Category Archives: food

Quantum dots cycling through the food chain

Rice University (Texas, US) researchers have published a study which follows quantum dot nanoparticles as they enter the water supply and are taken up by plant roots and leaves and eaten by caterpillars. From a Dec. 16, 2014 news item on ScienceDaily,

In one of the most comprehensive laboratory studies of its kind, Rice University scientists traced the uptake and accumulation of quantum dot nanoparticles from water to plant roots, plant leaves and leaf-eating caterpillars.

The study, one of the first to examine how nanoparticles move through human-relevant food chains, found that nanoparticle accumulation in both plants and animals varied significantly depending upon the type of surface coating applied to the particles. The research is available online in the American Chemical Society’s journal Environmental Science & Technology.

A Dec. 16, 2014 Rice University news release (also on EurekAlert), which originated the news item, provides insight into some of the issues being addressed with this research (Note: Links have been removed),

“With industrial use of nanoparticles on the rise, there are increasing questions about how they move through the environment and whether they may accumulate in high levels in plants and animals that people eat,” said study co-author Janet Braam, professor and chair of the Department of BioSciences at Rice.

Braam and colleagues studied the uptake of fluorescent quantum dots by Arabidopsis thaliana, an oft-studied plant species that is a relative of mustard, broccoli and kale. In particular, the team looked at how various surface coatings affected how quantum dots moved from roots to leaves as well as how the particles accumulated in leaves. The team also studied how quantum dots behaved when caterpillars called cabbage loopers (Trichoplusia ni) fed upon plant leaves containing quantum dots.

“The impact of nanoparticle uptake on plants themselves and on the herbivores that feed upon them is an open question,” said study first author Yeonjong Koo, a postdoctoral research associate in Braam’s lab. “Very little work has been done in this area, especially in terrestrial plants, which are the cornerstone of human food webs.”

Some toxins, like mercury and DDT, tend to accumulate in higher concentrations as they move up the food chain from plants to animals. It is unknown whether nanoparticles may also be subject to this process, known as biomagnification.

While there are hundreds of types of nanoparticles in use, Koo chose to study quantum dots, submicroscopic bits of semiconductors that glow brightly under ultraviolet light. The fluorescent particles — which contained cadmium, selenium, zinc and sulfur — could easily be measured and imaged in the tests. In addition, the team treated the surface of the quantum dots with three different polymer coatings — one positively charged, one negatively charged and one neutral.

“In industrial applications, nanoparticles are often coated with a polymer to increase solubility, improve stability, enhance properties and for other reasons,” said study co-author Pedro Alvarez, professor and chair of Rice’s Department of Civil and Environmental Engineering. “We expect surface coatings to play a significant role in whether and how nanomaterials may accumulate in food webs.”

Previous lab studies had suggested that the neutral coatings might cause the nanoparticles to aggregate and form clumps that were so large that they would not readily move from a plant’s roots to its leaves. The experiments bore this out. Of the three particle types, only those with charged coatings moved readily through the plants, and only the negatively charged particles avoided clumping altogether. The study also found that the type of coating impacted the plants’ ability to biodegrade, or break down, the quantum dots.

Koo and colleagues found caterpillars that fed on plants containing quantum dots gained less weight and grew more slowly than caterpillars that fed on untainted leaves. By examining the caterpillar’s excrement, the scientists were also able to estimate whether cadmium, selenium and intact quantum dots might be accumulating in the animals. Again, the coating played an important role.

“Our tests were not specifically designed to measure bioaccumulation in caterpillars, but the data we collected suggest that particles with positively charged coatings may accumulate in cells and pose a risk of bioaccumulation,” Koo said. “Based on our findings, more tests should be conducted to determine the extent of this risk under a broader set of ecological conditions.”

The researchers have a couple of images illustrating their work,

The buildup of fluorescent quantum dots in the leaves of Arabidopsis plants is apparent in this photograph of the plants under ultraviolet light. Credit: Y. Koo/Rice University

The buildup of fluorescent quantum dots in the leaves of Arabidopsis plants is apparent in this photograph of the plants under ultraviolet light. Credit: Y. Koo/Rice University

And, there’s a caterpillar,

Cabbage looper

Cabbage looper

Here’s a link to and a citation for the paper,

Fluorescence Reports Intact Quantum Dot Uptake into Roots and Translocation to Leaves of Arabidopsis thaliana and Subsequent Ingestion by Insect Herbivores by Yeonjong Koo, Jing Wang, Qingbo Zhang, Huiguang Zhu, E. Wassim Chehab, Vicki L. Colvin, Pedro J. J. Alvarez, and Janet Braam. Environ. Sci. Technol., Just Accepted Manuscript DOI: 10.1021/es5050562 Publication Date (Web): December 1, 2014

Copyright © 2014 American Chemical Society

This paper is open access but you must be registered on the website.

One final thought about the research, it did take place in a laboratory environment and there doesn’t seem to have been any soil involved so the uptake can not be directly compared (as I understand matters) to the uptake characteristics where plant cultivation requires soil. This seems to have been a study involving hydroponic framing practices.

Singaporeans’ perceptions of nanotechnology and consumer attitudes towards nanotechnologies in food production

This is the first time I’ve seen a study about nanotechnology perception and awareness from Asia. (As I’m sure this is not the first or the only such study, I lament my language skills once more. Since my primary search is for English language materials with my second language, French, as a very distant second, I am limited to translated materials.)

This piece of research comes from Singapore. From a Dec. 11, 2014 news item on the Asian Scientist magazine website,

A survey published in the Journal of Nanoparticle Research shows that while the Singaporean population is more familiar with nanotechnology than their Western counterparts in the US and Europe, they are also more wary of the risks involved.

Asia is expected to dominate the use and release of nanomaterials into the environment, largely due to the size of the population. Furthermore, the region in general—and Singapore in particular—has invested heavily in nanotechnology research, rapidly translating their findings into industrial and consumer products. However, there has been a lack of studies documenting public attitudes and acceptance of new technologies such as nanotechnology.

To address this gap of information, a team of researchers led by first author Dr. Saji George from the Nanyang Polytechnic (NYP) Center for Sustainable Nanotechnology conducted a survey of 1,080 Singaporeans above the age of 15. Their results revealed that approximately 80 percent had some understanding of nanotechnology.

