Nanocrystals: The Science Behind Creamy Plant-Based Ice Cream

Ice cream lovers, get ready to indulge in a whole new level of creamy goodness! The secret ingredient? Nanocrystals.

These tiny particles, smaller than the width of a human hair, have the potential to revolutionize the world of vegan ice cream. Typically less than 100 nanometers in size, they can be made from a variety of materials, including cellulose, starch, and lipids. And here’s the exciting part: they can make vegan ice cream creamier than ever before!

Figure 1. Vegan vanilla ice cream. Source.

Traditionally, guar gum and locust bean gum (LBG) are the most commonly used stabilizers in ice creams. Recent research, however, suggests that cellulose nanocrystals (CNCs) may provide a more effective alternative. CNCs play an important role in improving the texture of plant-based ice cream by preventing ice crystal formation. This is due to nanocrystals’ unique properties which prevent them from growing larger. This results in a smooth and creamy texture comparable to traditional ice cream that consumers with dietary restrictions can enjoy.

 

But how do nanocrystals work their magic? The answer lies in the physics of freezing. When the water molecules in ice cream freeze, they can form large ice crystals. These large crystals, with diameters larger than 50 μm, impart a grainy texture to ice cream and can make it less creamy. Nanocrystals, on the other hand, can prevent this by enclosing the ice crystals in a protective shell, slowing their growth and keeping them small.

Figure 2. Ice growth kinetics of 0.5% CNCs, guar gum, and LBG in 25% sucrose solutions. Adapted from source.

Figure 2 shows that CNCs at 0.5% concentration can completely stop ice crystal growth after 72 hours. This is a significant finding because the same concentrations of guar gum and LBG had different effects. In the presence of CNCs, the final ice crystal size was approximately 37 μm, which was smaller than the final crystal size in the presence of guar gum and LBG. These findings show that CNCs can be a more effective stabilizer than traditional ones, as they can prevent ice crystal growth and result in smaller ice crystal sizes.

Smaller ice crystals can improve the creaminess, smoothness, and mouthfeel of ice cream.

It’s amazing how such small particles can have such a big impact on the quality of plant-based ice cream. Take a moment to appreciate the incredible chemistry happening in your bowl the next time you enjoy a scoop of your favourite non-dairy treat.

~ Vivian Hou

Bhopal Gas Tragedy: The Deadliest Chemical Incident

On February 3rd, a derailed train in East Palestine, Ohio released 5 toxic chemicals into the area. The local authorities then burned some of the chemicals to avoid an explosion. Byproducts of this burning included dioxins, which are highly toxic compounds that persist in the environment. Local residents reported burning sensations in their throats and noses as a result of airborne chemicals. Residents are also worried how the water supply and air quality will be impacted in the long term.

While we cannot yet determine the long term effects on public health or the environment resulting from this chemical spill, this incident does remind chemists that our work can escape the controls of the laboratory or factory and cause devastation to the public. The scale and gravity of the impacts of a chemical incident are best demonstrated by the Bhopal gas tragedy of 1984, considered the world’s worst industrial disaster to date.

Exterior of the pesticide factory which caused the Bhopal gas tragedy. Image source: Bhopal Medical Appeal

On the night of December 2nd, 1984, 30-40 tonnes of the toxic gas methyl isocyanate (MIC) were released by a pesticide manufacturing facility over the city of Bhopal. In the immediate aftermath, over two thousand people died and over five-hundred thousand were injured. As Figure 1 shows, the immediate death toll of the Bhopal incident far exceeds that of the Beirut explosion of 2020 and the Chernobyl disaster, making it the deadliest chemical disaster ever. Those who survived in Bhopal showed higher rates of chronic illnesses, such as pulmonary fibrosis and bronchial asthma, and other health issues. To this day, the pollution resulting from the incident persists in the area and we observe high rates of congenital physical and intellectual defects in children born even decades after the disaster.

Figure 1. Shows the immediate death toll of the Bhopal gas tragedy, the Beirut explosion, and the Chernobyl disaster. Figure source: Ying Cai

The heartbreaking reality is that this incident could have been prevented. The manufacturing plant had many safety procedures and devices, but they were all malfunctioning, not used, or lacking supplies at the time of incident. For example, the refrigeration system to cool the MIC and the alarm for high temperatures in the MIC tank were removed months earlier and never replaced; the flare tower meant to burn the MIC as it escaped was also missing parts and therefore not functional. If the safety procedures were taken seriously by management of the plant, many lives would have been saved.

