Lettuce Gets a Healthy Sun Tan



FOR IMMEDIATE RELEASE

Contact:
Lyndsay Meyer
The Optical Society
+1.202.416.1435
lmeyer@osa.org

Devin Powell
American Institute of Physics
301.209.3099
dpowell@aip.org

Jason Socrates Bardi
American Institute of Physics
301.209.3091
jbardi@aip.org

Lettuce Gets a Healthy Sun Tan

Ultraviolet LEDs Create Darker, Redder Lettuce Richer in Antioxidants

WASHINGTON, May 18-- Salad dressing aside, a pile of spinach has more nutritional value than a wedge of iceberg lettuce. That's because darker colors in leafy vegetables are often signs of antioxidants that are thought to have a variety of health benefits. Now a team of plant physiologists has developed a way to make lettuce darker and redder—and therefore healthier—using ultraviolet light-emitting diodes (LEDs).

Steven Britz of the U.S. Department of Agriculture in Beltsville, Md., and colleagues will present the research at the 2009 Conference on Lasers and Electro Optics/International Quantum Electronics Conference (CLEO/IQEC), which takes place May 31 to June 5 at the Baltimore Convention Center.

The dark red tinges on a leaf of red leaf lettuce are the plant kingdom's equivalent of suntan lotion. When bombarded with ultraviolet rays from the sun, the lettuce leaf creates UV-absorbing polyphenolic compounds in its outer layer of cells. Some of these compounds are red and belong to the same family that gives color to berries and apple skin. They help block ultraviolet radiation, which can mutate plant DNA and damage the photosynthesis that allows a plant to make its food.

Polyphenolic compounds,which include flavonoids like quercetin and cyanidin, are also powerful antioxidants. Diets rich in antioxidants are thought to provide a variety of health benefits to human beings, from improving brain function to slowing the wear and tear of aging.

To create red leaf lettuce plants enriched with these compounds, Britz purchased low-power LEDs that shine with UVB light, a component of natural sunlight. In small quantities, this ultraviolet light allows humans to produce vitamin D, which has been cited for its health benefits. Britz exposed the plants to levels of UVB light comparable to those that a beach goer would feel on a sunny day, approximately 10 milliwatts per square meter.

After 43 hours of exposure to UVB light, the growing lettuce plants were noticeably redder than other plants that only saw white light. Though the team has yet to quantify this effect, it appears to increase as the intensity of the light increases. The effect also seems to be particularly sensitive to the wavelength used – peaking at 282 and 296 nanometers, and absent for longer wavelength UV. "We've been pleasantly surprised to see how effective the LEDs are, and are now testing how much exposure is required, and whether the light should be pulsed or continuous," says Britz.

To cut transportation costs and feed the market in the wintertime, more produce is grown in greenhouses. Crops grown in the winter in northern climes receive very little UVB to begin with, and plants in greenhouses are further shielded from UVB by the glass walls. Ultraviolet LEDs could provide a way to replace and enhance this part of the electromagnetic spectrum to produce darker, more colorful lettuces.

Britz also discussed the potential for using UV LEDs to preserve nutrients in vegetables that have already been harvested. Previous experiments have shown that the peel of a picked apple stays redder for a longer period of time when exposed to ultraviolet light. UVB LEDs are a promising technology for irradiating vegetables stored at low temperatures to maintain or even boost the amount of phytonutrients they contain.

Presentation PTuA3, "Shedding light on nutrition," Steven Britz, 10:30 a.m., Tuesday, June 2.

About CLEO/IQEC
With a distinguished history as one of the industry’s leading events on laser science, the Conference on Lasers and Electro-Optics and the International Quantum Electronics Conference (CLEO/IQEC) is where laser technology was first introduced. CLEO/IQEC combines the strength of peer-reviewed scientific programming with an applications-focused exhibition to showcase the present and future of this technology. Sponsored by the American Physical Society’s (APS) Laser Science Division, the Institute of Electronic Engineers (IEEE) Photonics Society and the Optical Society (OSA), CLEO/IQEC provides an educational forum, complete with a dynamic Plenary, short courses, tutorials, workshops and more, on topics as diverse as its attendee base whose broad spectrum of interests range from biomedicine to defense to optical communications and beyond. For more information, visit the conference’s Web site at www.cleoconference.org.

###

Share:
Keyword
Topics

Getting Hold of Quantum Dot Biosensors

Quantum dots (QDs) have found so many applications in recent years, they can now be purchased with a variety of composite structures and configurations. Some are available suspended in a biologically friendly fluid, making them well poised to serve as biomarkers for single-molecule tagging and tracking. But suppose you wanted to trap and move one of these single nanoparticle tags the same way other biologists might grab tissue samples with a tweezer?

