Food chain- Onion- from farm to kitchen

REPORT

ISSUES IN FOOD CHAIN ONION FROM FARM TO KITCHEN

SUBMITTED BY

PRADNYA DASHARATH PATIL ID/200, 2ND YEAR M.DES. INDUSTRIAL DESIGN, SCHOOL OF PLANNING AND ARCHITECTURE, NEW DELHI

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ACKNOWLEDGEMENT I want to thank my professors without whom this project wouldn’t be possible. Prof.Manoj Mathur, Ms. Krity Gera, Prof.Abid Bilal, Prof. Naveen Rampal.

I also want to thank my friends and classmates who helped me in this project.

Thanks to my family and relatives for support and encouragement.

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RESEARCH INDEX 

DESIGN METHODOLOGY

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WHY ONION

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ONION CROP LIFECYCLE

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POST HARVEST MANAGEMENT OF ONION

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UNDERSTANDING THE ONION STORAGE ISSUES

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ONION STORAGE STRUCTURES IN INDIA

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SUMMARY

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ARRIVING AT THE AREA OF INTERVENTION-CURING

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BRIEF

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REFERENCES

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DESIGN METHODOLOGY Aim: To study the food supply chain, find out the gaps between the continuity and then propose the solution in terms of product design.

Objective:   

To reduce the gaps in the food supply chain of a particular item.

To minimize the wastage of the food item.

To propose better handling practices which are cost effective and energy efficient.

Design Process: 1) Understanding food supply chain i) Selection of a particular food item for study (Onion) ii) Understanding food supply chain of the Onion iii) To study the life cycle of Onion 2) To find out the issues and gap in Onion’s supply chain i) Finding out issues at each level of the chain ii) Study how those issues have already been tackled 3) To decide the area of intervention (Storage system) 4) To come up with various solutions 5) Developing a design brief 6) Concept development 7) Concept finalization 8) To make a prototype of proposed design

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WHY ONION

At a time when millions of people live in the shadow of starvation enormous quantities of food are lost each year to rats, insects, and fungi. These losses occur between the time the crops are harvested and the time they are eaten because of lack of effective storage and distribution. Annual seed losses due to rats, insects and fungi are estimated to exceed 33 million tons (enough to meet America's requirements for one year). Post-harvest losses are equal to the total agricultural production on more than 12 million acres of farmland. In India, for example, the post-harvest losses of grain are running 15 percent a year; the annual losses of potatoes and onions alone average around 25 percent of its total crop.

Onions, rotting away, because of lack of storage facilities. The existing storage systems.

Given that the gap between food supply and demand in the developing countries is growing rapidly, and that their grain deficit is expected to reach 85 million tons by 1985 (triple what it is today), there is a real need to reduce those losses. It has been estimated that the world's total food supply could be increased by 25 to 30 percent if the post-harvest losses could be avoided.

Given that the gap between food supply and demand in the developing countries is growing rapidly, and that their grain deficit is expected to reach 85 million tons by 1985 (triple what it is today), there is a real need to reduce those losses. It has been estimated that the world's total food supply could be increased by 25 to 30 percent if the post-harvest losses could be avoided.

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If we want to take realizable steps toward preventing hunger and malnutrition in the near future, and we want the developing countries to enjoy greater benefits from their harvests much more emphasis should be placed on the effective storage of food crops.

Otherwise, the world will simply continue to feed enormous populations of rats, insects and fungi.

India’s Pathetic Food Supply Chain leads to 30% Wastage and Soaring Onion Prices which now equal Average Wages India’s Agriculture Sector account for only a minuscule percentage of GDP and growth,however most of India’s population continues to depend on it.Despite rapid growth of the services and industries sector as globalization leads to assimilation of foreign technology and practises,agriculture continues to live in medieval times. India’s Food Supply Chain leads to massive waste and inefficiency with 30% of India’s vegetable and fruit produce being wasted. This is criminal in a country where most of the children go hungry. However corporatization has been repelled by vested interests leading to a sorry situation. Food inflation has seen double digits since last year and despite a better harvest year,some food prices are touching the stratosphere. The inadequate supply chain leads to periodic shortages of key food items used by Indian as part of the daily diet.

Onion prices have hit around Rs 70-80/kg which is is equal to the average wage of $2 for 80% of the Indians. This has surprisingly caused consternation amongst the political classes who have clamped down on exports .Around 10% of India’s 12 million ton onion production is exported and has seen exports growing to around $500 million in 2010 up by almost 5x in the last 5 years. Can’t understand why a nation which sees so much hunger and starvation needs to export so much. The Indian government food policy is mostly adhoc and driven more by vested interests rather than any strategic long term policy. Out of the 5400 cold storages in the country almost 90% are owned by private investors which indicates the government’s lack of investment. India’s nodal agency for distribution of agriculture FCI is known for its endemic corruption and massive ongoing scams (which as usual leads to no prosecution).The Indian growth story keeps being celebrated in popular media even as crushing income disparity becomes wider and wider.

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ONION CROP LIFECYCLE

POST HARVEST MANAGEMENT OF ONION INTRODUCTION •

The annual average world production is at around 72 million metric tones.

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China is the leading producer and the other major onion producing countries are India, United States, United Arab Republic, the Netherlands, Japan, Brazil, Bulgaria, Spain, and Italy.

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In the international trade, these countries play an important role in exporting the onions contributing 74.6% of the total export (FAO 2008).

CHARACTERISTICS •

Onion is a short term crop with less pay-back period.

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Onion is highly perishable and therefore high post harvest losses occur during transportation and storage.

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Onion are also grown in large quantity in developed countries and they have better quality and longer storage life

PRODUCTION AND UTILISATION •

Onion (Allium cepa) is an important export-oriented crop of our country.

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Both immature and mature bulbs are used as vegetable and condiment.

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The cultivation of onion is done at different times throughout the year in different parts of the country.

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The crop comes to the market three times in a year Rainy Kharif 20%, Late little rainy Kharif 20% and Rabi 60% (April-May)

NUTRITIONAL AND MEDICINAL IMPORTANCE •

Onions (Allium cepa L.) are grown as vegetable as well as spice.

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They are highly valued for their flavour and for their nutritional value in supplying minor constituents such as minerals and trace elements.

