Subscription Center
Although a vibrant blue, this African fruit contains no blue pigment, according to new research by Silvia Vignolini and her colleagues at the University of Cambridge. The jewellike berry is from the plant Pollia condensata, which grows across Africa. Each plant produces up to 40 shiny bits of fruit. The blue and its beautiful iridescent shine are caused by a Bragg reflection—intense peaks of light generated at certain wavelengths and angles—created by spirally stacked cellulose fibers that form multiple layers in the fruit's skin. "The reflected color differs from [skin] cell to cell, as the layer thicknesses in the multilayer stack vary, giving the fruit a striking pixelated or pointillist appearance," Vignolini wrote in a paper published in the September 10 Proceedings of the National Academy of Sciences. The researchers note that the berry's coloration is more intense than any biological material studied to date.
—Ann Chin
See what we're tweeting about
BoraZ Are Humans the Greatest Things Created by the Human Hand? http://t.co/D1IjdgLOgG
Myrmecos Answer to the Monday Mystery: Ceratina http://t.co/fJeVfWlsKD
sciencegoddess Oops, going to a new plane that doesn't have a mechanical issue! #joyofflying
Deadline: Jul 30 2013
Reward: $100,000 USD
The Seeker desires a method for producing pseudoephedrine products in such a way that it will be extremely difficult for clandestine che
Deadline: Jul 25 2013
Reward: Varies
This challenge provides an opportunity for Solvers to build a web-based or mobile “app” to explore data relationships in scholarly conte
Powered By: 
YES! Send me a free issue of Scientific American with no obligation to continue the subscription. If I like it, I will be billed for the one-year subscription.
9 Comments
Add CommentI would imagine that, since the color only shows as a result of the special structure of the skin, mashing it up might destroy that structure and result in a substance without that blue color.
Reply | Report Abuse | Link to thisThat being said, I wonder what the "true" color of the fruit is. In other words, if you DID mash up the fruit and destroyed the cellular structure, what color would the skin be? (I'm also fascinated to know whether the berries are edible.)
Indigo is soothing and antiseptic. It can help balance fear, frustration, and negative emotions; it helps one to be less aware of pain yet fully conscious. Use indigo for pain, poor motor skills, posture, menstrual irregularities, hair loss, and eye and ear disorders.
Reply | Report Abuse | Link to thisIn foods, indigo appears as a blue with a black overtone, as in black beans, blackberries, or plums. Indigo foods are often good sources of Vitamin K and lycopene.
Indigo is inspiration, imagination and peace of mind. Similar to blue, indigo fruits and vegetables are high in antioxidants and phyto-chemicals which help promote healthy function of the brain, pituitary gland, sinus, vocal cords and the lungs, as well as boosting the immune and respiratory systems.
Source: http://www.sparkpeople.com/mypage_public_journal_individual.asp?blog_id=1382920
Hahahahaha.... I wonder if you're aware that you just dumped a load of pseudoscientific nonsense on a Scientific American post.
Reply | Report Abuse | Link to thisInteresting coming from a guy that probably believes in global warming / Global cooling / climate change.
Reply | Report Abuse | Link to thisThe drug companies are probably rushing to patent the key ingredient as I write this, then you will see it on Oprah.
But seriously, the side effects of most prescription drugs reads like a horror story. Can cause Heart failure, kidney failure, immune response failure resulting in Leukemia or TB susceptibility... you get the idea. No wonder she looked to the safer organic / natural cures.
And for what it is worth she is probably correct on many of the health effects.
@smswedenburg
Reply | Report Abuse | Link to thisBriefly:
The issue of global warming is not whether it is happening, but what do we do about it?
The side effects lists contain anything and everything that happened to participants in the drug trials. But correlation does not imply causation.
And leave the personal attacks outside.
According to NPR it isn't edible and is very hard.
Reply | Report Abuse | Link to thisBack to the subject, whether or not the berry is blue is nonsense. If I use lineed oil to stick some berries to a surface, I've "painted" it blue, though a bit coarse and probably quite degradable. What is "pigment" that makes it so different, except the size of the particle? And where's the limit there?
Reply | Report Abuse | Link to thisI am curious...what relation is this plant/seed to the Indigo plant that is used to produce Indigo dye? That is a plant from India. They dye (mostly synthetic today) is what is used to produce the blue of blue jeans. It's interesting that both are blue, but that the blue of Indigo dye comes from the leaves and stems and not the seeds.
Reply | Report Abuse | Link to thisThere was long ago an Amateur Scientist article about using black and white film to create color. Sadly I cannot recall the name of the technique, and SciAm appears to now have the back issues online.
Reply | Report Abuse | Link to thisThat film method created color by controlling the silver grain size, effectively filtering the color by diffraction. My son tried the technique and made a winning science fair project out of it.