Category Archives: food

Say goodbye to crunchy (ice crystal-laden) in ice cream thanks to cellulose nanocrystals (CNC)

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The American Chemical Society (ACS) held its 2022 Spring Meeting from March 20 – 24, 2022 and it seems like a good excuse to feature ice cream.

Adding cellulose nanocrystals prevents the growth of small ice crystals (bottom left) into the large ones (top left) that can make ice cream (right) unpleasantly crunchy. Scale bar = 100 μm. Credit: Tao Wu

A March 20, 2022 news item on phys.org introduces an ice cream presentation given at the meeting on Monday, March 20, 2022,

Ice cream can be a culinary delight, except when it gets unpleasantly crunchy because ice crystals have grown in it. Today, scientists report that a form of cellulose obtained from plants can be added to the tasty treat to stop crystals cold—and the additive works better than currently used ice growth inhibitors in the face of temperature fluctuations. The findings could be extended to the preservation of other frozen foods and perhaps donated organs and tissues

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A March 20, 2022 ACS press release, which originated the news item, provides more details about crunchy ice cream and how it might be avoided,

Freshly made ice cream contains tiny ice crystals. But during storage and transport, the ice melts and regrows. During this recrystallization process, smaller crystals melt, and the water diffuses to join larger ones, causing them to grow, says Tao Wu, Ph.D., the project’s principal investigator. If the ice crystals become bigger than 50 micrometers — or roughly the diameter of a hair — the dessert takes on a grainy, icy texture that reduces consumer appeal, Wu says. “Controlling the formation and growth of ice crystals is thus the key to obtaining high-quality frozen foods.”

One fix would be to copy nature’s solution: “Some fish, insects and plants can survive in sub-zero temperatures because they produce antifreeze proteins that fight the growth of ice crystals,” Wu says. But antifreeze proteins are costlier than gold and limited in supply, so they’re not practical to add to ice cream. Polysaccharides such as guar gum or locust bean gum are used instead. “But these stabilizers are not very effective,” Wu notes. “Their performance is influenced by many factors, including storage temperature and time, and the composition and concentration of other ingredients. This means they sometimes work in one product but not in another.” In addition, their mechanism of action is uncertain. Wu wanted to clarify how they work and develop better alternatives.

Although Wu didn’t use antifreeze proteins in the study, he drew inspiration from them. These proteins are amphiphilic, meaning they have a hydrophilic surface with an affinity for water, as well as a hydrophobic surface that repels water. Wu knew that nano-sized crystals of cellulose are also amphiphilic, so he figured it was worth checking if they could stop ice crystal growth in ice cream. These cellulose nanocrystals (CNCs) are extracted from the plant cell walls of agricultural and forestry byproducts, so they are inexpensive, abundant and renewable.

In a model ice cream — a 25% sucrose solution — the CNCs initially had no effect, says Min Li, a graduate student in Wu’s lab at the University of Tennessee. Though still small, ice crystals were the same size whether CNCs were present or not. But after the model ice cream was stored for a few hours, the researchers found that the CNCs completely shut down the growth of ice crystals, while the crystals continued to enlarge in the untreated model ice cream.

The team’s tests also revealed that the cellulose inhibits ice recrystallization through surface adsorption. CNCs, like antifreeze proteins, appear to stick to the surfaces of ice crystals, preventing them from drawing together and fusing. “This completely contradicted the existing belief that stabilizers inhibit ice recrystallization by increasing viscosity, which was thought to slow diffusion of water molecules,” adds Li, who will present the work at the meeting.

In their latest study, the scientists found that CNCs are more protective than current stabilizers when ice cream is exposed to fluctuating temperatures, such as when the treat is stored in the supermarket and then taken home. The team also discovered the additive can slow the melting of ice crystals, so it could be used to produce slow-melting ice cream. Other labs have shown the stabilizer is nontoxic at the levels needed in food, Wu notes, but the additive would require review by the U.S. Food and Drug Administration.

With further research, CNCs could be used to protect the quality of other foods — such as frozen dough and fish — or perhaps to preserve cells, tissues and organs in biomedicine, Wu says. “At present, a heart must be transplanted within a few hours after being removed from a donor,” he explains. “But this time limit could be eliminated if we could inhibit the growth of ice crystals when the heart is kept at low temperatures.”

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Interesting to see that this research into ice cream crystals could lead to new techniques for organ transplants.

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

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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.

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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.

Internet of living things (IoLT)?

