Tag Archives: food packaging

Clay film keeps your apples fresh

Which apple would you like to eat?

Caption: Extent of decay in apples treated with clay film and cling wrap. Credit: Miharu Eguchi National Institute for Materials Science eguchi.miharu@nims.go.jp

This research into food packaging comes from Japan’s National Institute for Materials in a March 8, 2022 press release (also on EurekAlert but published on April 12, 2022),

An international research team consisting of NIMS, The University of Queensland and National Taiwan University has succeeded in creating a clay film with its gas permeability optimized for long-term storage of fresh produce by adjusting the sizes of the clay nanosheet particles comprising it. The team then uniformly coated the surfaces of various fruits with the film. This treatment kept the fruits’ respiration rates low without completely depriving them of oxygen, preventing them from decaying.

Efforts have been made to develop gas barrier films using clay nanosheets. Although some researchers attempted to improve the film properties of clay nanosheets by adding organic polymers to them, films can also be formed using only clay nanosheets without additives. Only a few studies had previously evaluated the physical properties of clay films composed solely of clay nanosheets.

This international joint research team focused on the gas permeability of clay films and found that a film composed of clay nanosheets with particle sizes in the range of several dozen nanometers (1 nm = one millionth of 1 mm) had relatively high permeability to gas molecules as they can pass through gaps between particles. This gas permeability is equivalent to that of plastic bags with minute pores used to store fresh produce. These bags are able to adequately reduce oxygen supply to fresh fruit, preventing it from ripening too rapidly. The gas permeability similarities between the clay film and the plastic bags inspired the research team to assess the ability of the clay film to preserve the quality of fresh produce for long periods of time.

In this research, the team applied a suspension of clay nanosheets to the surfaces of various fruits (e.g., apples, bananas and oranges) to form uniform films on their surfaces. The team also prepared untreated fruits and fruits covered in cling wrap for comparison. The gas emissions and appearance of these treated and untreated fruits were monitored for several months. As shown in the figure [above], the untreated apples (the first photo from the left) had decayed by the end of the experimental period and the apples covered only in cling wrap (the fourth photo from the left) had also decayed and grown mold. By contrast, the apples coated with the clay film (the two middle photos) did not decay or grew mold, presumably because the film reduced the external oxygen supply needed for ripening and mold growth. In addition, the clay film was confirmed to be in tight contact with the surfaces of the apples it coated, suggesting that it may be able to effectively block the diffusion of ethylene into the air, a phytohormone which plays an important role in inducing fruit ripening.

In addition to its potential ability to restrict the external oxygen supply and ethylene diffusion, the clay film may be able to prevent odor compounds produced by fresh produce from diffusing into the air, possibly making them less attractive to pests. In future research, the team plans to improve the ease of application and strength of the clay film to make it more suitable for preserving the quality of fresh produce during its transportation to the market.

This project was carried out by an international joint research team consisting of Miharu Eguchi (Senior Researcher, Mesoscale Materials Chemistry Group, International Center for Materials Nanoarchitectonics, NIMS) and researchers from The University of Queensland and National Taiwan University. This work was supported in part by  JST-ERATO Yamauchi Materials Space-Tectonics Project.

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

Highly adhesive and disposable inorganic barrier films: made from 2D silicate nanosheets and water by Miharu Eguchi, Muxina Konarova, Nagy L. Torad, Te-An Chang, Dun-Yen Kang, Joe Shapter and Yusuke Yamauchi. J. Mater. Chem. A, 2022,10, 1956-1964 DOI: https://doi.org/10.1039/D1TA08837H First published 02 Dec 2021 Print version published January 28, 2022

This paper is behind a paywall.

Cellulose nanocrystals (CNC), protein, and starch eletrospun to develop ‘smart’ food packaging

A December 29, 2021 news item on ScienceDaily announces research into ;smart’ sustainable packaging from a joint Nanyang Technical University and Harvard University,

A team of scientists from Nanyang Technological University, Singapore (NTU Singapore) and Harvard T.H. Chan School of Public Health, US, has developed a ‘smart’ food packaging material that is biodegradable, sustainable and kills microbes that are harmful to humans. It could also extend the shelf-life of fresh fruit by two to three days.

The waterproof food packaging is made from a type of corn protein called zein, starch and other naturally derived biopolymers, infused with a cocktail of natural antimicrobial compounds. These include oil from thyme, a common herb used in cooking, and citric acid, which is commonly found in citrus fruits.

A December 28, 2021 Nanyang Technological University press release (PDF), also on EurekAlert but published December 27, 2021, which originated the news item, offers a few more details about the research (Note 1: Links have been removed; Note 2: I had to dig into the abstract to find the cellulose nanocrystals),

In lab experiments, when exposed to an increase in humidity or enzymes from harmful bacteria, the fibres in the packaging have been shown to release the natural antimicrobial compounds, killing common dangerous bacteria that contaminate food, such as E. Coli and Listeria, as well as fungi.

