Introduction to DMS1401CM “Chemistry of Food”

Hi all, I am Leong Zhi Sheng, a year 3 chemistry major specializing in Environment and Energy and this is my blog which will serve as a platform for me to share with everyone things that I have learnt in the workshops and online videos in this module. This module comprises of mainly 5 workshops covering various subjects such as Coffee, Fermentation of Kombucha, Pancake, Ice cream & Chocolate and Molecular Gastronomy. The module’s contents also include many online videos which help students to better understand relevant Chemistry and Biological jargon.

As an introduction to DMS1401CM, the concepts and basic knowledge of Food is essential in ensuring that we are better prepared when we attend the various workshops. For week 1 and 2, the main reading that I focused on can be found in the book titled “On Food and Cooking, the science and lore of the kitchen”. The topic that I plan to share today is about the four basic food molecules which are Water, Fats, Carbohydrates and Proteins. Water is the most prominent molecule present not only in food but also as a large percentage of the human body (almost 60% by weight). Water plays an important role in giving our food its flavour, texture, structure and stability. Water serves as a medium in the various food processes and it dissolves other substances very well due to the ease of the forming of hydrogen bonds which leads to molecular separation. Moving on to the next food molecule which is known as Lipids which are essentially Fats or Oils. This food molecule plays an important role in ensuring that many foods have their smooth and pleasant texture through a process known as tenderizing which breaks down the structure of foods. Fats and Oils act as a medium which allows us to heat up the food above the boiling point of water in order to create a dry and crispy surface of foods which we know as Fried foods. Fats can be also categorized as saturated or unsaturated which can be differentiated by the molecular structure of the lipid (presence of Carbon-Carbon double bond). Many different forms of fats are present in our body and they are formed through chemical processes such as hydrogenation or twisting of the C=C bond. Carbohydrates are basically the simple sugars or starch have the main role of storing chemical energy in living things and serve as the basis of skeletal structure stability for plants. Carbohydrates have various forms such as Simple sugar, Oligosaccharides and Polysaccharides (starch, glycogen, cellulose, plant gums). Simple sugars and Starch are the most common forms of carbohydrates but they have very different roles. Sugars are very important nutrients as our body are biologically designed to sense the presence of sugars which is characterized by sweetness. The last food molecule which is known as Proteins which are considered to unpredictable and the hardest to understand. Proteins are very susceptible to changes such as addition of heat, exposure to air and reaction with acids or bases. Proteins are made up of smaller molecular units known as Amino acids but in combination with other amino acids, they form macromolecules which make up RNA and DNA. Proteins are at the heart of all organic activity, growth and movement hence cooking allows us to take control the proteins dynamic nature to create new structures which can lead to a larger variety of food.

These four food molecules are just the tip of the iceberg and there are many more things to discover about the science of food which will be shared more on my blog in the coming weeks.

 

 

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