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 easily form from the meat fats. Anti oxidants are compounds which react with certain intermediary products necessary for the development of free fatty acids. Enzymatic Reaction: This is another common cause of food spoilage. Enzymes are protein substances will help speed up chemical reactions. Enzymatic reaction may reduced or totally stooped if you subject the meat to temperature below or above the temperature range needed for the activity of the meat enzymes.
METHODS OF MEAT PRESERVATION 1. Drying removal of moisture from meat. The method involves the reduction of the original water content. There are 2 ways of drying: a) Natural sun drying meat. b) Artificial drying a chamber equipped with heating elements maintained at a temperature of 110 F-120 F and relative humidity of 85% is used for drying. This is more expensive than sun drying but its dried products have a better quality and can be sold at a higher price. 2. Smoking there are 2 methods of smoking: a) Natural is the exposure of the meat to wood smoke which causes the deposition og pyroligenous acid on the meat surface that acts as preservative and flavoring agent. Hardwood saw dust, guava leaves or any kind of wood may be used. b) Artificial smoke flavor is incorporated in the pumping pickle for ham and bacon at the rate of 1 tsp. /litter. 3. Salting simple method of dehydration in which the salt caused the withdrawal of water from the tissue of both the meat and the spoilage organisms, resulting to the shriveling and inactivation of the cells. 4. Curing is the application of salt, sugar, salitre and other preservatives and adjunct to prolong the keeping quality og the product. Other substances such as sugar, spices, vinegar and wine may be used for different types of cure, but in small quantities, thus, may have no preservative effect. Although the essential oils retard bacterial growth and vinegar has similar action. There are 3 ways of curing: a. with salt alone b. with salt and sugar c. with salt,...