Added: 22 Aug 2017


Guide Star Alliance Team Receives OSA’s 2017 Paul F. Forman Team Engineering Excellence Award

The Optical Society (OSA) is pleased to announce that Guide Star Alliance is the winner of the 2017 Paul F. Forman Team Engineering Excellence Award. Under contract of and in close collaboration with the European Southern Observatory (ESO), industrial partners, TOPTICA Photonics and MPB Communications (MPBC), joined together to develop a high-power CW tunable laser system called the SodiumStar. The team’s development is now considered the quasi-standard for existing and planned telescopes around the world. The Guide Star Alliance will receive the award on 18 September 2017, during Frontiers in Optics (FiO) + Laser Science (LS) in Washington DC, USA.

Added: 18 Aug 2017


New Terahertz Imaging Approach Could Speed Up Skin Cancer Detection

Researchers have developed a new terahertz imaging approach that, for the first time, can acquire micron-scale resolution images while retaining computational approaches designed to speed up image acquisition. This combination could allow terahertz imaging to be useful for detecting early-stage skin cancer without requiring a tissue biopsy from the patient.

Added: 17 Aug 2017


New Tool Aims to Make Surgery Safer by Helping Doctors See Nerves

During operations, it can be difficult for surgeons to avoid severing crucial nerves because they look so much like other tissue. A new noninvasive approach that uses polarized light to make nerves stand out from other tissue could help surgeons avoid accidentally injuring nerves or assist them in identifying nerves in need of repair.

Added: 16 Aug 2017


Relativistic Self-Focusing Gives Mid-IR Driven Electrons a Boost

Conventional particle accelerators can range from large room-sized devices to facilities multiple kilometers across. One of the ways that scientists have looked to reduce the size and expense of future accelerators is by developing laser –driven plasma acceleration. Such accelerators, however, are growing in size and complexity in order to maintain relevance for one of their applications—high energy physics. However, there are many applications that can use a lower energy and higher repetition rate accelerated beam. For the first time, scientists have observed the production of relativistic electrons driven by low-energy, ultrashort mid-infrared laser pulses.

Added: 15 Aug 2017


OSA Laser Congress Plenary to Highlight Ultrafast Laser Systems and Black Hole Detection

The OSA Laser Congress 2017 will feature the latest advancements in solid state laser developments and related technologies for use in free space laser communication, laser-based sensing and numerous industrial applications.

Added: 10 Aug 2017


New Optical Method Pinpoints Weak Spots in Jet Engine Thermal Coatings

Researchers have demonstrated, for the first time, that an optical analysis method can reveal weak areas in ceramic thermal barrier coatings that protect jet engine turbines from high temperatures and wear. The technique could be used to predict how long coatings would last on an airplane and might eventually lead to new thermal barrier coatings, making engines more efficient and cutting both the cost and pollution of air travel.

Added: 09 Aug 2017


The Optical Society Congratulates Ed White on Selection as Chair of the NPI

The Optical Society (OSA) commends the selection of Edward White, associate vice president of test, assembly and packaging and corporate outreach for AIM Photonics, as the next National Photonics Initiative (NPI) Steering Committee Chair. White will succeed Alan Willner, the Steven and Kathryn Sample Chair in Engineering University of Southern California and 2016 president of OSA. The National Photonics Initiative is an alliance of top scientific societies uniting industry and academia to raise awareness of photonics, and its impact on society.

Added: 04 Aug 2017


See the World Differently at FIO + LS 2017

Whether you are in an autonomous vehicle looking to avoid collisions with nearby objects, or sitting on Earth and trying to detect collisions of black holes in the furthest galaxies, the Frontiers in Optics + Laser Science APS/DLS (FIO + LS) plenary presentations will detail recent achievements in gravitational wave science and today’s LiDAR applications.

Added: 03 Aug 2017


The Optical Society Foundation Concludes Successful 2017 Innovation School

The Optical Society Foundation (OSAF) hosted early-career professionals during its first Innovation School from 23-27 July at OSA headquarters in Washington DC. The four-day program focused on honing ‘intrapreneurial’ skills through a series of interactive ‘ideation and customer validation’ exercises. In addition, the hands-on program was accompanied by presentations led by CEO’s, entrepreneurs and innovation leaders in the optics and photonics industry.

Added: 01 Aug 2017


The Optical Society Creates Optical Design Innovator Award

The Optical Society (OSA) is pleased to announce the creation of the Kevin P. Thompson Optical Design Innovator Award recognizing significant contributions to lens design, optical engineering or metrology by an individual at an early career stage. The inaugural award will be given in 2018.

Added: 26 Jul 2017


Sophisticated Medical Imaging Technique Proves Useful for Automotive Industry

Many of today’s cars are coated with paint that exhibits a metallic or glittery shine. The exact sparkle and color you see is determined by the distribution and characteristics of tiny metal flakes used in the paint. A new approach based on the medical imaging technique optical coherence tomography (OCT) provides the car industry with a practical way to automatically analyze these metal flakes, which until now have been difficult to image, in order to improve the efficiency of the automotive finishing process.

Added: 25 Jul 2017