The Science of Cooking

Understanding the Biology and Chemistry Behind Food and Cooking

Joseph J. Provost, Keri L. Colabroy, Brenda S. Kelly, Mark A. Wallert

• Publisher: Wiley
• Year: 2016
• ISBN:
  9781119210337
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Biochemistry
• Index: Biological Sciences

The Science of Cooking

The first textbook that teaches biology and chemistry through the enjoyable and rewarding means of cooking

The Science of Cooking is a textbook designed for nonscience majors or liberal studies science courses, that covers a range of scientific principles of food, cooking, and the science of taste and smell. It is accompanied by a companion website for students and adopting faculty. It details over 30 guided inquiry activities covering science basics and food-focused topics, and also includes a series of laboratory experiments that can be conducted in a traditional laboratory format, experiments that can be conducted in a large class format, and take-home experiments that can be completed with minimal equipment at the student's home. Examples of these engaging and applicable experiments include fermentation, cheese and ice cream making, baking the best cookies, how to brown food faster, and analyzing food components. They are especially useful as a tool for teaching hypothesis design and the scientific process.

The early chapters of the text serve as an introduction to necessary biology and chemistry fundamentals, such as molecular structure, chemical bonding, and cell theory, while food-based chapters cover:

• Dairy products (milk, ice cream, foams, and cheeses)
• Fruits and vegetables
• Meat and fish
• Bread
• Spices and herbs
• Beer and wine
• Chocolate and candies

The Science of Cooking presents chemistry and biology concepts in an easy-to-understand way that demystifies many basic scientific principles. For those interested in learning more science behind cooking, this book delves into curious scientific applications and topics. This unique approach offers an excellent way for chemistry, biology, or biochemistry departments to bring new students of all levels and majors into their classrooms.

1
THE SCIENCE OF FOOD AND COOKING: MACROMOLECULES

Guided Inquiry Activities (Web): 1, Elements, Compounds, and Molecules; 2, Bonding; 3, Mixtures and States of Matter; 4, Water; 5, Amino Acids and Proteins; 6, Protein Structure; 7, Carbohydrates; 8, pH; 9, Fat Structure and Properties; 10, Fat Intermolecular Forces; 11, Smoking Point and Rancidity of Fats

1.1 INTRODUCTION

The process of cooking, baking, and preparing food is essentially an applied science. Anthropologists and historians venture that cooking originated when a pen holding pigs or other livestock caught fire or a piece of the day’s catch of mammoth fell into the fire pit. The smell of roasted meat must have enticed early people to “try it”; the curious consumers found culinary and nutritional benefits to this new discovery. The molecular changes that occurred during cooking made the meat more digestible and the protein and carbohydrates more readily available as nutrients. Contaminating microbes were eliminated during cooking, which made the consumers more healthy and able to survive. Moreover, the food was tastier due to the heat-induced chemical reactions between the oxygen in the air and the fat, proteins, and sugar in the meat. Harnessing the knowledge of what is happening to our food at the molecular level is something that good scientists and chefs use to create new appetizing food and cooking techniques.

We are all born curious. Science and cooking are natural partners where curiosity and experimentation can lead to exhilarating and tasty new inventions. Scientific discovery is driven by hypothesis (see Fig. 1.1 for a model of the scientific method). An observation of an event creates a question and/or a statement that explains the observation or phenomenon: the hypothesis. The hypothesis can then be tested by a series of experiments and controls that supports or falsifies the hypothesis, starting the cycle over again. For example, a scientist might observe that the growth rate of cancer cells in a petri dish slows when the cells are exposed to a sea sponge. The scientist may then hypothesize that a molecule found in the sponge binds to a protein in cancer cells. After adding the compound to a tumor, its growth slowed and the cells die. Looking at how all of the individual molecules found in the sea sponge affect the growth of cancer cells can test this hypothesis. These experiments can lead to a more advanced hypothesis, testing and eventually finding a new compound that can be used to fight cancer.

Figure 1.1 The scientific method. Scientists use a testable method originating from observations to generate a testable hypothesis to conduct their work. A cook or baker can also use this method to create a more interesting food.

Cooking can also be a hypothesis-driven process that utilizes biology, chemistry, and physics. As you cook, you use biology, chemistry, and physics to create hypotheses in the kitchen, even if you weren’t aware of being a scientist. Each time you try a recipe, you make observations. You may ask yourself questions about what you added to the concoction or how the food was baked or cooked. This creates a hypothesis or a statement/prediction that you can test through experimentation (your next attempt at the dish). A nonscientific idea is often approached as something to prove. That is different from hypothesis testing. A hypothesis is falsified rather than proven by testing. Cooking does just this; it will falsify your test rather than prove it. Tasting, smelling, and visualizing your results tell you if your hypothesis was supported or falsified. If wrong, you may create a new hypothesis that might be generated by the time you have washed the dishes from your first experiment! Learning more of the basic science behind food and cooking will help you appreciate the world around you and become a better scientist and a better cook, baker, and consumer.

1.2 FUNDAMENTALS OF FOOD AND COOKING

Bread baking provides a great example of the importance of having a scientific understanding of cooking and baking. Take a close look at bread. Notice that it is made of large and small caves surrounded by a solid wall (Fig. 1.2).

Figure 1.2 Structure of bread. A close look at bread demonstrates the requirement of proteins and carbohydrates needed to trap expanding gases.

The key to bread is making a way to trap expanding gases in the dough. Adding water to flour and sugar allows for the hydration and mixing of proteins and carbohydrates. Kneading the dough stretches a protein called gluten, which allows for an interconnected network of protein ready to trap gas that is generated by the yeast. During the proofing step of making bread, the yeast converts sugar into energy-filled molecules, ethanol, carbon dioxide gas, and other flavorful by-products. The heat applied during baking allows the water to escape as steam, which expands the bread, links the gluten protein molecules further, and traps carbon dioxide gas. While this is happening, the heat catalyzes chemical reactions between proteins and sugars, creating a beautiful brown color, a dense texture, and over 500 new aromatic compounds that waft to your nose. Clearly there is a lot of science that goes into making a loaf of bread.

Preparing food and drink is mostly a process of changing the chemical and physical nature of the food. Molecules react to form new compounds; heat changes the nature of how food molecules function and interact with each other, and physical change brings about new textures and flavors to what we eat. To gain a better appreciation for these chemical and physical processes, a fundamental understanding of the building blocks of food and cooking must first be understood. In the following two chapters we will study the basic biological principles of cooking, tasting, and smelling.

One of the most important building blocks of food is water; our bodies, food, and environment are dependent on the unique chemistry and biology of this molecule. Large biological molecules such as proteins, carbohydrates, and fats comprise the basic building blocks of food. Smaller molecules, including vitamins, salts, and organic molecules, add important components to cooking and the taste of food. Finally, the basics of plant and animal cells and cellular organization are key to understanding the nature of food and cooking processes. However, before we get into some of the science fundamentals, it is important to recognize and acknowledge the origins of and the chefs who first embraced the science behind their profession.

1.2.1 Science, Food, and Cooking

Many chefs and bakers embrace the collaboration of science and food. Historically, one means whereby science has been utilized in the kitchen is in the area of food technology—the discipline in which biology, physical sciences, and engineering are used to study the nature of foods, the causes of their deterioration, and the principles underlying food processing. This area of food science is very important in ensuring the safety and quality of food preparation, processing of raw food into packaged materials, and formulation of stable and edible food. College undergraduates can major in “food...