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Web Date: March 12, 2015

Turmeric Compound Spices Up An Antimicrobial Surface

Antibacterials: Nanosized vesicles filled with curcumin and attached to a glass surface destroy bacteria
Department: Science & Technology | Collection: Life Sciences
News Channels: Materials SCENE, Nano SCENE, Biological SCENE
Keywords: nanovesicle, curcumin, diacetylene, antibacterial, antimicrobial, food preparation, food packaging, turmeric
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NOT JUST A SPICE
Curcumin, found in the spice turmeric, has antimicrobial properties.
Structure of curcumin.
 
NOT JUST A SPICE
Curcumin, found in the spice turmeric, has antimicrobial properties.

Curcumin, the compound that gives turmeric spice its characteristic bright yellow hue, has well-known antimicrobial properties. Researchers have now put curcumin to work to create a food-safe antibacterial surface (J. Agric. Food Chem. 2015, DOI: 10.1021/jf505442w). Packaged inside nanosized vesicles attached to glass, the curcumin kills bacteria on contact. The work could lead to cutting boards, cleavers, and countertops that could actively prevent contamination during food preparation, the researchers say.

Commercial products made with antimicrobial materials range from stink-free socks to self-cleaning toilet seats. A countertop that could proactively kill bacteria would address one of the major problems of the food industry: cross-contamination, says Victor Rodov of Israel’s Agricultural Research Organization. When, for example, Escherichia coli from a piece of lettuce get onto a counter, the bacteria can contaminate the next piece of lettuce contacting that surface. Yet the germicides now laced into fabrics or plastics, including silver particles, synthetic polymers, or ammonium salts, are not generally recognized as safe for surfaces where food is prepared.

So Rodov and collaborators at Southern Illinois University (SIU), Carbondale, set out to create an antibacterial surface from food-grade materials.

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Spicy Surface
Nanovesicles housing curcumin (orange) turn glass (light blue surface) into an antibacterial surface. The curcumin resides mostly within a bilayer of diacetylene fatty acids (blue) and phospholipid (black) molecules. Glucose molecules (pink) stick to passing bacteria and expose them to the curcumin. N-hydroxysuccinimide groups (green) link the nanovesicles to the glass.
Credit: J. Agric. Food Chem.
Illustration of nanovesicles attached to glass to form an antimicrobial surface.
 
Spicy Surface
Nanovesicles housing curcumin (orange) turn glass (light blue surface) into an antibacterial surface. The curcumin resides mostly within a bilayer of diacetylene fatty acids (blue) and phospholipid (black) molecules. Glucose molecules (pink) stick to passing bacteria and expose them to the curcumin. N-hydroxysuccinimide groups (green) link the nanovesicles to the glass.
Credit: J. Agric. Food Chem.

They first screened 11 natural food compounds with known antimicrobial properties, including resveratrol from grapes, hydroxytyrosol from olives, and curcumin. In their tests, curcumin was the best at curbing E. coli growth.

The SIU researchers then packed curcumin inside custom-built nanovesicles consisting of a membrane bilayer constructed from diacetylene fatty acids and a phospholipid. Some of the diacetylene molecules were tagged with N-hydroxysuccinimide groups, which the researchers used to attach the nanovesicles to the glass. The vesicles also have molecules of glucose hanging on their surface, which stick to bacterial cell walls. The glass-bound vesicles, stocked with curcumin, can then nab passing bacteria.

The researchers compared glass slides coated with nanovesicles prepared with and without curcumin for their activity against bacteria. When the slides with curcumin were immersed for 48 hours in flasks spiked with E. coli, less than 0.5% of the bacteria survived, while no significant decline occurred in the flasks without curcumin.

How it works is still something of a mystery. The researchers know that curcumin tends to hang out within the bilayer more than in the vesicle’s central space. They suspect that when the sugar on the vesicle surface sticks to the cell wall of a passing bacterium, curcumin migrates into the cell and kills it from the inside.

Using a food ingredient as an antimicrobial is a good idea, says Kay Cooksey, who works in packaging science at Clemson University. But for commercial use, she says researchers will need to show that the antimicrobial surface works long term and that it does not convey an odor to the food or shed nanoparticles. She also would like to see if it fights the resistant biofilms that form on food processing equipment. Rodov’s group is now testing whether or not the active surface blocks the formation of biofilms.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Comments
Sushama Chittaldurg (Mon Mar 16 04:23:46 EDT 2015)
Cheers!Many food ingredients especially spices have such properties e.g. chilli/pepper or clove have pain relieving chemical molecules. It is interesting & such concepts also could be used for non invasive treatments. Keep it up! We may explore jointly on the concept as we work on spices in India.
Navneet Dogra (Thu Mar 19 19:08:45 EDT 2015)
Dear Sushama, Thanks for your comments. Yes you are right, there is a lot to explore in the field of spices.

Navneet Dogra
Ed Kosower (Thu Mar 19 15:01:46 EDT 2015)
Could the photochemical properties of circumin play a role in its antibacterial activities. A casual search brought up J Pharm Sci. 2010 Apr;99(4):1871-81. doi: 10.1002/jps.21964.
Formulation design and photochemical studies on nanocrystal solid dispersion of curcumin with improved oral bioavailability.
Onoue S1, Takahashi H, Kawabata Y, Seto Y, Hatanaka J, Timmermann B, Yamada S.
Jagadeesh (Fri Mar 20 06:29:46 EDT 2015)
Well, thanks to authors for proving again in innovative form of "nanovesicles", curcumin/turmeric act as anti microbial agent. Since it is well known in south part of India, turmeric used to protect from bacterial infection (as antibacterial) on injuries. It (Curcumin) is also well known method with fenugreek seeds to make paste for applying the food grain storage containers made up of bamboo reapers like tubs and bowls. Hope the concept will be commercialized sooner.
K.Sandeep (Fri Mar 20 08:03:15 EDT 2015)

Curcumin also should be used in food processing and as a preservative
because of its antibiotic nature.

Deepak chaudhary (Fri Mar 20 09:59:06 EDT 2015)
Thanks for recognising the values of turmeric .which India recognised centuries ago. There upteen no. Of spices and herbs which are being used in India in daily use. To day modern science is happy to discover and pet itself for these great finds.
Shahid Shaikh, Ph. D. (Fri Mar 27 12:46:53 EDT 2015)
I had inflammation at C3, C4 and C5 of backbone. Sometimes it was difficult to do physical work. Spent thousands of dollars for pain management treatment. A lady from Pakistan told me to use ~1.0 gm tumeric twice a day with a date (if you don't have diabetes). I used this cheap medicine and in a month my pain level went down to ~3 on scale of 10. I have not seen pain management Dr. for three years. Pain management specialist recognized the potency of turmeric. I still use it. It was a miracle for me.
James Dunning (Fri Mar 27 12:48:45 EDT 2015)
In 2003 the C&E News posted a news article announcing the development of curcumin natural product as an antitumor agent in Korea. Curcumin apparently functions as an inhibitor of angiogenesis in certain tumor cells. The compound has subsequently been under investigation at Emory University and at other sites. A tip from an Indian colleague led me to employ turmeric root as an effective remedy for acute inflammation. I had been prescribed such NSAIDS as indomethacin, etc. I tried a protracted regimen of turmeric root, and it proved successful.
Kymus Ginwala (Fri Mar 27 16:26:55 EDT 2015)
The is a lot of evidence that indigenous substances in nature have many biochemical benefits.
Check out fenugreek and the company www.fenugreen.com
Kymus
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