Experts hail practice of using cockroaches to process food waste
For most people, cockroaches are pests that can leave an offensive odor, transmit viruses and taint food.
But Li Yanrong, an official from a kitchen waste management association in Zhangqiu, East China's Shandong Province, has a very different view. He keeps 30 million cockroaches for the purpose of consuming kitchen waste in this city, China News Service reported recently.
These cockroaches help deal with a quarter of the city's kitchen waste, it reported.
Li said his cockroaches are no ordinary ones. "They are American cockroaches, which are big in size and favor rotten organic food. Also, they reproduce very fast."
This kind of cockroach weighs one gram on average, and is able to gobble up an equivalent of five percent of its body weight in waste.
Cockroaches are not picky about food, and will eat anything, whether it's spicy, sweet, sour or bitter, said Li.
Not only can cockroaches decompose the waste, leaving very little residue, they can also turn it into something useful. After the cockroaches die, their bodies, known to contain high protein and nitrogen levels, can be made into cockroach powder to be used as a protein source for animal feed.
In 2015, Li quit his job and began to raise cockroaches professionally. In 2014, there were only 400 kilograms of cockroaches in his plant. In 2015, the number had surged to four tons, and this year, he predicts that over 3,000 tons of cockroaches will be raised here.
According to official statistics, 60 million tons of kitchen waste are produced in China annually. According to a report by the School of Environmental Science and Engineering of Tianjin University, China's kitchen waste accounts for up to 62 percent of municipal solid waste, and they project the proportion will continue to rise along with improvements of people's living standards.
Li told the media that fermentation and landfilling have been the traditional methods of getting rid of kitchen waste, but they require large investment and pollute the water and air.
One restaurant owner in Southwest China's Chongqing Municipality told the Global Times that some of his peers also used to pour waste into sewers or rivers. "They don't want to pay the fee for fermentation because it's too expensive."
But the owner seemed incredulous when asked if he would consider using cockroaches as a method of dealing with food waste. "That would destroy my business if the customers find out I have such a thing in my kitchen."
But Chen Ke, a doctoral student in Chongqing Medical University, told the Global Times that cockroaches secrete enzymes that dissolve the waste's toxin, leaving only harmless elements. Once the cockroach dies, its body can be ground into powder and used as medicine.
"According to lab research, cockroach powder works effectively in helping people lose weight, keep healthy, and can even be used for cosmetics," Chen explained.
Other experts also hail the method, saying it is "in accordance with the law."
Chen explained that cockroaches are also a raw material used in traditional Chinese medicine, known to be able to promote detoxification.
Li decided to put this to the test by feeding the cockroach powder to chickens. He found that they were not only healthier, but also grew stronger and faster than normal chickens.
After doing more research, Li found there were already several cockroach farms in Shandong that provide raw materials for medicine companies. Li visited these farms seeking to gain experience, and was disappointed when he learned how costly it was to run the business.
Most of these family-run farms feed cockroaches with grain, and the cost for breeding one ton of cockroaches can be as high as 10,000 yuan (,527). The retail price, however, is sometimes only a few dozen yuan for a kilogram.
In his three years of studying cockroaches, Li applied for over 30 patents, and two have been approved.