Hong Kong ( CNN ) -- Two years ago , the sight of pristine-looking peas that had arrived all the way from Kenya to London made an impression on a would-be entrepreneur , Jenny Dawson . The peas had been tossed aside at a wholesale food market , getting ready to be sent to the landfill . Soon after that , on a friend 's farm , crates of apples , deemed too small for their buyer , were left out to rot . Seeing all this waste pushed Dawson , 27 , who formerly worked for a hedge fund , to start a business using surplus produce . The model for Rubies in the Rubble , her jam and chutney business , was born , with the goal using food that would otherwise get tossed to create foods that people would buy . `` Preserves seemed almost a natural thing to be doing with a glut of fruit and veg , because it then lasts up to 10 months , '' Dawson said . Infographic : Food waste ; From farm to fork and landfill . The massive global problem of food waste has received more attention in recent years , and the figures are staggering . A U.N. report estimated last year that around the world , one-third of all food produced for human consumption is wasted . Many food banks now collect leftover foods from hotels and restaurants and redistribute them to those in need . Composting has become a common method of recycling food as fertilizer or soil amendment . Interactive : Businesses making the most of our food waste . But businesses like Dawson 's have also cropped up to make use of food items that would otherwise end up in landfills . Awareness campaigns have helped the cause , she said , and change can be felt in the initiatives taken by supermarkets and restaurants . Waitrose , the U.K.-based supermarket chain , in October achieved its goal of sending zero food waste to landfills . Instead , unwanted food is donated or sent to anaerobic digestion plants to convert the material into biogas . Other major U.K. retailers are following suit , with Marks & Spencer announcing similar plans . And Dawson says consumers ' attitudes have changed too . `` Two years ago , people did n't like the word 'food waste , ' because people wanted to be seen as having the best , having the perfect thing , '' she said . `` Then as organic and being homegrown started to creep in , people actually liked the strange-shaped carrots or the small , different apples because it felt more organic and homegrown . '' In California , two entrepreneurs saw an opportunity in the mounds of coffee grounds thrown out each day by cafes in their own neighborhood . They now run a thriving business based on reusing waste . Interactive : Human misery behind high food prices . Nikhil Arora and Alejandro Velez were business students at the University of California , Berkeley , when they first heard in class that mushrooms could be grown entirely on discarded coffee grounds . The concept piqued their interest and led to the formation of Back to the Roots , a business that has gone from farming mushrooms to selling mushroom-growing kits , all relying on used coffee that gets thrown out by 35 cafes in and around Berkeley . Read : How severe weather impacts the global food supply . `` Since day one , our first vision for this company , why we fell in love with it , was this idea of 'waste to food ' and 'waste to wages , ' â€ ” that you could create a really cool company in an urban setting , create really good jobs out of what was waste , and something about that was so powerful to us , '' Arora said . The company 's main product , a mushroom-growing kit , is a cardboard box that houses a plastic bag filled with coffee grounds and mushroom spawn . Slit open the bag and mist the contents with water , and pearl oyster mushrooms will begin to grow , until they are spilling out the side of the box , reaching their full-grown size in about 10 days . Quiz : Test your knowledge of Xmas excess . Back to the Roots has sold 300,000 of the kits in the U.S. at outlets like Whole Foods , Nordstrom , and Bed Bath and Beyond stores . Arora said they use `` a massive stack '' of coffee grounds per day , and it comes to about 18,000 kilograms of reused grounds per week . However he realizes it is still but a tiny contribution to relieving the amount of food products that go to waste . `` We know our mushroom kit 's not going to solve world hunger , it 's not going to themselves reduce the entire issue . '' Arora hopes that growing one 's own food could bring to individuals , especially children , a greater awareness of where food comes from . And he says that the idea easily engages a wide spectrum of the public , from foodies to children to environmentally-conscious people . `` We like to say if you 're sitting on a flight , no matter who you 're sitting next to , you could talk to them about this mushroom kit , '' he said .
Annually around one third of all food produced is wasted , according to U.N . Entrepreneurs are starting businesses to turn food waste into something wanted . Used coffee grounds provide basis for Back to the Roots business .