PRINCIPLES OF MEAT PRESERVATION
Meat preservation is principally concerned with the application of measures to delay meat spoilage, which are caused by microbial, chemical and physical changes. Of these, microbial spoilage is most common. Microbes thrive in moisture and since meat is 70%-75% water, it spoils easily through microbial action. Meat, being rich source of nutrients, also becomes an excellent food for bacteria. Methods of meat preservation, however different from each are alike, in that, employ environmental conditions that discourage the growth of microorganisms. They may be grouped in three broad categories based on a) control of temperature, b) control in moisture and c) by lethal agents. Generally, the method to discourage microbial growth can be divided into groups. 1. By exposing meat to high (212 F or 100 C) or low (32 F or 0 C) temperature. 2. By treating meat with substances which will kill microorganisms or delay microbial actions. a) Microbial growth b) Atmospheric oxidation c) Enzymatic reaction Microbial growth: Meat contains abundant nutrients required for the growth of bacteria, yeast and molds. Thus, these microorganisms flourish in meat. Eliminating the growth requirement: a) temperature requirements, b) moisture content, c) considerations in the control of their growth. This can be achieved by removing one, two or all the required conditions for growth.
Atmospheric Oxidation Meat fats are susceptible to oxidation, when they are exposed to the molecular oxygen present in the air. This results in the production of a strong rancid color and flavor in the cooked product. When this chemical reaction occurs, it constitutes a defect referred to as oxidative rancidity. More popularly known as rancidity or manta, this can be avoided by eliminating the factors required for its development. These factors are a) light b) air and c) free meat fats. While the entry of light and air can be prevented, free fatty acids