The packaging is designed to release the necessary miniscule amounts of antimicrobial compounds only in response to the presence of additional humidity or bacteria. This ensures that the packaging can endure several exposures, and last for months.

As the compounds combat any bacteria that grow on the surface of the packaging as well as on the food product itself, it has the potential to be used for a large variety of products, including ready-to-eat foods, raw meat, fruits, and vegetables.

In an experiment, strawberries that were wrapped in the packaging stayed fresh for seven days before developing mould, compared to counterparts that were kept in mainstream fruit plastic boxes, which only stayed fresh for four days.

The invention is the result of the collaboration by scientists from the NTU-Harvard T. H. Chan School of Public Health Initiative for Sustainable Nanotechnology (NTU-Harvard SusNano), which brings together NTU and Harvard Chan School researchers to work on cutting edge applications in agriculture and food, with an emphasis on developing non-toxic and environmentally safe nanomaterials.

The development of this advanced food packaging material is part of the University’s efforts to promote sustainable food tech solutions, that is aligned with the NTU 2025 strategic plan, which aims to develop sustainable solutions to address some of humanity’s pressing grand challenges.

Professor Mary Chan, Director of NTU’s Centre of Antimicrobial Bioengineering, who co-led the project, said: “This invention would serve as a better option for packaging in the food industry, as it has demonstrated superior antimicrobial qualities in combatting a myriad of food-related bacteria and fungi that could be harmful to humans. The packaging can be applied to various produces such as fish, meat, vegetables, and fruits. The smart release of antimicrobials only when bacteria or high humidity is present, provides protection only when needed thus minimising the use of chemicals and preserving the natural composition of foods packaged.”

Professor Philip Demokritou, Adjunct Professor of Environmental Health at Harvard Chan School, who is also Director of Nanotechnology and Nanotoxicology Center and Co-director of NTU-Harvard Initiative on Sustainable Nanotechnology, who co-led the study, said: “Food safety and waste have become a major societal challenge of our times with immense public health and economic impact which compromises food security. One of the most efficient ways to enhance food safety and reduce spoilage and waste is to develop efficient biodegradable non-toxic food packaging materials. In this study, we used nature-derived compounds including biopolymers, non-toxic solvents, and nature-inspired antimicrobials and develop scalable systems to synthesise smart antimicrobial materials which can be used not only to enhance food safety and quality but also to eliminate the harm to the environment and health and reduce the use of non-biodegradable plastics at global level and promote sustainable agri-food systems.” 

Providing an independent assessment of the work done by the NTU research team, Mr Peter Barber, CEO of ComCrop, a Singapore company that pioneered urban rooftop farming, said: “The NTU-Harvard Chan School food packaging material would serve as a sustainable solution for companies like us who want to cut down on the usage of plastic and embrace greener alternatives. As ComCrop looks to ramp up product to boost Singapore’s food production capabilities, the volume of packaging we need will increase in sync, and switching to a material such as this would help us have double the impact. The wrapping’s antimicrobial properties, which could potentially extend the shelf life of our vegetables, would serve us well. The packaging material holds promise to the industry, and we look forward to learning more about the wrapping and possibly adopting it for our usage someday.”

The results of the study were published in the peer-reviewed academic journal ACS Applied Materials & Interfacesin October [2021].

Cutting down on packaging waste

The packaging industry is the largest and growing consumer of synthetic plastics derived from fossil fuels, with food packaging plastics accounting for the bulk of plastic waste that are polluting the environment.

In Singapore, packaging is a major source of trash, with data from Singapore’s National Environment Agency showing that out of the 1.76 million tonnes of waste disposed of by domestic sources in 2018, one third of it was packaging waste, and over half of it (55 per cent) was plastic.

The smart food package material, when scaled up, could serve as an alternative to cut down on the amount of plastic waste, as it is biodegradable. Its main ingredient, zein, is also produced from corn gluten meal, which is a waste by-product from using corn starch or oils in order to produce ethanol.

The food packaging material is produced by electrospinning[1] the zein, the antimicrobial compounds with cellulose, a natural polymer starch that makes up plant cell walls, and acetic acid, which is commonly found in vinegar.

Prof Mary Chan added: “The sustainable and biodegradable active food packaging, which has inbuilt technology to keep bacteria and fungus at bay, is of great importance to the food industry. It could serve as an environmentally friendly alternative to petroleum-based polymers used in commercial food packaging, such as plastic, which have a significant negative environmental impact.”

