Module 6. Meat and poultry processing

 

Lesson 24

POULTRY MEAT AND ITS PROCESSING

 

24.1 Introduction

In global meat production poultry meat is taking the second place after pork. Due to its widespread availability and popularity and its mostly very competitive production cost, poultry meat has an increasing share as a raw material in processed meat. Turkey and chicken meat is very suitable for further processing purposes.  Poultry meat is of higher nutritive value than that of other red meats, because of its higher protein content and better digestibility.

24.2 Characteristics of Poultry Meat

Muscle to bone ratio in the case of poultry is 1.8 thus the carcass yield is less as compared to other warm blooded animals (Table 24.1).

Table 24.1 Composition of carcass

Species

Meat %

Fat %

Bone %

Skin %

Broilers

52

6

30

12

Hen

37

12

40

11

Duck

34

18

38

10

Chicken meat is pinkish white in breast and wings and in other parts pink to light red. In general poultry meat is described as white meat while meat from other animals is called red meats. Total fat in chicken/broiler is 7.4g per 100 g portion of lean meat, of which is 27.53% saturated, 35.90% Mono-unsaturated and 22.81% Polyunsaturated fatty acids. The total conjugated linoleic acid (CLA) content of chicken and fresh ground turkey is 0.9 and 2.5 mg/g of fat respectively. On the other hand, typical composition chicken is moisture 73.7 %, protein   20-23% and fat 1.0%.

24.3 Processing of Poultry Meat

Either the entire carcass meat is used for further processing, or some of the cuts go in fresh meat sales and the remaining into the manufacture. Chicken carcasses are usually cut in wings, legs and breast. Legs can be further subdivided into thighs and drumsticks. The breast consists of the larger superficial breast muscle and the smaller profound breast muscle, the latter is also called “filet”.  Primary objective of poultry meat processing is to inhibit microbial growth and to stop deteriorative quality changes in the meat. Poultry meat processing utilises, the same principles viz. refrigeration, freezing, smoking, curing, dehydration, freeze drying, canning and ionising radiations  as applied in the beef and pork sector. Sometime antibiotics are also added to preserve raw poultry meat.

24.4 Slaughter and Dressing of Poultry

Poultry birds are generally not fed for 12 hrs before their slaughter and are killed by the method which utilizes minimum efforts/struggle. The poultry animal is stunned and made unconscious by attacking on the head. Larger poultry houses make use of electrical stunning devices. Jugular vein is cut in such a way that bleeding completes in 2-3 min of slaughter. Bird is then dipped scalding water (temp. 60°C for 45 sec or at 52°C for 2 min). Scalding results in loosening of feathers, thus easy removal of them. Evisceration of bird follows the defeathering, where in various parts of the birds are removed for subsequent processing e.g. chilling, freezing  etc. Dressed chicken and other fowls may be canned whole or dissected in their own juice. Use of low temperatures may be applied to improve the shelf life of dressed chicken:

a) Chilling – Chilling storage of poultry is for only less than a month. Birds to be stored longer should be frozen. The lower the temperature of storage, the longer the birds stored without undesirable changes. Compared to room temperature, the storage life was extended 2 days at 10°C, 6 days at 4.4°C and 14 days at 0°C. However, the rapid chilling is always advisable in the cases of poultry meat as the onset and outset of rigor takes at early.

b) Freezing -  Poultry can be kept in good conditions for months if freezing is prompt and rapid and storage temperature is low enough. Fairly rapid freezing is desirable since it produces a light golden colour because fine ice crystals are formed within the fiber while slow freezing causes the flesh to be darker. The storage temperature should be below – 17.8°C and RH above 95% to reduce surface drying. Rapid freezing of poultry is desirable since it causes tissues to become very pale, which is desirable since it cause tissues to become very pale, which is desirable. However, most poultry is sharp frozen at about – 29°C or less in circulating air or on a moving belt in a freezing tunnel.

c) Modified atmospheric storage – Increasing carbon dioxide concentration to 10 – 20%in the atmosphere of store chickens inhibits the growth of psychrotrophs. The use of store chicken inhibits the growth of psychrotrophs. The use of films of both high and low gas permeability in combination with Co₂ atmosphere shows that the Co₂ atmosphere is the significant factor in reducing microbial counts.

d) Ionising radiation – It is a potentially useful form of preservation. Besides from its desirable ability to inactivate micro – organisms, it also results in the breakdown of various lipids and proteins to often undesirable odours.

