Post-Harvest Technology of Handling and Storage of Agricultural Crops PDF

CHAPTER 1 2. Loss of Water: In this phase, fruits continue to ripen but at a slower pace....

CHAPTER 1 2. Loss of Water: In this phase, fruits continue to ripen but at a slower pace. Overripening and deterioration may occur if not consumed or Post-Harvest The loss of water through respiration and transpiration can processed promptly. lead to wilting, loss of turgidity, and shrinkage of the crop. Post-harvest management is a system of handling, Importance of Biological Understanding: storing, and transporting agricultural commodities after harvest. 3. Color Changes: Understanding the biological aspects of post-harvest - GrainPro.com Pigments responsible for color in fruits and vegetables handling is crucial for several reasons: can degrade, leading to changes in appearance. OVERVIEW 1. Quality Preservation: Respiration Post-harvest technology is inter-disciplinary "Science Proper handling, storage, and temperature control can slow and Technique" applied to agricultural produce after harvest for Respiration is a vital biological process that continues down the respiration process, preserving crop quality and its protection, conservation, processing, packaging, distribution, after harvest. It involves the breakdown of carbohydrates to extending shelf life. marketing, and utilization to meet the food and nutritional release energy, which is essential for various metabolic requirements of the people in relation to their needs. activities. Respiration affects post-harvest handling in the 2. Timing of Harvest: following ways: Importance Knowing the optimal stage of ripeness helps determine the Temperature Influence: best time for harvest to ensure crops reach consumers at their Importance of Post-harvest technology lies in the fact peak quality. that it has capability to meet food requirement of growing Higher temperatures can accelerate respiration rates, population by eliminating avoidable losses making more leading to increased energy consumption and faster 3. Minimizing Losses: nutritive food items from low grade raw commodity by proper deterioration of crops. processing and fortification, diverting portion of food material Effective management of biological processes can reduce being fed to cattle by way of processing and fortifying low grade Oxygen Consumption: post-harvest losses due to spoilage and degradation. food and organic wastes and by-products into nutritive animal Crops with high respiration rates can rapidly deplete Conclusion feed. Post-harvest technology has potential to create rural oxygen levels in storage, leading to anaerobic conditions and industries. potentially harmful microbial growth. In conclusion, post-harvest handling involves various biological processes that continue even after crops are POST-HARVEST TECHNOLOGY OF HANDLING AND Ethylene Production: harvested. Understanding the physiological changes, STORAGE OF AGRICULTURAL CROPS respiration, and ripening processes helps in making informed Some crops produce ethylene gas during respiration, decisions about storage conditions, transportation, and timing Lesson 1 which can influence the ripening of other nearby fruits and of consumption. By applying this knowledge, we can minimize BIOLOGICAL ASPECTS OF POST-HARVEST HANDLING vegetables. losses, extend shelf life, and ensure that consumers receive Ripening is a complex process that involves changes in high-quality, nutritious produce. Physiological Changes: color, flavor, texture, and aroma, making the crop more General characteristics of fruits, vegetables and cut After harvest, crops are still alive, and they continue to exhibit palatable and attractive. Understanding the stages of ripening is flowers various physiological changes. These changes can affect their essential for optimizing harvesting and storage: appearance, texture, flavor, and nutritional content. Some Fruits: common physiological changes include: Pre-climacteric Phase: ✓ Fruits are the mature ovaries of flowering plants and are 1. Respiration: This is the early stage of fruit development. The fruit is firm and typically formed after fertilization. has low ethylene production. Crops continue to respire, consuming oxygen and ✓ Their main function is to protect and aid in the dispersal releasing carbon dioxide. This process generates heat and Climacteric Phase: of seeds. energy, contributing to moisture loss and the breakdown of During this phase, fruits exhibit a rapid increase in stored nutrients. ✓ Fruits come in various shapes, sizes, colors, and respiration and ethylene production, leading to softening, textures. sweetening, and aroma development. Characteristics of Fruits Post-climacteric Phase:  ✓ Fruits contain seeds, which can vary in number and ✓ Cut flowers continue to take up water through their Ethylene production: size. stems, which helps prolong their freshness. Some fruits produce ethylene, which accelerates ripening ✓ Many fruits have edible parts that are rich in nutrients ✓ Proper care, including using clean water, trimming and decay. and sugars. stems, and avoiding direct sunlight and extreme temperatures, can extend the life of cut flowers. Impact of Deterioration on Product Quality ✓ Fruits develop from the ovary of the flower and may involve other floral parts. Product Deterioration Nutritional value: ✓ Fruits undergo a process of ripening, during which they Mean the falling from a higher to a lower level in quality, Vitamins and nutrients can degrade over time, affecting become softer, sweeter, and more colorful, making character, or vitality. the product's health benefits. them appealing to animals that aid in seed dispersal. Flavor and aroma: The process or fact of becoming worse Vegetables: Chemical changes alter taste and smell. Factors Contributing to Product Deterioration: ✓ Vegetables are various edible plant parts that are Texture: consumed for their nutritional value and culinary Environmental factors purposes. Temperature: Deterioration can lead to mushiness, toughness, or loss of crispness. ✓ They can come from different parts of the plant, such as High temperatures accelerate chemical reactions and leaves, stems, roots, and flowers. microbial growth. Appearance: Characteristics of Vegetables Humidity: Discoloration, shriveling, and blemishes affect visual appeal. ✓ Vegetables consist of different plant parts that are Excessive moisture can lead to mold and spoilage. eaten, such as leaves (lettuce), stems (celery), roots UNDERSTANDING SHELF LIFE (carrots), bulbs (onions), and flowers (broccoli). Light: Shelf life refers to the period during which a food ✓ Vegetables are rich in vitamins, minerals, fiber, and UV light can cause nutrient degradation and color product can be stored under specified conditions while other essential nutrients. maintaining its safety, quality, and intended characteristics. Oxygen and carbon dioxide: ✓ Depending on the type of vegetable, different plant It's the duration from the time a product is manufactured Improper gas levels can lead to oxidation or anaerobic or processed until it's considered no longer acceptable for parts are harvested and consumed. spoilage consumption. Understanding shelf life is crucial for both food ✓ Vegetables are commonly used in cooking to add manufacturers and consumers to ensure that products are safe Biological factors flavor, texture, and nutrition to meals. and of good quality. Microorganisms: Cut Flowers: 1. Product Characteristics: The composition of the food, Bacteria, fungi, and molds can cause spoilage and including its water content, fat content, pH level, and ✓ Cut flowers are harvested flowers that are typically used decay. presence of preservatives, affects how quickly it for decorative purposes in arrangements, bouquets, and displays. deteriorates. Insects and pests ✓ They are chosen for their aesthetic appeal and are often 2. Microbial Activity: Microorganisms like bacteria, Infestations can damage products and introduce chosen for their vibrant colors, shapes, and fragrances. yeast, and mold can grow on food and cause spoilage contaminants. or even foodborne illnesses. The presence of these Characteristics of Cut Flowers Physiological factors: microorganisms, as well as their growth rate, can impact shelf life. ✓ Cut flowers are selected based on their appearance, Respiration rate: including factors like color, shape, size, and fragrance. 