Cold storage facility is crucial to preservation of agricultural products. Most consumables are highly perishable and require adequate storage or refrigeration. This is where cold storage business is essential to prevent post-harvest losses. Harvesting requires minimal handling of produce, cleaning, sorting. Different stages of post-harvest are harvesting, precooling and transportation. Other stages are packaging the produce, cold storage before it hits the market.
- Minimal handling of produce
- packaging the produce
- cold s storage
What contributes to post harvest losses
There are many factors that contribute to post harvest losses. The main factor is poor handling of produce, high cost of transportation and marketing. Others include low incentives, government regulations, poor cleaning, cold storage and packaging facility. Most farmers are small hold entrepreneurs with limited funds with lack of knowledge of modern farm practices.
Cause of Post-Harvest Losses
- poor handling of produce
- high cost of transportation
- low incentives
- government regulations
- poor cleaning
- no cold storage facility
- no packaging facility
- limited funds
- lack of knowledge of modern farm practices
Cold Storage Small-scale Production
The business is energy intensive and a costly enterprise. To succeed proper inventory, log taking and equipment maintenance is mandatory. Things to consider before setting up a cold storage business is site selection and equipment.
Others are proper waste disposal system, drainage system, capital, skilled labor, water and electricity. Provide backup generating set, large storage facility, good road network with loading/offloading area.
Startup Considerations of Cold Storage
- site selection
- operational license
- cold storage equipment
- proper waste disposal system
- drainage system
- skilled labor
- backup generating set
- large storage facility
- good road network
- loading/offloading area
Appropriate site selection is important to the success of the enterprise. Lease or purchase site close to raw materials or major market. Make sure the site has good road network, utilities like electricity and water.
Secure an operational license from federal or state government. Then register a limited liability company and get tax identification number. Obtain different insurance cover for equipment, liability, health etc.
Cold storage is capital intensive and require huge funds. Approach a commercial or merchant bank for long term low interest loans. Other loan sources are venture capitalists, partnership, and crowdfunding.
There are many reasons farm produce deteriorate after harvest. Reasons include pests, humidity level, temperature, ethylene, carbon dioxide and bacteria. Cold storage increase shelf life of produce like animals carcass, fruits, vegetables, cereals.to prevent spoilage or deterioration of farm produce humidity, air velocity and temperature control is essential. Cooling reduces microbial activity or physiological change in produce. The vegetables and fruits remain fresh increasing the shelf live.
Short storage of multiple-produce
Once precooled and transported to cold storage facility the shelf life of produce is maximized in storage at optimum temperature. The requirements of each type of produce is taken into account in the facility. In short term storage certain items are kept together.
At a temperature of 7C-10C with humidity of 86-96% store tropical fruits and citrus fruits together. At zero degrees centigrade with relative humidity 90-98% store berries, Cole crops and leafy vegetables together. Root type vegetables, melons, most tropical fruits and winter squashes are stored at 13 – 18C with relative humidity at 86-95%.
Poor Storage Mix
We have established that storage mix is a common technique used by cold storage facilities. However some fruits and vegetables will cause ethylene production or odor transfer. Avoid storing pears with potatoes or pineapples with green peppers. Avoid cabbage with pears, strong scented vegetable with citrus fruits.
Effect of Temperature Control
The effect of temperature on relative rate of deterioration affects shelf life of produce. Zero temperature has a relative rate of 1% deterioration with self-life of 45 days. 10C has a 3% rate of deterioration with 15 days shelf life.
20 degrees centigrade has a 7.5% rate of deterioration with 5 days shelf life. 30 C temperature has 15% relative rate of deterioration with 2.5 days shelf life. While 40 degrees centigrade has 22% rate of deterioration with 1.3 days shelf live. This clearly shows the effect of low temperature to shelf life of produce.
Effect of temperature control on fruits/vegetables
We will look at effect of temperature control on some fresh vegetables like potatoes, tomatoes, peppers, cabbage, spinach and carrots. Recommended temperatures for handling and cooling of pepper is 12C, PHL 20 days (Post-harvest life). At zero degrees centigrade, Spinach PHL (14 days), Carrots (6 months), Cabbage (6 months). Tomatoes at 15C(14 days) potatoes 6C(10 months), sweet potatoes 15C (5 months)
Technologies for Cold Storage
There are three cooling technology the absorption refrigerator, passive cooler and refrigerator. The absorption refrigerator is either solar or kerosene powered they provide temperatures below 10C and are heat-driven technology. Refrigerators are electrically driven and use electrical grid, diesel powered generator or renewable sources like battery or solar. Passive evaporator coolers does not require fuel or electricity it works in dry humid areas.
Temperature and Cold storage management
Produce spoil if appropriate temperature is above or below requirement. Therefore cold storage facilities should work at optimum performance every day. Poor temperature management will cause chilling injuries, freezing injuries.
Signs of freezing or chilling injuries on fruit are internal discolorations, lesions, soaking, accelerated senescence, decay. Proper maintenance includes regular ventilation to remove odors or ethylene build-up. Others are regular cleaning, sanitizing and use of ozone generators to prevent fungi or molds.