meat notes--for wednesday's exam!!

UNDERSTANDING MEATS


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. As a cook, chef or food service operator, you will be spending more of your time and money on meats than on any other foods. It is important to understand meats thoroughly in order to cook them well and profitably. Why are some meats tender and some meats tough? How can you tell one cut from another, when there are so many? How do you determine the best way to cook each cut?

WHY MEAT?????
 Main focus of the meal.
 40-60% of total food expenditure.
 Determines selection of all other foods.

CLASSIFICATION
 Type of animal
 Country
 Age/sex of animal
 Grade of meat
 Cut of meat
 Condition of meat
 Uses in catering

Classification of Cattle







Classification of Sheep



CLASSIFICATION OF PORK






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.

COMPOSITION, STRUCTURE AND BASIC QUALITY FACTORS

Muscle tissue consists of these major components;

WATER (75% of muscle tissue)
With such a high percentage of water in meat, you can see why shrinkage can be a big problem in its cooking. Too much moisture loss means dry meat, loss of weight and loss of profit.

PROTEIN (20% of muscle tissue)
Protein is an important nutrient and the most abundant solid material in meat. Protein coagulates when it is heated. This means it becomes firmer and looses moisture. Coagulation is related to doneness. When protein has coagulated to the desired degree, the meat is said to be done. Too high heat toughens protein.

FAT (upto 5% of muscle tissue)
Of course there can be more fat surrounding the muscles. A beef carcass can have as much as 30% fat. A certain amount of fat is desirable for 3 reasons.

1 Juiciness
Marbling is fat that is deposited within the muscle tissue. The juiciness we enjoy in well-marbled beef is due more to fat than to moisture. Surface fat protects the meat (especially roasts) from drying out during cooking as well as in storage. Adding surface fats where they are lacking is called barding.

2 Tenderness
Marbling separates muscle fibers, making them easier to chew.

3 Flavour
Fat is perhaps the main source of flavour in meat. A well-marbled prime (top grade) steak tastes ‘beefier’ than the same cut of a lower grade.

CARBOHYDRATE
Meat contains a very small amount of carbohydrate. When you brown meat, you are in part caramelizing the carbohydrate.

COLOURING PIGMENTS
 COLOUR OF MEAT IS MAINLY DUE TO TWO PIGMENTS I.E. HAEMOGLOBIN AND MYOGLOBIN. BOTH CONTAIN IRON.
 HAEMOGLOBIN : PRESENT IN BLOOD. GIVES RED COLOUR TO THE MEAT.
 MYOGLOBIN : PRESENT IN FRESHLY CUT MEAT. ON EXPOSURE TO AIR GETS OXIDIZED INTO OXYMYOGLOBIN.

FLAVOURING AGENTS
 CONTRIBUTE TO THE FLAVOUR OF THE MEAT.
 THESE ARE MOSTLY BI-PRODUCTS OF LIVING MUSCLE METABOLISM.



STRUCTURE

Muscle fibers
Lean meat is composed of long, thin muscle fibers bound together in bundles. These determine the texture or grain of a piece of meat. Fine-grained meat is composed of small fibers bound in small bundles. Coarse textured meat has larger fibers. Feel the cut surface of a tenderloin steak, and compare its smooth texture to the rough surface of brisket or bottom round.

Connective tissue
Muscle fibers are bound together in a network of proteins called connective tissues. Each muscle fiber is also covered in a sheath of connective tissue. It is very important for the cook to understand connective tissue for one basic reason. Connective tissue is tough. To cook meats successfully you should know which meats are high in connective tissue and which are low, and, what are the best ways to make meats tender.

Meats are highest in connective tissue if;

a. They come from muscles that are more exercised. Muscles in the
leg, for example, have more connective tissue than muscles in the back.

b. They come from older animals. Veal is tenderer than meat from a young steer, which in turn is tenderer than meat from an old bull or cow. Young animals have connective tissue but it becomes harder to break down as the animal ages.