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It contains vitamin B and a trace of vitamin C and also traces of iron and calcium.

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The outstanding characteristic of onion is its pungency, which is due to a volatile oil known as allyl-propyl disulphide.

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Onion can lower blood lipids and prevent hardening of arteries.

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It contains selenium that can induce the human body to release large amounts of glutathione which lowers the occurrence of cancer.

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Onion flavonoids have antidiabetic, antiaging, and bacterial-inhibition effects.

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Presence of several sulphur compounds makes it antiseptic. Onion paste is reported to be effective for external applications in case of insect bites.

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Onion is said to possess stimulant, diuretic and expectorant properties and hence useful in flatulence and dysentery.

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High amounts of Sulphur in onions make them particularly effective in regenerating hair follicles and stimulating hair re-growth

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PREHARVEST OPERATIONS •

The post-harvest technology combined with pre-harvest factors determine the shelf-life.

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Restriction on use of excessive and delayed nitrogen application (not exceeding 100 kg/ha under normal fertility condition and application of N in 2-3 splits within 60 days of transplanting), use of ammonium sulphate instead of urea for top dressing, more use of organic manures to fulfill nutritional requirement, use of vermicompost, neem cake etc. have also showed encouraging results.

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Similarly last irrigation given 10-15 days before harvesting reduces microbial losses in stored onions compared to withholding of irrigation before five days.

POST HARVEST SPRAYS •

Pre-harvest pesticides sprays of 0.02% streptocyclin and 0.1% carbendazim ten days before harvesting.

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Application of thiophanate methyl @ 0.1% + streptocyclin or klorocin @ 0.2% + ekalux @ 0.25% immediately after neck cut and combined with field and shade curing is promising under North Indian conditions

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Use of maleic hydrazide @ 2000-3000 ppm 75 days after planting for kharif onions and @ 2500 ppm combined with 0.1% carbendazim spray 10 days before harvesting in rabi onions gives better post harvest storage.

HARVESTING •

Stage of harvesting also determines the shelf-life of onions

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Storage losses at optimum maturity are normally lower than those harvested before the tops collapse.

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Harvesting one week after 50% neckfall and field curing by windrow method for 3-5 days till foliage turn yellow is recommended.

CURING •

Single most important post-harvest treatment required for the long storage .

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Curing is a drying process intended to dry off the necks and outer scale leaves of the bulbs to prevent the loss of moisture and the attack by decay during storage.

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The essentials for curing are heat and good ventilation, preferably with low humidity.

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Shade curing for 10 days is optimum to eliminate the chances of microbial infection in storage.

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Curing of kharif onions in sun or solar dryer with foliage and storage with dried foliage is better

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Curing in perforated crates with forced air circulation is recommended for rabi onions.

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Bulbs cured artificially for 16-20 h were ready for market or further storage compared to 8 – 10 days (240 h) in traditional sun curing (Centre of AICRP on Post Harvest Technology).

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Artificially cured bulbs could be stored at ambient conditions for 30 days with a maximum weight loss of about 10.5%

GRADING •

The outer dry scales usually rub off during the grading process, giving the onions a better appearance for market.

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It has been experienced that if storage is arranged after proper sorting and grading losses in storage are reduced.

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For local market the onions are graded based on their size.

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Extra large onion (>6 cm dia.)

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Medium (4-6 cm dia.)

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Small (2-4 cm dia.)

IRRADIATION TO IMPROVE SHELF LIFE •

Exposure of onion bulbs after harvesting with 60-90 Gy inhibit their sprouting regardless of crop season, environmental condition and type of storage.

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However, to reduce the microbial and other losses, combined use of irradiation with improved storage and providing the irradiation facilities at production level may be considered.

CHARACTERISTICS OF GOOD ONION •

be reasonably uniform in shape, size colour and pungency of the variety /type

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be mature, solid in feel, reasonably firm with tough clinging skins.

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be throughout cured and dried.

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be free from dust and other foreign material.

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be free from defective, diseased, decayed and damaged bulbs caused by seed stems, tops, moisture, dry sun scald burn, sprouting, mechanical or other injuries and staining.

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be free from moulds, soft rot and insect attack.

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% of seed stem or bolted bulbs shall not exceed 20% in Nasik kharif onions.

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GRADERS FOR ONION •

The drudgery of human labour involved for grading of onion has been reduced by hand operated as well as motorized onion grader developed by NRCOG, PUNE.

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The cost of grading with machine is around Rs. 26/t as compared to Rs. 80/t in hand grading.

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The precision of grading achieved by grader is 98% as against 50% in hand grading.

PACKAGING •

For safe handling, 40 kg open mesh jute bags having 200-300 g weight should be used in domestic market.

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For export, common big onions are packed in 5-25 kg size open mesh jute bags. Bangalore Rose and multiplier onions are packed for export in 14-15 kg wooden baskets.

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Nylon net bags, when used for packing have resulted in less storage loss because of good ventilation.

HANDLING •

Bulbs intended for storage must be free from cuts and handled with extreme care.

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Onions should not be dropped on to non-resilient surface from more than 6 feet height.

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If onions are to be stacked after packing in store or trucks, the better height is 2-2.5 metres.

STORAGE •

Onions should not be stored unless adequately dried either in the field or by artificial means.

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It is necessary to dry the neck tissue and outer scales until they rustle when handled otherwise the bulbs will rot in storage.

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Sprouting in onion is controlled by temperature. The temperature between 10-25°C increases sprouting.

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Rooting is influenced by relative humidity (RH). More the relative humidity more is rooting.

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Weight loss is more when temperature is above 35°C.

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Under ambient conditions the onions are stored at a temperature of 30-35OC with RH of 6570%.

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In cold storage, temperature is maintained at 0-2°C while the RH is kept at 60-75%.

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Onions are stored in these sheds by spreading them on dry and damp proof floor or racks.

Periodical turning of bulbs or removal of rotten, damaged and sprouted bulbs should be done.

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Well-ventilated improved storage structures with racks or tiers having two or three layers of bulbs would be desirable for proper storage.

GOOD STORAGE PRACTICES •

Construction of storage godown should on raised platform

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Use of appropriate roofing material to prevent built up of high temperature inside.

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Increased centre height and more slope is better for air circulation and preventing humid microclimate inside godown.

