Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Light-protection for food packaging

01.02.2002


Oxygen and light can alter the taste of foodstuffs. Manufacturers of packaging materials therefore try to protect contents from their influence. The latest approach is to use natural dyes in transparent plastic wrappers that selectively filter light.



Light and oxygen adversely affect the quality of most foodstuffs. In combination they cause various ingredients to undergo photo-oxidation. Fatty food substances become rancid and milk products develop an unpleasant "light-induced" taste. Certain ingredients such as the plant pigment chlorophyll or riboflavin (vitamin B2), exacerbate the loss of product quality due to their catalytic effect: they absorb light and transfer this energy to the oxygen, making it more reactive.

Manufacturers of food packaging are tackling these processes with two strategies: they either exclude oxygen by sealing packaging with nitrogen or they prevent exposure to light. The disadvantage of the first method is that the plastic must have a special sealing layer to prevent atmospheric oxygen permeating into the packaging. With the second method, the contents are only partially or not visible. But being able to see through the packaging is frequently desired for product presentation to customers.


At the Fraunhofer Institute for Process Engineering and Packaging IVV, researchers have adopted a new approach: they dye transparent plastic films with the very substances that are catalysts for photo-oxidation. In this way, packaging material remains almost transparent yet they filter out light in the critical wavelength ranges. One product that exemplifies this is olive oil: "Cold-pressed olive oils of superior quality are dark because they contain large quanities of chlorophyll. This tone is what the customer wants to see", says Dr. Gertraud Goldhan, director of the Functional Films business field at the IVV. "Dying plastic bottles green using chlorophyll not only serves to emphasize this olive-green tone - the oil can also be stored for a considerably longer period of time under exposure to light."

Using chlorophyll, the institut`s scientists have already been able to dye a whole range of different plastic materials used for packaging foodstuffs. To do this they employ a wide range of techniques: depending on the type and thickness of the film and the desired intensity of color, the chlorophyll is either added to the raw plastic prior to processing or it is applied to the prepared film as a coating. In multi-layered composite films it is incorporated into the laminating adhesives. There are also plans to develop printing inks containing the natural pigments. "Every product requires its own customized packaging", summarizes Goldhahn. "With the experience gained, we are now much more oriented towards industrial manufacturers."

Dr. Johannes Ehrlenspiel | Fraunhofer-Gesellschaft - Presse

More articles from Materials Sciences:

nachricht Getting closer to porous, light-responsive materials
26.07.2017 | Kyoto University

nachricht Multitasking monolayers
25.07.2017 | Vanderbilt University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>