Author Archives: samantha mee

The Science Behind That Sweet Smell of Bacon

Bacon is a simple food. It’s salty and it’s crispy. It can be eaten with pancakes, eggs, for breakfast or for dinner. The smell of it alone is enough to drag someone out of bed first thing in the morning. The joy of bacon doesn’t arise solely when you eat it, but rather when you start to cook it, allowing its aromas to be released.

Bacon  Bacon Source: Wikipedia Commons

Bacon Source: Wikipedia Common

The question is, what makes bacon smell so good? The American Chemical Society (ACS), partnered with the Compound Interest Blog, together have come up with the answer as to why the smell of bacon can be so irresistible. The answer? Science! That particular smell of bacon is the product of 150 different organic compounds. As heat is applied, the sugars, amino acids and fats present in the meat break down, allowing the Maillard Reaction to take place. This reaction occurs at a high-temperature allowing the amino acids of the meat to interact with the reducing sugars present in the bacon fat. This mechanism is also responsible for turning your food brown as it cooks. It is this combination of the 150 compounds that produce the drool-worthy fragrance that bacon emits.

The chemistry behind the Maillard reaction.  Maillard Source: Wikipedia Commons

The chemistry behind the Maillard reaction.
Maillard Source: Wikipedia Commons

Among these organic compounds are aldehydes, hydrocarbons and nitrogen-containing pyridines. As referenced in the video below, a study conducted in 2004 by Carrapiso and colleagues researched the aromas released from friend bacon and fried pork loin. Their work concluded that the nitrogen-containing compounds present in bacon are likely the main cause of the preferential aroma, which are unique to bacon and not replicated in other pork products

Many different types of foods (for example, coffee, chocolate and bread) can all undergo a Maillard Reaction, each have their own distinct combination of organic compounds and thus different aromas. This is why baking bread doesn’t smell the same as frying bacon. However, it is these specific compounds that flavor scientists have targeted over the years in the generation of artificial flavors (which includes maple syrup).

Check out this video by ACS and the Compound Interest blog on the science behind bacon.

Thanks for reading!

Samantha Mee

Boosting Your Immune System with a Dose of Personality

Personalities and their effects on biological systems have become an increasingly popular focus of research over the last few years; the target of these studies is often related to the degree in which our personalities can regulate many aspects of our life, such as our wellbeing. A video from the Youtube series ASAPScience (see below) provides an example of the link between personality and biology. The video specifically discusses a relationship between personality and sleep habits (whether you’re a night owl or a morning person) and how the latter reveal your personality traits.

The science behind our personality is simple. It can be defined as a collection of characteristics or qualities that form an organism’s unique character. These specific traits that all combine to form a unique personality can affect different aspects of our life, such as our performance in school and the friendships we have. The question is, does personality really have an impact on our health?

Previous studies have linked personality and its role in the risk of developing health problems. More recently, research has shown that personality traits can be a factor in how well a body can fight a disease. Published in the journal Psychoneuroendocrinology, a study conducted by Kavita Vadhara and colleagues at The University of Nottingham has shown that some traits part of the ‘Big Five’ group, which are five primary dimensions of personality common to all humans, can play a role in the way the defence system of the body works. This system is also known as our immune system.

The 'Big Five' Model shows the five primary dimensions of personality. Big Five Source: Wikipedia Commons

The ‘Big Five’ Model shows the five primary dimensions of personality.
Big Five Source: Wikipedia Commons

The team of researchers asked 121 students to complete a questionnaire based on their personality. This questionnaire measured their degree of the ‘Big Five’ personality traits. Specifically, they looked how extroverted the participants were (energetic, talkative), their neuroticism (how anxious or moody) and their conscientiousness (how organized or thoughtful). In addition to the questionnaire, they also took a blood sample from each participant. This allowed the analysis of a number of genes that are involved in an inflammatory immune response, which is a response initiated by our immune system that helps the body fight infection and speed up the recovery from injury. Using microarray technology to determine which genes are active, the team of researchers were able to make a correlation between personality traits and the active genes required for an immune response.

