2-3.
OXIDATIVE RANCIDITY
a. General. Examine the product for abnormal color, flavor, and odor. A
discussion of oxidative rancidity may be found in paragraph 1-14a.
b. Definition. Oxidative rancidity is caused by oxidation of unsaturated fats.
The following are examples of meat and meat products with a high content of
unsaturated fats: chicken, poultry, pork, and bacon.
c. Color Changes. Yellowing of the fat and/or browning of the meat are color
changes that may indicate oxidative rancidity.
d. Flavor Changes. Flavor may vary and is dependent upon the stage of
reaction. A sharp, biting, acrid (burning) flavor is indicative of an advanced stage of
oxidative rancidity, sometimes called "rancid" flavor.
e. Cooking a Sample for Evaluation. A cook test may have to be performed to
evaluate the flavor. The rancid flavors may not be evident at the low temperatures at
which meat and meat products are stored.
2-4.
DEHYDRATION
a. General. Examine the product for a dried or porous surface or a dark color.
These may indicate dehydration.
b. Definition. Dehydration is a loss of water from the product, usually due to
improper storage conditions.
c. Appearance in a Nonfrozen Product. Dehydration in a nonfrozen product
results in a dried-out (dry, shrunken) appearance of the surface, usually accompanied
by a darkening of the product. The darkening is due to an accumulation of solid matter.
d. Appearance in a Frozen Product. Dehydration (freezer burn) in a frozen
product is evidenced by a porous texture, whereby the tissue becomes tough and
fibrous. When this condition exists, protein denaturation normally occurs. The abnormal
color may range from white to pale amber in affected areas and may appear as patch-
like areas. The affected product will retain its original shape. A discussion of freezer
burn may be found in paragraph 1-13.
2-5.
DISCOLORATION/DARKENING
a. General. Examine the product for discoloration/darkening.
b. Sources of Discoloration. Discoloration/darkening may be due to hydrolysis
MD0723
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