24.5 Preparation of Carcasses for Cooking

Chicken is available either chilled or frozen state. Chilled Poultry should be kept uncooked, loosely wrapped and unfrozen in the refrigerator. It is good practice to wash the residues from the surface of the carcass before using.

24.5.1 Frozen poultry

For freezing poultry should be tightly wrapped in moisture vapor proof film and then it should be frozen as soon as possible. Its undesirable to unfreeze poultry for a second time because freezing and thawing releases fluid which is called drip. And at that stage chances of bacterial contamination increase.

24.5.2 Thawing of poultry

For the thawing of chicken is placed in refrigerator for 12-24 hours, or place it in a pan under running cook water in its original wrapping for about ½- than. All frozen turkey should be thawed slowly and never at room temp or in warm water.  Turkey should be thawed in the following manners.

a.       Place the bird skill in its original wrapping under running cold water for about 2-6 hours depending upon size of birds.

b.      Leave the bird in its original body wrapping. Poultry a refrigerator of allow 1-3 days for thawing.

24.6 Cooking of Poultry

Raw chicken meat has no flavour, it is developed during cooking and sometime due to addition of spices. For the cooking of tough poultry meat moist heat is preferred on the other hand for soft variety of meat dry heat methods are recommended. Major physico-chemical changes taking place due to Cooking are listed as below:

1.      Heat causes coagulation of proteins ,

2.      Melting of fat

3.      Change in colour of red meat to pink & finally brown or grey. In the presence of moisture when is present naturally in the meat

4.      Collagen is hydrolyzed to gelatin when the meat is heated.

5.      Heat affects the tenderness of meat is coagulation of protein causes to toughening in meat tissues & hydrolysis of collagen to gelatin makes it tender.

6.      The change on flavor due to heat is caused partly due to volatiles, decomposition of protein or fats and/or caramelization of carbohydrates & coagulation of protein

7.      The shrinkage of meat is due to loss of the moisture and fat which are released from the meat and collect at the bottom of cooking pan.

24.7 Methods of Cooking

Poultry meat processing utilizes same principles (e.g. frying, roasting, broiling etc.) as are use in other meat processing.  It is necessary part of improving taste and flavour of the finished products. Sometime marination is done of the chicken portions to improve flavor and texture of the product. In marination meat is soaked in the acidic seasoned liquid (known as marinade) before the cooking.  Marinade contains vinegar, lemon juice, or wine or enzymes and oils, herbs and spices to add further taste and tenderize the meat. Before cooking sometime chicken is coated with flavoured batter to improve flavor. Breading of chicken is done prior to coating to provide crisp outer layer of beaten egg covered later with flour.

The cooking method includes both moist heat which are applied for older and tougher birds and dry heat methods which are given to young birds which improve their palatability.

Two general rules should be followed in cooking of poultry-1. First cook at a moderate heat so that the meat cooks evenly up to the bone and such meat will be tender and juicy. The poultry meat which is cooked intense heat has a high cooking shrinkage and is less juicy, flavour is lost and has hard and sogi flesh as compared to poultry which is cooked at moderate temperature.  2. The age and fattiness of the bird are considered to be main criteria to determine which cooking method should be used. Broiling, frying and open pan roasting are best for younger tender birds with a good covering of fat. For carcasses those are lean, braising in a covered roaster, produces tender and flavor full meat. Carcasses from older birds require long and slow cooking in water or stream to make them tender.