3. Oxidation: Exposure to oxygen can lead to the Higher respiration speeds up aging and reduces shelf life. degradation of certain nutrients and cause rancidity in ✓ Once cut, flowers have a limited lifespan due to the interruption of their natural growth processes.  fats and oils. This can affect the flavor, aroma, and Vacuum packaging: Removing air to slow down Adverse weather, like excessive rainfall or high temperatures, overall quality of the product. oxidation. can cause diseases, reduce quality, and lead to pre-harvest losses. 4. Enzymatic Activity: Enzymes present in foods can Sanitation and hygiene practices: cause changes in color, flavor, and texture over time. 4. Pesticide and Chemical Use: Proper processing and storage conditions can help Cleaning and disinfection: Preventing microbial slow down enzyme activity. contamination. The application of pesticides and other chemicals can influence the health and safety of the crop at harvest. Residue 5. Moisture Content: Moisture content affects microbial Pest control: Preventing infestations. levels must conform to safety standards for the produce to be growth and can lead to spoilage. It's particularly Post-harvest treatments: marketable. important in products prone to mold and bacterial contamination. Ethylene inhibitors: Slowing down ripening. 5. Fertilization and Nutrient Management: 6. Temperature: Storage temperature greatly influences Antioxidants: Reducing oxidative deterioration. Proper nutrient management throughout the growing the rate of deterioration. Higher temperatures can season ensures that crops are healthy and have the necessary Handling and transportation practices: nutrients for quality and shelf life. Deficiencies can lead to accelerate microbial growth, enzymatic reactions, and chemical changes, shortening shelf life. reduced quality. Gentle handling to avoid physical damage. 7. Packaging: Proper packaging can create a barrier 6. Irrigation Practices: Minimizing exposure to environmental factors. against moisture, oxygen, and contaminants, extending Adequate and timely irrigation is essential for crop health shelf life. Packaging also prevents physical damage to Chapter 2 and quality. Inconsistent or excessive irrigation can lead to the product. water stress or diseases. Pre-harvest Factors and Post-harvest Behavior of 8. Light Exposure: Light, especially UV light, can Horticultural Crops 7. Weed Control: degrade certain nutrients and cause off-flavors in foods. What is Pre-harvest? Packaging that offers protection against light can help Effective weed control reduces competition for resources preserve product quality. “Pre-harvest" refers to the period and various activities and can prevent the spread of diseases. Weeds can also harbor that take place before the actual harvesting of crops or pests that may damage crops. 9. pH Level: Foods with lower pH (more acidic) tend to be agricultural products. less susceptible to microbial growth and have a longer 8. Disease and Pest Management: shelf life. PRE-HARVEST FACTORS THAT INFLUENCE Proper management of diseases and pests is essential pre- POST-HARVEST 10. Preservatives: Some food products contain harvest. Infestations or infections can weaken crops, reduce preservatives to inhibit microbial growth and extend 1. Crop Maturity and Stage of Harvest: yield, and make the crop more susceptible to post-harvest shelf life. These can be natural or synthetic compounds. deterioration. Harvesting crops at the appropriate stage of maturity is Strategies to Mitigate and Prevent Deterioration crucial. Crops harvested too early may not have reached their 9. Varietal Selection: Temperature and humidity control optimal quality, while overripe crops can be more susceptible to The choice of crop varieties can have a significant impact damage and decay during post-harvest handling and storage. on post-harvest outcomes. Some varieties may be more Cold storage: Slows down microbial growth and resistant to diseases or better suited for storage and 2. Harvesting Methods: chemical reactions. transportation. Controlled atmosphere storage: Adjusting gas The method of harvest, such as manual picking, machine composition to extend shelf life. harvesting, or cutting, can affect the condition of the crop. 10. Harvest Timing: Careful handling during harvest minimizes physical damage and Harvesting at the right time of day, typically during cooler Packaging techniques: bruising. periods, can help maintain the quality of certain crops. For Modified Atmosphere Packaging (MAP): Modifying gas example, some vegetables are best harvested in the early 3. Environmental Conditions: composition in packages. morning when temperatures are lower. Weather conditions leading up to harvest, such as temperature, humidity, and rainfall, can impact crop quality. 11. Harvest Equipment and Tools:  The type and condition of equipment and tools used during Harvesting Techniques: Different crops require atmosphere storage can slow down metabolic harvest can affect the quality of the crop. Well-maintained and different harvesting techniques. For example, some fruits are processes, reducing ripening and spoilage rates. properly calibrated equipment can minimize damage. hand-picked, while others are mechanically harvested. Humidity: Maintaining the appropriate humidity levels 12. Field Hygiene: Packaging: The containers used to collect and store for different types of produce is important. Some crops the harvested produce should be clean and suitable for the type require high humidity to prevent moisture loss, while Keeping the harvesting area clean and free from of crop to prevent damage and contamination. others need low humidity to prevent mold and decay. contaminants, such as soil and debris, reduces the risk of post- harvest contamination and disease spread. Timing-Related Factors: Packaging: Packaging materials and methods can affect product quality. Packaging should provide 13. Training and Skill of Harvest Workers: Maturity Level: Harvesting at the correct stage of protection from physical damage, pests, and maturity is vital. Picking fruits and vegetables too early can environmental factors while allowing for proper The knowledge and skills of the labor force involved in result in underdeveloped flavors, while waiting too long can lead harvesting are critical. Properly trained workers can minimize ventilation. to overripeness and reduced shelf life. damage and handle crops with care. Ethylene Exposure: Ethylene is a natural plant Time of Day: Some crops are best harvested at specific hormone that can