Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Sunday, April 1, 2012

Nanotechnology and Food

             The word technology often makes the public nervous when it is coupled with the word food. It is understandable that when it comes to what is ingested and used to sustain the human body, the consensus is that Mother Nature knows best. It might seem, then, that the idea of nanotechnology being incorporated with food would not be welcomed with open arms. Yet, if a dairy farmer were to gaze at his product at the nano-level, it might intrigue him to see the natural occurrence of nanoparticles in the casein micelles that inspire such technology (Institute of Medicine).

            Nanotechnology is definitively broad; it is conducting science, engineering and technology at the nanolevel of 1 to 100 nanometers, according to the National Nanotechnology Initiative (NNI) at the Nano.gov website. This scale is not new to the processes of human digestion, as indicated in the introduction; most of the processes in the body take place at the nano-level (Institute of Medicine). What makes this technology different and unique is that at the nanometer range, materials have new and unique properties and novel functions (Poole and Owens 4). Due to its interdisciplinary possibilities, the funding and investment for research is quite high and can prove to provide innovation to food processing and products (Neethirajan 39). The benefits of using nanotechnology in food production would include nutrition enhancement and safety regulation enhancement, yet there exists a gap of knowledge of risks which need to be evaluated by national, global and private organizations.
Image credit: http://www.sustainpack.com/nanotechnology.html
            Nanotechnology currently offers many benefits outside the food industry. Manufactured nanotechnology has actually existed for thousands of years; evidenced in iridescent goblets from the fourth century A.D. and stained glass used for centuries following (Poole and Owens 1). Today it is found in everyday sports items like tennis rackets and baseball bats; in rechargeable batteries for automobiles; and in household cleaning products (Nano.gov). Besides the advantage of funding that such an interdisciplinary science has, the applications can also offer crossover applications.

Raj Patel, in the Introduction of his book Stuffed and Starved: The Hidden Battle for the World Food System, presents a problem in today’s society: while 800 million global citizens go hungry, one billion are at the same time overweight. Both groups are malnourished. Accompanying this problem of inadequate food is the issue of sustainable food. Currently, production has kept up with exponential human growth and the hunger of 800 million is likely due to a corrupt food market system and various global conflicts and not overpopulation (Patel). Yet the evidence of the inability to sustain our current production starts with the beginning of agriculture. While human population has spent most of its existence on earth in a steady state with little growth, the introduction of agriculture spurred the exponential population growth (Sagan 16). As human quality of life now depends on the continuation of agriculture, it is important to ensure its sustainability not only for population but also for the changing climate.
Wireless nanosensor networks. Image credit:
http://www.nano.org.uk/forum/viewtopic.php?p=8875


