Meat

Lecture III:

Meat

 Generally defined as the muscles of animals, but in a broader sense it also covers the organs and glands obtained from the animal.

Types of Meat

 Beef – originates from cattle and are classified according to age and gender

Classification of Beef

Steers – Male cattle that are castrated while young so that they will gain weight quickly.

Bulls – Older uncastrated males that provide stag meat are usually used for breeding and then later for processed meats and pet foods.

Heifer – Females that have not borne a calf.

Cows – Females that have borne calves, its meat is less desirable.

Calves – 3 to 8 months old

Veal – comes from the young calves of beef cattle, either male or female, between the ages of 3

weeks and 3 months.

- Typically fed a milk-based diet or formula and have their movements greatly restricted. Some veal are allowed to roam in a pasture and are called “Free-Range Veal”.

- The meat results with an exceptionally milky flavor, pale color, and tender texture. For Free-Range Veal, meat is slightly less tender.

- Veal is a hard to find as there have been objections over what is perceived as inhumane treatment of these animals.

Sheep

Lamb – Comes from Sheep less than 14 months old.

- To determine a lamb, the lower leg of its carcass breaks off above the joint.

- Has a lighter and tender meat with mild flavor.

 Mutton – Comes from Sheep over 14 months old.

- To determine a mutton, the lower leg of its carcass breaks off in the joint.

- Has a darker and tougher meat with strong flavor.

Pork – derived from young swine of either gender slaughtered between 5 ½ and 7 months of age.

- Pigs are less than 4 months old.

-Hogs are older than 4 months.

- one-third of all pork is sold fresh, while the rest is cured and provided to consumers as ham, sausage, luncheon meats, and bacon.

Composition of Meat

Structure of Meat

 Muscle Tissue - This is where most protein are found. Made up of a collection of individual muscle cells, that are each surrounded by an outer membrane called the sarcolemma. If the muscle fibrils are small, the result is finer muscle bundles, which gives the meat a very delicate, velvety consistency.

Connective Tissue - Acts as glue that holds muscle cells together, and is a part of ligaments and tendons. Composed primarily of a mixture of proteins and mucopolysaccharides.

3 Main Types of Connective Tissue Proteins

Collagen – the most abundant protein. It’s tough and fibrous, but converts to a gel when exposed to moist heat. The higher the concentration of Collagen, the tougher the meat.

Elastin – has elastic qualities, also called silver skin. It does not soften with heating and should be removed before preparation.

Reticulin – consists of very small fibers of connective tissue that form a delicate interlace around muscle cells.

Adipose (Fatty) Tissue - simply fat, which serves as insulation under the skin and as padding in the abdominal cavity for sensitive internal organs. When it appears outside of meat, it is known as Cover Fat.

- Cover Fat helps retain the moisture of meats.

- Marbling is the fat found within the muscles.

- White Color of Fat means it comes from a younger animal, while yellow color comes from a mature animal.

Bone - used as landmarks for identifying the various meat cuts from a carcass.

• Marrow is the soft, fatty material in the center of the most large bones.

• Yellow Marrow are found in long bones

• Red Marrow – found in other bones and is supplied with many blood vessels.

Pigments

 Meat’s color is derived form pigment-containing proteins chiefly myoglobin and, to a lesser extent, hemoglobin.

The higher the concentration of myoglobin, the more intense is the meat’s bright red color.

Factors affecting concentration of myoglobin are activity, age, and specie.

 Meat is typically purplish red, but once cut and exposed to oxygen becomes bright red.

Extractives

 These are nitrogen compounds where meat derives some of its flavor.

 Most common extractives are creatine and creatinine. Other extractives are urea, and uric acid.

 Extractives are water soluble, so some of the flavors are lost when boiling or simmering meat.

 Older animals contains more extractives, therefore it yields more flavor than that from younger livestock

Purchasing Meats

Inspection

It is a guarantee of only wholesomeness and does not ensure the quality or tenderness of the meat

itself. It is conducted by licensed veterinarians or by specially trained, supervised inspectors. Inspection is done on live animals prior to slaughter, as well as animal carcasses. They also inspect the entire slaughtering process, safety, and hygiene.  An inspection stamp is marked on meats that passed inspection.