promote ripening and senescence. Factors during Harvest times of the day to optimize quality. For example, leafy greens Separating ethylene-producing crops from ethylene- Environmental Factors: are often harvested in the early morning when temperatures are sensitive ones can help prevent premature ripening. Mechanical Factors: cooler. Timing-Related Factors: Pathogens and Pests: Effective pest and disease Harvest Frequency: Frequent harvesting of crops like management during storage and transportation is Environmental Factors: beans or tomatoes is essential to prevent over ripeness or critical to prevent contamination and spoilage. spoilage. Weather Conditions: Weather plays a crucial role in Chemical Treatments: Some post-harvest treatments, harvest quality. Rain or excessive moisture can lead to water Storage Conditions After Harvest: The harvested such as fungicides, antibrowning agents, and wax damage, fungal growth, and increased microbial activity, while produce should be stored properly immediately after harvest. coatings, can be applied to extend shelf life and extreme heat can accelerate product deterioration. Ideal This includes maintaining proper temperature and humidity enhance product appearance. weather conditions are typically dry and mild. levels and protecting the produce from direct sunlight. Storage Conditions: Different crops have specific Temperature: The temperature during harvest can Transportation: If the produce needs to be transported storage requirements in terms of temperature, humidity, impact product quality. Some crops, like leafy greens, are best to a processing facility or market, the method of transportation and ventilation. Failure to meet these requirements can harvested in the cooler parts of the day to reduce wilting. Others, and the conditions during transit can impact its quality. For lead to quality deterioration. like tomatoes, may benefit from warmer temperatures for better example, maintaining a cold chain for perishable items is flavor development. crucial. Duration of Storage and Transportation: The length of time that products are stored or transported can Humidity: High humidity can cause moisture-related FACTORS AFFECTING POST-HARVEST impact their quality. Prolonged storage or transportation issues like mold and spoilage. Proper humidity control is Maturity at Harvest: The stage of maturity at which a can lead to nutrient loss, flavor changes, and increased essential for post-harvest quality. crop is harvested can significantly impact its quality. spoilage risk. Mechanical Factors: Harvesting too early or too late can result in suboptimal Quality Grading and Sorting: Sorting and grading taste, texture, and shelf life. based on size, color, and quality criteria help ensure Harvesting Equipment: The type of equipment used that only high-quality products are marketed. can influence the quality of the harvest. For example, for fruits Handling Practices: Proper handling techniques, such like apples and pears, mechanical harvesters need to be gentle as gentle handling to avoid bruising or physical Post-Harvest Loss Prevention: Effective to avoid bruising. damage, are crucial. Rough handling can lead to management practices, such as regular inspections, mechanical injuries and increase the likelihood of proper inventory control, and efficient logistics, can help Handling Practices: How workers handle the produce decay. reduce post-harvest losses. during harvest is critical. Careless handling can lead to physical damage, which can accelerate deterioration. Temperature: Temperature control is critical in post- Environmental Factors: Ambient temperature, harvest management. Proper refrigeration or controlled humidity, and air quality in storage and transportation  facilities can influence product quality. Proper MATURITY INDICES Higher temperature gives early maturity. e.g. Gulabi ventilation and insulation are essential to mitigate these (Pink) grapes mature in 100 days in Western India but only 82 effects. MATURITY days are enough in the warmer Northern India. Lemon and It is the stage of fully development of tissue of fruit and guava takes less time to mature in summer than in winter. Sun- Market Demand and Timing: Knowing when and scorched portions of fruits are characterized by chlorophyll loss, where to bring products to market is crucial for vegetables only after which it will ripen normally. During the process of maturation, the fruit receives a regular supply of food yellowing, disappearance of starch and other alcohol insoluble maximizing their value and ensuring freshness for material, increase in TSS content, decrease in acidity and consumers. material from the plant. softening. Consumer Education: Educating consumers on Types of maturity 2. Soil: proper storage and handling practices can reduce food Horticultural maturity: It is a developmental stage of the fruit waste and improve product satisfaction. on the tree, which will result in a satisfactory product after Soil on which the fruit tree is grown affects the time of harvest. maturity. e.g. Grapes are harvested earlier on light sandy soils Traceability: Implementing traceability systems can than on heavy clays. help identify the source of any quality or safety issues Physiological maturity: It refers to the stage in the and enable targeted recalls when necessary. development of the fruits and vegetables when maximum 3. Size of planting material: Regulatory Compliance: Compliance with food safety growth and maturation has occurred. It is usually associated This factor in propagated fruits affects fruit maturity. e.g. and quality standards and regulations is essential to with full ripening in the fruits. The Physiological mature stage is In pineapple, the number of days taken from flowering to fruit ensure the safety and integrity of post-harvest products. followed by senescence. maturity was more by planting large suckers and slips than by Types of maturity smaller ones. CHAPTER 3 Commercial maturity - It is the state of plant organ required by 4. Closer spacing: Harvesting a market. It commonly bears little relation to Physiological Close spacing of hill bananas hastened maturity. MATURITY INDICES maturity and may occur at any stage during development stage. 5. Pruning intensity: HARVESTING METHODS Harvest Maturity - It may be defined in terms of Physiological maturity and horticultural maturity, it is a stage, which will allow It enhanced the maturity of Flordasun and sharbati HARVESTING fruits / vegetables at its peak condition when it reaches to the Peaches. The goals of harvesting are to gather a commodity from consumers and develop acceptable flavour or appearance and having adequate shelf life. 6. Girdling: the field at the proper level of maturity with a minimum of damage and loss, as rapidly as possible and at a minimum cost. Criteria of maturity for harvesting fruits and vegetables Process of constricting the periphery of a stem which This is achieved through hand-harvesting in most fruit, blocks the downward translocation of CHO, hormones, etc. vegetable and flower crops. Vegetables are harvested at harvest maturity stage, Beyond the constriction which rather accumulates above it. In which will allow it to be at its peak condition when it reaches the Grape vines it hastens maturity, reduces the green berries in 1. Hand Harvesting consumer, it should be at a maturity that allows the produce to unevenly maturity cultivar and lowers the number of short Hand harvesting has a number