Food chemistry is a major part of a larger discipline of study known as food science. Food science is an interdisciplinary study involving microbiology, biology, chemistry, engineering, and biotechnology. Food science is the application of science and engineering to the production, processing, distribution, preparation, evaluation, and utilization of food. Food chemistry encompasses the composition and properties of food components and the chemical changes they undergo during handling, processing, and storage. A food chemist must know chemistry and biochemistry and have knowledge of physiological chemistry, botany, zoology, and molecular biology to study and modify biological substances as sources of human food. Food chemists work with biological systems that are dead or dying (post-harvested plants and postmortem animal tissues) and study the changes they undergo when exposed to different environmental conditions. For example, during the marketing of fresh tomatoes, the food chemist must determine the optimal conditions to sustain the residual life in the tomatoes so the tomatoes will continue to ripen and arrive at the supermarket as a high-quality product for the consumer. Vital to understanding food science is the knowledge of the primary compounds in food. These compounds are carbohydrates, lipids, and proteins. The experiments and background information focus on the chemistry (functional properties) and structure of these compounds found in foods.
Food science also includes biotechnology, which is the use of biological processes to make new foods, enzymes, supplements, drugs, and vaccines. For thousands of years, people have been using microorganisms in the fermentation of beer and in the making of cheeses, wines, and breads. Today biotechnology also encompasses genetically engineered foods. In genetic engineering, scientists splice genetic material from plants, animals, or bacteria and insert this genetic material into the DNA of other organisms. These new organisms are called genetically modified organisms (GMOs).
Before we can discuss food chemistry, the students must understand basic chemistry concepts. The student introduction explains food chemistry. The introduction also includes general background information on chemical bonds.
Vocabulary
The atom is the smallest possible unit of an element, consisting of protons, neutrons, and electrons. The atom is the tiniest part of a chemical element that has all the properties of that element. The smallest speck that can be seen under an ordinary microscope contains more than 10 billion atoms.
A chemical bond is an attractive electrical force between atoms strong enough to permit them to function as a unit, called a molecule. Both positive (+) and negative (–) electrical charges attract, just as magnetic north and south poles attract.
The molecule is the smallest physical unit of an element or compound, consisting of one or more like atoms in an element and two or more different atoms in a compound.
This module, Food Chemistry, contains three major units: Carbohydrates, Lipids, and Proteins. Each unit includes a Teacher Activity Guide and a Student Activity Guide. Teacher Activity Guides present the teacher with all background information he or she will need to perform the experiments, as well as questions and answers and sample data tables. Student Activity Guides contain background information relevant to the unit, procedures, and key questions and data tables for the students to complete. Teachers may photocopy this section for distribution to the students.
The experiments in each unit are intended as demonstrations only. The food items and products produced should not be consumed.
There is a supplemental CD-ROM called "The Pizza Explorer" that the student can use as an independent study exercise on food chemistry. The Pizza Explorer is an interactive program that allows for further learning about food science at a student’s own pace.
Molecular models provide a tangible, visual means of introducing the relationships between chemical structure and functional behavior of food molecules. The pictures of chemical structures illustrated in this experiment book were made with a molecular model kit. This kit is available from Molecular Modeling Kits (Molymod) by Spiring Enterprises, Ltd. For further information contact Philip Spiring, Beke Hall, Billingshurst, West Sussex, England RH14 9HF, Telephone + 01403 782387, E-mail molymod@globalnet.co.uk, Web site www.molymod.com. The kit contains the four basic atoms found in foods: carbon, oxygen, hydrogen, and nitrogen. The kit can be used to build sugars (glucose and fructose), fatty acids and triacylglycerols, and amino acids. The models can also demonstrate stereochemical principles, such as cis and trans double-bond configurations in fatty acids, alpha and beta glycosidic linkages in sugars, and the L and D configurations of amino acids.
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