ABSTRACT
The various properties or parameters that define the
sensory quality of food products can be divided into
three groups: visual parameters, texture parameters,
and flavor and aroma parameters (1). By visual
parameters we understand those that we perceive with
the sense of sight. The various properties perceived by
the sense of sight can be further divided into three
subgroups: optical properties, properties depending on
physical form, and properties depending on the method
of presentation (2). By optical properties we understand those that
depend on geometrical or chromatic modification of
the light striking the product in question. These
properties are: color, gloss, translucency, and the
uniformity of these properties on the surface of the
product. If the reader should ask why we measure color and
what importance it has, the answer is that with the sense
of sight we obtain 83% of the information we receive
about our environment, while a mere 17% is obtained
from the other senses. Also, visual evaluation of
appearance precedes the evaluation of other parameters
(flavor, aroma, and texture), so that it may have an
excluding effect. If we reject a food product on the basis
of a visual examination, we do not go on to evaluate its
other properties, however excellent they may be. This
importance is recognized by food legislation in all
countries, where color always appears in the description
of any foodstuff and also features as a quality factor to
distinguish between different quality levels for a
particular product. The first and longest part of this chapter is devoted
to color, followed by a description of the measurement
of gloss, translucency, uniformity, and defects.
