, peaches, pears, persimmons, plums, and tomatoes.

Presentation 3.2

• Air ventilation of storage rooms.

• Avoid mixing ethylene sensitive products with those non sensitive to ethylene, during storage and transport.

Presentation 3.2

• Curing.• Heat treatments i.e.. dipping mangoes, 5 minutes to 50ºC

water to reduce anthracnose development).• Post-harvest pesticides (i.e.. imazalil, thiabendazole).• Biological control agents, (i.e.. Bio-save-pseudomonas

syringae y Aspire-Candida oleophila) in citrus fruits.• Growth Regulators as Gibberellic acid to delay senescence in

citrus fruits. • 15-20% of CO2 in the air or 5% O2 in strawberries,

pomegranates, figs, etc.• SO2 fumigation (100 ppm/1 hour) in grapes.

Presentation 3.2

• Irradiation.

• Quarantine treatments:– Chemical: methyl bromide, phosphine,

hydrogen cyanide) – Cold treatments (Low temperatures)– Heat treatments– Combination of the previous.

Presentation 3.2

Irradiation.• Dose varies in accordance with the species and

its stage of development.

• Doses of 250 Gy has been approved for: lychees, mangoes and papayas in USA for control of fruit fly.

• At doses above 250 Gy and up to1000 Gy some commodities could present damages.

.

Presentation 3.2

Modified and controlled atmosphere storage

Presentation 3.2

Range of storage duration (months)

Commodity

More than 12 Almond, Brazil nut, cashew, filbert, macadamia, pecan, pistachio, walnut, dried fruits and vegetables

6-12 Some cultivars of apples and European pears3-6 Cabbage, Chinese cabbage, kiwifruit, persimmon, pomegranate, some cultivars of Asian

pears1-3 Avocado, banana, cherry, grape (no SO2), mango, olive, onion (sweet cultivars), some

cultivars of nectarine, peach and plum, tomato (mature-green)<1 Asparagus, broccoli, cane berries, fig, lettuce, muskmelons, papaya, pineapple, strawberry,

sweet corn; fresh-cut fruits and vegetables; some cut flowers

Classification of horticultural crops according to their controlled atmosphere storage potential at optimum temperatures and relative humidifies

• Modify the concentration of gases in the produce packing.

• Reduce respiration rate.

• Reduce ethylene action.• Delay ripening &

senescence.• Increase product’s shelf

life.

O2

CO2

O2 CO2

21% O2 0.035% CO2

21% Oxigene0.35% CO2

2% O21% CO2

Filters

Cold room0ºC

Apples, as any l iving entit ies..breath

Presentation 3.2

Innovations:• Creation of nitrogen-on demand, using systems of

Membrane systems or sieve beds. • Use of low oxygen concentrations (0.7 a 1.5%) and

monitoring of such concentrations. • Ethylene free CA. • Programmed atmosphere.• Dynamic atmospheres- O2 y CO2 are modified through

monitoring of produce quality attributes such as: ethanol concentration and chlorophyll fluorescence.

Presentation 3.2

• Banana can be harvested at a later stage.

• In avocados CA allows the use of lower temperatures than the conventional ones and reduces chilling injury.

• In combination with temperature control, CA is used as quarantine treatment for the control of several insects.

Presentation 3.2

• Use of MAP during packing is highly increasing.

• Usually designed to maintain 2% - 5% of O2 and 8% - 12% of CO2, extend shelf life of fresh-cut fruits and vegetables.

Presentation 3.2

Plastic or cardboard box

Polymeric film-perforated one

Apples treated with TBZ

Storage temperature-0.5oC

Presentation 3.2

• CA is used for transporting and storage of apples, pears, less used in kiwifruits, avocados, nuts, dry fruits and persimmon.

• MA- for long distance transport is used in mangoes, apples, bananas, avocados, plums ,strawberries, blackberries, peaches, figs, nectarines.

Presentation 3.2

Genetic factors, production of hybrids and varietieswith….• High contents of carotenes and Vitamin A

(tomatoes, onions and carrots).• Long post-harvest life (tomatoes and onions).• High content of sugars (melon).• High content of ascorbic acid (pineapple).• In the future…Biotechnology will perhaps allow

the introduction of resistance to physiological disorders and/or pathogens associated to quality decay.

Presentation 3.2

Climatic conditions:

• Temperature and light intensity can influence the content of ascorbic acid, carotenes, riboflavin, thiamine and flavonoids.

• Rainfall affects the water supply and the susceptibility of plant organs to mechanical damage and decay.