Prof Demokritou added: “Due to the globalisation of food supply and attitude shift towards a healthier lifestyle and environmentally friendly food packaging, there is a need to develop biodegradable, non-toxic and smart/responsive materials to enhance food safety and quality. Development of scalable synthesis platforms for developing food packaging materials that are composed of nature derived, biodegradable biopolymers and nature inspired antimicrobials, coupled with stimuli triggered approaches will meet the emerging societal needs to reduce food waste and enhance food safety and quality.”

The team of NTU and Harvard Chan School researchers hope to scale up their technology with an industrial partner, with the aim of commercialisation within the next few years.

They are also currently working on developing other technologies to develop biopolymer-based smart food package materials to enhance food safety and quality.

Here’s a link to and a citation for the paper, followed by the key (nanocellulose crystal mention) sentences in the abstract,

Enzyme- and Relative Humidity-Responsive Antimicrobial Fibers for Active Food Packaging by Zeynep Aytac, Jie Xu, Suresh Kumar Raman Pillai, Brian D. Eitzer, Tao Xu, Nachiket Vaze, Kee Woei Ng, Jason C. White, Mary B. Chan-Park, Yaguang Luo, and Philip Demokritou. ACS Appl. Mater. Interfaces 2021, 13, 42, 50298–50308 I: https://doi.org/10.1021/acsami.1c12319 Publication Date: October 14, 2021 Copyright © 2021 American Chemical Society

This paper is behind a paywall.

Excerpt from abstract,

Active food packaging materials that are sustainable, biodegradable, and capable of precise delivery of antimicrobial active ingredients (AIs) are in high demand. Here, we report the development of novel enzyme- and relative humidity (RH)-responsive antimicrobial fibers with an average diameter of 225 ± 50 nm, which can be deposited as a functional layer for packaging materials. Cellulose nanocrystals (CNCs) [emphasis mine], zein (protein), and starch were electrospun to form multistimuli-responsive fibers that incorporated a cocktail of both free nature-derived antimicrobials such as thyme oil, citric acid, and nisin and cyclodextrin-inclusion complexes (CD-ICs) of thyme oil, sorbic acid, and nisin. …

I have been following the CNC story for some time. If you’re curious, just use ‘cellulose nanocrystal(s)’ as your search term. You can find out more about ComCrop here.

Bio-based standup pouches (food packaging) made from cellulose

CAPTION: VTT has developed lightweight 100% bio-based stand-up pouches with high technical performance. (Photo by VTT)

A March 14, 2017 news item on ScienceDaily describes a new nanocellulose-based product developed by the Technical Research Centre of Finland (VTT),

VTT Technical Research Centre of Finland Ltd has developed lightweight 100% bio-based stand-up pouches with high technical performance. High performance in both oxygen, grease and mineral oil barrier properties has been reached by using different biobased coatings on paper substrate. The pouches exploit VTT’s patent pending high consistency enzymatic fibrillation of cellulose (HefCel) technology.

A March 14, 2017 VTT press release (also on EurekAlert), which originated the news item, describes why the researchers want to change how food is packaged,

“One-third of food produced for human consumption is lost or wasted globally. Packaging with efficient barrier properties is a crucial factor in the reduction of the food loss. Our solution offers an environmentally friendly option for the global packaging industry”, says Senior Scientist Jari Vartiainen of VTT.

VTT’s HefCel technology provides a low-cost method for the production of nanocellulose resulting in a tenfold increase in the solids content of nanocellulose. Nanocellulose has been shown to be potentially very useful for a number of future technical applications. The densely packed structure of nanocellulose films and coatings enable their outstanding oxygen, grease and mineral oil barrier properties.

HefCel technology exploits industrial enzymes and simple mixing technology as tools to fibrillate cellulose into nanoscale fibrils without the need for high energy consuming process steps. The resulting nanocellulose is in the consistency of 15-25% when traditional nanocellulose production methods result in 1-3% consistency.

The stand-up pouch is the fastest growing type of packaging, growing at a rate of 6.5% per year from 2015-2020. Fossil-based plastic films still dominate the packaging market. However, the development of environmentally friendly new materials is of growing importance. Nanocellulose has been shown to be potentially very useful for a number of future technical applications.

VTT has solid expertise in various bio-based raw materials and their application technologies for producing bio-based coatings, films and even multilayered structures both at lab-scale and pilot-scale. A versatile set of piloting facilities are available from raw material sourcing through processing to application testing and demonstration.

I’m glad to hear they’re finding uses for nanocellulose and I keep wondering when Canadian scientists who at one point were leaders in developing crystal nanocellulose (CNC or sometimes known as nanocrystalline cellulose [NCC]) will be making announcements about potential products.

