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Better food security with cold storage and refrigeration
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Wednesday, 20 May, 2026, 16 : 00 PM [IST]
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Dr Prashant Sahni
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Walk into a mandi in peak season and you see crates of tomatoes, heaps of green chilies, shining mangoes and piles of leafy greens. India today is a horticulture powerhouse. Recent estimates place total horticulture production above 360 million tonnes a year, with fruits and vegetables together contributing well over 330 million tonnes. Yet only a small share of this bounty is processed. Roughly 2–3% of fruits and vegetables go into juices, jams, frozen or convenience foods; the rest has to move quickly as fresh produce or be stored briefly in fresh form. Thus, the perishability of fruits and vegetables in India is extremely dependent on how well we manage time, temperature and handling after harvest. India loses roughly 6–15% of fruits and about 5–12% of vegetables post-harvest, depending on the crop. When similar losses across other foods are added, that accounts for huge loss of billions of rupees every year.
What temperature is doing to our food
Every fruit or vegetable in a market is still alive. It respires, loses water and offers a good environment for microbes to grow. Temperature controls all of these processes. A useful rule of thumb is that spoilage can speed up roughly two- to three-fold for every 10°C rise in temperature. On a typical Indian afternoon, that temperature step can occur in less than an hour for a harvested crate left in the sun or on a hot truck bed. In a warming climate with more frequent heat waves, that risk only intensifies. Now think of “delicate” produce like strawberries, leafy greens, tender peas and grapes. The same heat that makes summer mangoes sweet can turn these into a loss within hours if they are not cooled and handled properly.
Lowering the temperature as quickly as possible after harvest is one of the simplest, most powerful ways to slow respiration, reduce microbial growth and extend shelf life. In practice, that means acting fast, often within the first four hours after harvest and to start bringing down the temperature. The race to improve the shelf life and quality of fruits and vegetables begins not in a city cold store, but in the field or sorting shed, minutes after picking.
Precooling the crop before it heats up your losses
The battle against postharvest losses begins the very moment a crop is picked. Freshly harvested fruits and vegetables continue to breathe, release heat, and lose moisture. If that field heat is not removed quickly, quality declines fast; firmness fades, freshness drops, and shelf-life shrinks. This is where precooling becomes one of the most powerful tools in the cold chain. In simple terms, precooling is the rapid removal of field heat from produce before storage, transport, or marketing. The rule is straightforward; the shorter the delay between harvest and cooling, the lower the losses. In postharvest handling, time lost is often quality lost. Different crops and supply chains demand different precooling strategies. From simple cold rooms to advanced vacuum systems, each method has its own strengths.
The simplest method, room cooling, relies on refrigerated air slowly surrounding stacked cartons and bins. It is affordable and easy to operate, but the cooling process can take many hours and often such span of time cannot be afforded for delicate produce and this method is often just used for tubers. Forced-air cooling improves on this by actively pulling cold air through the vent holes of cartons and bins. Instead of cooling only the outside of packages, the system cools the produce itself, dramatically shortening cooling time and improving temperature uniformity while reducing condensation risks. Crops that require much quicker cooling are cooled by hydrocooling.
The produce is showered or submerged in cold water, allowing rapid and even cooling. For sturdy commodities that tolerate wetting, it is one of the fastest and most effective options, provided water hygiene is carefully maintained. Vacuum cooling takes a more sophisticated route. Inside a sealed chamber, pressure is lowered so that water within the produce evaporates, instantly drawing out heat. Leafy vegetables respond particularly well, cooling within minutes rather than hours. Hydro-vacuum systems refine the process further by adding a fine mist to reduce moisture loss and preserve freshness. Then, there is top-icing, the old-school method still seen in long-distance transport. Crushed ice packed over cartons keeps produce cool and humid as it melts, and in some markets, “on ice” still signals freshness. Yet melting ice can also create wet pockets that encourage rots or even cause freezing injury. Today, ice works best as a backup partner to refrigeration, however, not a substitute for a well-managed cold chain.