The above instrument is used in microarray technology to identify active genes. Microarray Source: Wikipedia Commons

The above instrument is used in microarray technology to identify active genes.
Microarray Source: Wikipedia Commons

Results showed that participants who scored higher for extroversion in the questionnaire had an increased expression of pro-inflammatory genes (genes capable of promoting inflammation). However, participants who demonstrated a higher degree of conscientiousness subsequently had a decreased expression of pro-inflammatory gene expression. In other words, individuals with a more social behavior appear to have a greater ability to deal with infection and injury, whereas participants who were more cautious could not effectively handle the infections. The third trait mentioned, neuroticism, did not show an association with gene expression.

Before you celebrate that your outgoing disposition means you’re better at fighting illness, I think an important question that should be asked is, what is influencing what? Could it be the opposite cause-and-effect relationship, where our immune system influences our behaviour? Whatever the cause of the above results, the study conducted by Vadhara and colleagues provides further support to the dynamic relationship between health and personality.

Check out this video by Kurz Gesaft explaining how the immune system works:


Thanks for reading!

Samantha Mee


Life in a Petri Dish: From Skin Cells to Fertility

The number of partners facing infertility in Canada has doubled since the 1980s; it is now predicted that every one in six couples face infertility. With the numbers rising, due to factors such as obesity and substance use, this issue is becoming increasingly more common in our modern world and scientists across the globe are in a constant race to overcome it.

New research emerging from Cambridge University has provided hope in the form of a new infertility treatment. In collaboration with the Weizmann Institute of Israel, researchers have come forward with a potential new form of in-vitro fertilization. Its origin? Human adult skin cells.

IVF: the insertion of sperm into a human oocyte (egg cell).

IVF: The insertion of sperm with a glass pipette into a human oocyte (egg cell). In-vitro Source: Wikimedia Commons

For the first time, scientists have been able create manmade (reproductive) primordial germ cells, known as PGCs; these cells act as predecessors and are considered the common origin of  both sperm and egg cells. PGCs arise from pre-existing adult stem cells, which is an undifferentiated cell that has the ability to develop into many different tissue types. Their ancestor-like quality that creates a common origin, allows the eventual creation of  many different cell types, such as skin and liver cells.

Kyoto University used skin cells to create mice pups in 2012.  Lab Mouse Source: Google

Kyoto University used skin cells to create mice pups in 2012.
Lab Mouse Source: Wikimedia Commons

The team of researchers, led by Hanna and Azim Surani, followed a “recipe” originating from a Stem Cell Lab at Kyoto University, who created mice pups from a female germ cell by re-programming stem cells back in 2012. Based on this, the Cambridge-Weizmann team replicated the in-vitro portion of the experiment, where they grew the cells in a sterile and controlled environment.

The team was successful in making the primordial reproductive cells from human stem cells. The key finding was a gene known as SOX17, who is responsible for directing stem cells into their specialization; this is how primordial germ cells are created. This gene can also direct stem cells into becoming the external layer of skin, therefore showing that the reprogramming of an adult tissue type, such as skin cells, could give rise to the primordial germ cells.

Current British law has banned any fertility clinics in the United Kingdom from using a manmade sperm and eggs to treat an infertile couple, due to both ethical reasons as well as safety concerns. If this law is changed, the creation of a genetically identical sperm or egg cell can be taken from a patient for use in in-vitro fertilization.

Mother and Child Source: Wikimedia Commons

Mother and Child
Mother Source: Wikimedia Commons

This discovery has laid down foundation for all future research; scientists can now compare the development of both sperm and egg cells in both healthy as well as infertile people. Representing a huge step forward in the world of stem cell biology, the researcher’s work, published in the journal Cell, may mean a change in the age at which a woman can stop having children. This breakthrough means that manmade primordial germ cells are capable of passing on an offspring’s genetic code to their own offspring, creating the fundamental bond from generation to generation.

Check out Cambridge University’s video on a similar topic, the derivation of brain cells from skin cells:

Thanks for reading!

Samantha Mee