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Bottom ventilation for free and faster air circulation to avoid formation of hot and humid pockets between the onion layers.

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Avoid direct sunlight on onion bulbs to reduce sunscald, fading of colour and quality deterioration.

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Restriction on width of each stack to 60-70 cm for cool humid weather, 75-90 cm for mild and humid weather and 90-120 cm for mild and dry weather conditions

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Restriction of stacking height to 100 cm for small and multiplier onion and hot weather and 120 cm for mild weather and for big onion to avoid pressure bruising.

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Cubicles should be made instead of continuous stack leaving sufficient space for ventilation from all the sides.

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One cubic meter area of store accommodates about 750 kg onions.

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Mangalore tiled storage VALUE ADDED PRODUCTS •

Onion salt is prepared by mixing 19 to 20% onion powder with 78% free flowing pulverized refined table salt and 1to 2% anti caking agent which prevents water absorption, caking, etc.

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Onion juice is also gaining popularity. It has fresh characteristic flavour of onion because it is not subjected to high temperature at which thiosulphates (primary products associated with onion flavour) dissociate resulting in cooked onion flavour.

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Natural dye-The pink colored peel in the onion is also an excellent natural dye. It gives fast colour on cotton, silk and woolen fabrics.

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Onion pickle-Peeling, Blanching for 5 minutes, Filling blanched onions in a jar, Addition of salt, Standing for 24-48 hours, Draining off water, Addition of vinegar and spices and Storage

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Poly house solar dryer for onion Onions Shelf Life

Onions, cured, whole Onions, sliced or diced Onions, cooked Precooked Onion Rings^ Garlic Leeks Green Onions (scallions) Shallots

Pantry

Refrigerator

Freezer

2 weeks

2 months

1 year

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3-4 days

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3 days --

-1 year

1 month --

1-2 weeks 1 weeks

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3-5 days

1 month 10-12 months --

2 months

1 month

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Freshness Facts Drying conditions: Temperature: ....................... 100 F Relative humidity: ................... 65% Storage conditions: Temperature: ........................ 32 F Relative humidity: ................... 70% Freezing temperature: ................. 31 F Storage life: Refrigerated .............. 2 to 3 months Controlled atmosphere ...... 6 to 8 months

Understanding the Onion Storage issue Onion prices have hit around Rs 70-80 a kg in retail during Dec 2010 which is equal to the average wage of $2 for 80% of the India. This is a cold fact. Part of the blame lie in our ancient onion storage systems and inability of all stakeholders in onion industry to establish modern onion storage systems in India.

Onion, being high in water content, is a delicate commodity to store and requires special procedure and parameters, giving rise to the concept of Onion cold storage. Onion is an important vegetable crop grown in India and forms a part of daily diet in almost all households throughout the year. But due to non-availability of appropriate post-harvest storage facilities, 25-30% of the total produced onions are wasted, which in terms of value amounts to Crores of rupees. Building up of the cold storage unit would minimize the waste up to the level of 3 to 4% that would in turn help the onion growers, and stabilize onion prices in market for all types of consumers.

The fact that we Indians can store onions from one harvest to the next in bamboo challis and tatties and maintain outstanding quality, albeit rising prices during non-harvesting season, is taken for granted. The reality is that 30% of onion is wasted during storage.

The reality is that ability to hold onions in long-term storage and deliver quality product months after harvest is directly related to advances in ventilation system design and management. The ventilation system is really the key to maximizing profits from storage. Once the onions are harvested and placed in storage, the ventilation system is the only tool one has to interact with the crop. Anything that we do to the onions will occur using the ventilation system. For example, the processes of curing, cooling to holding temperature and dehumidification are all driven by the ventilation system and its components.

In short, the ventilation system is our life-line to the onions.

Ventilation System Design The ventilation system can be thought of like a car, in that it is composed of many components and control systems, each one with a specific job. Also like a car, each component must be the right size and

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the right part, or the car will not function properly. Modern onion ventilation systems are complex and composed of a variety of different components. These commonly include fans, fresh air doors, refrigeration equipment, burner systems, de-humidification equipment and control systems. In order for the ventilation system to operate effectively and promote onion quality, it must be properly deigned, properly installed, and properly controlled considering the product and environmental variables.

Proper ventilation system design is the foundation for the success of all onion storage efforts. In order for a ventilation system to function as desired, it must be properly designed and each component must be correctly specified and sized – in short customized as per the prevailing situation.

This is concept is the driving force behind the modern onion storage systems which are engineered and designed to conform to specific standards for airflow rate, fan selection, fresh air door sizing, plenum sizing, duct sizing and configuration, exhaust sizing, refrigeration system capacity, burner system capacity, and controls. The fact is that each component within the system will impact all of the others, and must be selected correctly. For example, undersized fresh air door area will increase inlet air velocity, increase total system static pressure, and reduce overall system airflow and performance. By specifying and sizing each component based upon a wealth of practical experience, as well as the most advanced engineering techniques, the grower and storage manager can be assured of optimized system performance, maximized energy efficiency, and the best onion quality possible from a modern onion storage system.

Ventilation System Operation Having said above, onion quality and storage profitability are maximized when the ventilation system is not only properly deigned, but also properly managed. Specific storage management practices vary with geographic location, status of the onion at harvest, ambient weather conditions, and intended end-use of the crop, but several fundamental concepts apply to every situation. First, it is critical that storage management decisions are based on the actual condition of the crop at harvest. Second, you must have the ability to control and modify the storage environment to precisely meet the needs of the onions.

This means you must be able to accurately control airflow, plenum temperature, plenum humidity, and return air temperature and humidity. To ensure accurate control of all system parameters you must have a control panel that continually monitors these key factors and maintains the desired environmental conditions using an advanced, integrated control strategy. The control panel provides the most advanced control capability, coupled with the most user-friendly programming found anywhere.

This panel continually monitors all environmental parameters and automatically controls all system functions, including refrigeration, burner systems, de- humidification equipment and airflow, to provide you with the ideal storage environment. Using advanced control logic is as easy to use.