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It’s not here yet but there are scientists working on an internet of living things (IoLT). There are some details (see the fourth paragraph from the bottom of the news release excerpt) about how an IoLT would be achieved but it seems these are early days. From a September 9, 2021 University of Illinois news release (also on EurekAlert), Note: Links have been removed,

The National Science Foundation (NSF) announced today an investment of $25 million to launch the Center for Research on Programmable Plant Systems (CROPPS). The center, a partnership among the University of Illinois at Urbana-Champaign, Cornell University, the Boyce Thompson Institute, and the University of Arizona, aims to develop tools to listen and talk to plants and their associated organisms.

“CROPPS will create systems where plants communicate their hidden biology to sensors, optimizing plant growth to the local environment. This Internet of Living Things (IoLT) will enable breakthrough discoveries, offer new educational opportunities, and open transformative opportunities for productive, sustainable, and profitable management of crops,” says Steve Moose (BSD/CABBI/GEGC), the grant’s principal investigator at Illinois. Moose is a genomics professor in the Department of Crop Sciences, part of the College of Agricultural, Consumer and Environmental Sciences (ACES). 

As an example of what’s possible, CROPPS scientists could deploy armies of autonomous rovers to monitor and modify crop growth in real time. The researchers created leaf sensors to report on belowground processes in roots. This combination of machine and living sensors will enable completely new ways of decoding the language of plants, allowing researchers to teach plants how to better handle environmental challenges. 

“Right now, we’re working to program a circuit that responds to low-nitrogen stress, where the plant growth rate is ‘slowed down’ to give farmers more time to apply fertilizer during the window that is the most efficient at increasing yield,” Moose explains.

With 150+ years of global leadership in crop sciences and agricultural engineering, along with newer transdisciplinary research units such as the National Center for Supercomputing Applications (NCSA) and the Center for Digital Agriculture (CDA), Illinois is uniquely positioned to take on the technical challenges associated with CROPPS.

But U of I scientists aren’t working alone. For years, they’ve collaborated with partner institutions to conceptualize the future of digital agriculture and bring it into reality. For example, researchers at Illinois’ CDA and Cornell’s Initiative for Digital Agriculture jointly proposed the first IoLT for agriculture, laying the foundation for CROPPS.

“CROPPS represents a significant win from having worked closely with our partners at Cornell and other institutions. We’re thrilled to move forward with our colleagues to shift paradigms in agriculture,” says Vikram Adve, Donald B. Gillies Professor in computer science at Illinois and co-director of the CDA.

CROPPS research may sound futuristic, and that’s the point.

The researchers say new tools are needed to make crops productive, flexible, and sustainable enough to feed our growing global population under a changing climate. Many of the tools under development – biotransducers small enough to fit between soil particles, dexterous and highly autonomous field robots, field-applied gene editing nanoparticles, IoLT clouds, and more – have been studied in the proof-of-concept phase, and are ready to be scaled up.

“One of the most exciting goals of CROPPS is to apply recent advances in sensing and data analytics to understand the rules of life, where plants have much to teach us. What we learn will bring a stronger biological dimension to the next phase of digital agriculture,” Moose says. 

CROPPS will also foster innovations in STEM [science, technology[ engineering, and mathematics] education through programs that involve students at all levels, and each partner institution will share courses in digital agriculture topics. CROPPS also aims to engage professionals in digital agriculture at any career stage, and learn how the public views innovations in this emerging technology area.

“Along with cutting-edge research, CROPPS coordinated educational programs will address the future of work in plant sciences and agriculture,” says Germán Bollero, associate dean for research in the College of ACES.

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I look forward to hearing more about IoLT.

Cellulose nanofiber (CNF) coating protects plants against rust disease

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A September 8, 2021news item on ScienceDaily describes some new research into rust disease,

A water-absorbent coat to keep rust away? It may seem counterintuitive but when it comes to soybean plants and rust disease, researchers from Japan have discovered that applying a coating that makes leaf surfaces water absorbent helps to protect against infection.

Caption: Researchers from the University of Tsukuba have found that coating soybean plant leaves with cellulose nanofiber (CNF) gives protection against an aggressive fungal disease. The CNF coating changed leaf surfaces from water repellent to water absorbent, and suppressed pathogen gene expression associated with infection mechanisms, offering resistance to the destructive Asian rust disease. This is the first study to examine CNF application for controlling plant diseases, and it offers a sustainable alternative to managing plant disease.. Credit: University of Tsukuba

A September 7, 2021 University of Tsukuba press release (also on EurekAlert but published September 8, 2021), which originated the news item, describes the disease and proposed solution in more detail,

In a study published this month in Frontiers in Plant Science, researchers from the University of Tsukuba have revealed that coating soybean plant leaves with cellulose nanofiber changes the leaf surface from water repellent to water absorbent and offers resistance against Asian soybean rust.

