Category Archives: Branches of Chemistry

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

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!

Breaking Down Plastic, One Worm at a Time

A 2022 study by Sanluis-Verdes et al. has found that wax worm saliva is able to break down plastic in just a few hours.

The researchers collected saliva from Galleria mellonella worms and applied it to polyethylene (PE) films. After a few hours, the films had visibly deteriorated and analysis of the films determined that the plastic had oxidized and released additives, evidence that it had degraded.

Credit: Catherine Sheila

Generally, plastics require decades or even centuries to completely degrade through natural exposure to the environment. Because of humanity’s high consumption of plastic, simply dumping them in landfills or waterways only leads to an accumulation that smothers habitats and leaks toxic substances into the soil and water.

This makes finding a safe and quick way of breaking down plastic crucial for sustainable waste management.

Scientists in recent years have been particularly interested in biodegradation, in which naturally-produced enzymes from bacteria, fungi, or animals are used to decompose plastic.

However, scientists have only identified a handful of enzymes that are capable of this, and these enzymes still require years to degrade plastic. They are unable to accomplish the first step of degradation – oxidizing the polymer – and still rely on exposure to UV light and other environmental factors to do it, which usually takes years.

Currently known process of plastic degradation. Credit: Rebecca Yang

Sanluis-Verdes et al.’s experiment demonstrated that the enzymes in wax worm saliva are in fact able to accomplish this crucial step under normal physiological conditions – room temperature, neutral pH, typical background levels of UV – in just a few hours rather than years. The researchers identified an increased presence of ketones in the PE after only applying the saliva a few times, proof that it had been oxidized by the enzymes alone.

The researchers also tried to identify the enzymes responsible. They were able to pick out two enzymes in the saliva that had a significant effect on PE degradation. Until now, it was believed that bacteria in the gut of wax worms were primarily responsible for plastic degradation, but this discovery indicated that it was the wax worms themselves that oxidized and broke down PE enough for it to then be completely decomposed by bacteria. The researchers also noted that the two enzymes were functionally different from known bacterial enzymes. This suggests that there may be other methods of biodegradation than what is currently known for bacteria.

The exact mechanism will require further studies to determine. If this can be identified and if the enzymes involved can be easily extracted or mass produced, using the enzymes found in wax worms may become a feasible way to naturally and quickly manage plastic waste.

The Gore-Tex Enigma

Gore-Tex is a highly versatile material that has garnered a lot of publicity in recent years.

Gore-Tex Logo

It is a magical material in many respects. Water simply glides off it, leaving it bone dry. Being also very breathable and light, it is no surprise that it is the ideal material for water resistant clothing.

First invented in 1968 by Wilbert and Robert Gore, it is made of polytetrafluoroethylene, more commonly known as Teflon. Not the hard stuff though. It’s basically Teflon that has been stretched… a lot.

With the likes of Adidas and Nike incorporating it into their outdoor wear products, its worldwide use and popularity has called into question the manufacturing process and its environmental impacts.

Teflon is a very durable material that does not degrade easy and lasts for a long, long time. This is a good thing right? Well, yes… But what happens when that fifteen year old jacket you own is discarded or lost, and finds itself buried in the dirt outside an abandoned parking lot?

It persists. And doesn’t degrade. For centuries.

PFC’s or perfluorinated compounds are those that contain only carbon and fluorine atoms. Teflon is made from these compounds.

Chemical structure of Teflon: repeating units of carbon and fluorine atoms

The problem with PFC’s is that they tend to accumulate within our bodies and the environment. They are difficult to break down as they are quite unreactive.

A class action lawsuit at a DuPont Teflon plant found a very strong association between working with PFC’s and two types of cancer. Since then, many other studies have found a correlation between exposure to certain PFC’s and negative health outcomes.

To be clear, it isn’t the wearing of Gore-Tex products that is concerning. Also, not all PFC’s are harmful. However, the manufacturing process dispels many harmful PFC’s into the environment.

Gore-Tex jackets are also near impossible to recycle. They are made in complex ways, and the design process involves multiple layers, glues, and components.

Gore-Tex must not be completely written off though. Gore and company have assured investors and the public that they are stopping the use of many harmful PFC’s in their manufacturing process. However, the effects of this are yet to be seen.

There are also other, more intriguing applications of this remarkable material.

