MEAT ● Meat refers to the flesh and some internal organs of animals that are used for human consumption. ● The main reason for the high price of meat is the amount of time, effort and feed it takes to rear animals for meat. ● Animals for meat are slaughtered in abattoirs (slaughterhouses). ● The butcher cut the meat into joints or cuts, according to: -the amount and position of bones, lean meat, and fat on the various parts of the body. ● Lean, tender joints are more popular and difficult to procedure and therefore cost more, so the butcher must separate these accurately. Structure and Composition of Meat ● Most lean meats are made up of : -muscle tissue -connective tissue -fat ● Liver and kidney are exceptions. They contain no muscle fibres or connective tissues and are cellular in structure. Muscle tissue ● Lean meat is composed of the muscles that move the body in an animal. Muscles are composed of cells in the form of long, slender fibres. ● Muscle fibres are made of 2 main proteins : -myosin -actin ● The size of muscle fibres affect the tenderness of the cooked meat. For example : - slender, small fibres are associated with tender meat. - large, long fibres are associated with tougher meat. ● The older the animal, the tougher the meat because of the increase in size of muscle fibres. ● Parts of the animal such as neck, skin and forearm, have the largest muscle fibres thus making them tougher meat due to receiving regular and the most physical work. ● Individual muscle fibres are formed into bundles, surrounded by a substance called connective tissue. ● Whole muscles are attached to bones by rough, gristly tissue called tendons. Connective tissue ● Connective tissue is made of 2 proteins: ❖ Collagen ❖ Elastin ● Collagen is the white to transparent tissue component of tendons and connective tissue surrounding muscles, particularly those that do the most work. ● Collagen is less flexible than elastin. ● Collagen when heated in the presence of moisture is converted into soluble gelatine, which greatly increases the tenderness of connective tissue and therefore of the meat. ● Gelatine is water-soluble and offers little or no resistance to chewing. The amount of collagen converted to gelatin during cooking increases with cooking time. ● Traditionally, tough cuts of meat were cooked by slow moist methods such as stewing to facilitate the conversion of gelatine to take place. ● Elastin is a main component of ligaments (in-between bones), and has the ability to stretch and return to its original shape. Very little change occurs in elastin during cooking. ● Elastin is an insoluble and tough protein, but there is less elastin than collagen in muscles. Thus, elastin does not have a major influence on the toughness of meat. Fats ● A certain amount of visible and invisible fat is found in meat. ● The amount and kind of fat in meat vary with the kind of meat, the age and diet of the animal. ● Invisible fat is the fat that is distributed between cells as tiny globules. ● Visible fat is located between muscles, around organs and directly under the skin of the animal. ● Fats are found in the following places: ○ Under the skin in adipose tissue around vital organs, e.g. kidneys (suet) ○ Between bundles of muscle fibres (invisible fat) ● The fat under the skin may be yellowish, because of the presence of carotenes from plants, depending on what the animal fed on. ● The visible fat between the bundles of muscle fibres gives the meat a ‘marbled’ effect. ● One of the reasons why lean meat is so expensive is because the large amounts of feed required producing it. ● The fat content of meat helps to give flavour, moisture and texture to the cooked meat. Texture and Colour of meat ● Texture refers to firmness and smoothness. Firmness is desirable because it suggests a good diet and therefore a good flavour. Smoothness is associated with short, fine fibres and tenderness. ● Meat colour is also a good indicator of tenderness and flavour. Darkcoloured meat is usually tough, and more strongly flavoured than light coloured meat. ● The darkness of colour may be a sign of staleness. In this case, meat has a brownish hue. ● Yellow fat and grey flinty bones are associated with older animals and are therefore signs of toughness and strong flavours. ● The colour of meat is mainly due to the presence of myoglobin, which is a purple/red tissue protein, and haemoglobin from the blood. ● Haemoglobin takes oxygen to the muscles, and myoglobin old it there to facilitate muscle work. It can be drawn that there is more myoglobin in wellused muscles e.g. heart and shin and in other animals. (the colour of the meat is darker in both cases.) ● Oxymyoglobin is bright red meat colour. ● Metmyoglobin is brown/red colour of meat Choosing Meat Consider