A June 20, 2014 Nanyang Polytechnic media release provides additional details about the research,

In a recent public perception study conducted in Singapore with 1,000 respondents, researchers from Nanyang Polytechnic’s (NYP) Centre for Sustainable Nanotechnology (CSN) found that 80% of respondents were aware of nanotechnology, while only 40% of them were positive about its benefits. This was shared at the official launch of the CSN today. The event was graced by Mr Derek Ho, Director-General, Environmental Public Health Division, National Environment Agency (NEA).

The Centre is the first-of-its-kind among institutes of higher learning (IHLs) in Singapore. It is dedicated to studying the potential impact of novel engineered nanomaterials, and developing ways to ensure that nanotechnology applications are adopted in a sustainable manner for individuals and the environment. This makes the $1 million facility a key training facility for NYP’s students from the Schools of Chemical & Life Sciences, Engineering, and Health Sciences.

Perceptions influenced by exposure to prior information

The perception study conducted in collaboration with the United Kingdom’s Newcastle University, is part of a worldwide study. [emphasis mine] About 1,000 respondents were surveyed in Singapore. Among them, 80% had some level of familiarity with nanotechnology,  while only 40% of them were positive about its benefits. One of the strong determinants that influenced the perception of the public was their prior exposure to news on adverse effects of nanotechnology. This could be due to negative information on nanotechnology carried in the media. Often these are over interpretations of laboratory studies that tend to dampen public confidence in nanotechnology.

“Nanotechnology may be a double-edged sword in some applications. A large proportion of the population is already aware of it, and interestingly, 60% have actually come across negative information on nanotechnology. This points to the need for the Centre for Sustainable Nanotechnology to conduct its work robustly and effectively, to sharpen the benefits, and blunt the risks associated with nanotechnology. This will enable industries to better apply the relevant solutions, and for people to use products containing nanotechnology more confidently. Another impetus for the Centre is that through such studies, companies will learn what consumers are concerned about in specific types of products and how these concerns can be addressed during product design and manufacturing stages,” said Dr Joel Lee, Director of NYP’s School of Chemical & Life Sciences where the Centre is located.

The study also found variations in perception among different socio-demographic groups, and among applications of nanotechnology across different product ranges, for example food, baby products, medicine, clothing, cosmetics, water filters and electronics.

While this is a segue, there’s a very interesting tidbit about silver nanoparticles in this media release,

Smarter Antibacterial Nanotechnology

Since the CSN started operations in 2013, senior lecturers, Dr Saji George and Dr Hannah Gardner, from NYP’s Schools of Chemical & Life Sciences and Engineering, respectively, have studied the effectiveness of nano-silver in eliminating bacteria – which accounts for 30% of commercial nanotechnology – in applications currently available in the market. Nano-silver is largely used as an alternate anti-microbial solution in a range of industries, including clothing, baby products, personal care products and medicine.

Their research findings, now filed as a patent, uncovered that some drug resistant bacterial strains could also develop resistance to silver, contrary to the general notion that all bacterial strains will succumb to it. The duo then designed and developed a cost-effective method to generate cationic polymer coated silver nanoparticles. They observed that these nanoparticles could eliminate pathogenic bacteria regardless of their ability to resist antibiotics and silver.

Dr Lee added, “Nano-silver has captured the attention of industry and researchers. What we hope to achieve with the CSN is two-fold. We aim to be a resource for industries and even government regulatory agencies to tap on to better understand nanotechnology, its effects, and improve on its applications. These would also translate into real-world industry projects for our students and equip them to better serve the industry when they embark on their careers.”

Here’s a link to and citation for the paper,

Awareness on adverse effects of nanotechnology increases negative perception among public: survey study from Singapore by Saji George, Gulbanu Kaptan, Joel Lee, Lynn Frewer. Journal of Nanoparticle Research November 2014, 16:2751 Date: 22 Nov 2014

This paper is behind a paywall.

I did search for the “… worldwide study” regarding nanotechnology awareness and perceptions but found instead a recently published study on the topic of consumer attitudes towards nanotechnologies used in food production practices which features George and Frewer,

Consumer attitudes towards nanotechnologies applied to food production by L.J. Frewer, N. Gupta, S. George, A.R.H. Fischer, E.L. Giles, and D. Coles. Trends in Food Science & Technology, Volume 40, Issue 2, December 2014, Pages 211–225 (Special Issue: Nanotechnology in Foods: Science behind and future perspectives)

This article is behind a paywall.

Who would buy foods that were nanotechnology-enabled or genetically modified?

A research survey conducted by scientists at North Carolina State University (NCSU) and the University of Minnesota suggests that under certain conditions, consumers in the US would be likely to purchase nanotechnology-enabled or genetically modified food. From a Dec. 2, 2014 news item on Nanowerk,

New research from North Carolina State University and the University of Minnesota shows that the majority of consumers will accept the presence of nanotechnology or genetic modification (GM) technology in foods – but only if the technology enhances the nutrition or improves the safety of the food.

A Dec. 2, 2014 NCSU news release (also on EurekAlert), which originated the news item, notes that while many people will pay more to avoid nanotechnology-enabled or genetically modified food there is an exception of sorts,

“In general, people are willing to pay more to avoid GM or nanotech in foods, and people were more averse to GM tech than to nanotech,” says Dr. Jennifer Kuzma, senior author of a paper on the research and co-director of the Genetic Engineering in Society Center at NC State. “However, it’s not really that simple. There were some qualifiers, indicating that many people would be willing to buy GM or nanotech in foods if there were health or safety benefits.”

The researchers conducted a nationally representative survey of 1,117 U.S. consumers. Participants were asked to answer an array of questions that explored their willingness to purchase foods that contained GM tech and foods that contained nanotech. The questions also explored the price of the various foods and whether participants would buy foods that contained nanotech or GM tech if the foods had enhanced nutrition, improved taste, improved food safety, or if the production of the food had environmental benefits.

The researchers found that survey participants could be broken into four groups.

