Biochemistry in the Kitchen

Biochemistry in the Kitchen is designed for an introductory one-semester course for nonscience students who need to fulfill a requirement for a “lab-science course.” The intent is to provide these students with a robust understanding of biochemical phenomena illustrated in the context of cooking and other practical everyday experiences in the world around them. The book is “self-contained,” assuming only minimal previous exposure to science courses in middle school or junior high school. Questions are posed such as “What happens during cooking?,” “Why does that happen?,” and “How does that work?” Scientific concepts necessary to understand the observed phenomena are presented, and answer these questions in a sequential order, starting with “first principles” in the early chapters and adding new information that builds on the initial concepts to explain more complicated phenomenon. Scientific jargon is avoided wherever possible, instead using “common terms” to explain what is happening. The book is accompanied by online “Laboratory Experiments” that can be conducted in the students’ home, kitchen, or classroom. As such, this course is appropriate for use at the introductory college level or high school level. Students who successfully complete Biochemistry in the Kitchen will be able to: Demonstrate a fundamental understanding of the principle concepts of biochemistry and be able to communicate scientific ideas effectively using common everyday terms and experiences to illustrate concepts. Understand the scientific method and be able to apply scientific reasoning to investigate questions, solve problems, and form conclusions. Be able to understand the fundamental role that water plays in biochemical processes, with particular application to food chemistry and cooking practices. Evaluate scientific data, develop hypotheses, interpret results, and apply this information to applications involving cooking, emulsifications, acid/base buffering action, hydration of polymers, denaturation of proteins, catalysis by enzymes, human metabolism, fermentation, food safety, and bacterial growth. Display an understanding of food ingredients and their purpose. Communicate what chemical transformations occur during cooking, explain why humans cook food, and how humans obtain energy from eating foods. Organization There are eleven broad topics addressed in this book, organized into four modules. Biochemistry cannot be understood without understanding the properties of water. Accordingly, the four chapters which constitute the first module explain the peculiarities of water and how we experience these properties of water in our everyday lives, explaining phenomena such as the following: Why cooking with steam is more effective than cooking with boiling water? Why cooling a hot beverage with ice is more effective than using cold water? What is wind chill? Why do oil and water separate into distinct layers? What are saturated fats, unsaturated fats, and omega 3 fats? How does soap work? How is mayonnaise made? Why is phosphoric acid or citric acid added to so many foods? Why do we breathe fast when we exercise? The four chapters comprising the second module describe biological polymers, specifically, polysaccharides and proteins. The behavior of these polymers in water explains the structures these polymers form and what happens to these polymers when we prepare the foods that we eat. For examples, topics addressed in the second module include the following: Why is sugar sweet but starch made out of sugar units is not? Why are some kinds of sugars sweeter than others? What happens to starch while making gravy? Why do noodles take on water when heated? Why does clear liquid “egg white” turn into a solid white gel when heated? Why is vinegar added to water when making poached eggs? How do you make meringue out of egg whites without cooking? How do you make yogurt, cheese, and butter out of milk? Why do meats become tender when you boil them in water? Why do foods turn brown when you cook them? What do meat tenderizers and meat marinades do? The third module describes what happens to biological polymers when we eat them, and how humans capture energy from the food nutrients that we eat. These chapters address the following: What is the difference between digestion and metabolism? Why do foods high in fats have a higher calorie content than do foods made primarily of starches or proteins? How do we get energy out of these foods? How does the Keto diet work? Why do we need oxygen to live? How is beer, wine, and vinegar made? Why is wheat “gluten” in so many foods? Why does bread rise when leavened? Why do cookies rise when baked in the oven? The last module includes a chapter on food safety, bacterial growth, why foods spoil, and why some bacteria cause food-borne illnesses. There is a chapter discussing the various techniques humans have developed over the centuries to preserve foods and how those processes work to suppress microbial processes. The final chapter introduces the concept of the human microbiome—the bacteria that live in partnership with humans that are essential to keep us healthy. Some of the questions addressed in this fourth module include the following: Why do we chill foods to prevent spoilage? Food recalls: Where do food-borne illnesses come from? Why can some foods be stored at room temperature? Why are bags of corn chips or potato chips sold “half-empty”? What are probiotic bacteria? What is a prebiotic food? When I was a university provost, I often heard complaints from students and their deans that the science courses intended for nonscience majors were “boring,” “over their heads,” “tedious,” or “irrelevant to their lives.” They wanted something “different,” something that would be useful to everyday life. When I returned to a faculty role, I committed myself to the endeavor of developing a “real science” course that would be meaningful to most people and present information to students in such a way that it would be readily understandable and applicable such that they would remember the basis of these biochemical phenomena throughout their lives. The most rewarding feedback that I have received from students are vignettes they tell me months or years later describing how they recalled at work why they used lemon juice in making guacamole or on vacation why lemon juice removes fish odor off their hands. I hope you have the same delightful experience with this book!