Not every commodity responds equally well to each method. Leafy vegetables with large exposed surfaces cool up to five times faster than dense fruits like melons. Bulb crops such as garlic and onion are poor candidates for hydrocooling. Waxy-coated fruits may not suit vacuum cooling. Matching method to crop is not a detail; it is central to designing a practical, affordable cold chain.
Transit cooling: the missing middle of the cold chain
Even when we precool properly and have good cold rooms, a lot can go wrong in between. Much of India’s fresh produce still travels in open trucks or poorly insulated vehicles, exposed to hot winds and sun. Hours of transport without adequate cooling can undo the benefits of careful precooling. Refrigerated trucks (reefers) and insulated small vans are the workhorses of a functioning cold chain, keeping produce within a safe temperature band from farm gate to markets, processors or retail hubs. But reefer penetration is still limited in many regions, and costs can be high for smallholder farmers. In this context, crushed ice is often used as a low-tech plug for the transit gap. It offers some protection but also carries the risks already mentioned. The long-term solution is a combination of better logistics, more energy-efficient reefer fleets and shared or cooperative transport models that spread costs over many small producers. A cold chain is exactly that—a chain—only as strong as its weakest link, which is often transit.
Inside a cold room: more than just a big fridge
When people imagine cold storage, they picture a giant refrigerator. In reality, a well-designed cold room is a carefully engineered space where insulation, airflow, doors, stacking and even roof colour matter. Good insulation in floors, walls and ceilings improves temperature control and lowers electricity use. Insulation must remain dry, with panel joints properly sealed and waterproof. Rooms designed to hold sub-zero temperatures are more expensive than those operating at 2–4°C, and very tight control (say ±0.2°C) costs more than a broader band, so the design should match product needs. No cold room is perfectly uniform. Warmer zones are usually near doors or back corners; the coldest zone is often just in front of the air delivery. Poor stacking can block airflow and create hot spots, leading to uneven quality. Better ducting or higher air circulation can reduce these variations but add cost. Heat enters from outside through walls and roofs and from inside through warm product, people and equipment.
In hot climates, roof shading and reflective paints can significantly reduce this load. Frequent door opening, especially in the afternoon, is another major challenge. Small personnel doors alongside larger roller doors, plastic strip curtains, fast doors and air curtains can cut warm-air ingress, saving energy and protecting produce. Electricity is often the biggest operating cost for cold rooms. Investing in insulation, seals and efficient equipment can pay back quickly via lower bills. Where quality requirements permit, some facilities cool more aggressively at night on off-peak tariffs and allow temperatures to drift slightly by day. Water-cooled systems can chill a cold-water “heat sink” at night and use it in daytime. Cleanable surfaces and proper drainage make sanitation easier, which is essential for food safety.
India’s cold chain opportunity
India’s horticulture output is at record levels, while organised retail, e-commerce and quick-commerce are expanding rapidly. Demand for high-value perishables from berries and salads to minimally processed vegetables is rising in cities. Yet much of the country’s cold storage capacity is clustered in a few states and in single-commodity potato stores, leaving many fruit- and vegetable-rich regions under-served. Analysts expect the cold chain and cold storage market to grow strongly, driven by urbanisation, rising incomes and changing diets.
New models are emerging: small solar-assisted cold rooms near farms, micro-warehouses on city fringes, multi-temperature facilities serving both food and pharma, and IoT-enabled monitoring that sends alerts if temperature or humidity stray from safe ranges. For farmers, a reliable cold chain means breathing space, not having to distress-sell perishable crops on harvest day, having time to sort and grade, and the option to reach distant, higher-value markets. For consumers, it means safer food, more consistent quality, year-round availability and more choice. For the country, every percentage point reduction in post-harvest loss is money saved, emissions avoided and nutrition preserved.
(Dr Sahni is an assistant professor at College of Dairy and Food Technology, Agriculture University, Jodhpur and can be contacted at ftech.sahni@gmail.com)
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