One field of nanotechnology application is in food quality monitoring. Nanosensors offer the ability to track contaminants from the farm to the table. Beginning in the fields, nanosensors, through remote sensing devices that may be applied to crops, can monitor pest infestation, soil conditions and growth, helping to minimize pesticide use and utilize the full potential of cropland (Meetoo 392). Currently being proposed for monitoring grain bins are nanosensors that can detect insects or fungus through thousands of nanoparticles distributed on single, lightweight sensors. Other sensors are being designed to detect E. coli and salmonella. These bacteria sensors, useful in the bulk and limited quantity transportation of foods, include Nano Bioluminescent spray being developed by Agromicron Ltd. The spray contains nanoparticles that react with bacteria and produce a visual glow to indicate infestation (Neethirajan 40). The application of sensors in the food system would be beneficial in assuring food safety and spoilage prevention. 
Another area of application in development is that of food packaging. This sector of the food industry seems to be advancing quickly, likely due to its indirect contact with food. It includes the use of nanosensors, but also takes advantage of the lightweight characteristic of nanotechnology. Silicon-based nanoparticles offer a lightweight, more heat-resistant and stronger covering for foods that require vacuum covering to stay fresh (Meetoo 394). Metal nanoparticles can be used for antimicrobial packaging, preventing bacterial and fungal growth on food and resisting dirt. Even edible food nanoparticles are being researched for such applications (Neethirajan 41).
Some of the most advantageous yet intimidating applications are those of nanotechnology being used for encapsulation. This is the use of nanoparticles containing nutrients, flavor enhancers or texture enhancers and utilizing a controlled release. This technology has been incorporated by an Australian company, George Weston Foods. Using encapsulation, the company fortifies its bread with fish oil and masks the taste and smell by keeping the oil encapsulated until digestion (Neethirjan 43). This is just one example of using the technology in this way.
Image Credit:
http://www.foodsci.uoguelph.ca/deicon/casein.html
The aforementioned milk protein, casein micelles, offers a natural model for encapsulation delivery. Water molecules are polar molecules; they have a positive end and a negative end. Micelles are made up of surfactants that have hydrophilic (water-favoring) heads that are also polar, and hydrophobic (water resistant) non-polar tails (Poole and Owens 326). These surfactants get together and form a nanoparticle (micelle) in nature that offers a biological delivery system. Scientists can take this design and synthesize a vitamin delivery system using these proteins (Neethrijan 43). Though encapsulation appears to present the most risk due to its direct interaction with food products, it also offers the most promise due to the natural blueprints available.
This particular delivery system can be incorporated with the sensor system to cater to individual needs and tastes. Sensors in nanocapsules can trigger a release of nutrients if it senses a lack of nutrients in the consumer. Microwaves can trigger sensors to release specific flavor or color enhancers. This delivery system can also be utilized for textures, adding the desired fatty texture to low-fat foods (Neethrijan 44).
Technology of any kind used in food processing and production is often viewed skeptically by the general public. This applies to not only western consumers, but also by what Raj Patel refers to in his book as the “global south,” the developing countries that while some of the biggest producers of agriculture are also the hungriest. Patel, in the For Africa! section of chapter 6 of his book, points out that countries such as Zambia have rejected food aid from the U.S. due to the incorporation of notorious genetically modified organisms (GMO’s) that the U.S. Food and Drug Administration (FDA) allows and that Zambia’s own scientists have been unable to vet for themselves. This aversion is completely understandable, and should be addressed by creating a global cooperation when it comes to incorporating nanotechnology into food; research should not rest solely in the hands of the profit-seeking corporations that seek to use it in their food products.
These concerns are not lost on regulators and scientists in the U.S. or even on global organizations. In 2010, the United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO) had a meeting on the potential applications and safety concerns of nanotechnology in the food and agriculture sectors. In 2009, the National Science Foundation’s Institute of Medicine hosted a workshop forum on the same, with members of the FDA, Environmental Protection Agency (EPA) and National Science Foundation in attendance as contributors to discussion.
Image credit: 2007 How Stuff Works

One of the knowledge gaps in such a young technology that has only recently come to be considered for application in the food industry is that of how nanoparticles are distributed once ingested (World Health Organization 29). Most of the toxicology research done thus far has been in the occupational sector of nanotechnology, where workers are exposed to nanoparticles for short periods of time and the path of intake is more likely inhalation or absorption (through the skin) then ingestion/oral intake, which was pointed out in both of the meetings. In summary, the World Health Organization’s assessment of risks read as following:
“Future needs and ways forward to prevent human health risks at international and national levels concern knowledge (scientific and market data), resources (funding for studies, facilities and trained investigators), and processes (international scientific collaboration on characterization, methods design and testing; international, multistakeholder collaboration on guidelines development and harmonization; public engagement and societal governance).”
The knowledge, resource and process needs were laid out in the meeting report, with emphasis on the necessity for collaboration and public engagement.
            At the 2009 Institute of Medicine workshop, many safety concerns were brought up. The fact that nanomaterials fall within the biological size scale makes it possible that there can and will be interactions at the biological level; cellular interference and possible DNA interference. The Institute of Medicine published the discussions on these risks in the last chapters of its book, Nanotechnology in Food Products. In chapter three of this book, it was noted by speaker Fred Degnan, an attorney, that even with the FDA encouraging early and often dialogue with industry producing Nanotechnology, the FDA should work to provide written guidance for what it requires in research and development to approve nanomaterials in food products.  This would be a vast improvement to the FDA’s requirements for GMOs, as Patel points out in chapter six of Stuffed and Starved; Patel describes the the US Food and Drug Administration’s handling of new GM crops; that the research into the safety of these foods was left entirely in the hands of the profit-seeking private sector that was engineering the crops for consumption. Where the FDA could have done much more in the way of research, it relied on the words of an industry that had already invested significant amounts of time and money into crops that were supposed to make food more nutritious for world population. The FDA speaker at the workshop does acknowledge that the burden of proof of safety lies in the hands of the manufacturers (Institute of Medicine).
            Though the FDA has not yet publicly produced a set of written guidelines, the European Food Safety Authority (EFSA) has, which is a start to a more conformed regulatory process for global major food manufacturers. In the abstract of the paper, the European Food Safety Authority claims that it “has developed a practical approach for assessing potential risks arising from applications of nanoscience and nanotechnologies in the food and feed chain.” The EFSA overview lays out a flow chart, beginning with the question of whether or not the material in question is even an engineered nano-material (or ENM) and how to proceed from there on assessing the risk (9). That this guidance exists should be taken into consideration and used as a model for other regulatory and health agencies and organizations on the national and global levels. This consistency would aid in the collaboration of top tier scientists, academics and manufacturers as well as give the process transparency for the public.
            Consumer education is the most important aspect of integrating nanotechnology into food production. In an informal survey of less then one hundred people, two things stand out about public awareness on the subject: That the public understands little about the actual technology, and that they don’t want manufacturers to be the ones researching its use in their food (Satterlee). A more formal survey of a similar nature was conducted by the National Science Foundation and found that not only did half of the participants know “little or nothing” about the technology, only six percent cared to apply it to use in food (National Institute of Medicine). Julia Moore, of the Woodrow Wilson International Center for Scholars, spoke at the workshop for Nanotechnology in Food Products and had this to say after analyzing the surveys taken on the subject: “public opinion is really up for grabs when it comes to nanotechnology. The public really doesn’t know very much to have an opinion.” This emphasizes that scientists and organizations still have the opportunity to form public opinion about it, and transparency is going to count for a lot.
            One lesson learned from the failure of public information on GMOs might be best summed up in Patel’s book in chapter 6’s I’d Like to Thank the Academy. Patel describes a story of a whistle-blowing scientist, Ignacio Chapela. Chapela submitted and had published in the peer-reviewed journal Nature an article on the cross contamination of genetically modified maize in Mexico. The article was mysteriously retracted. In an attempt to avoid this type of corruption in the research of other technology in the food industry, it is promising that such a wide collaboration is involved. From academics to global organizations, the importance of transparency cannot be stressed enough to ensure that the benefits of nanotechnology are safely integrated into the food system. As consistency and guidance is produced, all involved in regulation and research will be aware that it is their responsibility to ensure safe and effective applications of technology.