Summary Storage is the culmination of the enormous amounts of time, effort, and money required to produce the crop. Although it is tempting to view storage as simply piling onions in the bamboo challies, it is really much more complex and important. The design, installation, and management of the ventilation system are the most critical components to successful storage. Remember, once the onions are in the building

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the ventilation system is our only line of contact and defense. Growers and storage managers who take the time to analyze their storages and implement the changes required to maximize onion quality and ventilation system performance will reap the rewards of improved profitability.

ONION STORAGE STRUCTURES India is one of the largest producers of onion in the world second only to China, accounting for 16 percent of world area and 10 percent of production. In India, it is grown on 0.39 million hectares with production of 4.30 million tonnes of bulbs per annum (FAO,1995). The current year's production is estimated at 4.7 million tonnes. It is one of the most important vegetable crops of our country and forms a part of daily diet in almost all house holds.

Most of the farmers bring onion directly to the market after harvest as proper storage facilities are not available with them. The present storage capacities are quite inadequate and most of the available units are traditional and unscientific. Fearing losses, farmers usually unload their entire stock within a month of harvest. As a result, during this period prices rule very low due to glut situation. Thereafter, the rise in prices is quite rapid and sometimes wide fluctuations occur leading to dissatisfaction amongst the producers as well as consumers. To improve the situation, GOI desired to create appropriate storage structures for onion, both at farm level as well as at market places. It drew a capital subsidy programme for the infrastructure development in which a pivotal role has been assigned to NABARD for its successful implementation. It has been planned to create a storage capacity of 4.5 lakh tonnes of onion during 1999-2000 and 2000-2001 through capital investment subsidy programme. Subsidy to the extent of 25% of the investment cost subject to a maximum of Rs. 500 per tonne has been proposed to be routed through NABARD for the credit delivery system.

We endeavor to provide information on various broad technical and financial aspects of a onion storage unit to enable all the participants for the speedy clearance of such projects.

Status of Onion Storage Structures and its Potential in India Onion is grown almost round the year in one or other parts of the country. It is predominantly a Rabi season crop but is also grown under a wide range of agro climatic conditions in other seasons. There are three main crops of onion grown according to climatic conditions and they are called Kharif, Rangada and Rabi or summer. According to agro climatic conditions, specific varieties are developed for different seasons; Kharif varieties can be grown under relatively short photo period (10-11 hr) and cloudy atmosphere but have poor keeping quality while Rabi varieties require long photo period (12-14 hr) with clear sunny days and some of them have excellent keeping quality of four to six months. Onion storage structures are designed mainly to store the Rabi varieties.

World output of onion is about 43 m tonnes. The notable producing countries are China, USA, USSR, Netherlands, Spain and Turkey. Most of the onion produced in India comes from the state of Maharashtra, Gujarat, Uttar Pradesh, Orissa, Karnataka, Tamil Nadu, Madhya Pradesh, Andhra Pradesh and Bihar. Maharashtra is the leading producer accounting for 20% of the area and 25% of the production.

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The present storage capacity for onion is about 4.6 lakh tonnes. This is quite inadequate compared to our total production. Even most of the structures available are traditional and unscientific. If 40 % of the stocks are earmarked for scientific storage the potential for new storage structures is about 12.6 lakh tonnes. However, it has been projected by the Expert Committee on Cold Storage and Onion Storage that about 1.5 lakh tonnes on-farm capacity in production areas and 3.0 lakh tonnes capacity at APMCs and other market places are required in next 5 years. Thus there remains a vast potential to be tapped.

Extent of Storage Losses The onion bulbs are generally stored from May to November for a period of four to six months.

However, 50-90 per cent storage losses are recorded depending upon genotype and storage conditions.

The total storage losses are comprised of physiological loss in weight (PLW) i.e. moisture loss and shrinkage (30-40%), rotting (20-30%) and sprouting (20-40%). The PLW can be minimized by harvesting at right time, proper curing of onion bulbs and subsequent storage at desired temperature and humidity conditions. Generally, the rotting losses are at peak in initial months of storage, particularly in June and July, when high temperature coupled with high humidity result the losses. However, proper grading and selection of quality bulbs and good ventilation conditions can reduce the rotting losses. Application of post harvest fungicidal sprays can also reduce the rottings. But this is not a practice in India. Sprouting losses are usually recorded at the end of storage period or when exposed to high temperature of humid air. Noticeable sprouting losses are observed because of storage of poor quality bulbs having less rest and dormant period and also having thick neck. Comparatively, more sprouting losses are recorded in dark red and white onion cultivars than the light red onion cultivars.

Onion and its Physiology for Storage Every agricultural commodity is required to be stored properly to prolong the availability with minimum qualitative and quantitative losses. Onion is not an exception. The onion bulb is a natural food store for the plant, but it is a living system undergoing a process of development towards sprouting, and is subject to decay by various disease causing organisms. The objective of storage technology is to maintain the bulbs for as long as possible in an unchanged sound condition with longer shelf life, and allow them to transport and market after removal from store without much losses.

It is necessary to have the knowledge of the physiology of dormancy and epidemiology of storage disease while thinking of long term storage. Systems to provide long dormant condition and suitable condition which is unfavorable for disease development can be engineered using the physical principles of temperature and humidity control. Also in this process economic and technological constraints will have to be looked into. For this, two basic strategies i.e. high temperature dormancy of onion bulbs and maintaining storage temperature at around 300 C need to be exploited.

The physiological and pathological processes that proceed within a store of onion bulbs interact with the physical process of heat and water vapour exchange so as to mutually influence the environment within the store. Main factors which influence onion storage and bring change in the bulbs are summarized as under in sequence:  

With time, sprouting and internal root development proceed.

Sprouting and internal root development change bulb shape, tension of skins and crack the skins.

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    

    

This increases the conductivity of skins to water vapour and ultimately rate of water loss from the bulbs.

Increase in sprouting increases respiration.

Increase in respiration increases outputs of heat, CO2 and water loss from the bulb.

Diseases are developed in store when there are favorable conditions and bulbs thus get deteriorated.

Bulb deterioration due to diseases will also increase respiratory outputs. The onion skins has vital role in the physical and physiological processes in the storage, as it is the main barrier to water loss and to CO2 exchange. 65-70% relative humidity is desirable to maintain the skin fairly flexible and elastic. At lower RH, the skin become very brittle and gets easily cracked notably when skin moisture content falls below 20%.

