These are the third and fourth entries in a series of stories about the color purple in honor of Kansas State University's founding on Feb. 16, 1863. To see the rest of the series, check http://www.k-state.edu/media/ for updates.
PURPLE FOODS PROVIDE HEALTHY NUTRIENTS AND ANTIOXIDANTS
When it comes to healthy eating, consider adding some powerful purple foods to your diet.
That's because many purple foods contain anthocyanins, which are red, blue and purple natural pigments. Anthocyanins are healthy because they're powerful antioxidants and may help boost the immune system, maintain health and prevent disease, said J. Scott Smith, Kansas State University professor of food chemistry.
"It's the name of the game right now," Smith said. "Everybody is really interested in antioxidants because they are thought to be healthy."
Anthocyanins are more prevalent in fruits than vegetables, Smith said, noting the deep red and purple hues of apple skin and grapes. Because anthocyanins are pH sensitive, they can appear more red or blue depending on the type of food.
Anthocyanins are especially common in berries, including blueberries, cranberries, raspberries and blackberries.
"That's why people say 'Eat your berries,' because they are very healthy for you," Smith said.
Even the extracts from foods that contain anthocyanins are healthy, Smith said. A recent trend in the food industry is to use natural, instead of synthetic, food dyes. Anthocyanins can be extracted from fruits or vegetables and then used as a natural purple or blue-hued food dye.
Because red wine comes from grapes, it also contains anthocyanins. In addition, red wine contains resveratrol, which is an antioxidant and may be heart-healthy.
Some lesser-known purple foods also contain anthocyanins. South Americans have grown purple corn for centuries, Smith said, and a purple cauliflower and a purple carrot also exist.
While beets come in deep reds and purples, it's not because of anthocyanins, Smith said. The purple color found in beetroot comes from betalain pigments, which replace anthocyanins in some plants. Betalains are also healthy antioxidants.
In the ancient world, purple was universally associated with wealth and power, said David Stone, professor of history.
"The reason was a particular purple dye associated with the Phoenicians, a trading people who lived in what is now present-day Lebanon," Stone said.
The Phoenicians created a market surrounding the Mediterranean, and one of their most famous products was Tyrian purple, named for the city of Tyre.
"This purple was made from the murex, a kind of carnivorous sea snail," he said. "Since each snail produced only a few drops of dye, Tyrian purple was very expensive, and became associated with royalty and power."
Julius Caesar wore a purple toga, and subsequent emperors of Rome adopted it as their ceremonial dress.
"The emperors of Byzantium continued that tradition until their final collapse in 1453," Stone said. "The Byzantines referred to the heirs of their emperors as 'born into the purple.'"
For thousands of years textiles were limited to natural dyes, so the appearance of purple was scarce.
"In 1856 William Henry Perkin developed the first aniline -- or synthetic organic -- dye, a shade of purple he called mauve, from a derivative of coal tar," he said. "By the next year he had made the process commercially viable."
This development was a fairly significant moment in history, Stone said, marking the point at which chemistry and chemical engineering began to expand the range of materials available.
"The creation of Kansas State University in 1863 thus took place only a few years after a host of new possibilities for science and engineering," Stone said.