Kitchen Science

By Donovan Makus

 

When identifying similarities between environments, your kitchen and the scientific laboratory may not appear to be all that similar on first glance. One is a familiar environment, often the heart of the home, where family members spend time, eat and gather together. The other one is an impersonal environment, although it does offer a great opportunity to make friends, from which many students seem to be in a hurry to leave as quickly as possible. Yet the same scientific principles studied in the lab can also be applied in your kitchen at home. From the foundations of science in mathematics to the higher levels of organisms studied in biology, all scientific fields can be observed in the kitchen. After all, a cookbook is, in effect, a laboratory manual, with the results of this homemade research hopefully being more pleasant and palatable than dry numbers and statistics. Understanding these scientific principles can hopefully help us improve as cooks, reaching our full potential in the kitchen.

 

Math and physics. These are unpleasant topics for many students, who strive to either avoid these courses or just get through them unscathed if they are degree requirements. Yet when working in the kitchen, the concepts from these fields are foundational and never too far away. Thankfully, you don’t need a background in theoretical mathematics or physics to cook; fortunately, the grade school basics provide an ample foundation. Cooking, and especially baking, involve a great deal of measuring and adjusting. Stating that “some” flour should be mixed with “a few” bananas and “several” eggs can lead to wildly different results, as I can report from my banana pancake recipe experimentation. The amounts measured are critical to ensuring consistent results. Fractions, in the form of volumetric measuring cups, also make an appearance, and while I recognize not everyone is fastidious enough to eat their ice cream from a measuring cup as I do, fractions are key to kitchen science. Moving onto the field of physics opens up a wealth of applications, shaping many of our cooking processes. These processes, easily explained by physics, are vital in the process of cooking food. For instance, your appropriately-named microwave uses electromagnetic radiation to cook your food. Other heating processes, such as cooking in an oven, also involve the transfer of energy. Finally, physics also helps explain why the same amount of heat can lead to varying cooking results, from the perfect omelette to one that looks runny, through the study of thermal conduction, and surface area to volume relationships. While it is possible to cook without the benefit of math or physics, using these help make your cooking easier and more accurate.

 

Moving a level up in organization brings us to the field of chemistry. A great deal of kitchen science can be classified as chemistry, which is primarily concerned with the interactions occurring between substances that have matter. The foods we eat are mainly made up of substances such as carbon, oxygen, and hydrogen on the elemental level, with some other elements like nitrogen, potassium, and the controversial sodium present. As you move up from the level of individual elements, you reach the level of molecules, such as water, which is highly relevant to cooking. Water’s high heat capacity (its ability to absorb and retain a great deal of heat) permit dishes to be heated and kept stable. This is why it takes a while to bring a pot of water to a boil, but once it’s there, it can stay warm for a long time. Many chemical reactions also occur when cooking or storing food. Once such a reaction is the complex Maillard reaction, which is responsible for the browning of meats and other foods. By forming the basis of all matter, these elements and reactions play a key part in cooking, but this isn’t the last stop on our journey of food science. Continuing to move up to the next level of organization further broadens the horizons.

 

When we eat food, we don’t measure it in carbons, nitrogens, and oxygens, but in more familiar macromolecules consisting of these elements and a few others, which brings us to our next level of organization: biochemistry. Biochemistry is the study of how chemistry is relevant to living organisms and introduces us to a new level of organization with the macromolecules, namely proteins, lipids, and carbohydrates. Cooking leads to changes in structure in these biomolecules, such as denaturing or changing the shape of proteins with heat while cooking them. This is what happens when someone cooks an egg. The change in colour and composition of the final product, the omelette, results from denaturing the egg proteins. Biochemistry also explains how these individual molecules supply energy to us, measured in calories. By breaking the chemical bonds in molecules such as sugars, we are able to extract the energy that was stored and use it to power our own cells. Biochemistry is key to kitchen science, but at some point, we need to move beyond the small scale and enter the world of cells, tissues, and other living things–our final level of organization.  

 

As we move on from macromolecules, we reach the cellular level. These first consist of small bacteria and, finally, large organisms with organs such as ourselves. In doing so, enter the realm of biology. A great deal of time and energy in cooking is aimed at this level in attempting to generate pleasant tastes and smells. Our sense of smell and taste appear at this level and are the result of small molecules interacting with our organ systems, such as our noses. Many of the steps taken in food storage also fall squarely into the realm of biology, the study of life–or, from the perspective of the cook, the pursuit of stopping bacterial and fungal life from taking over stored food. Refrigeration, for instance, serves to preserve food by lowering the temperature outside of the comfortable range for many microbes. Unfortunately, some can still function, leading to some decay and spoilage, even if this does mean refrigerated food lasts longer than food left on the counter. Freezing food acts in a similar, but more extreme, fashion. By freezing food and maintaining it at temperatures below 0, we severely handicap any microbes from growing and spoiling food. Refrigeration isn’t the only application of biology in cooking, however; baking is another opportunity to use microbes, this time encouraging them to become active. The use of microbes isn’t limited to baked goods, as they are also key to the fermentation of alcohol. This can be of keen interest to many students. These are just some of the applications of biology in the kitchen.

 

Hopefully our journey through the science of the kitchen–from the mathematical to the biological level–has been enlightening and not left you too hungry. While a knowledge of these fields isn’t required to be a good cook, it certainly helps explain some of the results we see in the kitchen. So the next time you reach for the minute plus button on the microwave, crack an egg, or find that your bread has become a fungal incubator, remember how these relate to the various levels of science.

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