Ventilation is needed to maintain humidity between 65-70% and lack of this often adversely affects the quality and quantity by increase in water loss and respiration.

Ventilation is also needed to dissipate heat produced by bulbs.

With time, requirement of ventilation for the above will also increase.

Design of store should, therefore, match the requirements.

High humidity with high temperature favors spread of pathogens within the store.

It is necessary to counter the above changes by proper monitoring of internal environment. Heat and water vapour must be removed or introduced as necessary either by using heating or refrigeration or ventilation or a combination of all the mechanisms depending upon the economics. However, under Indian conditions in onion growing states designs to exploit natural ventilation is most economical.

Onion Storage Structure Requirements For effective long storage of onion the parameters essential to be looked after are the bulb size, choice of cultivars, cultivation practices, time of harvest, field curing, removal of tops, drying, grading, packing, storage conditions (optimum storage range of relative humidity 65% to 70% with the temperature ranging between 250 C to 300 C).

Salient Features of Improved Storage Structures are: 1. Construction of structure on a raised platform to prevent moisture and dampness due to direct contact of bulbs with the soil.

2. Use of Mangalore tile type roof or other suitable materials to prevent built up of high inside temperature.

3. Increased centre height and more slope for better air circulation and preventing humid micro climate inside godown.

4. Providing bottom and side ventilations for free and faster air circulation and to avoid formation of hot and humid pockets between the onion layers.

5. Avoid direct sunlight or rain water falling on onion bulbs to reduce sun scald, fading of colour and quality deterioration.

6. Maintenance of stacking height to avoid pressure bruising.

7. Periodical disinfection of structures and premises to check rottage.

8. Cost effectiveness of structures is based on utilization of locally available material for the construction.

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For onion storage, technology may be either with natural ventilation or with forced ventilation.

Although cold storage systems are used in certain countries for onion, this is normally not adopted in India due to poor economics and lack of cold chain facilities required to maintain the quality in the high ambient temperature prevalent in our country. Onion storage in ventilation condition is quite satisfactory when the temperature is maintained between 25oC to 30oC with a relative humidity range of 65% to 70%. This environment reduces the storage losses, which are in the form of physiological loss in weight, rotting and sprouting. The onion storage structure should be oriented in the North - South direction i.e., length facing the East-West direction. The storage of onion will be on raised perforated platform of 0.60 m height with bottom and side ventilations. The ground clearance may be 60 cm with side opening of upto 80%. Height of storage under ventilation storage should be in the range of 90 cm to 150 cm. For a 25 MT storage, the size of onion storage area will be 4.5m X 6.0m. The width of storage may be reduced depending upon the availability of local construction material and ambient condition.

The length of storage structure may be increased to suit the requirements of the individual farmers. The minimum overhang of 1.5 m on the windward side and 0.5 m on all other sides should be provided to protect the produce from sunlight and rain. At leeward side, the opening below the platform should be closed to direct the air upward for better ventilation. Where storms/ cyclones are expected, leeward side should not be closed when the windward side is open. During storm there should be a provision to close the windward side. Emphasis should be laid for better area utilization efficiency. The overall dimensions of a 25 MT structure may be 6.5 m X 7.0 m. The dimensions can be adjusted depending upon the capacity and site conditions. The roof of the structures may be either Mangalore tile type or ACC sheets for a single tire arrangement or RCC for two tier systems. In case of Mangalore tiles, proper fixation should be done at the ends to prevent damage by air. If cheaper materials are available which can prevent heat built up at the top of the structure, they can also be used. The foundations should only support the pillars to bear the load of the structure and wind. Continuous half brick thick wall may be provided on the leeward side below the storage platform to serve as a wind barrier. MS angles may be used for the truss and pillars. Half split bamboo sticks supported by MS angle frames may be used for storage of onion. Side walls can also be of chain link (GI wire) type. It has been observed that such structures can be constructed with an investment cost between Rs. 1500 to Rs. 2000 per MT. Therefore, adequate care is to be taken for economizing the structures.

Onion Storage Practices Onions are stored either loose or in bags. The beneficiaries may be advised to sort the onions prior to storage and thereafter atleast once in thirty days to take out the rotten/ infected onions in order to avoid further spread of diseases/ losses. Generally, a loss of about 20-30 % is there during a storage season in the form of weight loss of onions which can be controlled with proper care. However, the other types of losses can be controlled to a greater extent if the structure is designed to facilitate maximum natural ventilation through the stored onion and sorting is done at regular intervals.

Onions can be stored at two temperatures (ranges): Around 2°Celsius. This is the optimal storage temperature, under which good storable onions (see above) can be stored up till 12 months. The major disadvantage of this temperature is the long period necessary to raise the temperature above the Local Dew Point. If this is not done correctly, the whole batch of onions will become completely wet and great losses will be incurred.

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A good alternative temperature range, especially when storage time does not exceed 3 to 4 months, is from25 째Celsius to 32 째 Celsius. In this temperature range the bulb, which is still a living organism, hardly has any respiration and will, therefore, hardly lose any weight.

In both cases: Relative Humidity has to be maintained between 75% and 80%.

Note: The onion bulb will lose serious amount of weight while stored at temperatures between 5 to 25째Celsius, through respiration and the temperature range between 20 to 25째Celsius is especially dangerous because of the activity of certain bacteria and fungi.

During the storage process the ventilation will be minimal. Because DRY is DRY and we don't want to lose unnecessary weight through respiration, (despite the fact that at the storage temperature levels the expiration is close to zero). The only reason for the ventilation is to avoid the build-up of the CO2 in between the onions.

NATIONAL AGRICULTURE DEVELOPMENT PROJECT- ONION STORAGE STRUCTURE SUBSIDY SCHEME :

Maharashtra State produces 25-30% onion of the total production of the country. Maharashtra State contributes about 80-85% in the total onion export.

Out of the total onion production in the State, 10-15% onion production is in Kharif season, 30-40% production is in Late Kharif and 50-60% production is in Rabi/Summer season.

Generally onion produced in Kharif and Late Kharif season is not suitable for storage while onion produced in summer season can be stored upto 5-6 months and it can be brought in the market during rainy season i.e. from June to October.