Nano and food discussion for beginners

I try to make sure there are a range of posts here for various levels of ‘nanotechnology sophistication’ but over time I’ve given less attention to ‘beginner’ posts, i.e., pieces where nanotechnology basics are explained as best as possible. This is largely due to concerns about repetition; I mean, how many times do you want to read that nano means one billionth?

In that spirit, this June 22, 2016 news item on Nanowerk about food and nanotechnology provides a good entry piece that is not terribly repetitive,

Every mouthful of food we eat is teeming with chemical reactions. Adding ingredients and cooking helps us control these reactions and makes the food taste better and last longer. So what if we could target food at the molecular level, sending in specially designed particles to control reactions even more tightly? Well, this is exactly what scientists are trying to do and it has already produced some impressive results – from food that tastes salty without the health risks of adding salt, to bread that contains healthy fish oil but without any fishy aftertaste.

But while this nanotechnology could significantly enhance our food, it also raises big questions about safety. We only have to look at the strong reaction against genetically modified foods to see how important this issue is. How can we ensure that nanotechnology in food will be different? Will our food be safe? And will people accept these new foods?

Nanotechnology is an emerging technology that creates and uses materials and particles at the scale of a nanometre, one billionth of a metre. To get an understanding of just how small this is, if you imagine a nanoparticle was the size of a football then an animal like a sheep would be as big as our planet.

Working with such small particles allows us to create materials and products with improved properties, from lighter bicycles and more durable beer bottles to cosmetic creams with better absorption and toothpastes that stop bacteria from growing. Being able to change a material’s properties means nanotechnology can help create many innovative food products and applications that change the way we process, preserve and package foods.

For example, nanotechnology can be used for “smart” packaging that can monitor the condition of foods while they are stored and transported. When foods are contaminated or going off, the sensors on the packaging pick up gases produced by bacteria and change colour to alert anyone who wants to eat the food.

A June 22, 2016 essay by Seda Erdem (University of Stirling; UK) on The Conversation, which originated the news item, provides more information in this excerpt,

Silver is already used in healthcare products such as dental equipment for its antibacterial properties. Nano-sizing silver particles improves their ability to kill bacteria because it increases the surface area of silver the bacteria are exposed to. Israeli scientists found that also coating packaging paper with nano-sized silver particles [also known as silver nanoparticles] combats bacteria such as E. coli and extends product shelf life.

Another example of nanotechnology’s use in food manufacturing is nano-encapsulation. This technology has been used to mask the taste and odour of tuna fish oil so that it could be used to enrich bread with heart healthy Omega-3 fatty acids. Fish oil particles are packed into a film coating that prevents the fish oil from reacting with oxygen and releasing its smell. The nanocapsules break open only when they reach the stomach so you can receive the health benefits of eating them without experiencing the odour.

Meanwhile, researchers at Nottingham University are looking into nanoscale salt particles than can increase the saltiness of food without increasing the amount of salt.

As with silver, breaking salt into smaller nanosize increases its surface area. This means its flavour can be spread more efficiently. The researchers claim this can reduce the salt content of standard crisps by 90% while keeping the same flavour.

Despite all the opportunities nanotechnology offers the food industry, most developments remain at the research and development stage. This slow uptake is due to the lack of information about the health and environmental impacts of the technology. For example, there is a concern whether ingested nanomaterials migrate to different parts of the body and accumulate in certain organs, such as liver and kidneys. This may then affect the functionality of these organs in the medium to long term.

Unknown risks

However, our knowledge of the risks associated with the use of nanomaterials is incomplete. These issues need to be better understood and addressed for the public to accept nanotechnology in food. This will also depend on the public’s understanding of the technology and how much they trust the food industry and the regulatory process watching over it.

Research has shown, for example, that consumers are more likely to accept nanotechnology when it is used in food packaging rather than in food processing. But nanotechnology in food production was seen as more acceptable if it increased the food’s health benefits, although consumers weren’t necessarily willing to pay more for this.

In our recent research, we found no strong attitudes towards or resistance to nanotechnology in food packaging in the UK. But there was still concern among a small group of consumers about the safety of foods. This shows how important it will be for food producers and regulators to provide consumers with the best available information about nanotechnology, including any uncertainties about the technology.

There you have it.

Australia and New Zealand weigh in on nanotechnology and food

Two reports from FSANZ (Food Standards Australia New Zealand) on nanotechnology and food were released in early June 2016 according to a June 2, 2016 Science Media Centre New Zealand press release,

Nanomaterials currently used in food additives and packaging do not appear to pose a health risk but we will need to keep an eye on newer materials in the pipeline, reports Trans-tasman food regulator.

FSANZ (Food Standards Australia New Zealand) has released two reports reviewing the evidence for the safety of nanotechnologies in food packaging and food additives.