What is not talked about nearly enough is the role of Gore-Tex in medicine. It has shown to be ideal for use inside our bodies.

Being so unreactive, it allows the body’s cells and tissues to grow through it without any side effects. This makes it a viable material for many medical applications.

Like most technologies, Gore-Tex is complicated in many ways. Its strengths in one regard prove to be its downfall in another. It seems the jury is still out on this one

– Salik Rushdy

Non-Hormonal Birth Control Pills for Males May Be Within Reach

Recently, scientists at the University of Minnesota found two promising compounds that may become the first non-hormonal contraceptive drugs for males. Testing on mice found that these compounds reduce sperm count effectively and present no side effects.

There are currently no non-hormonal birth control pills on the market for females or males, despite these pills likely having fewer harmful side effects than the hormonal birth control methods available for females.

And since males continuously generate sperm while females are born with all potentially fertile eggs, it is easier for scientists to find approaches that reversibly stops sperm production in males rather than risk “spoiling” the non-renewable pool of eggs in females.

Picture depicting the meeting of sperm and egg, which leads to fertilization and pregnancy. Image Credit: https://flic.kr/p/MCcsUf

The first potential drug discovered is a chemical named YCT529, reported by Dr. Gunda Georg’s group in spring 2022. This molecule was designed to inhibit the function of the protein retinoic acid receptor alpha (RAR-α). Georg’s scientists found that a lack of RAR-α protein in male mice leads to sterilization, but no additional side effects. When YCT529 was orally administered to the mice for 4 weeks, their sperm count reduced drastically, and the drug was 99% effective in preventing pregnancy.

Chemical structure of non-hormonal male contraceptive YCT529. Image Credit: Ying Cai

The same group of scientists reported the second drug named EF-4-177 in early 2023. The target of this molecule is an enzyme named cyclin-dependent kinase 2 (CDK2) which helps in sperm cell production. The scientists reported an over 45% decrease in sperm count of the mice after 28 days of treatment with EF-4-177.

Currently, a startup named YourChoice Therapeutics based in Berkeley, California is working to market YCT529 to humans soon. According to their website, the company has tested on dogs and primates with positive results. Their graphics show that after two weeks of treatment with YCT529, sperm levels in dogs drop to zero and primates do not produce enough sperm to be fertile.

If a side effect-free non-hormonal birth control pill for males is introduced to the public, it would expand contraceptive options for those with testicles beyond condoms and vasectomy. As well, it would make it easier for the responsibility of pregnancy prevention to be shared between partners in a relationship.

Hopefully, more research to come will soon make non-hormonal birth control pills for males a reality.

~ Ying Cai

Enzymes – A Solution in the War Against Plastics

It should not be a surprise to people that it can take over 500 years for UV radiation – light from the sun to break down a piece of plastic. But what if there is a faster way to break down single-use plastics?

Researchers at the University of California, Berkeley invented a new way to decompose consumer plastics in a short amount of time, simply with heat, water, and nano-dispersed enzymes.

Plastic waste covering the shoreline. Source

UC Berkeley professor Dr. Ting Xu and her research group developed a nanoscale enzyme that can eat away at the polymers in plastics. These nanoscale polymer-eating enzymes can be embedded into plastics during manufacturing. The enzymes were wrapped around plastic resin beads. These beads are melted and can be manufactured into single use consumer plastics. To prevent the enzymes from activating when not required, a random heteropolymer (RHP) coating is applied to hold enzymes without restricting the flexibility of tensicity of the plastics.

Xu likened this process to organic composting. By adding water and heat, the RHP polymers is removed and starts eating away the polymers into smaller subunits.

The research conducted by Xu and her group found that the enzymes took about a week to degrade most of the plastics. Polylactic acid (PLA) and polycaprolactone (PCL) based plastics embedded with nanoscale polymer eating enzymes are able to break down the polymer chains into smaller molecules, such as lactic acid.

Plastic cups made from biodegradable plastics. Source

It is clear there is still more research needed in this field. Currently, Xu is developing other modified RHP-wrapped enzymes that can stop the degradation process at specific points in it’s degradation so that the polymers can be recycled into new plastics.

“[Humans] are taking things from the Earth at a faster rate than we return them,” said Xu. “Don’t go back to Earth to mine for these materials, but mine whatever you have, and then convert it to something else.”

