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Food chemistry
Enzymes are biochemical catalysts
used in converting processes from one substance to another. They are also
involved in reducing the amount of time and energy required to complete a
chemical process. Many aspects of the food
industry use catalysts, including baking,
brewing, dairy,
and fruit juices, to make cheese, beer, and bread. Enzymes are biomolecules
that increase the rates of chemical reactions. Almost all enzymes are proteins. In enzymatic reactions, the molecules at the beginning of the process are
called substrates, and the enzyme
converts them into different molecules, the products. Almost all processes in a
biological cell need enzymes in order to occur
at significant rates. Since enzymes are extremely selective for their
substrates and speed up only a few reactions from among many possibilities, the
set of enzymes made in a cell determines which metabolic
pathways occur in that cell. Enzyme activity can be affected by
other molecules. Inhibitors are molecules
that decrease enzyme activity; activators
are molecules that increase activity.
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Vitamins are nutrients
required in small amounts for essential metabolic reactions in the body. These
are broken down in nutrition as either water
soluble (Vitamin C) or fat
soluble (Vitamin E). An adequate supply of vitamins
can prevent such diseases as beriberi, anemia, and scurvy while an overdose
of vitamins can produce nausea and vomiting or even death. A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. A compound is called a vitamin when
it cannot be synthesized in sufficient
quantities by an organism, and must be obtained from the diet. Thus, the term
is conditional both on the circumstances and the particular organism. For
example, ascorbic acid functions as vitamin C for some animals but not others, and vitamins D and K are
required in the human diet only in certain circumstances.
A major component of food is water, which can encompass anywhere from 50% in meat products to 95% in lettuce, cabbage, and tomato products. It is also an excellent place for bacterial growth and food spoilage if it is not properly processed. One way this is measured in food is by water activity which is very important in the shelf life of many foods during processing. One of the keys to food preservation in most instances is reduce
the amount of water or alter the water's characteristics to enhance shelf-life. Such methods include dehydration, freezing, and refrigeration
Minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. Dietary minerals in foods are large and diverse with many required functioning while other trace elements can be hazardous if consumed in excessive amounts. Sometimes minerals are ingested as mineral dietary supplements, the most common being iodine in iodized salt.
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