Wednesday, April 17, 2013

I want me some sugar!

Species name: Saccharum officinarum

Common name: sugarcane

Location: Dominican Republic

Sugarcane is one of the most important crop species in Latin America. It is originally native to southeast Asia around Indonesia and Papua New Guinea, but has been transported all around the world and is widely grown in tropical countries. It is not only used to make sugar, but also as a food crop (black sugarcane can be eaten like a root vegetable), as a biofuel (in Brazil, sugarcane waste is burned for fuel and accounts for almost 80% of their power generation), and as a fermentable crop (to make rum).

White sugarcane is the primary crop species used for sugar production around the world (this isn't the case with sugar produced in northern climates; sugar in Canada and Europe is produced from sugar beets), and is chewed by children as a sweet treat. The canes are pressed either mechanically or physically using donkeys (rarely horses) to turn giant wheels of stone to press the juices into a big vat. The cane juice is boiled to condense the juices, and the molasses are filtered out from the rest of the cane juice. They can be added back in later in various amounts to make light or dark brown sugar, or left out to make white sugar. The filtered cane juice is heated to boil off the liquid and the purified sugar is left behind. Interestingly, this process was unlikely to have been "invented" in Latin America despite its widespread proliferation there. It is actually believed that the purification of sugar was first done in India.

Black sugarcane is very different from white sugarcane. It is not as sweet, and the centre of the stem isn't as woody. Superficially, it looks nearly identical to white sugarcane except for the colour of the stem. This variety of cane, however, is never used to produce sugar. Instead, the stem is peeled and cut into pieces and can be boiled and eaten like a very starchy, somewhat chewy and crunchy potato. It can be further sweetened (as ironic as it is to sweeten sugarcane) to be added into desserts. I've never tried black sugarcane, but people in Dominican eat it all the time as one of their traditional foods.

Sugarcane isn't just for making rum and sugar! Historically, sugarcane was a very important medicinal crop, and still is in Ayurveda in traditional Indian medicine. In fact, whenever you see the Latin epithet (the "second name" of a species) "officinarum," or a derivative of it, it means the plant was once used as a medicinal plant. In its medicinal use, young sugarcane stems are ground in a big mortar and pestle to produce a paste, and that paste can be applied on the skin to treat skin problems and to prevent infection. It might seem a little far fetched that this could be useful, but when you think about other very sugary products it actually makes complete sense. Honey, for example, doesn't need to be refrigerated (neither does maple syrup) because it is SO sugary. Very few organisms can grow in something that sugary not because it's so sweet, but because of the osmolarity of the substance. Osmolarity is a way of chemists and biochemists measuring how much water will move out of a cell; if a solution has high osmolarity it means that there is a high concentration of "stuff" (sugar, salt, another chemical, etc.) in the solution. Water always moves to equalize the solution with the cell, so water would move out of the cell and into solution (to try to get the ratio of molecules of solute to molecules of water to be the same). This means the cell will shrivel, and if too much water leaves the cell then it cannot survive. By drastically increasing the osmolarity on the surface of the skin, you make it a very hostile environment for pathogens to exist and so you may prevent infection. It can also draw water out of the skin and into the sugar creating a goopy mess; for this reason sugar is clearly not the favoured product to use for this purpose. This is the same idea that products like Polysporin operate on; if you read the ingredients label you'll see they contain a lot of salt to increase the osmolarity at the skin's surface, making it a hostile environment. Unfortunately, this is also the reason why your skin gets wrinkly and gross when you use too much of it too often. Skin needs the proper chemical balance, too!

Sugarcane can also be used to supplement animal feed; studies have shown that when piglets are fed sugarcane juice added with their regular soy diets grow faster and are susceptible to fewer pathogens than piglets fed a regular soy diet. Will sugary diets become the new norm in piglet feed? I doubt it. Pigs have the same reactions as humans to sugary diets. They get fat! This might not be a bad thing when you're raising piglets for their end product: consumption. If you want healthy pigs, weaning them off a high-sugar diet before they reach adulthood is very important; no one wants a fatty ham or a fatty tenderloin!