Certain compounds, when engineered as particles measuring on the nano scale (one billionth of a meter), can exhibit certain properties; for example, nano-silver particles have antimicrobial properties.

More information can be found on the FSANZ website’s Food and Nanotechnology Report webpage,

In 2015 an expert toxicologist prepared two reports for FSANZ on the potential use of nanotechnologies in existing food additives and food packaging. The reports were then peer reviewed by an expert pharmacologist and toxicologist to evaluate whether the conclusions for each of the reports were supported by the weight of evidence in scientific literature.  The peer review agreed with the overall conclusions of the reports.

Scope of the work 

The consultant was asked to review publically available scientific literature on whether there is reasonable evidence of health risks associated with oral ingestion of titanium dioxide, silicon dioxide and silver in food.  These food additives may contain a proportion of material with at least one dimension in the nanoscale range. 

As an extension of this work, evidence of risks to health from nanomaterials used in food packaging was also investigated.

Key findings

  • The consultant reviewed the evidence on nanoscale silicon dioxide, titanium dioxide and silver in food and found the weight of evidence does not support claims of significant health risks for food grade materials.
  • Titanium dioxide and silicon dioxide are used internationally in a range of food products and have been used safely for decades. They are approved food additives in Australia and New Zealand. Silver is also an approved additive in Australia and New Zealand but is permitted in very few foods.

  • Overall, the findings of the report are consistent with recently published information in the OECD’s Working Party on Manufactured Nanomaterials Sponsorship Programme for the Testing of Manufactured Nanomaterials toxicological dossiers on silicon dioxide, titanium dioxide and silver.

  • There is no direct evidence to suggest novel nanomaterials are currently being used in food packaging applications in Australia or New Zealand, with most patents found from the United States.

  • From the case studies on the use of nano-clay and nano silver in packaging, the report concludes that there is no evidence from the literature of migration of nano-clay from packaging into food.  The nanoscale nature of nanosilver (whether used in packaging or food) is also not likely to be dangerous to consumer’s health. 

  • An independent peer review agreed with the overall analysis and conclusions of both reports stating that they were appropriately balanced in their reporting and that none of the nanotechnologies described are of health concern.

You can find (1) Potential Health Risks Associated with Nanotechnologies in Existing Food Additives here and (2)  Nanotechnologies in Food Packaging: an Exploratory Appraisal of Safety and Regulation here.

There is also a June 7, 2016 essay about these reports by Ian Rae for The Conversation,

We know that nanoparticles in sunscreens and cosmetics can penetrate the skin, and this raises questions about what they can do in the body. …

For the most part, I found the piece informative and interesting but there is one flaw as can be seen in the sentence I’ve excerpted. In fact, there is very little penetration by nanoparticles found in sunscreens as noted in my Oct. 4, 2012 posting and those findings do appear to have been contradicted in the years since.

Brazilian company encapsulates silver nanoparticles in milk packaging for longer product life

They’ve managed to double the shelf life for fresh milk from seven days to 15 be encapsulating silver nanoparticles in ceramic microparticles in packaging for fresh milk. From an Aug. 4, 2015 news item on Nanowerk,

Agrindus, an agribusiness company located in São Carlos, São Paulo state, Brazil, has increased the shelf life of grade A pasteurized fresh whole milk from seven to 15 days.

This feat was achieved by incorporating silver-based microparticles with bactericidal, antimicrobial and self-sterilizing properties into the rigid plastic bottles used as packaging for the milk.

The technology was developed by Nanox, also located in São Carlos. Supported by FAPESP’s Innovative Research in Small Business (PIPE) program, the nanotechnology company is a spinoff from the Center for Research and Development of Functional Materials (CDFM), one of the Research, Innovation and Dissemination Centers (RIDCs) supported by São Paulo Research Foundation (FAPESP).

“We already knew use of our antimicrobial and bactericidal material in rigid or flexible plastic food packaging improves conservation and extends shelf life. So we decided to test it in the polyethylene used to bottle grade A fresh milk in Brazil. The result was that we more than doubled the product’s shelf life solely by adding the material to the packaging, without mixing any additives with the milk”, said the Nanox CEO, Luiz Pagotto Simões.

An Aug. 4, 2015 Fundação de Amparo à Pesquisa do Estado de São Paulo news release on EurekAlert, which originated the news item, expands on the theme,

According to Simões, the microparticles are included as a powder in the polyethylene preform that is used to make plastic bottles by blow or injection molding. The microparticles are inert, so there is no risk of their detaching from the packaging and coming into contact with the milk.

Tests of the material’s effectiveness in extending the shelf life of fresh milk were performed for a year by Agrindus, Nanox and independent laboratories. “Only after shelf life extension had been certified did we decide to bring the material to market,” Simões said.