of advantages over develop an acceptable flavour or appearance, it should be at a berries. It is ineffective when done close to harvest. CPA has an machine harvest. People can accurately determine product size required by the market and should have an adequate shelf additive effect with girdling. quality, allowing accurate selection of mature product. life. Time taken from pollination to horticultural maturity under warm condition, skin colour, shape, size and flavour and Maturity index 2. Mechanical Harvesting abscission and firmness are used to assess the maturity of the The factors for determining the harvesting of fruits, produce. vegetables and plantation crops according to consumer’s Mechanical harvest is currently used for fresh-market crops that are roots, tubers, or rhizomes and for nut crops. Time taken from pollination to horticultural maturity purpose, type of commodity, etc and can be judged by visual Vegetables that are grown below ground (radishes, potatoes, means (colour, size, shape), physical means (firmness, garlic, carrots, beets and others) are always harvested only Factors affecting maturity softness), chemical analysis (sugar content, acid content), once and the soil can be used to cushion the product from computation (heat unit and bloom to harvest period), 1. Temperature: physiological method (respiration). These are indications by machine caused mechanical injury. which the maturity is judged. Various index are as Follows; FEATURES USED AS MATURITY INDICES The maturation of commodities is associated with changes in their physiology, as measured by changing patterns 1. Visual indices Chronological features of respiration and ethylene production. It is most convenient index. Certain signals on the plant For certain crops (fast-rotation vegetables, such as Some measures of maturity or on the fruit can be used as pointers. E.g. drying of top leaves radish, and perennial tree crops growing in short summer in banana, yellowing of last leaf of Peduncle in jackfruit. environments), maturity can be defined chronologically, for Peel colour - citrus, papaya, pineapple, grapes, mango, example, as days from planting or as days from flowering. strawberry 2. Seed development Pulp colour - Mango, apple Size - citrus, apple, pear It can also be used as an index of fruit maturity, e.g. Shape - banana, pineapple, litchi, mango endocarp hardening for stone and fiber development for dessert Physical features Drying of plant parts - banana in mango. Surface characteristics - melon, mango Size, shape, and surface characteristics. Changes in the Ease of separation from plants - musk melon, grape, 3. Start of bud damage size, shape, or surface characteristics of fruits and vegetables mango (tapka stage) are commonly used as maturity indices. For example, Occasionally it can be used as an index of fruit maturity Tapping - watermelon vegetables in particular are harvested when they have reached Aroma - jackfruit in mango. a marketable size and before they become too large. Specific gravity - Mango, pineapple, guava 4. Calendar date Firmness - Melons, apple, pear Abscission Sugars - Melon and grapes For perennial fruit crops grown in seasonal climate Refers to the natural process by which plants and trees Total Soluble Solids (sugar content) - Grapes, sweet which are more or less uniform from year to year, calendar date drop or shed leaves, flowers, fruits, or other plant parts. It's the orange, papaya for harvest is a reliable guide to commercial maturity. way plants get rid of old or damaged parts to make room for new Acidity - Citrus, mango, pineapple Starch index - apple, pear, banana 5. Heat units growth. This process helps plants conserve energy and adapt Juice content - Citrus to changing seasons. Heat units - Mango, grape, apple, pear Harvest date of newly introduced fruits in a widely Days from anthesis - Melons, pineapple varying climate can be predicted with the help of heat unit. Color Days from full bloom - mango, citrus, apple, pear The color change that accompanies maturation in many Days from fruit set - banana, mango MATURITY INDICES OF FRUITS fruits is widely used as a maturity index. Objective measurement Banana of color requires expensive equipment and although the human Harvesting Methods eye is unable to give a good evaluation of a single color, it is The fruit is harvested when the ridges on the surface of skin extremely sensitive to differences between colors. Color A harvesting method is a specific technique or change from angularity to round i.e. after the attainment of 3% comparison techniques are therefore commonly used to assess approach used to gather crops or agricultural products from full stages. fruit maturity. Color swatches may be used to determine plants when they have reached maturity and are ready for Pomegranate external or internal color. consumption, processing, or sale. Sugar percentage should be 12-16% and acid percentage Chemical changes Harvesting Methods 1.5—2.5%, variety Ganesh harvest when seed colour becomes The maturation of fruits and vegetables is often There are the three different harvesting methods that pink. In this stage TSS 12.5% and sugar acid ratio 19.5%. accompanied by profound changes in their chemical take place when harvesting fruits and vegetables: Mango composition. Many of these changes have been used in studies of maturation, but relatively few have provided satisfactory 1. Hand Harvesting This can be judged when one or two mangoes ripen on the maturity indices because they usually require destructive 2. Harvesting with Hand Tools tree are fall on the ground of their own accord. This process of sampling and complex chemical analysis. fallen is known as tapaca specific gravity 1,01—1.02 and TSS 3. Harvesting with Machinery (total soluble solids) 10-14%. Physiological changes. 1. Hand Harvesting MATURITY INDICES OF VEGETABLE CROPS  Hand harvesting is just that: produce is harvested by hand, without the use of any tools. 2. Harvesting with Hand Tools This harvesting method is typically carried out when harvesting tree fruit, where some sort of clipper (usually specialized for the type of produce being harvested) is used to remove the fruit from the tree, and then the fruit is placed into harvesting containers. 3. Harvesting with Machinery There are a lot of different harvesting types that land under this category. There are operations that perform hand harvesting and harvesting with hand tools that also use harvesting machinery (e.g., harvesting rig) to aid in the overall harvesting and packing process. LESSON 5 TRANSPORT AND STORAGE Lettuce (head and leaf types) destined for institutional are equipped with leaf-spring suspension systems that can buyers are placed in plastic crates during harvesting and cause vibration damage. Storage then brought to the packinghouse. Chrysanthemums are sleeved using newspaper and loaded High value commodities such as lettuce are occasionally Storage losses of fruits and vegetables are high due to large in bulk in a vehicle, then brought to the packinghouse. transported to market by refrigerated trucks. variation in temperature and humidity between growing fields to 2. Packinghouse or collection center to wholesale markets the place of marketing in case of distant marketing. The lowest SEA TRANSPORT either by land or inter-island transport. temperature that does not cause chilling injury is the idle storage 3. Distribution to retail markets. The large capacity of many water transports makes this