Presentation 3.2

Cultural practices:• Nutritional conditions: Calcium related with long post-

harvest life; high Nitrogen related with shorter post-harvest life due to high susceptibility to mechanical damage, physiological disorders and decay.

• Several physiological disorders are associated with nutritional deficiencies.

• Water stress (from severe to moderate) is related with irregular ripening, reduced fruit size, increase Total Solid Soluble contents and acidity.

• Water excess increases the susceptibility to physical damage in some products.

Presentation 3.2

Primary damages…perceptible, what is easily identified by the consumer.

• Biological: pest and diseases. • Chemical: visible external contamination with pesticides and chemical products; toxics and unpleasant flavors produced by pathogens, etc. • Mechanical: injures, cuts, bruises, grazes, drops, scrapings, shatters during harvesting, etc.• Physical: heating, freeze, freezing, water loss. • Physiological: sprouting, rooting, senescence, and changes caused by transpiration and respiration.

Presentation 3.2

• inappropriate process of drying.inappropriate process of drying.• inappropriate Infrastructure for produce • inappropriate Infrastructure for produce packaging and storage.packaging and storage.• • improper transport conditions.improper transport conditions.• lack of planning (i.e.. harvesting). • lack of planning (i.e.. harvesting). • delays, improper conditions during • delays, improper conditions during distribution and marketing.distribution and marketing.

Primary damages are the result of inappropriate technologies and handling during the post-harvest chain:

Presentation 3.2

• during periods of oversupply-poor handling increase.• poor or inappropriate harvesting techniques.• poor produce handling. • damages originated during handling and transport. • delays during the distribution process.• loses of weight and water.

Presentation 3.2

Other Other treatmentstreatments

Pre-coolingPre-cooling

DryingDrying

Select ion,Select ion,cleaning and cleaning and disinfectiondisinfection

ReceptionReception

Grading Grading

Packing and Packing and packagingpackaging

StorageStorage TransportTransport

HarvestingHarvesting

Presentation 3.2

• inappropriate maturity at harvest (over ripening increases sensitivity to quality decay ; immature fruits market rejection).• inappropriate harvest technique (mechanical damages-physical injuries).• climatic conditions at harvesting (free water, exposition of product to direct sun light )• harvesting wet products (increase sensitivity to quality decay) • inappropriate harvesting recipes/containers ( physical injuries).

HarvestingHarvesting Associated hazardsAssociated hazards

Presentation 3.2

RecommendationsRecommendations

• training personnel on optimum maturity indices. • Application of appropriate maturity indices based on: external quality color, consistence, phenological stage, etc.• Harvesting time: early in the morning or late in the afternoon in order to minimize the sun effect. • Optimizing harvesting recipes/containers (size, materials, height, number of produce layers, conditions, etc. ) • protection of product of direct sun intensity.

Presentation 3.2

• uncovered areas (direct exposition of products to sun light and adverse climatic conditions) • inappropriate handling of the product during loading and unloading. • inappropriate product heaping (mechanical damages).• delays in the operations (if conditions are inappropriate they can generate increasing product temperature and quality decay) • lack of planning during harvesting (increase delays in the operations).• no methods applied to remove field heat or use of inappropriate ones.

Produce Produce receptionreception

Associated hazardsAssociated hazards

Presentation 3.2

Presentation 3.2

Possible Hazards associated

Pre-coolingPre-cooling

Definir actores/roles/Expectativas.If the methods of pre-cooling are inappropriate, they

can:• produce dehydration of the product (i.e.. high speed of cooling air) • tissue damage –i.e. as result of inappropriate packing -product contact with ice. • produce quality decay caused by sensitivity of the product to water exposition.• accelerate quality decay by accumulation of water in some areas of the product (between leaves and calyx)

Presentation 3.2

Definir actores/roles/Expectativas.Cleaning and Cleaning and

disinfectiondisinfection

Definir actores/roles/Expectativas.Washing methods:

Web methods:• Immersion (product floating).• Spraying .

Dried methods:• Brushing.• Inhalation/aspirate.

Objective: Removing impurit ies from the product.

Presentation 3.2

Definir actores/roles/Expectativas.Cleaning and Cleaning and

disinfectiondisinfection

Definir actores/roles/Expectativas.• product water sensitivity.

• poor water quality.• mechanical damage (inappropriate conditions of brushes, etc).• water accumulation in the product can cause product quality decay.

Possible Hazards associated

Presentation 3.2

Associated Hazards

GradingGrading

Mechanical damages by vibration, impact/hitting, compression, etc. caused either by poor handling or inappropriate equipment maintenance and design.