Rusts are plant diseases that get their name from the powdery rust- or brown-colored fungal spores on the surfaces of infected plants. Asian soybean rust (ASR) is an aggressive disease of soybean plants, causing estimated crop yield losses of up to 90%. ASR is caused by Phakopsora pachyrhizi, a fungal pathogen that requires a living plant host to survive. The timely application of fungicide is currently the only way of controlling ASR in the field. But the use of fungicides can be problematic, resulting in negative environmental effects, increased production costs, and fungicide-resistant pathogens.

“We investigated cellulose nanofiber (CNF) as an alternative method of controlling ASR,” says senior author of the study, Professor Yasuhiro Ishiga. “Specifically, we wanted to know whether coating soybean plant leaves with CNF protected plants against P. pachyrhizi.”

Of the available methods for isolating CNF, aqueous counter collision (ACC) has been shown to alter the hydrophilic (water absorbent) and hydrophobic (water repellent) properties of surfaces, switching one to the other. Previous research has indicated that CNF obtained via ACC has higher wettability than CNF isolated by other methods.

“We showed that CNF can change the soybean leaf surface from hydrophobic to hydrophilic,” explains senior author, Professor Yuji Yamashita. “This offers resistance against P. pachyrhizi.”

The team found fewer lesions and significantly reduced formation of P. pachyrhizi appressoria, which are specialized pre-infection structures used to break through the outer surface of the host plant, on CNF-treated leaves compared with control (untreated) leaves. The results also revealed suppressed gene expression linked to the formation of pre-infection structures in P. pachyrhizi on treated versus control leaves.

“In particular, chitin synthase gene expression was suppressed, and P. pachyrhizi needs chitin synthases to form pre-infection structures,” says Professor Ishiga.

This study is the first to investigate the application of CNF for controlling plant diseases in the field, and this technique offers new possibilities for sustainable and eco-friendly management of plant diseases.

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

Covering Soybean Leaves With Cellulose Nanofiber Changes Leaf Surface Hydrophobicity and Confers Resistance Against Phakopsora pachyrhizi by
Haruka Saito, Yuji Yamashita, Nanami Sakata, Takako Ishiga, Nanami Shiraishi, Giyu Usuki, Viet Tru Nguyen, Eiji Yamamura and Yasuhiro Ishiga. Front. Plant Sci., 03 September 2021 DOI: https://doi.org/10.3389/fpls.2021.726565

This paper appears to be open access.

Use AI to reduce worries about nanoparticles in food

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A June 16, 2021 news item on ScienceDaily announces research into the impact that engineered metallic nanoparticles used in agricultural practices have on food,

While crop yield has achieved a substantial boost from nanotechnology in recent years, alarms over the health risks posed by nanoparticles within fresh produce and grains have also increased. In particular, nanoparticles entering the soil through irrigation, fertilizers and other sources have raised concerns about whether plants absorb these minute particles enough to cause toxicity.

In a new study published online in the journal Environmental Science and Technology, researchers at Texas A&M University have used machine learning [a form of artificial intelligence {AI}] to evaluate the salient properties of metallic nanoparticles that make them more susceptible for plant uptake. The researchers said their algorithm could indicate how much plants accumulate nanoparticles in their roots and shoots.

A June 16, 2021 Texas A&M University news release (also on EurekAlert), which originated the news item, describes the research, which employed two different machine learning algorithms, in more detail,

Nanoparticles are a burgeoning trend in several fields, including medicine, consumer products and agriculture. Depending on the type of nanoparticle, some have favorable surface properties, charge and magnetism, among other features. These qualities make them ideal for a number of applications. For example, in agriculture, nanoparticles may be used as antimicrobials to protect plants from pathogens. Alternatively, they can be used to bind to fertilizers or insecticides and then programmed for slow release to increase plant absorption.

These agricultural practices and others, like irrigation, can cause nanoparticles to accumulate in the soil. However, with the different types of nanoparticles that could exist in the ground and a staggeringly large number of terrestrial plant species, including food crops, it is not clearly known if certain properties of nanoparticles make them more likely to be absorbed by some plant species than others.

“As you can imagine, if we have to test the presence of each nanoparticle for every plant species, it is a huge number of experiments, which is very time-consuming and expensive,” said Xingmao “Samuel” Ma, associate professor in the Zachry Department of Civil and Environmental Engineering. “To give you an idea, silver nanoparticles alone can have hundreds of different sizes, shapes and surface coatings, and so, experimentally testing each one, even for a single plant species, is impractical.”