the temperature for fresh fruits and vegetables. cheapest mode of carrying produce. Transport Systems Transportation Boats- small narrow boats are used in Quirino Province to bring The mode of transport should be the fastest and most efficient ‘Lakatan’, ‘Latundan” and “Saba” bananas from farms to Almost all horticultural produce is transported in non- that will deliver the produce in perfect condition at the lowest assembly areas by a river. The fruits are then loaded into trucks refrigerated trucks to distant markets leading to loss in quantity possible cost. It will also depend on availability of transport for transport to distant markets in Manila and other provinces. as well as quality. Temperature management during facilities and the volume of produce. It can either be specified transportation of fresh fruits and vegetables over long distances by the buyer or selected by a systematic approach considering This is also used for nearby markets where water transport is a is critical. Some of the important points needed to be kept in the buyer’s requirement, import regulations, terms of sale, convenient and cheap means of transporting fresh produce. mind during transportation are: speed of delivery requirement and destination. This is a common method of transport in Bangkok along the canals (klongs). Loads need to be stacked to enable proper air FIELD TRANSPORT Breakbulk cargo- either dry or refrigerated cargo that is loaded circulation, in order to facilitate the removal of the heat on and off a vessel by individual piece or palletized cargo. Due to difficult terrain and lack of farm access roads, highland Bananas packed in cartons are arranged on pallets, which are from the produce as well as to dissipate the incoming tomatoes are brought to assembly areas by horse in Liliw, then loaded into a ship’s hold by crane. The cartons are then heat from the atmosphere. Laguna. stacked in the cargo space by hand. Simple intervention like immediate transportation of produce after packaging and loading In Panganiban, small tractors or tricycles are used to bring the Inter-modal containers- these are usually referred to as Movement during cool hours preferably during night fruits from the field to wholesale markets. container vans. These can be mounted on a trailer for overland Optimum stacking provisions for proper aeration in the transport, or loaded on a ship for inter-island journeys, hence truck From small farms, harvested bananas are laid on padded trailers pulled by a tractor or by animal-drawn carts lined with they are considered as inter-modal transit vehicles. Cushioning to check vibrations impact etc for safe transportation several layers of banana leaves. Container vans are available with the following specifications: Transportation in refrigerated vehicle can also be used Since banana is susceptible to bruising caused by rubbing to reduce post-harvest losses of highly perishable 6 m (20 ft; dry freight): maximum cargo weight- 22, 100 kg; between adjoining hands, banana leaves could also be placed dimensions- 5.919 x 2.340 x 2.380 m; cargo space- 33.0 m3 produce. in between hands. In large plantations, an elaborate system of 12 m (40 ft; dry freight): maximum cargo weight- 27, 397 kg; rails is used to bring harvested bunches to a central dimensions- 12.051 x 2.340 x 2.380 m; cargo space- 67.3 LESSON 5.A TRANSPORT TYPES, THEIR ENGINEERING packinghouse. m3 ASPECTS AND CORRESPONDING HANDLING PRACTICES The rails are fabricated from steel pipe mounted on posts. Some 12 m (40 ft; reefer): maximum cargo weight- 22, 881 kg; The main objective of an effective transport is to ensure that the dimensions- 11.207 x 2.246 x 2.183 m; cargo space- 54.9 plantations use overhead steel cables instead of pipes. The fruit produce will arrive in top quality condition. m3 bunches are hung on chains or rope secured to rollers; the Transport Stages rollers are attached to each other in series and pulled along Vans for dry height (dry vans) are usually used to carry manually or by a motorized hauler. 1. Field to packinghouse or collection- for commodities that products with no special temperature requirements. Dry vans will be shipped in big volumes to distant markets, they are LAND TRANSPORT are of steel construction, with twin doors at one end. Reefer first transported or brought to the field packinghouse, vans are units equipped with packaged refrigeration systems Common vehicles for overland transport of fresh produce and are fully insulated on all sides. These are recommended for collection center or buying station. include jeepneys and trucks. Jeepneys are usually used for proper temperature management of perishable products. Pineapples for fresh fruit export are loaded in bulk in a public transport, but are also hired to bring small volumes to crown-to-crown and base to base pattern in trucks with AIR TRANSPORT market; loads can reach up to 3 tons. Types of trucks used padded or cushioned walls and floor. include flat-beds, dropsides, aand those with fully enclosed This is the most rapid movement of produce especially for highly cargo beds. Most vehicles have no transit cooling capability and perishable commodities such as cauliflowers and asparagus. Shipment by air is used to take advantage of brief market Air circulation comes from a low temperature area, insulation panels opportunities such as the beginning of season or during the off- can be retrofitted to the cargo space to reduce warming season when prices and supply is limited. Inthis mode of Allow air to circulate in the stacks. For unrefrigerated of the commodity. transport, the commodity is moved by a combination of vehicles, this can be achieved by providing space in o For non-refrigerated inter-island shipment, innovations passenger-cargo flights, all cargo flights or chartered fights. between stacks, horizontal dividers in trucks, horizontal or that were adopted to minimize the incidence of green soft vertical dividers in bulk loads in container vans, or leaving disorder, ripening and damage in bananas and yellowing Aircraft container and pallet are called a unit load device that one door of the van open to allow entry of fresh air. Room of calamondin include: can be assembled into a standard size unit for rapid loading and for air circulation must be provided under, around and Leaving one door of the van open during unloading. through the load. transit to dissipate heat and provide For refrigerated vans with bottom air delivery, as much floor ventilation. To discourage pilferage; the open PROPER TRANSPORT PRACTICES area as possible should be covered by the load; any end of the van is covered with slatted Loading and unloading exposed floor area left over after loading is completed bamboo. should be covered to ensure that the cool air does not Lining hog vans and steel banana crates with Handle commodities gently-containers of commodities bypass the load. Used cartons weighed down with a heavy banana leaf sheaths to cushion the sides, should not be dropped or thrown on to each other. object can be used for this purpose. and putting vertical dividers or horizontal Load more fragile commodities near the center of the Reefer vans given a stacking height limit as indicated by a dividers in container vans. This method will vehicle. Commodities located directly above the wheel axle red line on the interior walls. Stacks should not exceed this prevent heat buildup, depletion of oxygen are subject to more vibration and impact damage. limit to allow air