 NMIS – National Meat Inspection Services attached agency of DA, which is tasked to serve as the national controlling authority on all matters pertaining to meat and meat product inspection and hygiene.

Grading

 Factors considered in grading are color, grain, surface texture, and fat distribution. A cut is made between the 12th and 13th rib in order to expose the rib muscle.

 The term “no roll” is used to indicate ungraded meat.

 Fat, in the form of marbling is an important factor in grading a meat.

USDA Prime - Very tender, juicy; flavorful; the greatest degree of marbling. The most expensive of the grades, Prime is sold to finer restaurants and some meat stores.

USDA Choice - Quite tender and juicy, good flavor; slightly less marbling than Prime. The grade most frequently found in retail stores.

USDA Select - Fairly tender; not as juicy and flavorful as Prime and Choice; has least marbling of the three, and is generally lower in price.

Lecture IV

Tenderness of Meat

 Tenderness and Flavor are the two most important factors affecting consumer acceptance.

 Factors Affecting Tenderness

◦ Natural Tenderizing

◦ Artificial Tenderizing

◦ Mechanical Tenderization

◦ Electrical Stimulation

Natural Tenderizing

 Cut

- most important influence on tenderness of meat is location of the muscle from which it came.

- Muscles that are exercised are tougher than those that are not.

 Animal’s Age

- USDA grades usually come from relatively young animals.

- as muscle age, the diameter of the muscle fibers increases and more connective tissue develops, resulting in toughening of meat.

 Heredity - Genetic Factors affect variations on the tenderness of meat

Diet - the type of diet fed to the animal directly influences its fat accumulation, which is one of the factors affecting tenderness and flavor.

 Marbling - Fattening animals before slaughter is thought to increase tenderness by increasing marbling.

 Slaughtering Conditions - Conditions preceding slaughter and afterward both affect the tenderness of meat.

Rigor Mortis

- Within 6 to 24 hours after slaughter.

- the oxygen-deprived cells switch to glycogen as an energy source, converting it to lactic acid.

 Aging

- improves meat’s juiciness, tenderness, flavor, color, and their ability to brown during heating.

Problems with Improperly

Handled Meat

 Dark-Cutting Beef - If glycogen stores are depleted before death, insufficient lactic acid will be produced resulting in higher pH (above 5.8). It will result in deep-purple brown meat known as dark-cutting beef, which has sticky texture.

 PSE Pork - Pale, soft, and exudative pork results if the pH drops too low, resulting into a dry meat when cooked. pH of 5.4 and below can cause the pork to become extremely pale, mushy, slimy, flavorless, and full of excess drip.

Thaw Rigor - Freezing meat before it undergoes rigor mortis. A phenomenon in which the meat shrinks violently by almost 50% when thawed.

 Cold Shortening - When meat has been chilled too rapidly before rigor mortis.

 Green Meat / Cooked Rigor - Meat that is cooked while in a state of rigor mortis. Meat is prepared before stiffening begins.

Different Ways of Aging Meat

 Dry Aging - Carcasses or Meat are hung in refrigerated units at 1°C - 3°C with low or high humidity for 1.5 to 6 weeks.

- meat is more expensive than other types of aged meat because exposure to air can cause 20 percent lost in weight.

-Dry-aged meat’s flavor is concentrated making it more succulent and mellow.

Fast or Wet Aging - Placed in plastic shrink wrap in warmer temperatures of 21°C with a high humidity for 2 days.

- Ultraviolet lights are used to inhibit microbial growth.

 Vacuum-Packed Aging - Less weight loss and spoilage occurs.

Meats are packed in moisture-and-vapor-proof plastic bags, and then aged under refrigeration.

Artificial Tenderizing

 Enzymes - Papain and other proteolytic enzymes are injected ten minutes before slaughter. Commercial tenderizers containing enzymes are effective only on thin cuts as it can only penetrate to a depth of ½ to 2mm. - Enzymes are not active at room temperature, and can only be activated through heating.

Salts - Addition of salts in form of Potassium Chloride, Calcium Chloride, or Magnesium Chloride can also increase tenderness. These salts retain moisture and breaks down the component that surrounds muscle fibers, resulting in release of protein. Polyphosphates are added to the salts to increase water retention ability, thus improving juiciness.