Instead, for their study, the researchers chose two different machine learning algorithms, an artificial neural network and gene-expression programming. They first trained these algorithms on a database created from past research on different metallic nanoparticles and the specific plants in which they accumulated. In particular, their database contained the size, shape and other characteristics of different nanoparticles, along with information on how much of these particles were absorbed from soil or nutrient-enriched water into the plant body.

Once trained, their machine learning algorithms could correctly predict the likelihood of a given metallic nanoparticle to accumulate in a plant species. Also, their algorithms revealed that when plants are in a nutrient-enriched or hydroponic solution, the chemical makeup of the metallic nanoparticle determines the propensity of accumulation in the roots and shoots. But if plants are grown in soil, the contents of organic matter and the clay in soil are key to nanoparticle uptake.

Ma said that while the machine learning algorithms could make predictions for most food crops and terrestrial plants, they might not yet be ready for aquatic plants. He also noted that the next step in his research would be to investigate if the machine learning algorithms could predict nanoparticle uptake from leaves rather than through the roots.

“It is quite understandable that people are concerned about the presence of nanoparticles in their fruits, vegetables and grains,” said Ma. “But instead of not using nanotechnology altogether, we would like farmers to reap the many benefits provided by this technology but avoid the potential food safety concerns.”

This image accompanies the paper’s research abstract,

[downloaded frm https://pubs.acs.org/doi/full/10.1021/acs.est.1c01603]

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

Prediction of Plant Uptake and Translocation of Engineered Metallic Nanoparticles by Machine Learning by Xiaoxuan Wang, Liwei Liu, Weilan Zhang, and Xingmao Ma. Environ. Sci. Technol. 2021, 55, 11, 7491–7500 DOI: https://doi.org/10.1021/acs.est.1c01603 Publication Date:May 17, 2021 Copyright © 2021 American Chemical Society

This paper is behind a paywall.

Canadian and Guadeloupean oysters: exposure to nanoplastics and arsenic

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A May 27, 2021 news item on phys.org describes research into oysters and nanoplastics,

Oysters’ exposure to plastics is concerning, particularly because these materials can accumulate and release metals which are then absorbed by the mollusks. According to a recent study published in the journal Chemosphere, the combined presence of nanoplastics and arsenic affects the biological functions of oysters. This study was conducted by the Institut national de la recherche scientifique (INRS) in Québec City and the French National Centre for Scientific Research (CNRS) at the University of Bordeaux in France

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A May 27, 2021 INRS news release (French language version here and an English language version on EurekAlert), which originated the news item, provides fascinating details,

The international research team chose to study arsenic, since it is one of the most common metals absorbed by the plastic debris collected from the beaches of Guadeloupe. “Oysters easily accumulate metals from the environment into their tissues. We therefore wanted to test whether the combined exposure to nanoplastics and arsenic would increase the bioaccumulation of this contaminant,” reported Marc Lebordais, the Master’s student in charge of the research.

The scientists proved that the bioaccumulation of arsenic does not increase when nanoplastics are also present. However, it remained higher in the gills of the Canadian Crassostrea virginica oyster [emphasis mine] than in the Isognomon alatus oyster, found in Guadeloupe. These results are the first to highlight the diverging sensitivity of different species. [emphasis mine]

Gene deregulation

In addition to bioaccumulation, the team also observed an overexpression of genes responsible for cell death and the number of mitochondria–a cell’s energy centres–in C. virginica. In I. alatus, the expression of these same genes was less significant.

“Evaluating the expression of genes involved in important functions, such as cell death and detoxification, gives us information on the toxicity of nanoplastics and arsenic on a cellular level,” explained the young researcher, who is co-directed by Professors Valérie Langlois of INRS and Magalie Baudrimont of the University of Bordeaux.

The food chain

The next step, after characterizing the presence of nanoplastics and arsenic in oysters, would be to study how these contaminants are transferred through the food chain.

“Analytical tools are currently being developed to quantify the presence of nanoplastics in biological tissues,” said Marc Lebordais. “Understanding the amount of nanoplastics in farmed oysters currently boils down to a technical issue.” ?

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

Molecular impacts of dietary exposure to nanoplastics combined with arsenic in Canadian oysters (Crassostrea virginica) and bioaccumulation comparison with Caribbean oysters (Isognomon alatus) by Marc Lebordais, Juan Manuel Gutierrez-Villagomez, Julien Gigault, Magalie Baudrimont, and Valérie Langlois. Chemosphere Volume 277, August 2021, 130331 DOI: https://doi.org/10.1016/j.chemosphere.2021.130331 First published online 19 March 2021.

This paper is open access.