to return freely to the evaporator. and accumulation of ethylene that will result Containers at the bottom should not be used as steps to Similarly, a space of about 23 cm should be maintained in green soft disorder of banana. Horizontal allow stacking to a greater height, especially if flexible and between the top of a stack and the ceiling of a refrigerated dividers are better than vertical dividers since semi-rigid containers are used. truck to allow air to circulate freely within the cargo area. this allow heat dissipation and takes off load Loads should be utilized. This refers to the grouping on bottom fruits. However, this is more together of shipping containers where they can be Stacking difficult to build inside the van than vertical mechanically handled as a unit load. This is sometimes Vegetables that can resist top loads such as potato, sweet dividers. referred to as modularization. potato, jimaca (singkamas), chayote and carrot can be Using ventilated vans to allow heat to escape loaded at the bottom. and fresh air to enter. Palletizing- this is the most common method of unitizing Using block ice as a cooling source inside the Mango, citrus such as calamondin and mandarins and other wherein containers are stacked on a pallet and handled by cargo space. crops that are packed in semi-rigid containers should be forklift. provided with wooden lids and stacked lid to lid and bottom to bottom to prevent compression. If refrigerated transport is not possible, and daytime Pallets are low portable platforms usually made of wood, travel cannot be avoided, the following can be If bamboo baskets are used, always stack them upright. A plastic or metal or in combination thereof on which cartons employed: divider between layers will further minimize damage. are stacked to enable a forklift to lift and transport cartons o Use evaporative cooling- an Australian as a whole load by inserting its prongs underneath the Temperature management producer installed an evaporative cooling pallet. As many as 40 cartons can be stacked on a pallet. system in his truck with good results. Standard pallet sizes are the following: Avoid stacking the produce directly above or adjacent to a o Ice the packs if the commodity is of high value Europallet: 1.2 m x 0.8 m heated area such as the engine room of ships. and very perishable. ISO pallet: 1.2 m x 1.0 m (used in Europe and USA) Minimize heat buildup. This can be achieved through the Korea and Japan: 1.1 m x 1.1 m following: Handling o If canvass is used, provide space for air to pass through See to it that movement of containers is minimal. Containers Use slip sheets and handling by forklift with special push- at the bottom and at the top. must be immobilized in the stacks by any means. pull attachment- slip sheets are pallet size sheets usually o A white roofing material will reflect heat, thereby made of solid fiberboard or plastic with edges that could be minimizing heat build-up better than colored ones. Unit load stabilization prevents the hazard of containers falling gripped by a jaw and clamp mechanism of a forklift. The o If the truck is not refrigerated and loaded with precooled from the top of the stack or the entire load toppling during sheet is gripped, pulled on it carrying unit to load and produce or those coming from the highlands, travel as transport. This can be achieved by strapping or over-wrapping pushed outward to unload. However, this is not as popular early in the day as possible or travel at night or at dawn with low-density polyethylene stretch film such as the self- as the pallet. to take advantage of the cooler time of the day. Traveling clinging stretch film or the plastic stretch netting for products that with precooled produce is ideal for short distances where need ventilation. temperature will not increase greatly in transit. If the truck is loaded with precooled produce or where the produce Additional advantages of using stretch film:  o Protects paperboard shipping containers from outside Interlocked stacking- containers are re-arranged in alternate Only high-quality produce should be stored and transported to moisture tiers; this pattern increases stability of the load. achieve the maximum shelf life and ensure customer o Reduces moisture loss from the commodity acceptability. It must be kept in mind that refrigeration handling o Prevents pilferage in the distribution chain NON-CONVENTIONAL TRANSPORT can only maintain (up to a certain point), not improve, the o Reduces handling damage Thermal storage systems- these utilize materials that are first postharvest quality of a commodity. o Makes loading and unloading faster frozen in commercial freezing facilities or a household freezer SANITATION Minimize delays or facilitate transfers of packages. Transfer of to later serve as a cooling source. The material act as a heat commodities from one part of the market to another should be sink, absorbing heat from stored produce and other sources. As Cold storage facilities and equipment must be cleaned regularly done as fast as possible. heat is absorbed, the material gradually melts into liquid form; to avoid accumulation of latex and debris that can be sources of some systems use sturdy packaging for reusability of the pests and diseases. A solution for disinfection can be made from For bulk transport, put a cushion or straw on the floor and material. laundry bleach mixed with water. After rinsing, and disinfecting, against the front and rear walls of the vehicle to prevent the holding area must be air-dried thoroughly; fans can be used damage. Ice bank cooling- in countries with a pronounced winter for faster drying. Culls and rejects should not be allowed to season, a traditional method of storage is the use of accumulate in the facility, but should be disposed of quickly and Sanitation accumulated ice block as a cooling source during summer. properly. Trash that could block air vents and passages should Cleanliness in the transport vehicles and vans should be Dry ice- frozen CO2 can be used in air cargo or pallet containers be removed. properly observed. Losses can occur and produce safety is with special compartments. Permission from airlines should be TEMPERATURE MANAGEMENT compromised due to the following: confirmed, however, since dry ice is considered hazardous. Precooling- the commodity must be preferably be precooled to Decaying remains of produce from the previous Eutectic plates- eutectic solutions, also known as phase- the proper transit or storage temperature before loading. Cold shipment change materials, use inorganic salts dissolved in water to rooms and refrigerated vehicles should also be precooled prior Insects and rodents nesting in the transport vehicles produce a mixture that freezes at a desired temperature. to loading. Toxic chemical residues Cargo trucks with retro-fitted insulation- trucks can be Debris blocking drain openings and air circulation Avoid excessive loading rates- loading should be scheduled loaded with precooled produce, or loaded when ambient to avoid overloading the refrigeration system. This is especially temperatures are relatively low (early morning or at night). true when warm produce is to be loaded. In such cases, extra Insulation panels or sheets can be retro-fitted to the cargo space blowers are needed for added air circulation. Vehicle requirements and proper driving habits to reduce rewarming of the precooled commodity. Store commodities at the recommended temperature Ensure that