In addition to Agrindus, the material is also being tested by two other dairies that distribute fresh milk in plastic bottles in São Paulo and Minas Gerais and by dairies in the Brazilian southern region that sell fresh milk in flexible plastic packaging.

“In milk bags, the material is capable of extending shelf life from four to ten days,” he said.

Nanox plans to market the product in Europe and the United States, where much larger volumes of fresh milk are consumed than in Brazil.

The kind of milk most consumed in Brazil is ultra-high temperature (UHT), or “long life” milk, which is sterilized at temperatures ranging from 130°C to 150°C for two to four seconds to kill most of the bacterial spores. Unopened UHT milk has a shelf life of up to four months at room temperature.

Whole milk, known as grade A in Brazil, is pasteurized at much lower temperatures by the farmer and requires refrigeration. “Doubling the shelf life of whole milk translates into significant benefits in terms of logistics, storage, quality and food safety,” Simões said.

Countless applications

The silver-based microparticles developed by Nanox are currently being used in several other products other than packaging for fresh milk, including plastic utensils, PVC film for wrapping food, toilet seats, shoe insoles, hair dryers and flatirons, paints, resins, and ceramics, as well as coatings for medical and dental instruments such as grippers, drills and scalpels.

But the company’s largest markets today are makers of rugs, carpets, and white goods, such as refrigerators, drinking fountains and air conditioners.

“We’ve supplied several products to white goods manufacturers since 2007,” Simões said. “This material is shipped to the leading players in the market.” Nanox currently exports the product to 12 countries via local distributors in Chile, China, Colombia, Italy, Mexico and Japan, among others.

The company now wants to enter the United States, having won approval in 2013 from the Food & Drug Administration (FDA) to market the bactericidal material for use in food packaging.

“We’ve applied for clearance by the EPA [the Environmental Protection Agency] so that we can sell to a larger proportion of the US market,” Simões said.

Neither Brazil nor the US has clear legislation on the use of particles at the nanometer scale [a billionth of a meter] in products that involve contact with food, so the company uses nanotechnology processes that result in silver-based particles at the micrometer scale [a millionth of a meter], he said.

The core of the technology consists of coating ceramic particles made of silica with silver nanoparticles. The silver nanoparticles bond with the ceramic matrix to form a micrometre scale composite with bactericidal properties.

“The combination of silver particles with a ceramic matrix produces synergistic effects. Silver has bactericidal properties, and while silica doesn’t, it boosts those of the silver and helps control the release of silver particles to kill bacteria,” he said.

I wonder if they’ve done any ‘life cycle’ analysis. In other words, what happens to the packaging and those encapsulated silver nanoparticles when the milk jugs (and Nanox’s other silver-based products) are recycled or put in the garbage dump?

You can find out more about Nanox (English language version) here and about Agrindus, a division of Letti?, (you will need Portuguese language reading skills) here.

Glove sensors and toxic substances

Gloves that change colour as a signal you’re handling toxic substances have been developed by a research team at  the Fraunhofer Institute according to a May 2, 2013 Fraunhofer Research Institution for Modular Solid State Technologies EMFT news release (also on EurekAlert as a re-issued June 7, 2013 news release),

Employees in chemical production, the semiconductor industry or in laboratories are frequently exposed to harmful substances. The problem: Many of these aggressive substances are imperceptible to human senses, which makes handling them so risky. That’s why there is a broad range of solutions that employers can use to protect their staff from hazardous substances – from highly sensitive measuring equipment to heat imaging cameras. Soon, this spectrum will be enhanced by one more clever solution that is easy to handle, and that dispenses with a power supply. Researchers at the Fraunhofer Research Institution for Modular Solid State Technologies EMFT in Regensburg have engineered a glove that recognizes if toxic substances are present in the surrounding air.

Here’s an image of the glove,

The sensor glove turns blue in the presence of hazardous substances. (© Fraunhofer EMFT)

The sensor glove turns blue in the presence of hazardous substances. (© Fraunhofer EMFT)

The news release provides more details,

The protective glove is equipped with custom-made sensor materials and indicates the presence of toxic substances by changing colors. In this regard, the scientists adapted the materials to the corresponding analytes, and thus, the application. The color change – from colorless (no toxic substance) to blue (toxic substance detected), for example – warns the employee immediately. …

….