Eighteen percent of participants belonged to a group labeled the “new technology rejecters,” which would not by GM or nanotech foods under any circumstances. Nineteen percent of participants belonged to a group labeled the “technology averse,” which would buy GM or nanotech foods only if those products conveyed food safety benefits. Twenty-three percent of participants were “price oriented,” basing their shopping decisions primarily on the cost of the food – regardless of the presence of GM or nanotech. And 40 percent of participants were “benefit oriented,” meaning they would buy GM or nanotech foods if the foods had enhanced nutrition or food safety.

“This tells us that GM or nanotech food products have greater potential to be viable in the marketplace if companies focus on developing products that have safety and nutrition benefits – because a majority of consumers would be willing to buy those products,” Kuzma says.

“From a policy standpoint, it also argues that GM and nanotech foods should be labeled, so that the technology rejecters can avoid them,” Kuzma adds.

Here’s a link to and a citation for the paper,

Heterogeneous Consumer Preferences for Nanotechnology and Genetic-modification Technology in Food Products by Chengyan Yue, Shuoli Zhao, and Jennifer Kuzma. Journal of Agricultural Economics DOI: 10.1111/1477-9552.12090 Article first published online: 12 NOV 2014

© 2014 The Agricultural Economics Society

This paper is behind a paywall.

I have mentioned Jennifer Kuzma’s work previously in an Oct. 29, 2013 posting titled, Nano info on food labels wanted by public in the US?

FOE, nano, and food: part three of three (final guidance)

The first part of this food and nano ‘debate’ started off with the May 22, 2014 news item on Nanowerk announcing the Friends of the Earth (FOE) report ‘Way too little: Our Government’s failure to regulate nanomaterials in food and agriculture‘. Adding energy to FOE’s volley was a Mother Jones article written by Tom Philpott which had Dr. Andrew Maynard (Director of the University of Michigan’s Risk Science Center) replying decisively in an article published both on Nanowerk and on the Conversation.

The second part of this series focused largely on a couple of  research efforts (a June 11, 2014 news item on Nanowerk highlights a Franco-German research project, SolNanoTox) and in the US (a  June 19, 2014 news item on Azonano about research from the University of Arizona focusing on nanoscale additives for dietary supplement drinks) and noted another activist group’s (As You Sow) initiative with Dunkin’ Donuts (a July 11, 2014 article by Sarah Shemkus in a sponsored section in the UK’s Guardian newspaper0).

This final part in the series highlights the US Food and Drug Administration’s (FDA) final guidance document on nanomaterials and food issued some five weeks after the FOE’s report and an essay by a Canadian academic on the topic of nano and food.

A July 9, 2014 news item on Bloomberg BNA sums up the FDA situation,

The Food and Drug Administration June 24 [2014] announced new guidance to provide greater regulatory clarity for industry on the use of nanotechnology in FDA-regulated products, including drugs, devices, cosmetics and food.

In this final guidance, the agency said that nanotechnology “can be used in a broad array of FDA-regulated products, including medical products (e.g., to increase bioavailability of a drug), foods (e.g., to improve food packaging) and cosmetics (e.g., to affect the look and feel of cosmetics).”

Also on the agency website, the FDA said it “does not make a categorical judgment that nanotechnology is inherently safe or harmful. We intend our regulatory approach to be adaptive and flexible and to take into consideration the specific characteristics and the effects of nanomaterials in the particular biological context of each product and its intended use.”

This July 18, 2014 posting by Jeannie Perron, Miriam Guggenheimm and Allan J. Topol of Covington & Burling LLP on the National Law Review blog provides a better summary and additional insight,

On June 24, 2014, the Food and Drug Administration (FDA) released three final guidance documents addressing the agency’s general approach to nanotechnology and its use by the food and cosmetics industries, as well as a draft guidance on the use of nanomaterials in food for animals.

These guidance documents reflect FDA’s understanding of nanomaterials as an emerging technology of major importance with the potential to be used in novel ways across the entire spectrum of FDA- regulated products.

The documents suggest that FDA plans to approach nanotechnology-related issues cautiously, through an evolving regulatory structure that adapts to manufacturers’ changing uses of this technology. FDA has not established regulatory definitions of “nanotechnology,” “nanomaterial,” “nanoscale,” or other related terms. …

The notion of an “evolving regulatory structure” is very appealing in situations with emerging technologies with high levels of uncertainty. It’s surprising that more of the activist groups don’t see an opportunity with this approach. An organization that hasn’t devised a rigid regulatory structure has no investment in defending it. Activist groups can make the same arguments, albeit from a different perspective, about an emerging technology as the companies do and, theoretically, the FDA has become a neutral party with the power to require a company to prove its products’ safety.

You can find the FDA final guidance and other relevant documents here.

Finally, Sylvain Charlebois, associate dean at the College of Business and Economics at the University of Guelph, offers a rather provocative (and not from the perspective you might expect given his credentials) opinion on the topic of ‘nano and food’  in a July 18, 2014 article for,

Nanotechnology and nanoparticles have been around for quite some time. In fact, consumers have been eating nanoparticles for years without being aware they are in their food.

Some varieties of Dentyne gum and Jell-O, M&M’s, Betty Crocker whipped cream frosting, Kool-Aid, Pop-Tarts, you name it, contain them. Even food packaging, such as plastic containers and beer bottles, have nanoparticles.

While consumers and interest groups alike are registering their concerns about genetically modified organisms, the growing role of nanotechnology in food and agriculture is impressive. When considering the socio-economic and ethical implications of nanotechnology, comparisons to the genetic modification debate are unavoidable.

The big picture is this. For years, capitalism has demonstrated its ability to create wealth while relying on consumers’ willingness to intrinsically trust what is being offered to them. With trans fats, genetically modified organisms and now nanoparticles, our food industry is literally playing with fire. [emphasis mine]

Most consumers may not have the knowledge to fully comprehend the essence of what nanotechnology is or what it can do. However, in an era where data access in almost constant real-time is king, the industry should at least give public education a shot.

In the end and despite their tactics, the activist groups do have a point. The food and agricultural industries need to be more frank about what they’re doing with our food. As Charlebois notes, they might want to invest in some public education, perhaps taking a leaf out of the Irish Food Board’s book and presenting the public with information both flattering and nonflattering about their efforts with our food.