Chocolate at Canada’s synchrotron (Canadian Light Source; CLS)

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An August 31, 2021 Canadian Light Source (CLS) news release by Erin Matthews describes research which could change how chocolate is made,

Scientists used synchrotron technology to show a key ingredient can create the ideal chocolate structure and could revolutionize the chocolate industry.

Structure is key when it comes creating the best quality of chocolate. An ideal internal structure will be smooth and continuous, not crumbly, and result in glossy, delicious, melt-in-your-mouth decadence. However, this sweet bliss is not easy to achieve.

Researchers from the University of Guelph had their first look at the detailed structure of dark chocolate using the Canadian Light Source (CLS) at the University of Saskatchewan. Their results were published today in Nature Communications.

“One of the major problems in chocolate making is tempering,” said Alejandro Marangoni, a professor at the University of Guelph and Canada Research Chair in Food, Health and Aging. “Very much like when you temper steel, you have to achieve a certain crystalline structure in the cocoa butter.”

Skilled chocolate makers [emphasis mine] use specialized tools and training to manipulate cocoa butter for gourmet chocolate. However, Marangoni wondered if adding a special ingredient to chocolate could drive the formation of the correct crystal structure without the complex cooling and mixing procedures typically used by chocolatiers during tempering.

“Imagine if you could add a component that directs the entire crystallization process to a high-quality finished product. You wouldn’t need fancy tempering protocols or industrial machines — you could easily achieve the desired crystalline form just by the addition of this component,” Marangoni said.

His team went to the CLS to see if their secret ingredient, a specific phospholipid, could drive the formation of an ideal chocolate structure. The facility’s bright light, which is millions of times brighter than the sun, allowed the team to get images of the interior structure of their dark chocolate in exquisite detail.

“We have some of the most beautiful micrographs of the finished chocolate that were only possible because we did this work at the CLS,” said Marangoni.

In a world first, the researchers were able to get detailed imaging of the internal structure of dark chocolate, thanks to the synchrotron’s state of the art BMIT beamline.

“Working with the CLS, I would call it a next level interaction,” Marangoni added. “It was extremely easy to set up a project and we had enormous support from beamline scientists.”

In collaboration with CLS Plant Imaging Lead Jarvis Stobbs, Marangoni and colleagues were able to confirm the positive effect their ingredient had on obtaining the ideal structure for chocolate.

“We screened many minor lipid components that would naturally be present in chocolate and identified one preferred group. We then added a very specific molecule, a saturated phospholipid, to the chocolate mass and obtained the desired effect. This phospholipid formed a specific liquid crystal structure that would ‘seed’ the formation of cocoa butter crystals,” said Marangoni.

Their discovery that this phospholipid ingredient will drive the formation of ideal cocoa butter crystals could have a big impact on the way that chocolate is made.

“It could potentially revolutionize the chocolate industry, because we would not need very complex tempering machines,” Marangoni said. “This could open up the possibility for smaller manufacturers to produce chocolate without having the big capital investment for tempering machinery.”

Synchrotron research allows scientists to identify important details that are not possible to find with other techniques. Marangoni said that any small improvement on current manufacturing methods can have a very large impact on the food industry and can potentially save money for companies.

He added that while chocolate research pales in comparison to global problems, he emphasizes the impact food can have on our everyday lives.

“We have more serious problems like climate change and alternative energies and maybe even vegan foods, which we’re working on as well, but chocolate gives us that psychological pleasure. It’s one of these foods that makes us feel happy.”

This video shows the researcher’s delight,

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

Tempering of cocoa butter and chocolate using minor lipidic components by Jay Chen, Saeed M. Ghazani, Jarvis A. Stobbs & Alejandro G. Marangoni. Nature Communications volume 12, Article number: 5018 (2021) DOI: https://doi.org/10.1038/s41467-021-25206-1 Published 31 August 2021

This paper is open access.

According to a Sept. 2, 2021 article by Marc Fawcett-Atkinson for Canada’s National Observer, this work could lead to making chocolate production more sustainable

What happens to the skilled chocolate makers?

That’s one of my big questions. The other is what happens to us? In all these ‘improvements’ of which there are many being touted these days, what I notice is a lack of sensuality. In this particular case, no touch and no smell.

Five country survey of reactions to food genome editing

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Weirdly and even though most of this paper’s authors are from the University of British Columbia (UBC; Canada), only one press release was issued and that was by the lead author’s (Gesa Busch) home institution, the University of Göttingen (Germany).

I’m glad Busch, the other authors, and the work are getting some attention (if not as much as I think they should).

