Table of Contents
Meat is muscle tissue. It is the flesh of domestic animals (cattle, hogs, lamb) and of wild game animals such as venison. Meat is a main stay of our diet
Slaughtering
Five main stages:
1)Antemortem Inspection
2)Stunning
3)Bleeding
4)Dressing
5)Inspection
1)Ante –mortem Inspection
Brought to slaughter house 24 hours in advance.
Resting.
Inspection for disease, injury, etc.
2)Stunning
Three methods:
1)Captive bolt: large animals, pithing by long metal rod.
2)Electrical Stunning: Small animals, pass current through animal for at least 7 seconds, leaves animal unconscious for 1 ½ minutes.
3)CO2 stunning: Pigs, pass through tunnel of CO2.
3)Bleeding
Make a small incision at the neck to cut the main blood vessel.
Remove as much blood as possible as it is ideal medium for bacterial growth.
4)Dressing
Remove hide, only hair for pigs.
Offal and viscera are removed and carcass is cleaned.
Large animals cut into two parts from the spine
5)Inspection
Continuous process.
Tagging of carcass and offal may be done.
Done in cooling room under 7C.
Rigor Mortis
Rigor Mortis is a condition that occurs in the body soon after death. This is characterized by muscle spasm and the stiffening of muscles and occurs not only in Human beings but also in animals.
We know that all living beings respire and there are two types of respiration, aerobic and anaerobic. Aerobic respiration takes place in the presence of Oxygen and the end product is Carbon Dioxide. This would take place normally and produces ATP (Adenosine Try Phosphate), which is a high chemical bond energy compound derived from Amino Acids and provide energy for body functions.
Anaerobic respiration takes place in the absence of oxygen and its end product is Ethyl Alcohol. In animals, the end product of anaerobic respiration is Lactic Acid which when accumulated in the carcass decreased the pH and stiffens the muscles.
In living animals, the myoglobin stores oxygen in the muscles. When the animal is slaughtered, the external source of oxygen is cut off and the tissues use the stored oxygen to continue aerobic respiration and subsequent ATP and Carbon Dioxide production. Within a few minutes, the store of oxygen is depleted and the tissues now opt for anaerobic respiration, which then results in the accumulation of Lactic Acid in the muscles. Hence the acidity of the cells increases and the pH decreases. This in turn causes the muscles to stiffen. This condition is known as Rigor Mortis. This condition is aided by the fact that the supply of ATP is cut off and hence there is no energy for the tissue to work. The Lactic Acid gradually breaks up into lactate and water and indicates the end of Rigor Mortis and the production of water. This is characterized by bloating of the carcass.
Storage
The quality if the finished product depends not only on proper selection of meats but on proper storage as well. Fresh meat is highly perishable. The high cost of meats makes it essential to avoid spoilage
Fresh meats
1 Check purchases on arrival, to ensure that the meat is of good quality.
2 Do not wrap tightly. Bacteria and mold thrive in moist, stagnant places. Air circulation inhibits their growth. Store loosely, but cover cut surfaces with plastic wrap to prevent excessive drying.
3 Do not open Cryovac-wrapped meats until ready to use.
4 Store at 32-36ºF (0-2ºC). Meat does freeze until 28ºF (-2ºC).
5 Keep meats separate in cooler and on work table to avoid cross contamination.
6 Use as soon as possible. Fresh meats keep well for only 2-4 days. Ground meat keeps even less well because so much surface is exposed to bacteria. Cured and smoked products may keep upto a week.
7 Do not try to rescue meats that are going bad by freezing them. Freezing will not improve the quality of spoiling meat.
8 Keep coolers clean.
Frozen meats
1 Wrap frozen meats well to prevent freezer burn.
2 Store at 0ºF (-18ºC) or colder.
3 Rotate stock – first in, first out. Frozen meats do not keep indefinitely. Recommended shelf life, at 0ºF (-18ºC), of beef, veal and lamb – 6 months; for pork – 4 months. Pork fat turns rancid easily in the freezer.
4 Defrost carefully. Tempering in the refrigerator is the best. Defrosting at room temperature encourages bcterial growth.
5 Do not refreeze thawed meats. It increases loss of quality.