Works Cited
European Food Safety Authority. “Guidance on the risk assessment of the application of nanoscience and nanotechnologies in the food and feed chain.” EFSA Journal 9.5 (2011) : 1-36. Web. 24 Feb 2012.
Institute of Medicine of the National Academies. Nanotechnology in Food Products Workshop Summary. Washington, D.C.: National Academies Press, 2009. Electronic book.
Meetoo, Danny D. “Nanotechnology and the food sector: From the farm to the table.” Emirates Journal of Food and Agriculture. 23.5 (2011): 387-403. Web.
Nano.gov. National Nanotechnology Initiative. Web. 22 Feb 2012
Neethirajan, Suresh. “Nanotechnology for the Food and Bioprocessing Industries.” Food and Bioprocess Technology. 4.1 (2010): 39-47. Web.
Patel, Raj. Stuffed and Starved: The Hidden Battle For the World Food System. Brooklyn, N.Y.: Melville House Publishing, 2007. Electronic book.
Poole, Charles P. and Frank J. Owens. Introduction to Nanotechnology. New Jersey: John Wiley & Sons, Inc, 2003. Print.
Sagan, Carl. Billions & Billions. New York: Randomhouse, 1997. Print.
Satterlee, Dorian. “Survey on Nanotechnology and Food.” Survey monkey, Feb. 2012. Web.
World Health Organization. “FAO/WHO Expert meeting on the application of nanotechnologies in the food and agriculture sectors: potential food safety implications Meeting report.” Rome : FAO and WHO, 2010. 1-130. Web.

Friday, November 11, 2011

Galaxies!

This is another guest post from my nine-year-old daughter, Lilian. Lilian loves astronomy and was excited to do this one! -Dorian

By Lilian Satterlee

When you look up at the night sky, you might only see tens of stars in the area of your galaxy. But all you see is not all there is! Our galaxy has not only 50 stars, but billions. We live in a galaxy called the Milky Way, a spiral galaxy with hundreds of thousands of billions of stars.

Our Milky Way Galaxy

IC 1011, largest known galaxy
 As big as it is, it is only a speck compared to this giant: IC 10-11 is the largest galaxy ever found. It is 60 times larger than our Milky Way.
M 87 is one of the oldest galaxies in the known universe.

M87
Our neighbor, Andromeda
Andromeda is our nearest neighbor. All galaxies are different, unique, big and everywhere.


How Galaxies Formed!
It takes gravity to make stars and pull them together. Early galaxies were a big mess; lumpy clumps of stars, dust and gas. Today, galaxies are neat and organized, and gravity is what makes that happen.



So remember, galaxies are made of billions of stars and there are billions of galaxies!

Sunday, August 7, 2011

Plan to Save the Whales

This is a guest blog post written and illustrated by my daughter, Lily. She is 9 years old and has a passion for these wonderful creatures. These views are not all necessarily the views of anyone BUT a wonderful and curious little girl, so please, Enjoy!