Acids - Acid or Alcohol containing marinades break down the outside surface of the meat which makes meat more tender. Various Acids founds in marinades include: vinegar; wine; lemon; tomato; and other fruit juices. Acids do not just tenderize the meat, but they increase flavor and also contribute to color.

Mechanical Tenderizing

Common Mechanical Tenderizing Methods

Grinding – increases surface-area-to-volume ratio, causing the teeth to have less work to do

Cubing - increases surface-area-to-volume ratio, causing the teeth to have less work to do

Needling – uses special piece of equipment to send numerous needle-like blades into the meat, separating the tissues.

Pounding – simply “pounding” the meat with a special hammer that breaks apart its surface tissue

Electrical Simulation

 The meat of beef cattle and sheep, but not swine, becomes more tender when a current of electricity is passed through the carcass after slaughter and before the onset of rigor mortis.

 Electrical Simulation speeds up rigor mortis by accelerating glycogen breakdown and enzyme activity, which disrupts protein structure, making the meat more tender.

Storage of Meats

Ways to Store Meat

Refrigerated – Temperature must be between 0°C to 2°C.

Wrapping Meat – Meats are tightly wrap and refrigerated for 2 days and then replaced by loosely wrapped plastic wrap, wax paper, or aluminum foil.

Controlled-Atmosphere Packaging – CAP is a new patented way to store meat for wholesalers that can extend shelf life of fresh red meat from 2 days up to 28 days. The process involves using a special package that allows the removal of oxygen and its replacement with a mixture of 70% nitrogen and 30% carbon dioxide

Freezing – Meats should be wrapped tightly in aluminum foil, heavy plastic bags, or freezer paper and stored at below 0°C. Frozen Cuts can last from 6 to 12 months, while ground meats should be frozen for no longer than 3 months.

Processed Meats

Processing Methods

Curing - it is meat cured by saturating it with salt.

- Dry Curing and Brining

- Commonly cured meat products include ham, bacon, sausages, corned beef, luncheon meats.

 Smoking - Most cured meats are also smoked. Smoke imparts flavor, aroma, and color to foods.

 Canning - Canned Meats are processed through either pasteurization or sterilization.

- Pasteurized canned meats require refrigeration and are labeled “Perishable – Keep Refrigerated”.

- Sterilized canned meats require no refrigeration as long as the can remains sealed.

 Drying - it is not widely used for meat. Cooked/Smoked meats such as pepperoni, salami, and beef brisket are dried under specific conditions of humidity and temperature.

Types of Processed Meats

 Ham

- cured pork meat from the hind leg of a hog.

Types of Cooked Ham

Canned Ham – Boneless, fully cooked ham that can be served cold or heated.

Water-added Ham – no more than 10% by weight of water added. The added moisture contributes to a moist, juicy, tender texture.

Imitation Ham – Ham that retains more than 10% moisture after curing.

Country Ham – Ham cured by the dry salt method and usually hickory smoked to develop a distinctive flavor.

Picnic Ham – Cured pork that comes from the front leg. This is less tender and higher in fat than regular ham.

Sausage

- meat that has been finely chopped or ground and blended with various ingredients, seasonings, and spices, and then stuffed into casings or skins.

Classification of Sausage

Uncooked – Made from ground, uncooked meat. Fresh pork sausage, bratwurst are examples.

Cooked – Made from cured meat, which may be slightly smoked before or after stuffing. Examples include hotdogs, and bologna.

Dry/Semidry – Made of cured meat that has been dried. Examples are pepperoni and salami.

Bacon

- Cured and smoked meat from the side of the hog. It should have a balance lean-to-fat ratio.

 Lower-Fat Processed Meat

- Products produced by using leaner cuts of meat, adding more water, and/or including ingredients such as fiber, gums, modified starches, and whey protein concentrates.

 Mechanically Deboned Meat - Traces of meat that are left on the bones after butchering. It consists of ground bone, bone marrow, and soft tissue.

 Restructured Meat - also called fabricated meat is made from meat trimmings and/or lower grade carcasses.