There are certain problems which arises during conventional storage of onion viz. loss in weight, sprouting and rotting of bulb. To overcome these losses onion must be stored in scientific manner and its prices.MSAMB with the help of NABARD and National Research Centre for Onion and Garlic, Rajgurunagar has developed revised plan for scientific onion storage (Kanda chawl) to promote onion producers for scientific onion storage. The onion storage as per this plan will minimize the storage losses and quality deterioration of the onion which will in turn help the farmers to fetch better prices for their

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produce. To encourage the farmers for setting up of scientific onion storage systems, MSAMB has formulated the subsidy scheme for scientific onion storage. Under National Agriculture Development Project Govt. of India, MSAMB has submitted a proposal for implementing the subsidy scheme for scientific onion storage. To get benefit of this scheme farmer should erect onion storage structure according to proposed plan only. The construction cost of the onion storage structure is assumed at Rs. 6000/- per MT for this scheme. As per the scheme, subsidy 25% of the construction cost or to the extent of Rs.1500/- per MT storage capacity. The onion storage structure of 5, 10, 15, 20, 25 & 50 MT capacity are eligible for subsidy. Under National Agriculture Development Project MSAMB will give Rs.1500/subsidy for above mentioned capacity of onion storage. The scientific drawing on modern lines and cost estimates for onion storage structures are available at free of cost with Head Office, Divisional Offices of MSAMB and District De[uty Regisrar, Assistant Registrar, Co-operative Societies & Agriculture Produce Market Committee.

BENEFICIERIES OF SCHEME : The main beneficiaries of this scheme implemented by MSAMB are farmers, Agriculture Produce Market Committee, Onion Growers Co-op Soc., and Marketing Socs.

CONSTRUCTION OF ONION STORAGE STRUCTURE: Modern onion storage structures have been so planned to aerate the onions from all sides. Following points to be followed during its construction.

1. It is necessary that lower base of onion storage structure should be raised from the ground level by 1.5' to 2.00' for that the foundation should be laid out according to soil type. Pillar height should be 1.5' to 2'.

2. Skeleton of structure should be rest on these pillars and it should be made up of iron angles/wooden material. Lower base can be made up of iron angles wooden battens. Its breadth should be a 5'.

3. Side wall should be made up to bamboo battens/iron angle with the support and help of iron angles.

Its height should be 5'. Bamboo battens/iron angles should be so arranged that onions should not come out of it and also proper air circulation should be made which should be at 5' height.

4. Height of roof of onion storage structure should be 2' above onion stored. For roof iron/cement/Manglore tiles should be used. Material of roof should be heat resistant. Also, according structural design roof should have sufficient slope.

5. To avoid droplets rain water and sunlight, sides of roof should be sufficiently projected outside and also same from direction of rain (south-west).

Do's and Don'ts able for onion storage structure: 1. Site selected for onion storage structure should be well drained and should be easily accusable to good road. Ill drained and deep site should be avoided.

2. Onion storage structure should be naturally ventilated from lower and other sides. Circumstance for natural ventilation should be avoided or minimise.

3. There should not be tall civil work close to structure. Tall civil work should be 1.5 times height of onion storage structure away from onion storage structure.

4. The width of onion storage structure should be 610 cm. for natural air circulation. In high humid area width of storage structure should be less otherwise there should be provision of mechanism for air circulation. The width of onion storage structure should not be more.

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5. The length of onion storage structure should be right angle to the direction of wind (East-West). While constructing onion storage structure the length of structure should not be in the direction of wind.

6. Windward side of storage should have closing system during storm and heavy rain and opening facility when necessary. During storm and heavy rain windward side of storage should not be open.

7. The sides of the roof should be sufficiently forwarded to avoid rainwater and to resist heat. The sides should not be short.

8. There should be heat resistant material at the upper side of roof of onion storage structure. Do not use galvanised iron sheets for roof.

Onion storage structure of 25 M.T. Capacity:

Onion storage structure of 50 M.T.Capacity:

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TECHNO - FINANCIAL PARAMETERS AFDOPTED FOR WORKING OUT THE ECONOMICS OF A 25 MT ONION STORAGE STRUCTURE 1

Land requirement

6.5 m X 7.0 m

2

Storage space requirement 4.5 m X 6.0 m

3

Technology preferred

Natural or forced ventilation maintaining a temperature between 25 and 30 o C with a relative humidity range of 65 to 70 %.

4

Clearance of storage platform from the ground

60 cm

5

Height of the storage platform

90 to 150 cm

6

Cost of construction

Rs. 45000 ( unit cost of Rs. 1800 per MT)

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Capacity

25 MT

8

Capacity utilization

100%

9

Weight loss in onion upto 3 12.50% months

10 Onion sold upto 3 months

50%

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Weight loss in onion from 3rd to 6th month

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Onion sold between 3rd and 50% 6th months

12.50%

13 Sale price: (a) Sale price of onion sold Rs. 2.00 per kg at the time of harvest (b) Sale price of onion sold Rs. 3.50 per kg upto 3 months (b) Sale price of onion sold between 3rd and 6th Rs. 5.50 per kg months 14

Handling/ transport/ grading/ sorting charges

Rs. 0.90 per kg

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15

Interest loss to the farmer on Rs 45000

14%

16 Life of the storage structure 15 years DO'S AND DON'TS DOS

DON'TS

1

Suitability of site with proper elevation, drainage Site in a low lying area with poor road and linkages by road. communication must be avoided.

2

Adequate bottom and side natural ventilation Any obstruction to the natural ventilation should facilities should be provided. be avoided or minimized.

3

No tall structures should be located nearer to Tall structures within a distance of 1.5 times the the onion sheds. height of onion storage structures should be avoided.

4

For natural ventilation, storage width should be Wider storage structures should be avoided. restricted to 610 cm. In the areas having high humidity, the storage width may be reduced/ necessary mechanical ventilation provision may be made.

5

Onion storage structures should be oriented to Structures along the wind direction should be face wind ward direction. avoided.

6

Leeward side wall opening below the platform Where storms and cyclones are expected, should be closed. leeward side should not be closed when windward side is open.

7

During storm/ heavy rains, provision should be During storm/ heavy rains, windward side should made to close the windward side and wherever not be kept open. necessary to open the leeward side.

