The world’s population is growing and steadily becoming more prosperous. But while there are ever more mouths to feed, one third of all the food produced annually – some 1.3 billion tonnes – is left unconsumed. Clearly, at a time when an alarming proportion of the world is malnourished, mountains of discarded food are morally indefensible.
Yet food left to rot is an environmental problem too. Not only does food waste represent a massive squandering of resources and energy, it is also a major source of carbon emissions. In the US, food production accounts for a tenth of the country’s energy budget, half of its land and 80 per cent of the freshwater it consumes. The global carbon footprint of rotting food, meanwhile, amounts to 3.3 gigatonnes of CO2, which is 10 per cent of annual global CO2 emissions, according to the Food and Agriculture Organisation (FAO).
The problem is tricky to solve because wastage occurs at every stage of the production process. On the farm, when food prices fall sharply relative to transportation costs, food-crops often go un-harvested.
And even when they are harvested, tonnes of blemished and misshapen – yet perfectly edible – fruit and vegetables are thrown away because they fail to meet strict specifications on size and appearance.
According to Food Tank, a non-profit organisation, up to 30 per cent of vegetables never leave the farm in the UK because they fail to meet the aesthetic standards of supermarkets.
Then, when food is processed, it is trimmed, causing even more waste, while further losses occur due to mishaps in refrigeration and transportation. The food that has survived and lands on the shelf is still not guaranteed to find its way into the shopping basket.
It may not be bought before its sell by date, leaving the food retailer to throw it away. Finally, not everyone eats everything on their plate so yet more is discarded by restaurants and households.
Clearly, waste can be minimised at each of these stages. Restaurant portions could be smaller, supermarkets could replace ‘buy one, get one free’ offers with ‘buy one get one later’. Changing people’s habits would also help, particularly in rich economies. The average US consumer discards 10 times as much as their counterparts in southeast Asia, according to the FAO.
A number of national and local governments in the rich world have woken up to the problem. The European Parliament, for example, has set out a blueprint to halve the region’s food waste by 2025.
Some of this can be achieved by simple thrift. But technology can also cut the food waste mountain down, through improvements in transportation, farming or preservation.
Farmers in the US, for example, are increasingly using social media to find buyers for unsold produce. Out of this initiative came the CropMobster online exchange where farmers connect with restaurants and hunger relief charities.
Other innovations are more hi-tech.
New technologies are being developed to monitor food decay as well as assess the ripeness of fruit so that the timing of its sale can be gauged more accurately. Poor transportation and storage are major causes of food waste worldwide, but a new family of ultra-sensitive electronic sensors are proving effective in tackling such problems.
These new wireless technologies can now remotely collect information on food freshness and bacterial growth, picking up variations in milk pH levels to give an early warning before it spoils. This information is then sent to a database and users are alerted via text or email when pre-determined limits are reached, helping improve storage.
Food producers are making increasing use of so-called “electronic noses”, devices able to smell food and drink to detect chemical compounds that act as early warning signals of defects or spoiling.
If the world’s food waste were its own country, it would be the world’s third largest emitter of greenhouse gases.
“Of all the human senses, smell has always been the most arbitrary to define,” says the European Food Information Council (EUFIC), a non-profit organisation. “The odour of a food comprises many chemical substances that give it its unique quality and character. The ability to reliably measure and identify optimal flavour development and constant taste characteristics is therefore crucial.”
In a similar vein, scientists have also developed devices that can taste. These “e-tongues” – as they have become known – can obtain data on sourness or bitterness in alcoholic drinks, for example. This sensory technology has also been used to create labelling and food packaging that changes colour when the food inside starts to turn.
In other parts of the food chain, sophisticated biological additives and preservatives have been developed that extend the shelf-life of many basic foodstuffs and allow food manufacturers to increase production volumes and reduce waste without compromising the quality of their produce.
The dairy industry has been an early adopter of such technology.
One persistent problem for cheesemakers is contamination by naturally occurring yeast and mould. In response, a number of companies have developed “bio-protective enzymes”, which prolong the shelf life of cheese and protect it from spoiling during the ripening process. The use of more modern coagulants in cheesemaking, meanwhile, could reduce production costs in Europe by around EUR160 million per year, according to one analysis. One company making these products is Chr. Hansen which offers the FreshQ brand of bio-protective enzymes.
“(Our) cultures have been reported to increase the perceived freshness of several dairy products in customer applications, especially towards the end of shelf life,” says Morten Boesen, Global Marketing Manager at the firm.
Such innovations will not bring food waste down to acceptable levels on their own but they can help in finding a solution to one of society’s biggest problems. Writing recently in the Financial Times, Professor Vaclav Smil, who has written extensively on sustainability and the depletion of the planet’s natural resources, highlighted the scale of the waste issue facing the food industry.
“If the world’s food waste were its own country, it would be the world’s third largest emitter of greenhouse gases,” he said.
Scientists have also developed devices that can taste.