Part one (an FOE report is published)

Part two (the problem with research)

ETA Aug. 22, 2014: Coincidentally, Michael Berger has written an Aug. 22, 2014 Nanowerk Spotlight article titled: How to identify nanomaterials in food.

ETA Sept. 1, 2014: Even more coincidentally, Michael Berger has written a 2nd Nanowerk Spotlight (dated Aug. 25, 2014) on the food and nano topic titled, ‘Nanotechnology in Agriculture’ based on the European Union’s Joint Research Centre’s ‘Workshop on Nanotechnology for the agricultural sector: from research to the field”, held on November 21-22 2013′.

FOE, nano, and food: part two of three (the problem with research)

The first part of this roughly six week food and nano ‘debate’ started off with the May 22, 2014 news item on Nanowerk announcing the Friends of the Earth (FOE) report ‘Way too little: Our Government’s failure to regulate nanomaterials in food and agriculture‘. Adding energy to FOE’s volley was a Mother Jones article written by Tom Philpott which had Dr. Andrew Maynard (Director of the University of Michigan’s Risk Science Center) replying decisively in an article published both on Nanowerk and on the Conversation.

Coincidentally or not, there were a couple of news items about ‘nano and food’ research efforts during the ‘debate’. A June 11, 2014 news item on Nanowerk highlights a Franco-German research project into the effects that nanomaterials have on the liver and the intestines while noting the scope of the task researchers face,

What mode of action do nanomaterials ingested via food have in liver and intestine? Which factors determine their toxicity? Due to the large number of different nanomaterials, it is hardly possible to test every one for its toxic properties. [emphasis mine] For this reason, specific properties for the classification of nanomaterials are to be examined within the scope of the Franco-German research project “SolNanoTox”, which began on 1 March 2014. The [German] Federal Institute for Risk Assessment (BfR) requires data on bioavailability for its assessment work, in particular on whether the solubility of nanomaterials has an influence on uptake and accumulation in certain organs, such as liver and intestine. “We want to find out in our tests whether the criterion ‘soluble or insoluble’ is a determining factor for uptake and toxicity of nanomaterials,” says BfR President Professor Dr. Andreas Hensel.

A June 13, 2014 German Federal Institute for Risk Assessment (BfR) press release, which originated the news item, details the research and the participating agencies,

A risk assessment of nanomaterials is hardly possible at the moment and involves a very high degree of uncertainty, as important toxicological data on their behaviour in tissue and cells are still missing. [emphasis mine] The German-French SolNanoTox research project examines which role the solubility of nanomaterials plays with regard to their accumulation and potential toxic properties. The project is to run for three and a half years during which the BfR will work closely with its French sister organisation ANSES. Other partners are the Institut des Sciences Chimiques de Rennes and Universität Leipzig. The German Research Foundation and French Agence Nationale de la Recherche (ANR) are funding the project.

The tasks of the BfR include in vitro tests (e.g. the investigation of the influence of the human gastrointestinal system) and analysis of biological samples with regard to the possible accumulation of nanomaterials. In addition to this, the BfR uses modern methods of mass spectrometry imaging to find out whether nanoparticles alter the structure of biomolecules, e.g. the structure of the lipids of the cellular membrane. So far, these important tests, which are necessary for assessing possible changes in DNA or cellular structures caused by nanomaterials in food, have not been conducted.

Metallic nanoparticles are to be studied (from the press release),

In the project, two fundamentally different types of nanoparticles are examined as representatives for others of their type: titanium dioxide as representative of water insoluble nanoparticles and aluminium as an example of nanomaterials which show a certain degree of water solubility after oxidation. [emphases mine] It is examined whether the degree of solubility influences the distribution of the nanomaterials in the body and whether soluble materials may possibly accumulate more in other organs than insoluble ones. The object is to establish whether there is a direct toxic effect of insoluble nanomaterials in general after oral uptake due to their small size.

Different innovative analytical methods are combined in the project with the aim to elucidate the behaviour of nanomaterials in tissue and their uptake into the cell. The main focus is on effects which can trigger genotoxic damage and inflammation. At first, the effects of both materials are examined in human cultures of intestinal and liver cells in an artificial environment (in vitro). In the following, it has to be verified by animal experimentation whether the observed effects can also occur in humans. This modus operandi allows to draw conclusions on effects and mode of action of orally ingested nanomaterials with different properties. The goal is to group nanomaterials on the basis of specific properties and to allocate the corresponding toxicological properties to these groups. Motivation for the project is the enormous number of nanomaterials with large differences in physicochemical properties. Toxicological tests cannot be conducted for all materials.

In the meantime, a June 19, 2014 news item on Azonano (also on EurekAlert but dated June 18, 2014) features some research into metallic nanoparticles in dietary supplement drinks,

Robert Reed [University of Arizona] and colleagues note that food and drink manufacturers use nanoparticles in and on their products for many reasons. In packaging, they can provide strength, control how much air gets in and out, and keep unwanted microbes at bay. As additives to food and drinks, they can prevent caking, deliver nutrients and prevent bacterial growth. But as nanoparticles increase in use, so do concerns over their health and environmental effects. Consumers might absorb some of these materials through their skin, and inhale and ingest them. What doesn’t get digested is passed in urine and feces to the sewage system. A handful of initial studies on nanomaterials suggest that they could be harmful, but Reed’s team wanted to take a closer look.

They tested the effects of eight commercial drinks containing nano-size metal or metal-like particles on human intestinal cells in the lab. The drinks changed the normal organization and decreased the number of microvilli, finger-like projections on the cells that help digest food. In humans, if such an effect occurs as the drinks pass through the gastrointestinal tract, these materials could lead to poor digestion or diarrhea, they say. The researchers’ analysis of sewage waste containing these particles suggests that much of the nanomaterials from these products are likely making their way back into surface water, where they could potentially cause health problems for aquatic life.

This piece is interesting for two reasons. First, the researchers don’t claim that metallic nanoparticles cause digestion or diarrhea due to any action in the gastrointestinal tract. They studied the impact that metallic nanoparticles in supplementary drinks had on cells (in vitro testing) from the gastrointestinal tract. Based on what they observed in the laboratory, “… these materials could lead to poor digestion or diarrhea… .” The researchers also suggest a problem could occur as these materials enter surface water in increasing quantities.

