The big picture on coffee

We drink so much coffee that it is a major, and justified, subject of much research. There is a factoid around that coffee is the second most traded commodity in the world but that is one of those self-perpetuating myths that gets repeated because it sounds right. Certainly coffee is a highly popular commodity but where it ranks in global trading pecking order depends on a whole lot of definitions and estimations of value. If you want to be impressed by the sheer scale of coffee though, you can latch onto this estimate that around 75 million people depend on coffee for all or most of their living. However, you want to brew it though, the popularity and ubiquity of coffee warrants all the research. Just last week researchers from Monash University published a paper (PLoS ONE) detailing how the antioxidant effects of coffee continue through the roasting and brewing process. There is more to coffee though than the effects it has on or health because such a significant commodity also has an impact on the planet as has been highlighted in a new study.

There are about two billion tonnes of coffee by-products produced each year. Coffee silverskin is the outer layer of the coffee bean and is usually removed during after the beans have been dried and then of course there are coffee grounds. Some small use of these by-products is made; coffee grounds are very useful in domestic composting and can also be used as homemade skin exfoliants or even as an abrasive cleaning product. Composting can make use of a large amounts of home-generated coffee grounds but for the most part commercially generated coffee grounds and silverskin are not put to use; which means a lot of coffee by-products going into landfill every year.

In the new research however, it has been shown that these coffee by-products do have recycling potential.

According to the researchers both coffee grounds and silverskin are rich in fibre and antioxidant polyphenols. They found for instance that coffee grounds have 500 times the antioxidant activity of vitamin C. The researchers think these coffee by-products could therefore be used to create functional foods. They also say that melanoidins that are produced during the roasting process and give coffee its brown colour have antifungal properties that could be used to prevent harmful pathogens from growing in food products.

Adding coffee by-products back into reconstructed foods may not be a terribly holisitic approach but at least it is a first step toward considering what we do with the “waste” products of this widespread commodity.