Disasters such as the Bhopal gas tragedy should be taught to chemists as a grim reminder of the potential consequences of our actions and the importance of chemical safety. We should take safety seriously even when running small scale or familiar reactions to build good habits. As well, these disasters should motivate the chemistry community to work towards green chemistry, where hopefully highly toxic reagents will not be needed in industrial quantities anymore.

~ Ying Cai

The lingering effects of Pandemic Screen time: a result of parental stress

Children’s screen time increased by 65% during the COVID-19 Pandemic and hasn’t changed since.

Unsplash Photo by @emily_wade (Child, Technology) Unsplash

In 2019 Dr. Henderson and her team at Permanente Californian Research Center began a longitudinal study on 228 children aged 4-12 across the United States. From July 2019 to August 2021, they found that prepandemic mean screen time increased by 1.75 hours per day after Dec 2020, and 1.11 hours per day after May 2021.

During the pandemic, with school and daycare closures, many parents and families were under tremendous amounts of social, emotional, and financial stress. Occupying kids with technology reduced parents’ stresses around having to constantly stimulate their children.

Researchers point out that screen time increased because children were spending more time at home instead of doing extracurricular outside and because schools transitioned online. 

The graphic below illustrates Dr. Henderson’s findings, showing a clear increase in educational, recreational, and total mean screen time.

Longitudinal 228-child cohort study (ages 4-12) from July 2019 to August 2021 in the USA. Measuring Prepandemic (July 2019-Mar.2020), First Pandemic Period (Dec. 2020-Apr. 2021), and Second Pandemic Periods (May 2021-Aug 2021), and their Educational, Recreational, and Total Mean screen times. JAMANetwork 

The long-term effects of high-screen time in children are still relatively unknown, but given that socializing and exercising are fundamental for healthy brain development in children, the pandemic undoubtedly has affected a generation of kids and youth.

More recently, in 2022, ABC news interviewed Dr. Heather Berlin, Neuroscientist and Clinical Psychologist at New York University, about the harmful effects of high-screen time.

“Consequences for kids’ of endless screen time” A 2022 ABC News interview with Dr. Heather Berlin, Neuroscientist and Clinical Psychologist at New York University. Youtube

While a lot is still unknown about screen time and how it affects children, the COVID-19 Pandemic gave impetus to necessary research at an unprecedented time in history. Research that could prevent further effects in the future and potential recurrence.

Exposing the Dark Side of The Skin-Lightening Industry

Skin colour has long been the social-economic benchmark in many countries, predominantly in Asia-Pacific, where individuals often affiliate lighter complexions with attractiveness and more career opportunities. Skin lightening products (SLPs), the practice of lightening complexion by reducing the skin’s natural pigments, is often the solution to this dilemma. This growing demand created the lucrative business of skin-lightening products (SLPs), which was valued at US$8.8 billion in 2020.  

 

Skin beauty is very important to many people by enhancing users’ self-esteem and confidence. Oftentimes, people reported wanting a lighter, radiant, and youthful skin, an indicative symbol of beauty and youth. 

Some active ingredients in SLPs shown results in correcting the effects of age, stress, UV exposure, pollution, and poor eating. They also help maintain a luminous skin by preventing skin dryness, reducing oxidative damage, and balancing skin tone. SLPs coat the skin’s surface and act as a protection layer, thereby preventing issues like tanning and sunspots. 

For most people, the utility that SLPs offer are essential to maintaining their beauty and confidence.

 

However, a major concern when it comes with SLPs is the uncontrolled concentrations of these active ingredients and their negative side effects. 

Hydroquinone, a potent SL agent for hyperpigmentation treatments, causes blue-black facial discoloration (Figure 1) or skin thinning with high-dosage applications, said Dr. Desai, a board-certified dermatologist at the University of Texas Southwestern Medical Center. This condition is hard to treat, and can result in permanent discoloration of the skin. 

Figure 1: Discoloration from long-term usage of hydroquinone-containing products. Source: Wikimedia

Mercury, another dominating ingredient in many unregulated SLPs, inhibits skin pigmentation production to reveal a lighter complexion. The well-documented report from the Pan American Health Organization list of associated risks from mercury poisoning does not look so pretty.