Here’s a link to and a citation for the paper,

Supplement Drinks and Assessment of Their Potential Interactions after Ingestion by Robert B. Reed, James J. Faust, Yu Yang, Kyle Doudrick, David G. Capco, Kiril Hristovski, and Paul Westerhoff. ACS Sustainable Chem. Eng., 2014, 2 (7), pp 1616–1624 DOI: 10.1021/sc500108m Publication Date (Web): June 2, 2014

Copyright © 2014 American Chemical Society

With Paul Westerhoff as one of the authors and the reference to metallic nanoparticles entering water supplies, I’m guessing that this research is associated with the LCnano (lifecycle nano) project headquartered at Arizona State university (April 8, 2014 posting).

Getting back to the Franco-German SolNanoTox project, scientists do not know what happens when the cells in your intestines, liver, etc. encounter metallic or other nanoparticles, some of which may be naturally occurring. It should also be noted that we have likely been ingesting metallic nanoparticles for quite some time. After all, anyone who has used silver cutlery has ingested some silver nanoparticles.

There are many, many questions to be asked and answered with regard to nanomaterials in our foods.  Here are a few of mine:

  • How many metallic and other nanoparticles did we ingest before the advent of ‘nanomaterials in food’?
  • What is the biopersistence of naturally occurring and engineered metallic and other nanoparticles in the body?
  • Is there an acceptable dose versus a fatal dose? (Note: There’s naturally occurring formaldehyde in pears as per my May 19, 2014 post about doses, poisons, and the Sense about Science group’s campaign/book, Making Sense of Chemical Stories.)
  • What happens as the metallic and other engineered nanoparticles are added to food and drink and eventually enter our water, air, and soil?

Returning to the ‘debate’, a July 11, 2014 article by Sarah Shemkus for a sponsored section in the UK’s Guardian newspaper highlights an initiative taken by an environmental organization, As You Sow, concerning titanium dioxide in Dunkin’ Donuts’ products (Note: A link has been removed),

The activists at environmental nonprofit As You Sow want you to take another look at your breakfast doughnut. The organization recently filed a shareholder resolution asking Dunkin’ Brands, the parent company of Dunkin’ Donuts, to identify products that may contain nanomaterials and to prepare a report assessing the risks of using these substances in foods.

Their resolution received a fair amount of support: at the company’s annual general meeting in May, 18.7% of shareholders, representing $547m in investment, voted for it. Danielle Fugere, As You Sow’s president, claims that it was the first such resolution to ever receive a vote. Though it did not pass, she says that she is encouraged by the support it received.

“That’s a substantial number of votes in favor, especially for a first-time resolution,” she says.

The measure was driven by recent testing sponsored by As You Sow, which found nanoparticles of titanium dioxide in the powdered sugar that coats some of the donut chain’s products. [emphasis mine] An additive widely used to boost whiteness in products from toothpaste to plastic, microscopic titanium dioxide has not been conclusively proven unsafe for human consumption. Then again, As You Sow contends, there also isn’t proof that it is harmless.

“Until a company can demonstrate the use of nanomaterials is safe, we’re asking companies either to not use them or to provide labels,” says Fugere. “It would make more sense to understand these materials before putting them in our food.”

As You Sow is currently having 16 more foods tested. The result should be available later this summer, Fugere says.

I wonder if As You Sow will address the question of whether the nanoscale titanium dioxide they find indicates that nanoscale particles are being deliberately added or whether the particles are the inadvertent consequence of the production process. That said, I find it hard to believe no one in the food industry is using engineered nanoscale additives as they claim  (the other strategy is to offer a nonanswer) in Shemkus’ article (Note: Links have been removed).,

In a statement, Dunkin’ Donuts argues that the titanium dioxide identified by As You Sow does not qualify as a nanomaterial according to European Union rules or draft US Food and Drug Administration regulations. The company also points out that there is no agreed-upon standard method for identifying nanoparticles in food.

In 2008, As You Sow filed nanomaterial labeling resolutions with McDonald’s and Kraft Foods. In response, McDonald’s released a statement declaring that it does not support the use of nanomaterials in its food, packaging or toys. Kraft responded that it would make sure to address health and safety concerns before ever using nanomaterials in its products.

While Shemkus’ article appears in the Guardian’s Food Hub which is sponsored by the Irish Food Board, this article manages to avoid the pitfalls found in Philpott’s nonsponsored article.

Coming next: the US Food and Drug Administration Guidance issued five weeks after the FOE kicks off the ‘nano and food’ debate in May 2014 with its ‘Way too little: Our Government’s failure to regulate nanomaterials in food and agriculture‘ report.

Part one (an FOE report is published)

Part three (final guidance)

FOE, nano, and food: part one of three (an FOE report is published)

It seems the food and nano debate of Spring/Summer 2014 has died down, for a while at least. The first volley (from my perspective) was the May 2014 release of ‘Way too little: Our Government’s failure to regulate nanomaterials in food and agriculture’ by the Friends of the Earth (FOE) Australia. Here’s how the report is described in a May 22, 2014 news item on Nanowerk,

Friends of the Earth’s new report, Way too little (pdf), looks at the now widespread presence of nanomaterials in our food chain and how little Food Standards Australia New Zealand (FSANZ) is doing to ensure our safety.

You can find the following passage on p. 6 of FOE’s report ‘Way too little: Our Government’s failure to regulate nanomaterials in food and agriculture‘,

This report will examine the changes since our 2008 report including the development of new food, food contact and agricultural products. It will review the current literature relating to the potential environmental, health and safety impacts associated with nanotechnology and summarise the Australian regulatory responses to date.

This updated report uncovers the:

•accelerating rate of commercialisation and rapidly increasing number of commercial products containing nanomaterials in the food and agricultural sectors;

•lack of information regarding which nanomaterials have been released and the likely exposure of humans and natural systems to these materials;

•lack of basic steps to allow us to track nanomaterials that have been released, such as
labelling and a register of products containing nanomaterials;

•growing gap between the pace of commercialisation and environmental, health and safety assessments;

•increasingly large body of peer reviewed evidence that certain nanomaterials may cause harm to human health or the environment;

•failure of regulators to respond to the growingevidence of risks;

•lack of basic knowledge that is critical in order to fully analyse the particular environmental, health and safety issues associated with nanotechnology.