Plan to Save the Whales


You know, lots of people love whales and they love to see whales; but the whales are endangered. To keep up the fun of whale watching, we need to do something before they are extinct.
Easy Home ways to save the whales:
  • Cool down the earth by biking or walking to places that aren't far away
  • Turn off electronics when not in use
  • When you go to the bathroom, don't use a lot of toilet paper, because everything that goes down the toilet or drain ends up in the ocean
  • Take short showers and don't make them that hot.

Whales sometimes get beached. So here is how you can save them if they do. If the whale is light enough, put wet blankets over it and wait for a helicopter to pick up the whale and move it back to the ocean. If the wale is like a Sperm Whale or a Blue Whale, put wet blankets on it and wait for the tide to come in and quickly pull off the blankets.


So keep your ocean clean and don't allow whaling!

References:
Mom & Dad propaganda


Briarcrest Elementary 3rd Grade Class

Saturday, July 30, 2011

Microwave Ovens

Have you ever wondered how your microwave warms up your food, or worried that this mysterious process might be mutating what you ingest or even that those microwaves are escaping the box and penetrating your insides? Well, hopefully I can shed at least a little light on this magic hotbox and allay, well, some of your fears anyway.
Speaking of light, let me start with explaining what a microwave is. As in the actual, electromagnetic wave. You may have heard that light travels in waves, and that each color has a different wavelength. The rainbow shows the spectrum, and these colors are always in the same order...based on their wavelengths and frequencies. These visible waves are only a fraction of the spectrum. Other electromagnetic waves include radio waves, infra-red, x-rays, etc. (see spectrum below definitions).
Wavelength: Physics . the distance, measured in the direction of propagation of a wave, between two successive points in the wave that are characterized by the same phase of oscillation. Or:
Frequency: the number of cycles or completed alternations per unit time of a wave or oscillation. Symbol:  F; Abbreviation:  freq. Or:
1 Hz means that an event repeats once per second.
To demonstrate where your everyday waves fall on a spectrum, including the microwaves we are preparing to discuss, here is a helpful little picture:

Fantastic. Now we realize that the force we are working with in a Microwave Oven is electromagnetic, and have a basic understanding of the spectrum.
      The most important part of your microwave oven is the Magnetron. This nifty device is what is actually creating the microwaves and sending them into the box. When power is supplied electronically (i.e., plug it in and turn it on), the magnetron produces simultaneous electric and magnetic fields that oscillate at the right frequency to create microwaves. These microwaves emit from the magnetron, and are reflected off metal surfaces: A metal fan sends waves into the oven segment, the metal lined walls of the microwave oven reflect the waves throughout and back and forth.
      So now you have microwaves being reflected around the oven. What happens when you add food? First, let’s look at the make-up of the food you eat. Do you know what is common in almost everything you ingest? It’s water molecules. It is these molecules of H2O that are the key to microwaves increasing the temperature of the object inside the oven. This is due to the fact that these molecules are polarized.
      When the Oxygen (O) atom combines with the two Hydrogen (H2) atoms, it pulls the electrons partly from the Hydrogen…creating a negative charge on the Oxygen end of the molecule. This in turn creates a positive charge on the H2 end of the molecule, and there you have your polarization.
      As the fluctuating electric field of a microwave passes by these water molecules, it causes the polarized water to in turn fluctuate…and at the speeds that they begin to fluctuate, heat is in turn created! The excited water is turning the work energy into heat and that is a thermodynamics lesson for another post.
This leaves us with a couple of questions still from the introduction.
Are these microwaves escaping and cooking your insides? The answer is no. Take a look at your microwave oven. All the walls, save the door, are all-metal surfaces. The door is a mesh design of metal and amazingly, those holes in the mesh are TOO SMALL to allow the escape of the microwaves. Fabulous, right?
Are these microwaves mutating your food? Pure water molecules are not going to be changed by the effects of microwaves. That being said, the complex carbon chains that make up the rest of most foods may be affected by the microwaves, but to what extent, I don’t know. If you know, please feel free to post a response, I would love to hear what others have to say!
Experiment:
Try (with adult supervision, if you are a minor) microwaving an ice-cube or ice-cubes. What happens? Can you explain why?
Formula (for the math-happy science geeks):
C = λ(ν) or speed of light = wavelength times frequency
Electromagnetic waves always travel at the speed of light, and therefore, the higher the frequency, the shorter the wavelength.


References:

Bloomfield, Louis A. How Things Work. John Wiley & Sons, Inc. 2006. p 432.

 Fischetti, Mark. How the Microwave Works. Scientific American. Oct 30, 2008.
http://www.scientificamerican.com/article.cfm?id=how-the-microwave-works
viewed at link on Jul 30 2011.

Definitions from: http://www.dictionary.com/