Risks from prolonged exposure to mercury ranges from multiple major organ failures to psychological issues such as psychosis, depression, anxiety, and early-childhood development issues.

Minnesota Department of Health revealed that most SLPs contain mercury ranging from 135 to 33,000 parts per million (ppm). This level is much higher than the recommended level of 1 ppm by the US Food and Drug Administration (FDA). 

Additionally, the high levels of corticosteroids in most SLPs have resulted in steroid-dependent reactions (SDRs) – the tell-tale signs of chronic misuse of corticosteroids over an extended period (FIgure 2). Rashes, skin sensitivity to sunlight, and infections occur when SDR patients withdraw from topical steroids. 

Figure 2: Steroid-Dependent Reactions. Source: Wikimedia

While these active ingredients in SLPs are effective in brightening consumers’ skin complexions along with providing additional skin care benefits, they pose significant and unwarranted health risks. Personally, the turmoil from experiencing side effects of some over-promising SLPs that are constantly promoted on social media is not worth sacrificing the highly-appraised fair skin.  Not to mention the society that pressures those who are chasing after a fairer skin might be the first to criticize the consumers if SLP’s side effects arise. It is therefore crucial to pressure the SLPs’ manufacturers to move away from these dangerous compounds and towards safer ingredients.



Missing Capsule of Cesium-137 Sparks Manhunt in Western Australia

Authorities in Western Australia have quite literally found a radioactive needle in a haystack.

Carrying case for radioactive capsules. Source.

On January 12th, a tiny capsule of radioactive cesium-137 from a radiation gauge fell off a transport truck that was on its way from a Rio Tinto mine site to a storage facility in Perth, Western Australia, along a 1400 km stretch of highway in the rural Australian outback.

Due to the radioactive nature of cesium-137, Australia’s Department of Fire and Emergency Services, as well as nuclear scientists quickly launched a desperate search for the tiny capsule, about 8 mm in length. As the search intensified, the public was warned to say at least 5 meters from the radioactive capsule.

Figure 1: The bar chart compares the size of cesium-137 to the size of commonly used Australian coins.

Cesium-137 is a radioactive isotope that is formed from the nuclear fission of uranium-235. Although it is tiny, cesium-137 is very dangerous to the health and wellbeing of anyone who come in contact with it. The radioactive isotope can emit both beta and gamma rays, which can penetrate skin, causing severe radiation burns, sickness, or even death.

Capsule of cesium-137. Source.

With a half-life of about 30.05 years before decaying to barium-137m, a stable and non-radioactive isotope. However, “the cesium inside the capsule will [still] be dangerous [until] the next century.” That is according to Edward Obbard, a nuclear materials engineer with the University of New South Wales.

Miraculously, on February 1st, the radioactive capsule of cesium-137 was found just off the side of the highway around 200 km from the mining site. Authorities quickly cordoned off a 20 meter perimeter and safely contained the capsule inside a lead container.

It is important for companies to be extremely careful when transporting radioactive substances. This incident highlights the need to scrutinize the transport of radioactive substances so that a similar incident will not happen again in the future.

–Raymond Tang

 

The Swelling Concerns on Food Allergies: Prevalence or Awareness?

Food allergies appear to be an increasing worry to the Canadian public, with common allergens such as nuts, milk, and eggs being frequently used in foods of all cultures. Some allergic reactions produce the immunoglobulin E antibody, which can lead to life-threatening anaphylactic shock. The question is whether allergy prevalence is rising alongside these concerns.

Some Common Food Allergies                                 Source: NIAID

Health Canada and AllerGen NCE supported the University of Calgary and the University of Waterloo’s research to estimate the prevalence of food allergies in the country. The study surveyed 5,784 Canadian households in 2016, asking people to report their food allergies. 

The percentage of Canadians that had a perceived food allergy, claimed by self-report, was noticeably higher than the percentage with a probable food allergy, supported by family history or physician diagnosis.

Food Allergy Prevalence in Canada                    Source of Data: Government of Canada

Clarke et al. compared these results to data from 2010, observing a noticeable increase in overall food allergy claims (7.1% to 9.3%), but only a minimal change in supported food allergy claims (5.9% to 6.1%). 

While the actual prevalence of food allergies did not rise significantly, Clarke et al. states that the increase in self-reported allergies is likely due to raised awareness.

