Nature
PUBLISHED
Bacon. Love it or hate it, we all have the same question: why the hell is it sometimes green? While there hasn't been a whole lot of research on the topic (there are plenty of more interesting mysteries to solve before we move on to sandwich fillings), there has been a little, so let's dive right into it.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.In 2012, a team of researchers from the University of Oklahoma wondered if the green discoloration could be harmful to health. The discoloration is to do with how bacon is cured with nitrites (as well as salt and sodium). Before you become disgusted and throw away your butty in disgust, you should know that nitrates and nitrites are also responsible for the particular pink color you know and love.
The team found that the green color comes from a chemical reaction between nitrites and the protein myoglobin within the meat, termed "nitrite burn".
"No one really knows if 'nitrite burn' is bad for you or not because there is so little information about the physiological effects on humans," George Richter-Addo from the University's Department of Chemistry and Biochemistry explained in a press release.
"But, we have discovered that a simple chemical process, which inhibits the flow of oxygen in the blood and degrades the blood protein hemoglobin, causes the blood to turn from red to green. Identifying the degraded blood components allowed us to characterize the related green pigment seen in bacon and other meats."
Nitrites have been used for centuries to cure meat due to their ability to slow bacteria and spoiling, keeping it safe to eat for longer, which was particularly useful prior to refrigeration. There is a debate about whetherthey are carcinogenic, with some evidence suggesting that they can interact with amines and amides to form N-nitroso compounds known to be carcinogenic in certain animals.
The team planned to conduct further studies in other meats to determine if the discoloration was an indication of cancer-causing components, but that has not been forthcoming.