Six years ago, inaction was based on a perceived lack of data. Inaction is still the norm but that is no longer an excuse our Government can use. Scientists and scientific bodies such as the US National Research Council have given us more than enough evidence to justify a pro-active regulatory regime and a properly funded R&D program that will effectively target those areas of greatest environmental and health concern.

Unfortunately, our Federal Government seems unwilling to provide the levels of funding required for such work or to adopt appropriate regulation. The notion of precaution has been replaced with an attitude that it is the obligation of industry to determine whether their products are safe and regulators will only act when harm is shown. While France, Belgium and Denmark are implementing a mandatory register for nanomaterials and the EU’s is in the process of implementing a nano food labelling regime, Australian consumers remain in the dark.

This needs to change.

One of the issues with increased regulation and labeling is whether the benefits outweigh disadvantages such as the increased difficulty of getting needed foodstuffs to the marketplace and, of course, cost.

Tom Philpott in a May 28, 2014 article for Mother Jones magazine titled ‘Big Dairy Is Putting Microscopic Pieces of Metal in Your Food’ is a strong proponent for FOE’s position, albeit his geographic focus is the US and he seems most concerned with metallic nanoparticles (Note: Links have been removed),

Examples include Silk Original Soy Milk, Rice Dream Rice Drink, Hershey’s Bliss Dark Chocolate, and Kraft’s iconic American Cheese Singles, all of which now contain nano-size titanium dioxide*. As recently as 2008, only eight US food products were known to contain nanoparticles, according to a recent analysis [May 2014 report] from Friends of the Earth—a more than tenfold increase in just six years.

Philpott goes on to mention the US Food and Drug Administration’s (FDA) 2012 draft guidance on nanomaterials and food,

Back in 2012, the FDA released a draft, pending public comment, of a proposed new framework for bringing nano materials into food. The document reveals plenty of reason for concern. For example: “so-called nano-engineered food substances can have significantly altered bioavailability and may, therefore, raise new safety issues that have not been seen in their traditionally manufactured counterparts.” The report went on to note that “particle size, surface area, aggregation/agglomeration, or shape may impact absorption, distribution, metabolism and excretion (ADME) and potentially the safety of the nano-engineered food substance.”

What FDA is saying here is obvious: If nanoparticles didn’t behave differently, the industry wouldn’t be using them in the first place.

So what’s the remedy? Rather than require rigorous safety studies before companies can lace food with nanoparticles, the FDA’s policy draft proposes “nonbinding recommendations” for such research. Even that rather porous safety net doesn’t yet exist—the agency still hasn’t implemented the draft proposal it released more than two years ago.[emphasis mine]

June 27, 2014, the FDA issued a final ‘food and nanotechnology’ guidance document (more on that later).

In the meantime, Dr. Andrew Maynard (Director of the University of Michigan’s Risk Science Center) strongly countered Philpott’s Mother Jones article with his own article published both on The Conversation (June 3, 2014) and on Nanowerk (June 4, 2014),

Recently the American publication Mother Jones published an article on the dangers of food laced with tiny metal oxide particles. The article, however, is laced with errors and misinformation.

The source material for the article came from a report by the environmental organisation Friends of the Earth, an online database of nanotechnology-based consumer products and a peer-reviewed paper published in 2012. However, the analysis of the information is flawed.


Bad journalism

The inventory Philpott cites is the Project on Emerging Nanotechnologies Consumer Products Inventory, which I helped establish in 2006 as a way better understand the increasing number of consumer products that were using engineered nanomaterials. It provides a useful but only qualitative sense of what was being used where, and relies on intermittent web searches and other sources of intelligence. The inventory was never meant to be comprehensive or authoritative.

Briefly, Andrew’s argument is that the FOE report (Way too little) which claims a tenfold increase since 2008 of food products with added nano titanium dioxide (and which Philpotts uses to build his case) is erroneous. In 2006, the inventory was voluntary and there was no oversight. At that time, eight food products had been added to the list. In 2013, the inventory was revived (Oct. 28, 2013 posting) and new information added from a 2012 academic paper. The products from the 2012 paper may have predated the 2006 inventory products, or not. There is no way to tell. Andrew notes this in his measured way,

As someone who works on the risks and benefits of nanotechnology, I can see how errors in translation crept into this story. The 2012 paper was addressing a legitimate concern that little is know about how much titanium dioxide is in the processed food chain. The Consumer Products Inventory provides important and unique insights into nanoparticles being used in products. Friends of the Earth have every right to ask what is known about the potential risks in what we’re eating. And reporters like Philpott have a professional obligation to highlight issues of concern and interest to their readers.

The problem with exaggerated and inflated claims is that FOE proves itself to be an unreliable source and Philpott’s failure to investigate adequately puts his own credibility into question. How can you trust either FOE’s materials or Philpott’s articles? The easiest way to begin rebuilding credibility is to admit one’s mistakes. To date, I have not seen any such attempts from FOE or Philpott.

Coming next: a research initiative into the health effects of nano and food and a research paper on nano in commercial drinks both of which help illustrate why there are concerns and why there is a reluctance to move too quickly.

Part two (the problem with research)

Part three (final guidance)

Inhibiting pathogens in meat with edible antimicrobial films

Food poisoning is, at best, unpleasant and, at worst, lethal, so anything which helps people and other animals to avoid that condition is to be lauded, assuming there are no significant shortcomings with the solution to avoiding bad meat. According to a May 4, 2014 news item on Nanowerk a team at Penn (Pennsylvania) State University has developed an antimicrobial, edible film which may help solve the problem,

Antimicrobial agents incorporated into edible films applied to foods to seal in flavor, freshness and color can improve the microbiological safety of meats, according to researchers in Penn State’s College of Agricultural Sciences.

Using films made of pullulan — an edible, mostly tasteless, transparent polymer produced by the fungus Aureobasidium pulluns — researchers evaluated the effectiveness of films containing essential oils derived from rosemary, oregano and nanoparticles against foodborne pathogens associated with meat and poultry.

