As a veterinary food inspection specialist, you are interested in how to detect
deteriorative changes in foods. Even though the changes are extremely complex, signs
of the changes are easily recognized by the use of sensory evaluation.
a. All Physical Senses Used. In most cases, the only equipment the inspector
needs to detect deterioration is his physical senses. All senses, including hearing, are
used in making a sensory evaluation. Hearing may be used to detect abnormal signs in
a canned item by shaking the item. Hearing may also be used to detect the escape of
gas from a canned item when opened.
b. Characteristics Common to Food Items. Physical senses are used to
evaluate the following characteristics of a food item:
(1) Color. Color is an appearance attribute (characteristic) of a food that
aids in the identification of its condition. An off-color (abnormal) is indicative of a
deteriorative condition. To be considered off-color, the color of the food item must be
judged to differ from that of the normal color and the permissible variations possessed
by a high-quality like item.
(2) Odor. Odor is a characteristic of a food item that makes it perceptible to
the sense of smell. The odor qualities of a food aids in the identification of its condition.
An off-odor (abnormal) is indicative of a deteriorative condition. Terms that have been
used to describe off-odors are fruity, spicy, burnt, sharp, sweet, rancid, metallic, and
(3) Texture. Texture refers to the physical properties of a food that
perceived as tenderness or toughness, crispness or softness, and other evaluations.
An abnormal texture is indicative for a deteriorated condition. Terms that have been
used to describe abnormal textures are water-soaked, slimy, soft, hard, brittle, spongy,
and others. If dealing with a liquid product, the term texture is defined to be
synonymous with the term consistency.
(4) Taste (flavor). Taste is a comprehensive term used to refer to the four
primary sensations (sweet, salty, sour, bitter) and their variations in the mouth. An off-
flavor (abnormal) usually offends the senses of taste and smell and is indicative of a
deteriorated condition. An off-flavor, however, might also be a pleasant odor which is
not characteristic of the product. Terms that have been used to describe off-flavors are
fishy, putrid, grassy, sour, musty, and others.