a. Sharp Freezing. The temperature used in this method is 10F (-12C), which
freezes the product solid in 3 to 72 hours. The process results in large ice crystal
formation, which will rupture cell membranes, cause enzyme leakage, and hasten self-
decomposition. This is not the method of choice.
b. Quick Freezing. This is the air blast method and uses forced air at a
temperature of -40F (-40C), which freezes the product solid in about 30 minutes. (Note
that -40F and -40C is the only point in the two temperature scales where the scales
have the same numerical value.) This method results in small ice crystal formation with
minimum cell membrane rupture and the food thaws to a more natural state. This is the
method of choice and is widely used in industry.
At: -5.0F (-20.6C)
BASED UPON BEEF CONTAINING 70% FREE MOISTURE WITH A FREEZING
POINT OF 29.5F (-1.4C).
Figure 3-1. Temperature, ice, free moisture relationship.
3-20. PRESERVATION BY CANNING
a. Two Types of Canned Meats. There are two general types of canned meats
relative to their storage temperature requirements. These two types of canned meats
are: shelf-stable meats and cured meats requiring storage temperatures below 50F
(10C), with best storage conditions being in a range of 32 to 40F (0 to 4C).
b. Four Groups of Spoilage Microorganisms. There are four groups of
spoilage microorganisms in canned meats, based upon their reactions to heat, salt, and