A May 1, 2014 Penn State University news release by Jeff Mulhollem, which originated the news item, describes the research in further detail,

In the study, which was published online in the April issue of the Journal of Food Science, researchers determined survivability of bacterial pathogens after treatment with 2 percent oregano essential oil, 2 percent rosemary essential oil, zinc oxide nanoparticles or silver nanoparticles.

The compounds then were incorporated into edible films made from pullulan, and the researchers determined the antimicrobial activity of these films against bacterial pathogens inoculated onto petri dishes.

Finally, the researchers experimentally inoculated fresh and ready-to-eat meat and poultry products with bacterial pathogens, treated them with the pullulan films containing the essential oils and nanoparticles, vacuum packaged, and then evaluated for bacterial growth following refrigerated storage for up to three weeks.

“The results from this study demonstrated that edible films made frompullulan and incorporated with essential oils or nanoparticles have the potential to improve the safety of refrigerated, fresh or further-processed meat and poultry products,” said Cutter. “The research shows that we can apply these food-grade films and have them do double duty — releasing antimicrobials and imparting characteristics to protect and improve food we eat.”

The edible films are a novelbut effective way to deliver antimicrobial agents to meats, Cutter explained, because the bacteria-killing action is longer lasting. Liquid applications run off the surface, are not absorbed and are less effective. The pullulan films adhere to the meat, allowing the incorporated antimicrobials to slowly dissolve, providing immediate and sustained kill of bacteria. In addition, the microorganisms do not have the opportunity to regrow.

There’s at least one problem with the pullulan films and its not, as far as the researcher is concerned, the silver or zinc oxide nanoparticles (from the news release),

Cutter conceded that pullulan films are not as oxygen-impermeable as plastic packaging now used to package meats, so the edible films are not likely to replace that material.

“The meat industry likes the properties of the polyethylene vacuum packaging materials that they are using now,” she said. “However, the one thing I really want to be able to do in the next few years is to figure out a way to co-extrude antimicrobial, edible films with the polyethylene so we have the true oxygen barrier properties of the plastic with the antimicrobial properties of the edible film.”

Knowing that edible films can release antimicrobials slowly over time and keep bacteria in meat at bay, further research will be aimed at creating what Cutter referred to as “active packaging” — polyethylene film with antimicrobial properties.

“Right now, we have two different packaging materials that are not necessarily compatible, leading to a two-step process. I keep thinking there’s a way to extrude edible, antimicrobial film in one layer with polyethylene, creating all-in-one packaging.

“The chemistry of binding the two together is the challenge, but we need to find a way to do it because marrying the two materials together in packaging would make foods — especially meat and poultry — safer to eat.”

Here’s a link to and a citation for the paper,

Incorporation of Essential Oils and Nanoparticles in Pullulan Films to Control Foodborne Pathogens on Meat and Poultry Products by Mohamed K. Morsy, Hassan H. Khalaf, Ashraf M. Sharoba, Hassan H. El-Tanahi and Catherine N. Cutter. Journal of Food Science, April 2014, Volume 79, Issue 4, pages M675–M684. DOI: 10.1111/1750-3841.12400 Article first published online: 12 MAR 2014

© 2014 Institute of Food Technologists®

This is behind a paywall.

Nanocellulose from sugarcane?

Iran adds to this blog’s growing catalogue of plant materials from which nanocellulose can be derived. From an April 27, 2014 news item on Nanowerk,

Researchers from University of Tehran utilized sugarcane waste to produce nanocomposite film (“All-cellulose nanocomposite film made from bagasse cellulose nanofibers for food packaging application”).

The product has unique physical and mechanical properties and has many applications in packaging, glue making, medicine and electronic industries.

An April 28, 2014 Iran Nanotechnology Initiative Council (INIC) news release, which originated the news item, describes the advantages of this potential product and the research that led to it,

These nanofibers have simpler, faster and more cost-effective production method in comparison with other production methods. The size of the produced cellulose nanofiber has been reported about 39±13 nm while tension resistant of the nanocomposite produced from the nanofibers has been reported about 140 MPa. The produced nanocomposite has higher strength in comparison with the majority of biodegradable and non-biodegradable films. It seems that the produced nanocomposite can be considered an appropriate option for the elimination of artificial polymers and oil derivatives from packaging materials.

In order to produce the product, cellulose fibers were produced through mechanical milling method after separation and purification of cellulose from sugarcane bagasse, and then nanopapers were produced. Next, full cellulose nanocomposite was produced through partial dissolving method, and its characteristics were evaluated.

Results showed that as the time of partial dissolving increases, the diffusivity of the nanocomposite into vapor decreases due to the increase in glassy part (amorphous) to crystalline part. However, thermal resistant decreases as the time of partial dissolving increases because a decrease is observed in the crystalline part.

In addition, when cellulose microfibers turn into nanofibers, resistance against the tension of the produced films increases. The researchers believe that the reason for the increase is the reduction in fault points (points that lead to the fracture in cellulose fibers), increase in specific area, and integrity of nanofibers. Transparency of samples significantly increases as the size of particles decreases to nanometric scale.

Here’s a link to and a citation for the paper,

All-cellulose nanocomposite film made from bagasse cellulose nanofibers for food packaging application by Moein Ghaderi, Mohammad Mousavi, Hossein Yousefi, & Mohsen Labbafi. Carbohydrate Polymers, vol. 104, issue 1, January 2014, pp. 59-65

This paper is behind a paywall.

How do you know that’s extra virgin olive oil?

Who guarantees that expensive olive oil isn’t counterfeit or adulterated? An invisible label, developed by ETH researchers, could perform this task. The tag consists of tiny magnetic DNA particles encapsulated in a silica casing and mixed with the oil.

So starts Barbara Vonarburg’s April 24, 2014 ETH Zurich (Swiss Federal Institute of Technology or Eidgenössische Technische Hochschule Zürich) news release (also on EurekAlert). She goes on to describe the scope of the situation regarding counterfeit foods,

The worldwide need for anti-counterfeiting labels for food is substantial. In a joint operation in December 2013 and January 2014, Interpol and Europol confiscated more than 1,200 tonnes of counterfeit or substandard food and almost 430,000 litres of counterfeit beverages. The illegal trade is run by organised criminal groups that generate millions in profits, say the authorities. The confiscated goods also included more than 131,000 litres of oil and vinegar.