As consumers, we can play an important role reducing our consumption on single use plastics and create a more sustainable environment for ourselves and future generations.

Raymond Tang

Aspartame Health Risk Claims Seem Artificial

Aspartame is an artificial sweetener that replaces sugar in several food products. Ever since James M. Schlatter discovered it in 1965, the public has had ongoing questions about whether consumption poses a potential threat to our health. The low-calorie sugar substitute is appealing with diabetes cases in Canada rising to 8.9% of the population. Canada approved the usage of aspartame in 1981, so why is there still a controversy?

Equal Sweetener Source: 怡口糖 by SoQ錫濛譙

People have accused aspartame of causing health issues related to toxicity, diabetes, cancer, seizures, and allergies. The reality is that most of these speculations are unsupported, and the government of Canada had to examine numerous research studies to allow Aspartame’s approval in the first place.

Haighton et al. reviewed past cancer epidemiology investigations that claimed to present evidence for these suspicions. After evaluating them, they concluded that the results did not give reasons to believe there was a correlation between aspartame and cancer risk. Considerations going into this decision included how many experiments used diet soft drinks as their main sample source, which contain other compounds and sweeteners besides aspartame.

Aspartame Structure Source: Benjah-bmm27

However, there are health risks that have been discovered in regards to aspartame. It metabolizes into methanol and aspartic acid, as well as phenylalanine, a compound that negatively impacts patients with the disorder phenylketonuria. Therefore companies are required to label products to caution people of phenylalanine content.

The uncertainty around aspartame encourages the need for continued studies to identify the definitive effects of long-term aspartame consumption. It will keep Canada informed to lower the discrepancy between the public view and make sure that the acceptable daily intake, currently 40 milligrams per kilogram body weight, is up to date with health safety precautions.

For now it seems aspartame is here to stay, and we can continue to enjoy the sweetener.

A Breakthrough in Nuclear Fusion

On December 5th 2022, scientists at the Lawrence Livermore National Laboratory (LLNL) in the United States successfully created the reaction that powers the sun – nuclear fusion ignition – for the first time in human history.

The announcement was made by the US Department of Energy on December 13th. Described as a “historic, first-of-its-kind” achievement, the event has excited the scientific community because of its potential as a clean energy source.

Inside the LLNL’s National Ignition Facility, where the experiment took place. Credit: LLNL

To achieve ignition, the scientists had constructed “the world’s most energetic laser”, consisting of 192 powerful laser beams. This laser was used on a small canister containing the compounds deuterium and tritium, causing the compounds to fuse together. The reaction generated 3.15 megajoules of energy from an input of 2.05 megajoules, a markup of 54%.

After over 60 years since researchers first began to study nuclear fusion, this result finally proved that controlled fusion that produces more energy than it consumes is possible.

Depiction of fusion: deuterium(D) and tritium(T) fuse to form the larger Helium(He) and release energy. Credit: US Department of Energy

Nuclear fusion is the process that allows the Sun to emit vast amounts of energy in the form of light and heat. It involves the joining of two atoms of a lighter element to form a heavier one, releasing energy in the process.

Compared to nuclear fission, which is how nuclear power plants generate energy, fusion is much more powerful. It is also much cleaner as it does not produce radioactive materials as a byproduct.

Because of this, many believe that nuclear fusion is a promising avenue for sustainable and eco-friendly energy in the future. However, there is still a long way to go until fusion can be viable for commercial use.

When asked to comment on the time needed, Kim Budil, the director of the LLNL, stated that “It’s probably two or three decades. Scaling from where we are today to what you would require for a power-generating plant is a pretty significant challenge.”

Director Kim Budil at the announcement of the achievement of ignition on December 13th, 2022. Credit: Mary Calvert/REUTERS

For the 8000 engineers, physicists, and chemists at the LLNL, this event is just the first step. Researchers will have to find ways to conduct nuclear fusion that are faster and cheaper, while also generating much more power. According to Budil, “What we need now is a scientific and investment strategy that allows us to make progress on all of these fronts simultaneously… [because] we need gain of a few hundred [megajoules] to make an energy system.”

Despite the many challenges ahead, Tim Luce, one of the leaders of the international fusion research project ITER, remains hopeful. “A result like this will bring increased interest in the progress of all types of fusion, so it should have a positive impact on fusion research in general,” he states.