The warning signal is triggered by an indicator dye integrated into the glove that reacts to the presence of analytes, in this case, the toxic substances. The experts at EMFT used a variety of techniques in order to furnish textiles with sensor-activated dyes. The sensor-activated dyes are applied to the clothing with the customary dye and print process, for example, by affixing them in an immersion bath. Previously, the researchers used targeted chemical modification to adapt the color molecules to the fiber properties of the respective textile. Alternatively, the textiles can also be coated with sensor particles that are furnished with sensor dyes. For this purpose, the scientists integrated the dye molecules either into commercial pigments or they built them up on an entirely synthetic basis. The pigments are then manufactured according to the customary textile finishing process, for instance, the sensor particles are also suitable for silkscreening. “Which version we opt for depends on the requirements of the planned application,” says Trupp [Dr. Sabine Trupp, head of the Fraunhofer EMFT Sensor Materials group].

The challenge lies foremost in the tailored development of sensor dyes. “The dye molecule must detect a specific analyte in a targeted manner – only then will a chemical reaction occur. Moreover, the dye must adhere securely; it cannot disappear due to washing. We aim for the customer’s preferences in the color selection as well. All of these aspects must be kept in mind when developing the molecule and pigment properties,” explains Trupp.

The technology could be extended to do more and could be adapted for other applications (from the news release),

The expert already has new ideas about how the solution could be developed further. For example, a miniaturized sensor module, integrated into textiles, could record toxic substances, store the measurement data and even transmit them to a main unit. This way, you could document how frequently an individual within a hazardous environment was exposed to poisonous concentrations over a longer period of time.

The researchers also envision other potential applications in the foodstuffs industry: In the future, color indicator systems integrated into foils or bottle closures are intended to make the quality status of the packaged foods visible. Because the sell-by date does not represent a guarantee of any kind. Foodstuffs may often spoil prematurely – unnoticed by the consumer – due to a packaging error, or in the warehousing, or due to disruptions in the refrigeration chain. Oil-based and fat-containing products are specifically prone to this, as are meats, fish and ready meals.

The notion that food packaging could be designed to include sensors that alert consumers and retailers about product spoilage is not new and was mentioned recently and briefly in my Mar. 25, 2013 posting which featured excerpts from an interview with biotechnologist Christoph Meili about nanotechnology-enabled food packaging.

The Swiss talk about ‘smart’ food packaging

Biotechnologist Christoph Meili discusses the impact nanotechnology-enabled packaging could have on food in a Mar. 25, 2013 Q&A with Christian Raaflaub (adapted from German by Simon Bradley) for the International Service of the Swiss Broadcasting Corporation (swissinfo.ch),

swissinfo.ch: You argue that the future of packaging will be closely tied to advances in nanotechnology. What additional properties can nanotechnology offer?

Christoph Meili: …

Here I’m talking mostly about the shelf life of food, which can be extended. The amount of information and the quality of information on packaging will also increase. The consumer will learn about the state of the product, whether the food is still edible or if there is oxygen present in the packaging, for example.

Hopefully, this will also lead to a conservation of resources so that better biodegradable packaging is developed.

swissinfo.ch: Are there any smart alternatives to packaging so that we use less in the future?

C.M.: Edible packaging is something on our radar screens. On the other hand it’s important for consumers to be able to differentiate clearly between the product and the packaging. …

They also discuss the problem of people throwing good food away because they cannot confirm it is still edible. In Switzerland, it’s estimated some 2 million tonnes of food is discarded per year (worldwide the figure is 1.3 billion tonnes).

One final question from the interview,

swissinfo.ch: You are a biotechnologist and a molecular biologist but you also work as a risk researcher. What are the possible future health threats of integrating minute nanoparticles in packaging?

C.M.: The question we have to ask ourselves is: can nanoparticles escape from packaging? If so, where do they go? Into food, or are they dispersed into the environment? Or do they transform into something else in the biological cycle?

In active packaging, where a considerable part involves active elements escaping and interacting with foodstuffs, we have to look at what is happening. The migration and dispersion of low-molecular substances is an issue. …

I last mentioned food and nanotechnology-enabled packaging in a Nov. 1, 2012 posting about Canada, nano, and mangoes.

Better beer in plastic bottles

This innovation in beer bottling was developed in Ireland and I’m pretty sure the Irish have themselves braced for the humourous comments sure to follow given the legends about the Irish and beer.

Here’s more about the nanotechnology-enabled plastic beer bottles from the Sept. 18, 2012 news item on Nanowerk,

Scientists at CRANN [Centre for Research on Adaptive Nanostructures and Nanodevices], the Science Foundation Ireland-funded nanoscience institute based at Trinity College Dublin, have partnered with world-leading brewing company SABMiller on a project to increase the shelf life of bottled beer in plastic bottles. The new deal will see SABMiller invest in the project over a two year period.

Professor Jonathan Coleman and his team in CRANN are using nanoscience research methods to develop a new material that will prolong the shelf-life of beer in plastic bottles. Current plastic bottles have a relatively short shelf life, as both oxygen and carbon dioxide can permeate the plastic and diminish the flavour.

