In most instances, you’d probably be looking for a red/purple color as opposed to a blue one. In order to keep red cabbage in your preferred color, you have to control the acidity of the environment. Notice what a different those few drops make! Controlling the color of red cabbage These are two blueberry pannacottas, the only difference being the addition of some lemon juice to the pannacotta on the right. Blueberries also contain pH-sensitive anthocyanins. pH ≈ 6: violet (aka dark purple), this is approximately the color of your ‘native’ red cabbage, how you buy itĪt an even higher pH value, the red cabbage can even turn green/yellowish, however, you won’t generally encounter this when prepping red cabbage.pH ≈ 2: red/bright pink, lime juice (which we sprinkled on top of our salad) will cause the pH to sink down this low and make the cabbage red. In the case of red cabbage the color roughly changes as follows (from: Stanford): The type of anthocyanins present determines just how they will respond to a change in the pH-value of the environment. We’ve discussed acid base reactions in more detail here. A value between 0-7 is acidic, from 7-14 it’s alkaline. Some anthocyanins can even completely lose color due to these changes. These structural changes cause the molecule to interact differently with light and that results in a different color. However, under less acidic conditions, this O +-group will lose its positive charge, resulting in other structural changes. This results in the anthocyanin structure we shared above (with the O +). It influences how it organizes the electrons within the molecule.Īn acidic environment contains a lot of protons (H +). This structure happens to be very sensitive to the acidity of the environment surrounding it. So the chemical structure and coordination of anthocyanins determine their color. There are a few notable exceptions: tomatoes (lycopene) & red beets ( betanins)! Why does red cabbage change color? It’s the mix of molecules that give each product its unique color and behavior.Īnthocyanins are responsible for most reds/purples in plants. None contain just one type of anthocyanin molecule, it is always a mixture. Blueberries, blackberries, and certain red grapes, all contain anthocyanins. Instead, it contains over 15 different ones!Īnthocyanins are quite common in fruits and vegetables. Red cabbage doesn’t just contain one type of anthocyanin molecule. All anthocyanins share the core structure, but differ in the R-groups. The basic anthocyanin structure under acidic conditions. This is just one group of molecules that can give foods a red-ish color, there are many more. In the case of red cabbage, the color stems from the presence of a group of molecules called anthocyanins. This reflection and absorption are often done by complex molecules with quite specific structures. For a color to be visible, certain wavelengths of light have to be reflected and absorbed to reach our eyes. It depends on how light is reflected from the color’s surface and gets into our eyes. Colors can change depending on how and where you look at them (e.g. Color and how we perceive color is a fascinating (but complex) topic. They’re so common that you might think they’re simple as well. Plenty of products in nature change color, depending on their environment! What gives red cabbage its color?Ĭolors are all around us. Wondering why this happens? It’s a great combination of complex molecules, pH, and our eyes. Want to give your red cabbage salad a nice vibrant pinkish color? Just sprinkle in a little lime juice and your previously purple cabbage will turn pink! Or, to lighten up your cooked cabbage, add a few pieces of apple while cooking and it will turn into a lighter color.
0 Comments
Leave a Reply. |