Grading methods: by size, weight, color, etc.

Presentation 3.2

Packing and Packing and packagingpackaging

Definir actores/roles/Expectativas.

• poor packing design (reduces efficiency and increases the risk of mechanical and biological hazards).• improper packing (lack of ventilation, low material resistance, sharp and wrinkled surfaces, etc.).• Over packing (many product layers).

Associated Hazards

Presentation 3.2

Definir actores/roles/Expectativas.

• Inappropriate pile up during packing. • packing products with different degree of maturity.• mechanical damages caused by personnel or improper design of mechanical grading machines.• Problems regarding over-handling of products and inappropriate process flows during post-harvest handling.

Packing and Packing and packagingpackaging Associated Hazards

Presentation 3.2

Storage Storage

• Inappropriate design of cooling rooms. • Poor or lack of equipment maintenance and cleaning programmes.• Lack of control of temperature and Relative Humidity conditions.• Lack of control on personnel entrance to the cooling rooms.• Poor or lack of cooling rooms cleaning programmes. • Inappropriate distribution/location of the product inside the cooling room (reducing air circulation).

Associated Hazards: mechanical, physical, biological damages.

Presentation 3.2

TransportTransportAssociated hazards: chemical,

biological, mechanical damages.

• Bad conditions of the vehicles tents/covers. • Poor cushioning systems of the vehicles. • Inappropriate systems of loading and unloading. • Uncovered vehicles, expose the product to the negative effect of the environmental conditions. • poor control of temperature and relative humidity in the refrigerated transport systems. • Inappropriate systems of packing (p.e. in bulk).

Presentation 3.2

Definir actores/roles/Expectativas. INNOVATIONS IN THE TRANSPORT

Presentation 3.2

Definir actores/roles/Expectativas. Loading and unloading systems

efficiency

Presentation 3.2

Efficiency of the loading and unloading systems

Presentation 3.2

Other Post-Other Post-harvest harvest

treatmentstreatments

Definir actores/roles/Expectativas.

Associated hazards: increase product’s susceptibil i ty to

biological, mechanical damages and quality decay.

• Improper handling during treatment application.• Inappropriate application of the treatments (p.e. temperatures above or below the optimum recommended). • Improper RH conditions. • Poor equipment maintenance and cleaning. • Doses above the recommended ones (i.e.. irradiation dosages).

Presentation 3.2

• the selection of “the best technologies” to be applied, among a range of available post-harvest technologies, should take into account: the product characteristics, the market distance and requirements, and the social and economical conditions of the actors involved.

Presentation 3.2

To protect the product from direct sun light.Quick transport to the packaging.

Minimize delays before pre-cooling. Uniform product’s cooling.

Store the product at optimum temperature conditions .Practice first in first out rotation.Ship to market as soon as possible.

Use refrigerated loading area.Cool truck before loading.Load pallets towards the center of the truck. Avoid delays during transport.Monitor product temperature during transport.

Presentation 3.2

• There is not a direct relation between a given post-harvest technology efficiency and its cost. Expensive equipment does not always imply high efficiency, and even the best equipment, without proper management may have little utility and poor results. Effective training and supervision of personnel must be an integral part of quality and safety assurance programs.

Presentation 3.2

Proper product handling during the post-harvest Chain

relies in understanding the factors that affect the quality

and safety of the product, and the different mechanisms to

minimize their impact. Simple handling practices can have

important impact on product quality and safety

maintenance.

Proper harvesting time, avoid direct sun light,

proper handling, proper ventilation, etc.

Presentation 3.2

Product quality maintenance and enhancing implies:

• To identify the problems problems (main causes) and their magnitude (quality and physical loses). Also to identify the opportunitiesopportunities associated to the post-harvest technologies.

• Search the available solutions to the problems identified, or mechanisms to take advantage of the opportunities. (training, application of available technologies, adjustment and validation of technologies if needed, practical research if need).

• To evaluate the impact of small changes during the post-harvest chain.

• To train the personnel involved in implementing the changes.• To identify the problems needing practical research in order to

identify possible solutions.

Presentation 3.2

Photographic Material Photographic Material ::Fernando Maul. Archives FAO.

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS (FAO)

Food Quality and Standards Service (ESNS)Food and Nutrition Division

Viale delle Terme di Caracalla 00100 Rome, Italy.

E-mail: food-quality@fao.orgTel.: +39 06 57053308

Fax.: +39 06 570 54593/53152http://www.fao.org/