From a July 9, 2021 University of Göttingen press release (also on EurekAlert but published on July 12, 2021),

A research team from the University of Göttingen and the University of British Columbia (Canada) has investigated how people in five different countries react to various usages of genome editing in agriculture. The researchers looked at which uses are accepted and how the risks and benefits of the new breeding technologies are rated by people. The results show only minor differences between the countries studied – Germany, Italy, Canada, Austria and the USA. In all countries, making changes to the genome is more likely to be deemed acceptable when used in crops rather than in livestock. The study was published in Agriculture and Human Values.

Relatively new breeding technologies, such as CRISPR [clustered regularly interspaced short palindromic repeats) gene editing, have enabled a range of new opportunities for plant and animal breeding. In the EU, the technology falls under genetic engineering legislation and is therefore subject to rigorous restrictions. However, the use of gene technologies remains controversial. Between June and November 2019, the research team collected views on this topic via online surveys from around 3,700 people from five countries. Five different applications of gene editing were evaluated: three relate to disease resistance in people, plants, or animals; and two relate to achieving either better quality of produce or a larger quantity of product from cattle.

“We were able to observe that the purpose of the gene modification plays a major role in how it is rated,” says first author Dr Gesa Busch from the University of Göttingen. “If the technology is used to make animals resistant to disease, approval is greater than if the technology is used to increase the output from animals.” Overall, however, the respondents reacted very differently to the uses of the new breeding methods. Four different groups can be identified: strong supporters, supporters, neutrals, and opponents of the technology. The opponents (24 per cent) identify high risks and calls for a ban of the technology, regardless of possible benefits. The strong supporters (21 per cent) see few risks and many advantages. The supporters (26 per cent) see many advantages but also risks. Whereas those who were neutral (29 per cent) show no strong opinion on the subject.

This study was made possible through funding from the Free University of Bozen-Bolzano and Genome BC.

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

Citizen views on genome editing: effects of species and purpose by Gesa Busch, Erin Ryan, Marina A. G. von Keyserlingk & Daniel M. Weary. Agriculture and Human Values (2021) Published: DOI: https://doi.org/10.1007/s10460-021-10235-9

This paper is open access.

Methodology

I have one quick comment about the methodology. It can be difficult to get a sample that breaks down along demographic lines that is close to or identical to national statistics. That said, it was striking to me that every country was under represented in the ’60 years+ ‘ category. In Canada, it was by 10 percentage points (roughly). For other countries the point spread was significantly wider. In Italy, it was a 30 percentage point spread (roughly).

I found the data in the Supplementary Materials yesterday (July 13, 2021). When I looked this morning, that information was no longer there but you will find what appears to be the questionnaire. I wonder if this removal is temporary or permanent and, if permanent, I wonder why it was removed.

Participants for the Canadian portion of the survey were supplied by Dynata, a US-based market research company. Here’s the company’s Wikipedia entry and its website.

Information about how participants were recruited was also missing this morning (July 14, 2021).

Genome British Columbia (Genome BC)

I was a little surprised when I couldn’t find any information about the program or the project on the Genome BC website as the organization is listed as a funder.

There is a ‘Genomics and Society’ tab (seems promising, eh?) on the homepage where you can find the answer to this question: What is GE³LS Research?,

GE3LS research is interdisciplinary, conducted by researchers across many disciplines within social science and humanities, including economics, environment, law, business, communications, and public policy.

There’s also a GE3LS Research in BC page titled Project Search; I had no luck there either.

It all seems a bit mysterious to me and, just in case anything else disappears off the web, here’s a July 13, 2021 news item about the research on phys.org as backup to what I have here.

Edible nano-structured holograms could decorate food one day

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Caption Nanostructures (yellowish-green images; scale bar, 5 μm) were patterned onto dried corn syrup films, producing edible, rainbow-colored holograms (scale bar, 2 mm). Credit Adapted from ACS Nano 2021, DOI: 10.1021/acsnano.0c02438

Where food safety is concerned, much of the research I’ve seen is focused on adding senors to the packaging rather than direct application to the foodstuff but this is different, from a February 17, 2021 news item on phys.org,

Holograms are everywhere, from driver’s licenses to credit cards to product packaging. And now, edible holograms could someday enhance foods. Researchers reporting in ACS [American Chemical Society] Nano have developed a laser-based method to print nanostructured holograms on dried corn syrup films. The edible holograms could also be used to ensure food safety, label a product or indicate sugar content, the researchers say.