Continuing to spread awareness on food allergies is actually beneficial, as they are not curable. Severe allergic reactions are treated by an epinephrine injection in emergency situations, making educating people and properly labelling food products that much more important.

From catnip to bug spray

Researchers from Iwate University in Japan have published a new paper that explains one aspect of the intriguing response cats have to catnip. The paper, published on June 14th 2022, shows that chewing catnip leaves maximize the release of organic compounds and repels insects. Tamako Miyazaki, who led the research, hopes that the work will pave the way for development of new insect repellants.

A photo of a domesticated cat eliciting a behavioral response to catnip. Source

Catnip is a non-toxic plant in the mint family and it has been long known to elicit several responses in cats. And, it’s not just domesticated cats that are affected, catnip induced behavior has been seen across the feline family including leopards, cougars, tigers, and lions.

Figure 1: Effect of leaf damage on the airborne emission of nepetalactone. Data adapted from Miyazaki et al.

The behavioral response which includes rolling, licking and chewing is seen in two thirds of all felines. The prevalence of these responses led Miyazaki and his team to believe there was a biological importance of the behavior.

Miyazaki and his group have previously identified nepetalactone as the compound responsible for triggering the behaviors.

Nepetalactone is a iridoid compound that is present in high concentration in several plant species including catnip. The group’s previous work, published in 2014, showed that nepetalactone had a strong insect repellant effect. The behavioral response of rolling resulted in the transfer of nepetalactone to the cats fur and provided protection from insect bites.

Following on from this study the team turned there attention to why cats are often seen chewing catnip. Considering that this behavior was also linked to insect repellence the team began by measuring the airborne emission of Nepetalactone from intact and manually damaged leaves. The manual damage was intended to simulate the effects that chewing had on the leaves.

The results, shown in figure 1, was a 20 fold increase in nepetalactone emission in the manually damaged group. When tested on mosquitos, the damaged leaves showed a much greater repellant effect than intact ones. The research group also found that leaf damage affected the cat’s response duration. On average, the studied cats responded to damaged leaves 6 minutes longer than were presented with intact leaves.

The researchers propose that chewing the catnip leaves is an important evolved response that maximizes the amount of airborne nepetalactone. When combined with rolling, the behavior maximizes the protective qualities of catnip and offers a significant benefit to cats.

The paper concludes that there maybe something to be learnt from catnip. Specifically, further studying into the structure and synthesis of nepetalactone may lead to new kinds of insect repellents. While more studies are needed to assess the effectiveness of such a use one thing for sure is that it would have the seal of approval from cats.

 

 

Are Your Non-Stick Pans Casing Celiac Disease?

Recent discoveries suggest persistent organic pollutants (POPs) may increase the likelihood of celiac disease, especially in females. 

What is celiac disease? 

Celiac disease is an autoimmune disorder where the small intestine reacts negatively to the wheat protein (gluten) in foods containing white, rye, and barley. The current solution for celiac disease is to follow a gluten-free diet. Celiac disease is believed to be genetic, however, some research suggests a possible environmental connection. 

Research from the New York University School of Medicine found that high levels of Persistent organic pollutants (POPs) in blood samples correlate to an increased likelihood of a celiac disease diagnosis. 

POPs are toxic chemicals generated by human activity. Examples of POPs include polybrominated diphenyl ether (PBDEs), perfluoroalkyl substances (PFASs), and p,p’-dichlorodiphenyldichloroethylene (DDE). These pollutants are found in all aspects of daily human life and serve many purposes, as shown in Table 1. 

Table 1: Common POPs’ Location and Function 

Spraying pesticides on bananas in the 1980s | Location: Big … | Flickr

Pesticides used in fruit farming occasionally contain DDE (Credit: Scot Nelson, Flickr)

In a study of 88 patients from NYU Langone’s Hassenfeld Children’s Hospital outpatient clinic, blood samples were measured for the aforementioned POPs. Subsequent testing for celiac disease was also performed and resulted in 30 patients receiving positive results. 

As seen in figure 1, the concentration of POPs in patients with celiac disease is slightly higher than in “healthy” patients. When age, BMI, sex, and genetic predisposition are accounted for, DDE was correlated with a two-fold increase in celiac disease diagnosis. 

Figure 1: PBDE, PFAS, and DDE Median Concentrations in Celiacs vs. Non-Celiacs. These bar graphs compare the median blood concentrations of various POPs in patients diagnosed with celiac disorder and non-celiacs. Notably, this figure does not account for age, sex, genetic predisposition, and BMI. (Credit: Carissa Chua, Modified from Gaylord, et. al.)

