Written by Staff Writer at CNN
The supermarket shelf was not so long ago sealed with sticky tape.
But thanks to a cold warehouse in Nigeria’s busy commercial capital, this national shopping list can now be packed in pouches of ice for up to a month.
The shelves are home to jumbo frozen food, but beyond this ice pack are some of the world’s coldest atmospheric storage devices — state-of-the-art airtight blocks that are designed to ensure goods in refrigerated stores are as good as fresh.
Two cold-storage facilities, in central Lagos and Port Harcourt, are filled with tomatoes, carrots, chicken and a variety of other soft fruits and vegetables that were once stored in barns in the UK.
The refrigerated warehouses are split into two: one houses fresh produce such as onions, tomatoes and bananas; the other is for frozen foods such as meat, cheese and chicken, which would be sent to British stores after the UK closed its borders to Nigerian goods in 1993.
Each fridge is packed with airtight pressure-tight bin-sized barrels. These are connected to tubes to form ‘machines’ that move air around the warehouse.
Each barrel can hold 4,400 gallons of air — enough to cover all the produce at the Yaba market each day for up to 30 days. All the air is collected in mobile refrigeration trailers, which meet up regularly to pump air into the barrels for quick dispersal.
“Basically, air has to be released in about three to four breaths. It’s through these mini drums or little containers that are prepped, fitted with a desiccant or salt (which cools the air),” said Matthew Oh, product manager for Corona Frozen Food, which runs both facilities.
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To prevent ice and moisture from attaching to the vegetable container walls, the air sits at the back of the bin. Around an inch or two of air is also provided in any container — in case of any condensation that can form in a transport container.
Dicing potatoes in a grocery store is measured by surface area and amount of moisture. By cutting the potatoes and cutting out air from the bin, a measure of food can be prepared in a fraction of the time.
Pedant critics of the scheme will point out that about 3,000 gallons of air must be kept in refrigeration vehicles for the refrigerated ports at Port Harcourt and Yaba to operate.
However, the negatives are countered by the cost: refrigeration units at Port Harcourt cost $190,000, while a similar unit at Yaba costs around $20,000.
Corona’s offerings include the Jumbo Sushi Kit, which is essentially a sushi container with a built-in ice cylinder — but with incredibly low temperatures.
On a chilly morning, a fishmonger squeezed red sauce out of a cup of beef sirloin steaks in a red glass box, before slipping them into the freezer containers. His hands must have been shaking, as he slit and sliced to the victor in the next compartment, just over 3 pounds of steak.
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Another worker counted the rice kernels, then popped in a spoonful of the pilaf and flicked it out of the microwaved container. It was packed with frozen grains, and coated in chilli powder. Again, the rice kernel was defrosted and sealed.
Across the table, another young man unwrapped a bag of beans. They still looked like peas, but had been mixed with — and simmered with — the mirliton mash on the other side of the table.
The supermarket queue being used as a test-run for an artificial indoor night light. Credit: JUDE KEOGH/AFP/AFP/Getty Images
More such examples are lined up at Yaba, with doors that open into the market to provide fresh air to the cold chambers and generate steam for generating heat during the cold days. The team also use plant remnants to give the greenhouse a vaguely vegetabley taste.
Between 1993 and 2015, imports of Nigerian goods fell from 6% of total national trade to around 1%. A string of trade deals have helped to improve levels, but still shows Nigeria’s reliance on imports.