Meats high in connective tissue can be made more tender by using proper cooking techniques. There are two kinds of connective tissue; Collagen, which is white in colour, and Elastin which is yellow.

Collagen
Moist heat turns collagen into gelatin and water. Moist heat at low temperatures for a longer time is most effective in creating a tender, juicy finished product. Meat in an acid mixture or adding an acid such as tomato or wine to the cooking liquid helps tenderize the collagen.
Enzymes are naturally present in meats. They break down the connective tissue and some other proteins as the meat ages. These enzymes are inactive at freezing temperatures, slow acting under refrigeration, active at room temperature and destroyed by heat above 140°F (60°C).

Tenderizers are enzymes such as papain (extracted from papaya) that are added to meats by the cook, or injected into the animal before slaughter. Exercise care when using enzyme tenderizers. Too long an exposure at room temperature can make the meat undesirably mushy.

Elastin
Older animals have a higher proportion of elastin than younger animals. Cooking does not break down elastin. Tenderizing can only be accomplished by removing the elastin (cutting away the tendons) and by mechanically breaking up the fibers as in pounding or cubing the meat, grinding (hamburgers) or slicing the cooked meat thinly against the grain.


INSPECTION AND GRADING

Cooks and food service operators are assisted in their evaluation of meats by a federal inspection and grading system.

Inspection
1 Inspection is a guarantee of wholesomeness, not of quality or tenderness. It means that the animal was not diseased and the meat is clean and fit for human consumption.

2 It is indicated by a round stamp.

3 It is required by federal law – all meat must be inspected.

Quality grading
Quality grading is based on the texture, firmness and colour of the lean meat, the age or maturity of the animal and the marbling. All these factors must be considered together. For example, old, tough meat can still have marbling but it would rate a low grade because of the other factors.

Yield grading
In addition to quality grading, beef and lamb are graded according to how much usable meat in proportion to fat they have. The meatiest grade is Yield Grade 1. Poorest grade is Yield Grade 5 (much exterior fat).
Pork is yield graded from 1 to 4 but most pork is sold cut and trimmed. Veal, which has little fat, is not yield graded.


AGEING

Green meat
Soon after slaughter, an animal’s muscles stiffen due to chemical changes in the flesh. This stiffness called rigor mortis gradually disappears. Softening takes place three to four days for beef, less time for smaller carcass like veal, lamb and pork. Enzymes in the flesh cause this softening.
Green meat is meat that has not had enough time to soften. It is tough and relatively flavourless. Since it takes several days for meats to reach the kitchen from the slaughterhouse, green meat is seldom a problem except when meat is frozen while still green.

Aged meat
Enzyme action continues in muscle tissue even after meat is no longer green. This tenderizes the meat even more and develops more flavour. Holding meats in coolers under controlled conditions to provide time for this natural tenderizing is called ageing.

Beef and lamb can be aged because high quality carcasses have enough far cover to protect them from bacteria and from drying. Veal had no fat cover so it is not aged. Pork does not require ageing.

The three major types of ageing are described as follows;

1 Dry ageing: Ageing does not mean just storing meat in your refrigerator. There is a difference between aged meat and old meat. Temperature must be carefully monitored. Airflow and humidity must be controlled because bacteria will grow on cut surfaces if there is too much moisture. Ultraviolet lights are sometimes used in ageing coolers to kill bacteria and mold

2 Fast ageing: To speed ageing meat can be held at a higher temperature and humidity for a shorter time. Ultraviolet lights to control bacteria are especially important in fast ageing. Most fast aged meat is sold in the retail market rather than to food service establishments.

3 Vacuum-pack ageing: The modern trend is to break down carcasses into smaller cuts and wrap them in are and moisture proof plastic bags. This is called Cryovac ageing. The wrapping protects the meat from bacteria and mold, and prevents weight loss due to drying. However Cryovac aged meats often lose more weight in cooking than dry aged meats. Cryovac meats must be refrigerated.

