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Unit 1 The Science of Food
Brittleness refers to how easily a food shatters or breaks apart.
Pie crust and crackers are very brittle. Strawberries, cake, and caramels
would not be considered brittle.
Firmness describes a food’s resistance to pressure. Tough foods
require considerable biting force to chew them. Beef jerky is a good
example. Tender foods require so little force to chew, they almost seem
to melt in your mouth. Tenderness is desired in most cakes and high-
quality steaks.
Consistency describes the thinness or thickness of a product.
It can be measured in terms of pourability. “Au jus,” the fl avored
drippings from meat, is very thin. Milk gravy is usually thick enough
to not soak into biscuits or toast.
As you evaluate foods in the lab, think about these characteristics
that defi ne texture. Remember that texture preferences are also
subjective. Most French people, for instance, like their bread chewy.
They want their bread to have a brittle, crunchy crust with a slightly
chewy, moist center. Many people in the United States want a very
tender bread with a soft crust. Some people react so strongly to
texture that they like or despise a food based on texture rather than
fl avor. For example, a child may “hate” strawberries, but “love” a
strawberry-fl avored candy.
Measuring Texture Objectively
Food texture can be evaluated objectively by measuring its
resistance to force. Physicists and engineers have developed an
assortment of instruments that can measure how much force is needed
to compress, tear, or juice a food. These types of measurements are
used to evaluate uniformity, keeping quality, and packaging needs.
However, they will not determine whether a consumer will like one
variation of a food over another.
One example of an instrument that measures food texture is a
compression machine. Compression machines show how much pressure
it takes to compress one food compared to another. These machines
may be used to determine how to modify ingredients or processing
procedures to provide a standard texture for a food product. They
can also tell a manufacturer how much packing is needed to allow a
product to be shipped without being crushed.
A penetrating probe is another instrument that measures food
texture. It is used to determine the quality of beef. Inspectors insert
the probe into the meat carcass. The pressure needed to penetrate a
given distance has been compared to how tender the meat will be
after cooking. In this way, beef can be labeled as prime or choice before
it is cut apart.
Like texture, other sensory characteristics of foods can be measured
objectively. For instance, scientists can test fl avor components by
measuring a food’s sugar, salt, and acid content. Appearance factors
such as color, size, and shape can be measured, too. In the fi nal analysis,
however, what will matter is what the consumer wants. Manufacturers
determine this by using taste test panels.