Jon Henley’s Jan. 4, 2012 article for the UK’s Guardian provides more insight into the specifics of counterfeit olive oil (Note: A link has been removed),

Last month [December 2011], the Olive Oil Times reported that two Spanish businessmen had been sentenced to two years in prison in Cordoba for selling hundreds of thousands of litres of supposedly extra virgin olive oil that was, in fact, a mixture of 70-80% sunflower oil and 20-30% olive.

… So with a litre of supermarket extra virgin costing up to £4, and connoisseurs willing to pay 10 times that sum for a far smaller bottle of seasonal, first cold stone pressed, single estate, artisan-milled oil from Italy or Greece, can we be sure of getting what we’re paying for?

The answer, according to Tom Mueller in a book out this month [January 2012], is very often not. In Extra Virginity: the Sublime and Scandalous World of Olive Oil, Mueller, an American who lives in Italy, lays bare the workings of an industry prey, he argues, to hi-tech, industrial-scale fraud. The problem, he says, is that good olive oil is difficult, time-consuming and expensive to make, but easy, quick and cheap to doctor.

Most commonly, it seems, extra virgin oil is mixed with a lower grade olive oil, often not from the same country. Sometimes, another vegetable oil such as colza or canola is used. The resulting blend is then chemically coloured, flavoured and deodorised, and sold as extra-virgin to a producer. Almost any brand can, in theory, be susceptible: major names such as Bertolli (then owned by Unilever [see Henley’s article for details about the 2008 Italian olive oil scandal]) have found themselves in court having to argue, successfully in this instance, that they had themselves been defrauded by their supplier.

Meanwhile, the chemical tests that should by law be performed by exporters of extra virgin oil before it can be labelled and sold as such can often fail to detect adulterated oil, particularly when it has been mixed with products such as deodorised, lower-grade olive oil in a sophisticated modern refinery.

Given the benefits claimed for olive oil, I imagine lower grade olive oil which is more highly processed or, worse yet, a completely different kind of oil would diminish or, possibly, eliminate any potential health benefit.

Getting back to the ETH Zurich news release, here’s more about the anti-counterfeiting ‘label’,

Just a few grams of the new substance are enough to tag [label] the entire olive oil production of Italy. If counterfeiting were suspected, the particles added at the place of origin could be extracted from the oil and analysed, enabling a definitive identification of the producer. “The method is equivalent to a label that cannot be removed,” says Robert Grass, lecturer in the Department of Chemistry and Applied Biosciences at ETH Zurich.

A forgery-proof label should not only be invisible but also safe, robust, cheap and easy to detect. To fulfil these criteria ETH researchers used nanotechnology and nature’s information storehouse, DNA. A piece of artificial genetic material is the heart of the mini-label. “With DNA, there are millions of options that can be used as codes,” says Grass. Moreover, the material has an extremely low detection limit, so tiny amounts are sufficient for labelling purposes.

However, DNA also has some disadvantages. If the material is used as an information carrier outside a living organism, it cannot repair itself and is susceptible to light, temperature fluctuations and chemicals. Thus, the researchers used a silica coating to protect the DNA, creating a kind of synthetic fossil. The casing represents a physical barrier that protects the DNA against chemical attacks and completely isolates it from the external environment – a situation that mimics that of natural fossils, write the researchers in their paper, which has been published in the journal ACS Nano. To ensure that the particles can be fished out of the oil as quickly and simply as possible, Grass and his team employed another trick: they magnetised the tag by attaching iron oxide nanoparticles.

Experiments in the lab showed that the tiny tags dispersed well in the oil and did not result in any visual changes. They also remained stable when heated and weathered an ageing trial unscathed. The magnetic iron oxide, meanwhile, made it easy to extract the particles from the oil. The DNA was recovered using a fluoride-based solution and analysed by PCR, a standard method that can be carried out today by any medical lab at minimal expense. “Unbelievably small quantities of particles down to a millionth of a gram per litre and a tiny volume of a thousandth of a litre were enough to carry out the authenticity tests for the oil products,” write the researchers. The method also made it possible to detect adulteration: if the concentration of nanoparticles does not match the original value, other oil – presumably substandard – must have been added. The cost of label manufacture should be approximately 0.02 cents per litre.

The researchers have plans for other products that could benefit from this technology and answers to questions about whether or not people would be willing to ingest a label/tag along with their olive oil,

Petrol could also be tagged using this method and the technology could be used in the cosmetics industry as well. In trials the researchers also successfully tagged expensive Bergamot essential oil, which is used as a raw material in perfumes. Nevertheless, Grass sees the greatest potential for the use of invisible labels in the food industry. But will consumers buy expensive ‘extra-virgin’ olive oil when synthetic DNA nanoparticles are floating around in it? “These are things that we already ingest today,” says Grass. Silica particles are present in ketchup and orange juice, among other products, and iron oxide is permitted as a food additive E172.

To promote acceptance, natural genetic material could be used in place of synthetic DNA; for instance, from exotic tomatoes or pineapples, of which there are a great variety – but also from any other fruit or vegetable that is a part of our diet. Of course, the new technology must yield benefits that far outweigh any risks, says Grass. He concedes that as the inventor of the method, he might not be entirely impartial. “But I need to know where food comes from and how pure it is.” In the case of adulterated goods, there is no way of knowing what’s inside. “So I prefer to know which particles have been intentionally added.”

Here’s a link to and a citation for the researchers’ paper,

Magnetically Recoverable, Thermostable, Hydrophobic DNA/Silica Encapsulates and Their Application as Invisible Oil Tags by Michela Puddu , Daniela Paunescu , Wendelin J. Stark , and Robert N. Grass. ACS Nano, 2014, 8 (3), pp 2677–2685 DOI: 10.1021/nn4063853 Publication Date (Web): February 25, 2014

Copyright © 2014 American Chemical Society

This article is behind a paywall.

The Swiss aren’t the only ones interested in tagging petrol (gas), they’re already tagging petrol with nanoparticles in Malaysia with as per my Oct. 7, 2011 posting on the topic.