the following: ● Value for your money - Too much bone in a joint reduces its value of money - Cheaper, tougher cuts of meat are just as nutritious as more expensive, leaner cuts. - There should not be too much visible fat on the joint. ● Appearance The following physical characteristics should be noted: -Colour Meat Colour of lean Colour of fat Lamb pink/ brown cream/ white Mutton dark pink/ brown white Beef red/brown cream/ pale yellow Pork pink white -Moist but not dripping -smell fresh -marbled appearance if lean meat -slightly springy to the touch ● Intended use ○ Allow for possible shrinkage during cooking when choosing a joint. ○ When stewing or casseroling, it is uneconomic to use expensive, lean joints of meat. ○ 100 grams of meat per person The effect of heat and changes during cooking ● Texture and tenderness ○ The protein s of the meat denature at temperatures of 40 degrees Celsius to 65 degrees Celsius. As this occurs, the structure of the meat tightens and the meat becomes firmer. ○ The protein of muscle fibres may toughen during some cooking methods. ○ The connective tissue is tenderized during cooking. It becomes shorter and thicker so that the meat shrinks in size. Meat can be partially tenderized before cooking by: ❖ Mechanically pounding, scoring, and cutting across the muscle fibres to reduce their length. ❖ The use of enzymes, such as papain, which partially digests the protein ❖ Marinating in vinegar or alcohol ● Fat ○ The adipose tissue becomes more tender when cooked ○ The fat melts, and penetrates the lean meat during cooking, which increases the energy value of the lean meat. ○ The fat content may also make the meat appear more juicy ○ On the skin of roasted meat, the fat becomes crisp and brown ● Colour ○ During cooking, the colour of the meat changes from red to brown, due to the oxymyoglobin being converted to haemochrome. ● Flavour ○ Cooking meat improves it palatability. ○ In dry cooking methods, extractive containing flavour are squeezed out of the meat on to the surface as the protein denatures and shrinks. These extractive give meat its characteristic taste. The fat melts and gives a crisp surface to the meat. ○ In moist methods of cooking, the extractives are leached into the cooking liquid, which should be served with the meat to give it flavour. ● Nutritive value ○ Protein: -affect very little during normal methods of cooking -if overcooked, they become less digestible ○ Vitamins: -fat-soluble vitamins remain stable -In moist methods of cooking, the water-soluble b vitamins may be leached into the cooking liquid. -In dry methods of cooking, thiamin, being heat sensitive may be destroyed. ○ Minerals: -some leaching of minerals into the cooking liquid may occur in moist methods of cooking. -the liquid should be served with the meat. The importance of meat in the diet ● Meat is an important food as it is a good source of : -protein -B vitamins -iron -zine ● Meat is a main source of high biological value for many people. ● The nutritional value of lean meat of most types is an average: ○ Protein - 20% ○ Fat - 5% ○ Minerals - 1% ○ Water - 74% ● Pork is a good source of thiamin ● Both the protein and fat in meat are readily digested and absorbed in the body Ways to tenderizing Meat 1. Pounding 2. Salting 3. Marinating 4. Velveting 5. Slow Cooking 6. Enzymatic Application 7. Scoring Processed Meats ● Meat can be bought cured, canned, frozen or dried ● Cured products include: ○ Ham ○ Bacon ○ Salted meats ○ Sausages ○ Luncheon meats ● Ham is usually made from the hind legs and shoulders of the pig. ● Bacon is made from the side and belly ● Sausages and luncheon meats are made from chopped or ground meats blended with a variety of seasonings and spices. ● Canned products are usually fully cured or cooked products such as ham, corned beef and stew. Most can be stored without refrigeration. Dried meats may be prepared by sun or over drying. Meats that are dried in commercial quantities are cured or cooked, then dried under controlled conditions, to allow moisture to evaporate. Cuts of Meat Lamb and Mutton Joint Scrag end Middle neck Shoulder Cutlets Best end of neck Loin Chump chops Leg (fillet end) Leg (shank end) Leg (whole) Chops Breast Method of cooking Stew, braise Stew, braise Roast, braise, barbecue Grill, fry, barbecue Roast, braise Fry, grill, roast Grill, fry, roast, barbecue Braise, pot-roast Roast, boil Roast, braise Grill, fry, roast, barbecue Stew, roast, braise Pork Joint Method of cooking Blade bone Pot-roast, braise Spare rib As chops - fry, grill, roast, barbecue Loin As chops - fry, grill, roast, barbecue Fillet of leg Roast - slice and salt skin Salt and boil Chump Fry, grill, barbecue Knuckle/shank end of leg Roast, Salt and boil Belly Pot-roast, boil, braise