The new material, when added to plastic bottles will make them extremely impervious, meaning that oxygen cannot enter and that the carbon dioxide cannot escape, thus preserving the taste and ‘fizz’.

The Sept. 18, 2012 CRANN news release does not include many more details about the technology,

The team will exfoliate nano-sheets of boron nitride, each with a thickness of approximately 50,000 times thinner than one human hair. These nano-sheets will be mixed with plastic, which will result in a material that is extremely impervious to gas molecules. The molecules will be unable to diffuse through the material and shelf life will be increased.

As well as increasing the shelf life of the beer itself, less material is required in production, reducing cost and environmental impact.

If you are lucky enough to have a subscription or have some other access to Science magazine, you can read more about Coleman’s and his team’s work on boron nitride and thin films. Here’s the citation and abstract for the article,

Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials by Jonathan N. Coleman, Mustafa Lotya, Arlene O’Neill, Shane D. Bergin, Paul J. King, Umar Khan,  Karen Young, Alexandre Gaucher, Sukanta De, Ronan J. Smith, Igor V. Shvets, Sunil K. Arora, George Stanton, Hye-Young Kim, Kangho Lee, Gyu Tae Kim, Georg S. Duesberg, Toby Hallam, John J. Boland, Jing Jing Wang, John F. Donegan, Jaime C. Grunlan, Gregory Moriarty, Aleksey Shmeliov, Rebecca J. Nicholls, James M. Perkins, Eleanor M. Grieveson, Koenraad Theuwissen, David W. McComb, Peter D. Nellist, and Valeria Nicolosi in Science 4 February 2011: Vol. 331 no. 6017 pp. 568-571 DOI: 10.1126/science.1194975

If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. We show that layered compounds such as MoS2, WS2, MoSe2, MoTe2, TaSe2, NbSe2, NiTe2, BN, and Bi2Te3 can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solutions, we can prepare hybrid dispersions or composites, which can be cast into films. We show that WS2 and MoS2 effectively reinforce polymers, whereas WS2/carbon nanotube hybrid films have high conductivity, leading to promising thermoelectric properties.

This announcement comes during Ireland’s Nanoweek 2012 (Sept. 14 – 21, 2012) which I mentioned along with other nano-themed events currently taking place in Ireland in my Sept. 14, 2012 posting.

India, Sri Lanka, and Canada team up for nanotechnology-enabled food packaging

Canada’s University of Guelph keeps coming up on my radar these days. The latest news concerns a nanotechnology-enabled food packaging technology. From the June 20, 2012 University of Guelph news release,

University of Guelph scientists led by Prof. Jayasankar Subramanian will work with South Asian colleagues to develop innovative packaging using state-of-the-art nanotechnology to reduce post-harvest losses in mangoes, a vital fruit crop in South Asia.

The $2.3 million project, announced today by Canada’s International Development Research Centre (IDRC) and the Canadian International Development Agency (CIDA), will improve livelihoods for nearly one-third of the populations of India and Sri Lanka, mostly small-scale farmers.

The Guelph scientists will work with researchers from the Tamil Nadu Agricultural University in India and Sri Lanka’s Industrial Technology Institute.

“We welcome the opportunity to work with leading scientists and institutes in Asia to raise the income of poor farmers and make food more nutritious and secure,” said Subramanian, a professor in Guelph’s Department of Plant Agriculture.

“Invented in part at U of G, this new packaging system should reduce post-harvest losses in fruits in India and Sri Lanka, where optimal storage conditions are not readily available.”

Mangoes are the second largest fruit crop in India and third in Sri Lanka. Farmers lose 35 to 40 per cent of their crops ─ worth $800 million a year ─ because of poor storage.

The researchers will combine patented technologies to develop special fruit cartons, dividers and wraps lined with nanoparticles from coconut husks and banana plants. Using these farm waste products will help provide income for small-scale entrepreneurs, particularly women.

I hope to hear more about this project as it progresses and hopefully next time, there’ll be a few more technical details. The mention of coconut husks and banana plants makes me wonder if they are talking about nanocellulose in some form or other.

For anyone who’s interested in the international aid aspects (from the news release),

The project is among six new initiatives funded by IDRC and CIDA under the Canadian International Food Security Research Fund (CIFSRF). The five-year, $62-million project links researchers in Canada and developing countries to address hunger and food insecurity in the developing world.

I last wrote about Sri Lanka and its nanotechnology efforts in my June 4, 2012 posting and I have mentioned India’s nanotechnology efforts several times but perhaps the most relevant, as per this item was in my April 4, 2012 posting.

ETA Oct. 31,2012: Minor grammatical changes were made in the final sentence. ‘Time’ was changed to ‘times’ and I removed the words ‘recent mention’ as they made no sense in the sentence.