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A February 17, 2021American Chemical Society news release (also on EurekAlert), which originated the news item,

Most holograms are imprinted with lasers onto metal surfaces, such as aluminum, but the materials aren’t edible. For foods, holograms made with nanoparticles have been proposed, but the tiny particles can generate reactive oxygen species, which might be harmful for people to eat. In a different approach, food scientists have molded edible holograms onto chocolate, but the process only works for certain types of the confection, and a different mold is needed for each hologram design. Bader AlQattan, Haider Butt and colleagues wanted to find a safe, fast and versatile way to pattern edible holograms onto a variety of foods.

To develop their method, the researchers made a solution of corn syrup, vanilla and water and dried it into a thin film. They coated the film with a fine layer of non-toxic black dye. Then, they used a technique called direct laser interference patterning to etch off most of the dye, leaving behind raised, nanoscale lines that formed a diffraction grating. When struck by light, the nanostructure diffracted the light into a rainbow pattern, with different colors appearing at different angles of viewing. The team could control the intensity and range of colors by varying the spacing between lines in the grating or the sugar content of the corn syrup film. Before edible holograms are ready to hit store shelves, however, the researchers want to adapt the method to a food-grade dye that could replace the synthetic black dye used in these pilot experiments.

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

Direct Printing of Nanostructured Holograms on Consumable Substrates by Bader AlQattan, Joelle Doocey, Murad Ali, Israr Ahmed, Ahmed E. Salih, Fahad Alam, Magdalena Bajgrowicz-Cieslak, Ali K. Yetisen, Mohamed Elsherif, and Haider Butt. ACS Nano 2021, 15, 2, 2340–2349 DOI: https://doi.org/10.1021/acsnano.0c02438 Publication Date:February 1, 2021 Copyright © 2021 American Chemical Society

This paper appears to be open access.

It seems these scientists are also considering the aesthetic possibilities. Ffrom the paper, Note: Links have been removed,

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The use of holograms in food could potentially improve sensory appeal [emphasis mine] and, through biosensing, could increase health and safety.(1,2) Holograms can even be used to store information as edible microtags.(3) They are also attractive to the eye as they produce rainbow patterns with light. Using edible holograms on foods, not only as decoration but also to sense harmful bacteria, could improve food quality/lifetime monitoring.(4,5) Food holograms which signify a qualitative information about the sugar contents could be of value in controlling the sugar consumption, that is challenging to be measured at the moment.(6)

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As it is, I find food pretty attractive. So, I’m not sure why there’s a need to improve its sensory appeal. On the other hand, I can’t argue with increased food safety.

Should you be interested in more about holograms and their current applications, including chocolate decoration, you can check out Michael Berger’s February 17, 2021 Nanowerk Spotlight article.

Holographic chocolate surfaces. (Image: Morphotonix) [downloaded from https://www.nanowerk.com/spotlight/spotid=57310.php]

What do you think about decorating food with holograms? If you feel inclined, do let me know in the comments.

Living plants detect arsenic by way of embedded nanosensors

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There’s a lot of arsenic in the world and it’s often a factor in making water undrinkable. When that water is used in farming It also pollutes soil and enters food-producing plants. A December 11, 2020 news item on Nanowerk announces research into arsenic detectors in plants,

Researchers have developed a living plant-based sensor that can in real-time detect and monitor levels of arsenic, a highly toxic heavy metal, in the soil. Arsenic pollution is a major threat to humans and ecosystems in many Asia Pacific countries.

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Caption: Non-destructive plant nanobionic sensor embedded within leaves to report arsenic levels within plants to portable electronics, enabling real-time monitoring of arsenic uptake in living plants. Credit: Dr. Tedrick Thomas Salim Lew

I was not able to find the source for the news item but I did locate something close. From a December 13, 2020 Singapore-Massachusetts Institute of Technology (MIT) Alliance for Research and Technology (SMART), also on EurekAlert,

Scientists from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) research group at the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, have engineered a novel type of plant nanobionic optical sensor that can detect and monitor, in real time, levels of the highly toxic heavy metal arsenic in the underground environment. This development provides significant advantages over conventional methods used to measure arsenic in the environment and will be important for both environmental monitoring and agricultural applications to safeguard food safety, as arsenic is a contaminant in many common agricultural products such as rice, vegetables, and tea leaves.

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Arsenic and its compounds are a serious threat to humans and ecosystems. Long-term exposure to arsenic in humans can cause a wide range of detrimental health effects, including cardiovascular disease such as heart attack, diabetes, birth defects, severe skin lesions, and numerous cancers including those of the skin, bladder, and lung. Elevated levels of soil arsenic as a result of anthropogenic activities such as mining and smelting are also harmful to plants, inhibiting growth and resulting in substantial crop losses.