vehicle is in good order and has a good air Package icing- traders in Davao City transport broccoli from suspension system. A suspension system that is stiff upland farms to the city market using polystyrene boxes. The Product temperature is the single most important factor allows vibration frequency to pass into the truck body, heads are packed together with coarsely crushed ice; the size affecting shelf life of a commodity. Commodities should intensifying damages on the commodity. Radial tires of the ice chunks is probably too large and leaves air spaces be stored at the optimum temperature and relative absorb more impact that other kinds. that reduce efficiency of cooling. These ice chunks could also humidity. The best storage temperature is the lowest Drive properly and carefully. The vibrations transmitted cause physical injuries to the commodity during transit. Other temperature a commodity can tolerate without from the vehicle through packages to the produce commodities such as sweet corn and green onion can also be developing abnormalities in its metabolism. cause sustained bouncing of fruits against each other iced. Recommended storage temperatures for different and against the container, resulting in mechanical commodities. damage. Sources of high vehicle impacts are braking Top icing- before the widespread use of reefer vans, ice in If a commodity will only be stored for a short period, and accelerating, potholes on rough roads and railway various forms was used for cooling palletized containers of slightly lower temperatures than the optimum can be crossings. produce. used to reduce the risk of microbial decay without LESSON 5.B STORAGE TYPES AND TECHNIQUES developing chilling injury. TYPES OF STACKING TIERS Most tropical produce are best stored at 12oC while Method of stacking containers affect also the stability of the load Operation and Management temperature or highland produce are stored at 00C. ripe or stack. fruits can be stored at lower temperatures than unripe To ensure a successful outcome of refrigerated handling, ones of the same variety. Column stacking- all tiers have the same pattern arrangement; sufficient knowledge is needed on the following: proper handling this improves the bearing capacity of containers in lower tiers; practices, specific commodity requirements for storage, stability problem may be solved by external stabilization. economics of storage, refrigeration technology and marketing. Given below are recommended practices for refrigerated Avoid re-warming- a commodity that is already cool should be storage and transport of perishables. kept in this condition until it is purchased by the consumer. However, it is common for re-warming to occur between links in moisture leading to a reduction in their load-bearing vehicles are not provided with curtains, the refrigeration unit a cold chain system. For example, in one supermarket in Manila, capacity. should be shut off during loading. vegetables delivered by refrigerated truck are unloaded and o At low RH, disease development is less; however, other placed in a non-refrigerated area while documents are quality defects can result such as wilting, shriveling, Check door and doorway gaskets of cold rooms and refrigerated processed, which can take up to two hours to complete. reduced turgor and firmness, and loss of nutrients or vehicles for holes, cracks and loose or detached portions. vitamins. These should be repaired promptly or replaced. Re-warming reduces the benefits of refrigerated handling since it: How to increase RH- for refrigerated storage, the following PROPER STACKING measures to increase RH can be used: For cold rooms o Results in condensation on the commodity. The presence of surface moisture, in turn, encourages 1. Install an evaporator coil with a large surface area. This o Keep stacks 8 cm away from walls; this should be disease development and weakening of fiberboard allows the evaporator to operate at a higher increased to 10-12 cm for walls exposed to direct packaging. temperature than a smaller coil, thereby minimizing sunlight. This will ensure that heat transmitted through o Hastens respiration of the commodity, accelerating condensation on the coils and reducing the amount of walls is brought to the evaporator and not to the ripening and deterioration. moisture removed from the storage air. The difference commodity. Provide gaps between containers and o Increases operating costs since additional energy is between air temperature and evaporator coil stacks to ensure maximum exposure to cold air. needed to re-cool the commodity. temperature must not be greater than 30C. o A layer-reversed chimney stacking pattern will provide 2. Using humidifiers to supply water vapor to an enclosed the necessary vertical gaps between wooden or Temperature monitoring- air temperature is controlled in a area by evaporation. Wetted cloth or sacks can be hung refrigeration system using a thermostat. To ensure that a fiberboard boxes. Four containers are placed at right in the cold room provide evaporating surfaces. angles to each other with a space at the center. A space thermostat is properly working, immerse a properly calibrated glass thermometer in a water-filled bottle and place inside the How to lower RH- for cold storage facilities. The following of not less than 1 cm should be kept between each cold room to check thermostat settings; allow the thermometer measures can be used: carton. Successive layers should be replaced in a to sit for about an hour before reading the temperature. The reversed pattern for stability. water bottle prevents temperature fluctuations while the 1. Install small evaporators that will require a lower coil o The maximum height of a stack depends on the load- thermometer is being read. The air temperature being temperature to achieve the same refrigeration capacity. bearing strength of the packaging material used. measured must be representative of the cold room. Therefore, When the coil temperature becomes lower than the Containers at the lowest layer should be able to support do not place the thermometer near heat sources such as doors, dewpoint of the storage air, moisture will condense on the entire stack without incurring damage to the walls, fans and lights, or directly in the path of supply air coming the evaporator coils, thereby lowering the RH. contents. For manual handling of containers, the stack from the evaporator. 