8

Adequate overhang should be provided to Structures with small overhangs should be prevent splashing of rain water or sunlight falling avoided. on the onion

9

The roof of material should prevent heat built-up Roof materials like corrugated GI sheets should at the top of the structure. be avoided.

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ONION CURING Curing & Drying Both curing and drying remove excess moisture from the outer layers of the bulb prior to storage. The dried skin provides a surface barrier to water loss and microbial infection, thereby preserving the main edible tissue in a fresh state. Drying also reduces shrinkage during subsequent handling, reduces the occurrence of sprouting, and allows the crop to ripen before freshconsumption or long-term storage (Opara and Geyer, 1999). This process of dehydration is sometimes called ‘curing’, but the use of the word ‘curing’ for onion drying is rather inaccurate since no cell regeneration or wound healing occurs as in other root crops such as yam and cassava. Drying reduces bulb weight and since they are sold mostly on a weight basis, achieving the desired level of dehydration is critical. Weight losses of 3-5% are normal under ambient drying conditions and up to 10 % with artificial drying.In traditional small-scale operations, onion drying is carried out in the field in a process commonly called ‘windrowing’. It involves harvesting the mature bulbs and laying them on their sides (in windrows) on the surface of the soil to dry for 1 or 2 weeks. In hot tropical climates, the bulbs should be windrowed in such a way to reduce the exposed surface to minimise damage due to direct exposure to the sun. In wet weather, the bulbs can take longer time to dry and may develop higher levels of rots during storage. The side of the bulb in contact with wet soil or moisture may also develop brown strains or pixels, which reduce the appearance quality and value. Obviously, successful windrowing is weather dependent and therefore cannot be relied upon for large scale commercial onion production business. Bulbs harvested for storage require in total 14-20 days of ripening or drying before being stored. Harvested onions may also be placed in trays, which are then stacked at the side of the field to dry. In some tropical regions, the bulbs are tied together in groups by plaiting the tops, which are then hung over poles in sheds to dry naturally.Harvested bulbs can also be taken straight from the field and dried artificially either in a store, shed, barns, or in a purpose-built drier. This method is commonly used when crops are stored in bulk but it can also be applied to bags, boxed or bins. Under this method, bulbs are laid on racks and heated air is rapidly passed across the surface of the bulbs night and day *O’Connor, 1979; Brice et al., 1997+.

Drying may take 7-10 days and is considered complete when the necks of the bulbs have dried out and are tight and the skins shriek when held in the hand. The control of humidity level in the store is critical.

Under very high humidity, drying is delayed and fungal infection can increase. However, if relative humidity is too low (below 60%), excessive water loss and splitting of the bulb outer skins can occur, resulting in storage losses and reduction of bulb value. Placing onions on wire mesh in well ventilated conditions and using air at about 30°C, 60-75% rh and 150 m³.h -1.m-3is generally recommended for mechanical drying of onions.

Drying Methods Pallet Bins A fan and pallet bin arrangement similar to that used in forced-air cooling applications and located in an open building may be used to dry onions. (See Cooperative Extension Service publication AG-414-

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3,Maintaining the Quality of North Carolina Fresh Produce: Forced-Air Cooling.) This method will give satisfactory results with unheated air, provided that the atmospheric humidity is low enough for good drying. The time required for complete drying ranges from 3 to 7 days or more, depending on the temperature and relative humidity. Although low in initial cost, this method may be too slow for many growers, and it increases the risk of infection from neck rot and other postharvest diseases.

Such an arrangement may also be assembled with a heat source inside a closed building, as shown in Figure 2. Adding a suitable properly vented gas or oil heater will reduce drying time considerably. The building should be relatively tight and have a concrete floor. A building with a dirt floor is not suitable for dry-ing onions. A moderate amount of building insulation (for example, 1/2 inch of foil-backed polyisocyranuate foam) would improve energy efficiency. The relative humidity inside the building can be regulated with a combination of louvered vents and exhaust fans.

Figure 2. Fan and pallet bin arrangement used to dry onions.

A more sophisticated system that uses permanently mounted fans and a heat source will dry as many as 10,000 bushels (500 20-bushel pallet bins) at one time. Such a structure is known as a horizontal air ventilation system. This system could, with slight modifications, be used for several crops. For example, such a building might be used to cure and store sweetpotatoes. With the addition of refrigeration, the same building can be used for forced-air cooling of fruits and vegetables. Sample plans may be obtained through your county Cooperative Extension Center or from the Department of Biological and Agricultural Engineering at North Carolina State University.

Peanut Drying Wagons In the Southeast, some onions are grown in peanut-producing areas. In these areas, onions have been successfully harvested into peanut wagons and dried with peanut dryers. This arrangement allows growers to make efficient use of their equipment since onion harvesting and peanut harvesting occur several months apart. From the standpoint of energy efficiency, however, this alternative may not be the best. For a given volume, onions dry much slower than peanuts. Since most peanut-drying equipment does not have provisions for air recirculation, a large percentage of the heated air is not efficiently used.

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Tobacco Barns Onions have also been successfully dried in both rack- and box-type tobacco barns. Many bulk-curing barns have slotted metal (grain) floors onto which mesh bags of onions may be stacked and dried.

Unfortunately, not all barns are designed with floors that will support the substantial weight of the onions. Barn manufacturers can supply information on the suitability of their units for this purpose.

Box barns are particularly well suited for drying onions. Wooden or metal boxes of the same dimensions as the tobacco boxes may be built for less than $100 each. Depending on the make and model of the barn, these boxes may have a capacity of up to 75 bushels each and can be trucked to the field for filling.

Figure 3 illustrates onion drying in a tobacco-curing barn.

Figure 3. Onions drying in a box-type tobacco barn.

The 5 different storage systems to dry cure and store onions, potatoes, carrots and other crops are: 1.

2.

3.

4.

5.

Box storage with lateral ventilation, Bin storage with lateral ventilation and climate control, Bulk storage, Box storage withpressurized ventilation, Box storage with suction ventilation.

Storage systems 2 to 5 are also fit for cold storage

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Lateral ventilation for box (bin) storage with limited climate control.

Lateral ventilation for box (bin) storage using COMBIVENTS.

Box storage with forced ventilation using a pressure wall.

Box storage with forced ventilation using a suction wall.