Food crops can absorb arsenic from the soil, leading to contamination of food and produce consumed by humans. Arsenic in underground environments can also contaminate groundwater and other underground water sources, the long-term consumption of which can cause severe health issues. As such, developing accurate, effective, and easy-to-deploy arsenic sensors is important to protect both the agriculture industry and wider environmental safety.

The novel optical nanosensors exhibit changes in their fluorescence intensity upon detecting arsenic. Embedded in plant tissues, with no detrimental effects on the plant, these sensors provide a nondestructive way to monitor the internal dynamics of arsenic taken up by plants from the soil. This integration of optical nanosensors within living plants enables the conversion of plants into self-powered detectors of arsenic from their natural environment, marking a significant upgrade from the time- and equipment-intensive arsenic sampling methods of current conventional methods.

“Our plant-based nanosensor is notable not only for being the first of its kind, but also for the significant advantages it confers over conventional methods of measuring arsenic levels in the below-ground environment, requiring less time, equipment, and manpower,” says Lew. “We envision that this innovation will eventually see wide use in the agriculture industry and beyond. I am grateful to SMART DiSTAP and the Temasek Life Sciences Laboratory (TLL), both of which were instrumental in idea generation and scientific discussion as well as research funding for this work.”

Besides detecting arsenic in rice and spinach, the team also used a species of fern, Pteris cretica, which can hyperaccumulate arsenic. This fern species can absorb and tolerate high levels of arsenic with no detrimental effect — engineering an ultrasensitive plant-based arsenic detector, capable of detecting very low concentrations of arsenic, as low as 0.2 parts per billion. In contrast, the regulatory limit for arsenic detectors is 10 parts per billion. Notably, the novel nanosensors can also be integrated into other species of plants. The researchers say this is the first successful demonstration of living plant-based sensors for arsenic and represents a groundbreaking advancement that could prove highly useful in both agricultural research (e.g., to monitor arsenic taken up by edible crops for food safety) and general environmental monitoring.

Previously, conventional methods of measuring arsenic levels included regular field sampling, plant tissue digestion, extraction, and analysis using mass spectrometry. These methods are time-consuming, require extensive sample treatment, and often involve the use of bulky and expensive instrumentation. The new approach couples nanoparticle sensors with plants’ natural ability to efficiently extract analytes via the roots and transport them. This allows for the detection of arsenic uptake in living plants in real time, with portable, inexpensive electronics such as a portable Raspberry Pi platform equipped with a charge-coupled device camera akin to a smartphone camera.

Co-author, DiSTAP co-lead principal investigator, and MIT Professor Michael Strano adds, “This is a hugely exciting development, as, for the first time, we have developed a nanobionic sensor that can detect arsenic — a serious environmental contaminant and potential public health threat. With its myriad advantages over older methods of arsenic detection, this novel sensor could be a game-changer, as it is not only more time-efficient, but also more accurate and easier to deploy than older methods. It will also help plant scientists in organizations such as TLL to further produce crops that resist uptake of toxic elements. Inspired by TLL’s recent efforts to create rice crops which take up less arsenic, this work is a parallel effort to further support SMART DiSTAP’s efforts in food security research, constantly innovating and developing new technological capabilities to improve Singapore’s food quality and safety.”

The research is carried out by SMART and supported by the National Research Foundation (NRF) Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) program.

Led by MIT’s Strano and Singapore co-lead principal investigator Professor Chua Nam Hai, DiSTAP is one of the five Interdisciplinary Research Groups (IRGs) in SMART. The DiSTAP program addresses deep problems in food production in Singapore and the world by developing a suite of impactful and novel analytical genetic and biosynthetic technologies. The goal is to fundamentally change how plant biosynthetic pathways are discovered, monitored, engineered, and ultimately translated to meet the global demand for food and nutrients. Scientists from MIT, TTL, Nanyang Technological University, and National University of Singapore are collaboratively developing new tools for the continuous measurement of important plant metabolites and hormones for novel discovery, deeper understanding and control of plant biosynthetic pathways in ways not yet possible, especially in the context of green leafy vegetables; leveraging these new techniques to engineer plants with highly desirable properties for global food security, including high yield density production, drought and pathogen resistance and biosynthesis of high-value commercial products; developing tools for producing hydrophobic food components in industry-relevant microbes; developing novel microbial and enzymatic technologies to produce volatile organic compounds that can protect and/or promote growth of leafy vegetables; and applying these technologies to improve urban farming.

…

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

Plant Nanobionic Sensors for Arsenic Detection by Tedrick Thomas Salim Lew, Minkyung Park, Jianqiao Cui, Michael S. Strano. Advanced Materials DOI: https://doi.org/10.1002/adma.202005683 First published: 26 November 2020

This paper is behind a paywall.