Ageing increases tenderness and flavour. An off taste is not characteristic of aged meat. If meats smell or tastes spoilt, it probably is. Sometimes meats in Cryovac have a musty aroma when first opened but this disappears soon.

Ageing costs money. Storage costs, weight loss due to drying, heavier trimming due to dried and discoloured surfaces, all add to the price of aged meat (although Cryovac aged meat costs less than dry ageing). As a meat purchaser you will have to decide how much quality is worth how much cost for your establishment.

Curing of meat
 Major objective is preservation.
 It also affects the colour and flavour of the meat.
 Originally done for preservation prior to the days of refrigeration.
 Curing salt = 96% common salt + 4% nitrite or nitrate of sodium or potassium NaNO3 or KNO3
 (antioxidants (BHA) Curing accelerators, Flavor – yeast extracts, color enhancer.
 Helps to preserve the colour of the meat.

Curing of Meat
The prime object of ageing or ripening and use of tenderizers is to increase the tenderness of meat. The curing of meat has additional objectives. Curing brings about the modification of meat that effects preservation, flavour, colour and tenderness due to added curing agents.

Originally curing was practiced as a means of preservation before the days of refrigeration. The prime purpose of curing is to produce the unique flavoured meat products and a special purpose is to preserve the red colour of meat. Thus, cured beef (corned beef) and cured pork (ham) remain red on cooking while in the uncured condition they become brown.

The ingredients used for curing are common salt, sodium nitrate or nitrite, sugar and spices. (Curing salt is 96% common salt and 4% sodium nitrate or nitrite). Salt retards microbial growth and gives flavour to the meat. Nitrite fixes the red colour of myoglobin. Nitrite has also a beneficial effect on the flavour of cured meats and an inhibitory effect on clostridium botulism. Sugar helps to stabilize colour, counteract saltiness and also adds flavour. Spices are added mainly for flavour.

During the curing process, the curing mixture may be rubbed dry on the surface of a cut of meat or the meat may be immersed in a solution of the curing agent. The high osmotic pressure of the external fluid initially draws water and soluble proteins out of the meat. Later, salt diffuses into the meat and binds to the proteins, causing some expelled protein to diffuse back in. This causes a swelling of the meat. The salt-protein complex that forms binds water well.

Curing has also some detrimental effects during storage. The pink colour of nitrite cured meat changes to brown, in the presence of oxygen. Thus cured meat should preferentially be packed in containers from which oxygen has been excluded (Curing salts enhance oxidation of lipid components and thus reduce shelf life; also there is some concern about the carcinogenic effect of nitrite, particularly when cured meat is heated to a high temperature).



UNDERSTANDING THE BASIC CUTS

Meat cuts are based upon two factors;
1 The muscle and bone structure of the meat.
2 Uses and appropriate cooking methods of various parts of the animal.

Available forms: Carcasses, Partial Carcasses, Primal and Fabricated Cuts.
Beef, lamb, veal and pork may be purchased in some or all of these forms.

Carcasses
The carcass is the whole animal, minus entrails, head, feet and hide (except pork, which has only the entrails and head removed). Whole carcasses are rarely purchased by food service operators because of the skill and labour required in cutting, and because of the problem of total utilization.

Sides, quarters, foresaddles, hindsaddles
These represent the first step in breaking down the carcass. Again these larger cuts are no longer frequently used in food service. Fewer establishments are cutting their own meats.

1 Beef is first split through the backbone into sides. Sides are divided between ribs 12 and 13 into forequarter and hindquarter.

2 Veal and lamb are not split into sides but are divided between ribs12 and 13 into foresaddle and hindsaddle.

3 Pork carcasses are not divided in this way. They are cut directly into primal cuts.
Primal or wholesale cuts
These are the primary divisions of quarters, foresaddles, hindssaddles and carcasses. These cuts are still used to some extent in food service, because they are
a. Small enough to be manageable in many food service kitchens.
b. Still large enough to allow a variety of different cuts for different uses or needs.
c. Easier to utilize completely than quarters or halves.