2. Install portable dehumidifiers in the cold storage room. height should not be too high so it will not be difficult to Dehumidifiers are actually small refrigeration units that reach the top layers of the stack. This will also minimize HUMIDITY CONTROL remove moisture from air by the same process accidents during stacking. Stacks should not block air mentioned above. The capacity of the dehumidifier flowing coming from the evaporator. Relative humidity (RH) is defined as the ratio of the existing must be sufficient for the volume of the produce stored. o Commodities that have been precooled or have partial pressure of water vapor to the saturation pressure of pure 3. Armstrong and Brusewitz (1984) described an attained optimum storage temperature can be stacked water at the same temperature. Since fresh produce are experimental dehumidification system for use in animal closer together to save space. composed mainly of water, internal air of produce can be livestock housing that could be used for fresh produced. o Return air flow in a cold room must not be blocked by considered as saturated with water vapor (100% RH). A calcium chloride (CaCl2) solution was used as rows of pallets or containers crossing the path of Problems may be encountered during extremes of RH adsorbent. The system consisted of a cylindrical frame returning air. rotating around a horizontal axis. o If the RH cannot be brought down to 70-80%, sprouting of bulb and root crops during storage will occur. Measuring relative humidity- RH may be monitored by several devices. A sling or Assman psychometer is equipped with wet For refrigerated vehicles- ensure proper air distribution inside o Disease development is enhanced under saturated the cargo area by following recommended stacking patterns and conditions or in the presence of condensed moisture and dry-bulb thermometers and is used in combination with a psychrometric chart to determine RH. practices. These may be varied according to the design of the loss is minimal. Under tropical conditions, it is very vehicle or van. difficult to have an entirely disease-free lot of produce. Digital meters are also available that use electronic sensors and The few commodities with slight disease that may provide a convenient digital readout in % RH. These must be PRODUCT COMPATIBILITY escape unnoticed during sorting or grading will be a calibrated regularly to ensure that sensors are working properly. source of microorganisms that will spread. Storage spaces is scarce, especially in developing countries. o Fiberboard packaging materials are also easily Minimize air infiltration- provide plastic curtains in doorways This may result in mixing of different types of commodities, damaged at a very high RH since these absorb of cold rooms as mentioned previously. Since refrigerated especially in large storage facilities that must be utilized fully to maximize profit and recover costs. Operators of storage facilities must, therefore, be aware of the commodities being (CI). This is especially true for tropical produce that are more high levels of sugar since they result in dark bitter-flavored chips conflicting requirements of different commodities being loaded sensitive to chilling conditions. and fries. into their cold rooms. Stored produce should be compatible with each other with respect to the following: Sweetening may be reversed by exposing tubers to higher temperatures before or after storage, although results may vary o Temperature- tropical commodities that cannot tolerate TERMINATING STORAGE according to cultivar and duration of storage. very low temperatures sould not be stored with those Length of storage depends on the kind and quality of produce, that can. An acceptable practice is to group Conditioning of cut flowers- conditioning is performed variety, preharvest history, storage conditions, marketing immediately after storage to reverse effects of a slight commodities based on storage temperature and requirements, prevailing prices and storage costs. Do not over- humidity ranges that provide a reasonable shelf life dehydration during storage. store to avoid unnecessary expense and loss. Most tropical without compromising quality excessively. commodities are stored for only short periods of time mainly to Cutflowers stored in dry packs must be re-cut by removing 3 cm o Relative humidity- most tropical commodities benefit allow flexibility inn marketing. Exceptions to this are onion, of stem using a slanting cut. The stem must be crushed or from high RH conditions. Bulb and tuber crops, garlic, potato and imported fruits. However, if extended storage scraped. however, sprout easily at high RH and should be stored is necessary, the following practices should be observed: separately. Flowers should then be soaked for 12-24 hours in warm o Atmospheric composition- this refers to levels of O2, o Conduct inspections periodically to reduce losses. preservation at 200C after re-cutting. If flowers are stored as CO2 and ethylene in the storage atmosphere. Avoid over-storing by setting aside a small amount of buds, the treatment is used to induce flower opening and is the commodity that can be moved to room temperature termed bud opening. For bud opening, sugar is added. BACKUP POWER SUPPLIES at intervals for observation. o Allow flexibility when removing commodities from cold- Deciding refrigeration for transport and Storage If power supply is unreliable, a standby generator should be installed. If a generator is not available, ice blocks can be storage- ensure that these are still marketable for 7-10 Many farmers and/or traders feel that a cold storage facility or brought in to serve as a temporary source of cooling. days under ambient conditions to give allowance for refrigerated truck will solve any problem they may have such as retail and consumption. The longer a fruit stays in postharvest losses, low quality, or low market prices. In many CAUSES OF LOSS DURING STORAGE storage beyond the optimum period, the shorter its shelf cases, a deeper look into the situation may reveal that better life after storage. planning of production, improved harvesting and handling Microbial attack- high temperatures combined with high relative humidity encourage disease development. Therefore, POST-STORAGE CONDITIONS practices, establishment of market links in advance of temperature variations in the storage space, extended cooling harvesting, or better scheduling of transport are all that is times, inappropriate packaging or power interruptions are some Condensation of moisture- condensation occurs when warm needed to solve these problems. Therefore, before deciding to conditions that may result in losses at these extreme conditions. air comes in contact with the cold surface of a commodity or refrigerate a commodity, the following must be considered: container as it is brought out of storage. As the air cools, its Excessive moisture loss- improper maturity at harvest, capacity to hold moisture in vapor form decreases, causing o Use refrigeration if it is profitable to do so- whether delayed storage, lack of precooling, temperature variations in moisture to form on the commodity in droplets. facilities or equipment are to be rented or the storage space, low relative humidity or excessive air established/purchased, refrigeration is justified only if circulation can all result in high weight loss manifested as wilting Measures to minimize the effect of condensation produce is valuable enough to bear the added cost. or shriveling. o The cold storage facility should not be too far to reach- o Provide blowers to hasten evaporation of condensed very few producers or traders have their own cold Development of physiological disorders- these can occur moisture; leave gaps between containers and pallets for storage facilities or refrigerated vehicles. A cold store especially during extended periods of storage. better air circulation. Warm dry air is best for removing far from production areas is still conveniently located condensation. when it is close to the intended market of the commodity Greening of potato- development of green areas on the o Gradually bring the temperature of the commodity to to be stored. surface of the tuber is associated with the formation of solanine, ambient levels be setting the system at progressively a bitter and potentially toxic compound. higher temperatures. The temperature of the NON-CONVENTIONAL REFRIGERATED STORAGE commodity must be higher than the dewpoint when it is Ammonia injury- this is caused by ammonia leaking from