When separated by sex, PFAS pollutant concentration was found in higher concentrations in females with celiac disorder. Similarly, men with celiac disorder displayed higher levels of PBDEs. While this discovery is interesting, a more thorough, sexually stratified study should be performed using a greater sample size. 

Gluten free bread | ????????Professional Photographer ????Twitch C… | Flickr

Attempting to avoid these pollutants may complement a gluten-free diet (Credit: Marco Verch, Flickr)

Continued exploration into the interaction between POPs and celiac disease should be performed to definitively prove any relationship. However, attempting to cautiously avoid toxic pollutants as mentioned above may be a helpful addition to a gluten-free diet. 

 

 

 

-Carissa Chua

Forensic science: chemists are detectives in lab coat

Ever wonder how evidence is processed from a crime scene?

In the 19th century, British chemist James Marsh first developed a forensic method for detecting arsenic. And just in a period of ten years, the Marsh test solved 98 poison related cases all over England and Wales. Since then, forensic chemistry has always been an important aspect in a criminal investigation.

Source: Wikimedia

 

Nowadays, different substances can be identified using familiar laboratory instruments such as Fourier Transform Infrared Spectroscopy, Thin Layer Chromatography, High Performance Liquid Chromatography, and more. These identifications play a crucial part in a police investigation as they provide investigators with leads suggesting how a crime is committed.

 

 

Different body fluids detection through FTIR. Source: Ayari Takamura and others

 

Remember that scene in the movie where a crime scene investigator sprays chemical onto something, and then trace of blood becomes apparent? This is called Luminol test. In the presence of blood, luminol reacts by fluorescing, thus emitting a blue glow in a dark room. Luminol is a water-based solution that detects blood even after it has been diluted 10,000 times.

The Kastle–Meyer test is another blood detection test that is common in crime labs. Phenolphthalein reacts with hydrogen peroxide in the presence of hemoglobin to turn from colorless to pink.

One important branch of forensic science is toxicology. A toxicology test uses principle of analytical chemistry , biology, and the study of poisons to determine the identity and relative amount of substances presence in one’s body fluids. A tox screen can provide the police with valuable information to the nature of the investigation, such as poisoning, overdose, suicidal or homicidal.

A forensic scientist is Sherlock with a microscope!

Artificial Snow at Beijing Winter Olympics

Beijing’s bid for the 2022 Winter Olympics relied solely on covering their cold-but-dry mountain venues, Yangqing and Zhangjiakou, with 100% artificial snow. 

Snow machines were essential to Beijing’s Olympic bid (Source: Wikimedia Commons)

For every cubic meter of snow produced, half a cubic meter of water was required, raising concerns about Beijing’s bid. 

Clean water is a scarcity in the northern region around Beijing and within the city itself. The region pumps in 70% of its water from southern China. 

In their bid, Beijing estimated 49 million gallons of water would be needed to maintain the slopes, but, in reality, 343 million gallons were turned into snow.

Snow machines mix and cool compressed air and water, releasing tiny balls of ice onto the slopes and compacting four times denser than natural snow. 

The presence of artificial snow has increased in the Winter Olympics. Artificial snow made up 80% of Sochi’s snow, 90% of Pyeongchang’s snow, and 100% of Beijing’s snow.

Figure 1. Water consumption estimates for artificial snow production at the past four Winter Olympics

In 1980, Lake Placid was the first Olympic venue to use artificial snow, but troubles with lack of snowfall are a recurring theme. In 1964, Austrian soldiers hauled 20,000 blocks of ice to prevent cancellation of the winter games. Vancouver, in addition to snow machines, transported snow with semi-trucks from higher to lower elevations of Cypress mountain.

Cross-country skier competing at the 2022 Beijing Winter Olympics (Source: Wikimedia Commons)

Skiers expressed concerns over artificial snow courses. The snow’s closer packing allows faster ski times but increases the likelihood of collisions. Athletes crash on snow that “feels like concrete”. In turn, the density allows for easy construction of ski and snowboard ramps.

A study found that, with global temperatures rising, only one of the past 21 Winter Olympic venues, would be able to provide natural snow by the 2080 games.

To keep the global athletic competition alive, fake snow will be the way to go.

-Julia Sawitsky