Bulk storage with pressurized floor ventilation.

The MULTISERVER and Control Panel with its 6 basic basic components to fully control onion storage systems.

The Turbines

The Hedges

The Sensors

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<<—— The MULTISERVER The 6 basic components of onion or potato storage systems.

All these components are brought together by an AgroVent MULTISERVER and its Control Panel.

The Control Panel ——>>

The Heaters and Condensors

The Humidification Systems

The Wooden Storage Boxes

Storage Boxes for Onions and Potatoes.

The wooden boxes for onion or potato storage have to be constructed with special attention, because: 1. The boxes have to be very straight and square, otherwise the suction or pressure systems will lose far too much pressure by escaping air in the slots created by the badly formed boxes.

2. The boxes have to be constructed very ruggedly otherwise they would not last more than a couple of years. Normally well constructed boxes will last more than 10 years.

Measurements of a Standard Box Size are: Length: 1.600 mm Width:1.195 mm Height: 1.232 mm. All outside measurements.

Capacity of this standard size: 1.000 Kg of onions 1.250 Kg of potatoes.

Sometimes lower boxes are seen when storing especially delicate onions. But the smaller the box the higher the costs per kg of product. The standard size is very easy to handle with a simple forklift truck.

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3. The boxes not only have to be ruggedly built but have to be able to sustain the weight of some times 4 to 5 boxes on top of each other.

4. The inside of the boxes should not have sharp edges otherwise the onions or potatoes will be damaged.

Two storage boxes for a suction storage system.

The boxes for a pressure system need hermetically closed sides, while the boxes for the suction system need ventilation slots in the four sides.

The inside of a storage box. Note the rounded support struts.

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SUMMARY Onion is a seasonal crop and has comparatively low storage ability and bulbs are usually stored until the harvest of next season crop or for longer period due to seasonal glut in the market. Significant losses in quality and quantity of onion occur during storage. Storage of onion bulbs has, therefore, become a serious problem in the tropical countries like India. The post-harvest losses, viz., sprouting, rotting and physiological loss in weight pose a great problem.

It is reported that annual storage losses were over 40 per cent and between 40 to 60 per cent in India. It is estimated that out of the total production of 41 lakh tonnes of onion, 40 to 50 percent valued at more than Rs 600 crores are lost due to desiccation, decay and sprouting in storage. This results in raise in their price to the tune of four to five times when they are in short supply.

Onions are traditionally stored by conventional methods in various parts of the country. These include hanging in bunches along with tops particularly in case of sets and planting materials or in various types of godowns known as Chawls in Maharashtra, Kup or Tat in Haryana, Delhi and Meda in Gujarat.

The losses, where no bottom ventilation is provided, are estimated to the extent of 30 to 35 per cent due to driage, 10 to 12 per cent by decay and 8 to 12 per cent on an account of sprouting, depending upon the relative humidity and temperature during the rainy season.

Although the techniques have been found for controlling post-harvest losses , it involves a considerable amount of cost investment, equipment and specialised storage structures. Therefore, these are not economically feasible methods for control of storage losses in the developing countries like India.

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Low cost farm level technology is, therefore, required to be developed to extend the shelf life of fresh vegetable produce, such as onion to increase its marketability and to make fresh onion available to the consumer round the year at a reasonable price.

ARRIVING AT THE AREA OF INTERVENTIONCURING Curing is the most important operation in the post-harvest technology of onion.

It helps in reducing the post-harvest decay and moisture loss due to the removal of excess moisture from the outer skin and neck of freshly harvested onion to a level where shrinkage from the interior will be minimum and reduction in microbial infection.

Improving the curing techniques will reduce about 15-20 % losses of onion in the storage systems. Braiding the onions while curing seems to be most effective method as it exposes onion for overall ventilation. But it is followed only when there is small scale cultivation. So there is a need to innovate a technique which is as effective as braiding and easier than it to practice.

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ONION CURING- DIFFERENT WAYS

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35

36

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DESIGN BRIEF ISSUES IN FOOD CHAIN (Onion)-From Farm to Kitchen AIM: To study the food supply chain of a particular food item cultivated in India.

OBJECTIVE: To find out the issues and gaps in food supply chain and propose the solutions to minimize them.

METHODOLOGY: General food supply chain is to be studied. Particular food item which has crucial facts in supply chain has to be selected. Onion is selected considering its issue about wastage in storage. Whole supply chain of Onion is studied by primary resources and secondary resources.

Post harvest management of Onion •

Cleaning

•

Curing

•

Sorting and grading

•

Storage

•

Consumer packing

Arriving at the area of intervention Curing is the most important operation in the post-harvest technology of onion.

It helps in reducing the post-harvest decay and moisture loss due to the removal of excess moisture from the outer skin and neck of freshly harvested onion to a level where shrinkage from the interior will be minimum and reduction in microbial infection.

Improving the curing techniques will reduce about 15-20 % losses of onion in the storage systems.

Braiding the onions while curing seems to be most effective method as it exposes onion for overall ventilation. But it is followed only when there is small scale cultivation. So there is a need to innovate a technique which is as effective as braiding and easier than it to practice.

BRIEF: TO DEVELOP AN EASIER AND MORE EFFICIENT CURING TECHNIQUE FOR ONION IN TERMS OF COST, SPACE AND FUNCTION TO REDUCE FURTHER LOSSES IN THE STORAGE OF ONION.

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REFERENCES Visits (Includes library visits) Krishi Anusandhan Bhawan I, Pusa, New Delhi Krishi Vigyan Kendra, Ujwa, Delhi - http://www.icar.org.in/ National Horticultural Research and Development Foundation, Janakpuri, New Delhi Other Sources Krishi Vigyan Kendra, Nashik - http://www.kvknashik.com/ Post Harvest Research Complex (PHRC), Lasalgaon Internet http://www.keralaagriculture.gov.in/htmle/bankableagriprojects/ae%5Conionstorage.htm http://www.msamb.com/english/schemes/onionstorage.htm http://www.onions-potatoes.com/storage/storage-onions/storage-onions-ventilationsystems.php http://www.nabard.org/modelbankprojects/onion.asp http://www.fao.org/fileadmin/user_upload/inpho/docs/Post_Harvest_Compendium_-_Onion.pdf

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