Each primal cut may be fabricated or cut up or trimmed, in several different ways. They are always the starting point for smaller cuts.
Learn the names of the primals, their location on the carcass, and the most important cuts that come from each. Then whenever you work with a piece of meat, try to identify it exactly and match it with its primal cut.

Fabricated cuts
Primal cuts are fabricated into smaller cuts for roasts, steaks, chops, cutlets, stewing meat, ground meat and so forth according to customer requirements. Portion controlled cuts are ready-to-cook meats, cut according to customer specifications. Steaks and chops are ordered either by weight per piece or by thickness. Portion control cuts require the least work of all meat cuts. They are also the most expensive per kg. of all categories of cuts.



Characteristics of good quality beef








Characteristics of good quality mutton



CUTS OF MEAT
















COOKING AND HANDLING MEATS

Tenderness and appropriate cooking methods

The heat of cooking affects tenderness in two ways.

1 It tenderizes connective tissue if moisture is present and cooking is slow.

2 It toughens proteins. Even meats low in connective tissue can become tough if cooked at excessively high heat for too long.

The principle of low-heat cooking.

1 High heat toughens and shrinks protein and results in excessive moisture loss. Therefore low heat cooking should be the general practice for most meat cooking methods.

2 Broiling seems to be the contradiction to this rule. The reason that carefully broiled meat stays tender is that it is done quickly. It takes time for the heat to be conducted to the interior of the meat so the inside never gets very hot. Meat broiled well-done, however, is likely to be dry.

3 Roasts cooked at low temperature have better yields than those roasted at high heat. That is they shrink less and lose less moisture.

4 Moist heat penetrates more quickly than dry heat. Meat should be simmered, never boiled.

Other factors influencing choice of cooking methods

Fat content
Meats high in fat, such as prime beef or lamb are generally cooked without added fat, such as by roasting and broiling. Meats low in fat, such as veal, should be cooked with added fat to prevent dryness. Sautéing, pan-frying, or braising are preferable to broiling for veal chops.
Fat can be added to lean meats in two ways;

a. Barding: tying thin slices of fat, such as pork fatback, over meats with no natural fat cover, to protect them while roasting.

b. Larding: inserting strips of fat with a larding needle into meats low in marbling.

These two techniques were developed in Europe when meats were much leaner. They are not oftened used with today’s grain-fattened, well-marbled meats. These techniques are valuable techniques, however when cooking lean game such as venison.

Developing tenderness is not the only goal of cooking.
Other goals are;
a. Developing flavour
b. Preventing excessive shrinkage and nutrient loss
c. Developing appearance

You will often have to compromise to get a balanced result. For example preliminary browning of a roast at high heat increases shrinkage, but may be desirable for some roasts to develop flavour and appearance.

Searing and sealing
The purpose of searing meats at high temperatures is to create desirable flavour and colour by browning the meat’s surface. It was long believed that searing the surface of meat seals the pores keeping in the juices. This does not actually happen. Meat does not have pores, but is an open network of fibers. Think of the surface of the steak as resembling the cut end of a thick rope. There are no pores to seal. Roasts cooked from the start at low temperature retain more juices than roasts that are seared at high heat first.
Steaks, chops and cutlets cooked very quickly at high heat drives the juices away from the hot surface into the meat. This permits browning, because moisture would create steam and inhibit browning. However, overcooked steaks will be dry whether or not the steak was seared.

Blanching and sealing
Dropping the meat into boiling water doesn’t seal it either. What actually happens is this; many proteins dissolve in cold water. When heated these proteins coagulate and become scum or froth on the surface of the water. When meat is placed in boiling water some of the protein coagulates inside the meat and not as much is carried out with the lost moisture. Prolonged cooking will shrink meat as much as if started with boiling water than if started in cold water.


COOKING FROZEN MEATS

Some sources recommend cooking some meats from the frozen state without thawing in order to eliminate drip loss that occurs during defrosting. However, it is usually better to thaw before cooking because of the following reasons.