As slices - fry, grill Hand and spring Roast, braise, Salt and boil Beef Joint Chuck Fore rib Sirloin Fillet Rump Topside Silverside Buttock steak Top rump Flank Wing rib Brisket Thick rib Shin Method of cooking Braise, stew Roast Roast As steak - grill, fry, barbecue Grill, fry, barbecue Grill, fry, barbecue Roast, pot-roast, braise Roast, pot-roast, braise Boil, salt and boil Braise, pot-roast, stew Pot-roast, braise Salt and boil, stew Roast Braise, pot-roast Salt and boil Roast Stew, braise POULTRY What is Poultry? ● Poultry are domesticated birds kept by humans for their eggs, their meat or their feathers. ● Poultry is the name given to birds eaten for food and includes: Chicken Duck Goose Turkey Pigeon Structure and Composition ● Poultry meat has the same basic structure as other meat, except that there is less connective tissue, so the meat is more tender. The legs and wing muscles which do the most work are generally tougher and darker because of the presence of myoglobin ● Except for goose and duck, there is less fat in the meat of poultry, so it is drier when cooked. ● The flavour of poultry is generally not strong, and develops during cooking similarly to that of other meat. Choosing Poultry Appearance 1. Poultry meat (except for pigeon, which is darker) should be pink/white, with darker meat on the wings and legs. 2. It should be plump and springy to the touch. 3. It should have a fresh smell Intended use ● Poussins are a very young bird that are cooked and served whole or in half. Nutritive Value ● The protein of poultry is easily digested and of high biological value. Except for goose and duck, poultry contains less fat than red meat. There is also less iron, thiamin, riboflavin, and nicotinic acid than in red meat. Uses of poultry in food preparation Chicken ● Whole or joints - roast, braise, boil, casserole. ● Joints - coat in egg and breadcrumbs and fry; grill, casserole. ● Cooked chicken can be eaten cold, in salads, snacks, and picnic meals Turkey ● Turkey can be cooked similarly to chicken. Boneless turkey rolls can be roasted to provide 3 to 4 servings Duck and goose ● Duck and goose are usually roasted. To reduce the fattiness of the meat, they can be placed on a rack during cooking and pricked with a knife at regular intervals to release the fat. Bones can be boiled to produce stock for use in the soups, stews and sauces. Poultry products ● A variety of poultry products are available, including: ○ Chicken nuggets and nibbles ○ Chicken wings ○ Poultry burgers ○ Poultry sausages ○ Rissoles Storage of poultry ● Freshly killed birds should be hung in a cool, dry place, with all the internal organs in place. This is to ensure that the meat becomes tender before it is cooked. ● Fresh poultry should be kept in a cold place after the goblets (internal organs-neck, gizzard, and liver) and other organs have been removed. It should be eaten soon after purchase. (two to three days if kept in the refrigerator). ● Frozen poultry should be allowed to thaw completely before being cooked, and then thoroughly cooked to avoid salmonella food poisoning. Reflection Despite a time-planning hiccup while preparing sweet and sour chicken, the post-frying addition of seasoning and sauce resulted in a delightful surprise. The unconventional approach yielded a unique blend of crispy exterior and succulent tenderness, with flavors harmonizing perfectly. OFFAL What is Offal? ● The edible entrails, internal organs of an animal used as food. Examples of offal Liver Heart Brain Kidney Tongue ● Sweetbread (the pancreas and thymus glands) ● Tripe (stomach of an ox or sheep) ● Chitterlings (pig’s intestine, often used as sausage casing) ● Tail (e.g. oxtail) ● Feet (e.g. pig’s trotters) ● Ears ● Head ● Eyes Choosing offal All offal, particularly the kidneys, liver and heart, should be bought very fresh. It should be eaten within 24 hours of purchase, and carefully washed and prepared before eating. Thorough cooking is necessary to prevent food poisoning and to tenderize the offal. Importance of offal in the diet ● Protein: ○ The protein of offal is of high biological value, and it well cooked is readily digested. ● Carbohydrate: ○ Liver may contain a little glycogen, but is not an important source. ● Vitamins: ○ Retinol (vitamin A) is stored in the liver, so liver is a very rich source. Kidney and heart also contain some retinol. ○ Heart and liver contain useful amounts of thiamin. This is some vitamin C in liver, but it is not a valuable source. ● Minerals: ○ Tripe contains a useful amount of calcium. Liver and, to a lesser extent, kidney, are important sources of iron. Storage for offal Offal should be kept in a cold place and used as soon as possible after purchase. It can be frozen for long-term storage.