24.7.1 Frying

Only young tender & low fat poultry meat should be cooked by frying. They can be fried by general methods such as frying cooking, deep fat frying, pan frying, oven frying, and deep fat frying under pressure. Generally carcasses are use into portions suitable for serving and then they are seasoned, salts, pepper and other spices as required are added, chicken should be rolled in floor or dipped in a batter generally containing eggs, milk, flour, and seasoning. Another medium sometime used for dipping of poultry meat pieces is the egg. & milk batter. Coated meat pieces are then dipped into the cooking medium i.e. oil/fat heated to 358°F. Generally temp of fats/oils between 300-325°F during frying. When the meat is to be preserved, the parts of the meat are first to be deep fried for a short period to ensure browning and then they are cooked under pressure for about 5-8 minutes. A thick pan should be used which contain about ½” hot fat. The coated parts are added to fat and then pan as covered with a lid. Moderate heat should be used and process should be turned when they brown. Generally the boiled fried chicken cooked by this method taken about 20-25 minutes after frying the piece should be kept in absorbent paper in order to remove excess oil.

24.7.2 Broiling

Broiling,  is a type of cooking which involves exposing food to direct radiant heat, either on a grill over live coals or below a gas burner or electric coil. Broiling differs from roasting and baking in that the food is turned during the process so as to cook one side at a time. Temperatures are higher for broiling than for roasting; the broil indicator of a household range is typically set around 550°F (288°C), whereas larger commercial appliances broil between 700° and 1,000° F (371° and 538°C).  Fish, fowl, and most red meats are suitable for broiling. Young tender poultry e.g. chicken, turkeys & duckling can be cooked by broiling at 400ºF. Before cooking the meat is brushed with fat, seasoned with salt and pepper and some sauce instead of adding fat. Then portion is placed in a shallow pan with a skin side down and pan of meat is placed in preheated broiling. After cooking for about 30 minutes the pieces are turned and again basted. Generally broiler is placed 10 cm away from the flame and cooked till the internal temperature of breast reaches to 95°C which takes around 45-60 minutes. Low fat content of the broiled chicken and basting of melted fat results in improved flavour and texture and palatability of the chicken.  The chicken is considered to cook when the drum stick or the wings twist out of their poultry.

24.7.3 Roasting

Young broiler pieces of any weight may be used for the purpose of roasting. A plump chicken of at least 2.5 lb are desirable.  It may be stuffed or unstuffed.  While roasting whole birds, tender parts e.g. breast may be overcooked before the legs and thighs are cooked to the desirable state. In order to avoid any food poisoning the temperature of the internal parts of the stuffed chicken must reach to 74°C. if the poultry is roasted without stuffing, it is cooked to temperature of 163°C till the temperature of the interior side reaches to 85°C.  However the exact time temperature combination of the roasting depends upon the size of the carcass.

24.7.4 Tandoor chicken

This product is always tagged with typical Indian chicken dish and widely accepted worldwide. It is a kind of barbecued chicken wherein cooking is done on a clay oven called as tandoor. Charcoal is used inside the tandoor to produce the heat and increase the temperature. The combination of heat and the smoke generated due to charcoal gives typical savory flavour, taste and texture to the finished product. Chicken cooked this way is really found to be very delicious. 

24.7.5 Braising and stewing

Braising is a combination cooking method using both moist and dry heat. This is the technique which is used to cook older and tougher birds. Disjointed pieces of chicken are generally cooked this way. Initially frying is done to darken the colour to the brown which is then followed by addition of water and simmering of the meat until it gets tender.

In the stewing the frying step is eliminated and the bird whole or its pieces are cooked in water with seasoing and some vegetables till they get tenderize. A stew is a combination of solid food ingredients that have been cooked in liquid and served in the resultant gravy. Ingredients in a stew can include any combination of vegetables (such as carrots, potatoes, beans, peppers and tomatoes, etc.), meat, especially tougher meats suitable for slow-cooking, such as beef. Poultry, sausages, and seafood are also used. While water can be used as the stew-cooking liquid, wine, stock, and beer are also common. Seasoning and flavourings may also be added.