1 Frozen meats lose no moisture from defrosting but lose more during cooking. The total loss is about the same as for thawed meats. Besides the perception of juiciness depends as much as or more on the fat content than on moisture content.

2 Cooking frozen meats complicates the cooking process and requires adjustments in procedure. It is possible for roasts to be cooked on the outside but be still frozen in the center. Frozen steaks too are more difficult to cook evenly than thawed steaks. Thawed meats on the other hand are handled like fresh meats.

3 Cooking frozen meats require extra energy, and energy is expensive. A hard frozen meat may take three times as much as long to cook as a thawed roast.


DONENESS

The meaning of the term “doneness” depends on whether the cooking method uses dry or moist heat.

Dry heat: Meat is done when the proteins have reached the desired degree of coagulation as indicated by internal temperature.

Moist heat: Meat is done when connective tissue have broken down enough for the meat to be palatable. Meat cooked by moist heat is always well done.

Dry heat cooking
The object of dry heat cooking is to achieve the desired degree of doneness (protein coagulation) while still preserving natural tenderness and juiciness.

Degree of doneness
As meat cooks its pigments change colour. These colour changes indicate degree of doneness.
Red meat changes from red to pink to grey or grey-brown.

Rare: browned surface
thin layer of cooked (grey) meat
red interior

Medium: thicker layer of grey
pink interior

Well done: gray throughout

There are stages in between too.

White meat changes from pink or gray-pink to white or off white. It is generally cooked well done although many cuts of veal may be considered well done when still slightly pink in the center.








Interior Temperatures of Cooked Meats
Meat Rare Medium Well done

Beef 140ºF(60ºC) 160ºF(71ºC) 170ºF(77ºC)

Lamb 140-150ºF 160ºF(71ºC) 170ºF(77ºC)
(60-66ºC)
Veal _ _ 170ºF(77ºC)

Pork _ _ 165-175ºF
(74-79º)



Beef is frequently cooked rare. Most customers prefer lamb cooked medium. Recommended temperature for pork has been lowered. It is no longer considered necessary to cook pork to 185ºF(85ºC) to eliminate the danger of trichinosis.

Testing doneness
Determining doneness is one of the most difficult and critical aspects of meat cooking. Anyone can put a steak on the grill or a roast in the oven, but it takes experience and skill to take it off the fire at the right time.
Colour change cannot be used by the cook to test doneness, as it would be necessary to cut the meat. Piercing the meat and examining the colour of the juices is no a reliable method.

Internal temperature
Testing the interior of the meat with a thermometer is the most accurate method of testing doneness. Thermometers are of two types: standard, which is inserted before roasting and left in the roast; and instant-read, which is inserted at anytime, read as soon as the needle stops moving and pulled out. Whatever thermometer you use make sure it is clean and sanitary before inserting into the meat.
The tip of the thermometer should be inserted into the center of the thickest part, not touching fat or bone.

Carry-over cooking
Internal temperature continues to rise even after the meat is removed from the oven. This is because the outside of roasting meat is hotter than the inside. This heat continues to be conducted into the meat until it is equalised throughout the roast. Carry-over cooking can raise internal temperatures from 5ºF (3ºC) for small cuts to as much as 25ºF (14ºC) for very large roasts, such as a steamship round. Usual range is 10-15ºF (6-8ºC) for average roasts. Exact temperature change depends on the size of the cut and on the oven temperature.
Remove roasts from the oven when internal temperature is 10-15ºF (6-8ºC) below desired reading. Let roast stand 15-20 minutes before slicing. For example a beef rib cooked rare should be removed from the oven when the thermometer reads 125-130ºF (52-54ºC). Carry-over cooking will bring the temperature to 140ºF (60ºC) after the roast has stood for 30 minutes.








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.

6 Keep freezers clean.






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.



VERNON COELHO
IHM MUMBAI
2009-2010