Chapter 2 protein structure 29 a s described in chapter 1, the watsoncrick model helped to bridge a major gap between genetics and biochemistry, and in so doing helped to create the discipline of molecular biology. Feb 27, 2018 therefore, protein, not counting water is the most prominent macronutrient in the nutritional composition of chicken. The structure of intact muscle meat is highly organised figure 1 consisting of many muscle fibres or cells within the muscle. Texture measurement can be visually, touched or chewed. Lipids sources of energy, cell membrane structure and. Composition of meat water, carbohydrates, minerals and vitamins. With respect to the chemical composition of the fillet and upper thigh, turkey meat showed measurements similar to those of broiler meat. Chicken also has a remarkable content in phosphorus mineral present in bones and teeth, selenium with antioxidant action and contains vitamins such as b3 and vitamin b6. How muscle structure and composition influence meat and. Meat can also be cured by pickling, preserving in salt or brine see salted meat and other curing methods.
In the live fish, glycogen is the source of stored energy. Part i fresh meat technology chapter 111 containing history and development. Pdf how muscle structure and composition influence meat. Since the predominant portion of the edible flesh of animal carcasses consists of muscular tissue, meat can be conveniently regarded as the post mortem aspect of muscles. Meat nutritional composition and nutritive role in the. The postmortem changes of muscle structure and its main componentproteinsplay a key role in the conversion to meat.
This chapter describes the muscle composition and the conversion of muscle into meat, the meat components nitrogen compounds and enzymes, lipids, carbohydrates, vitamins, minerals, and water, their influence in meat quality, and the factors that affect meat composition. Chemistry in the meat industry nz institute of chemistry. Muscle contains 60% to 70% moisture, 10% to 20% protein, 2% to 22% fat, and 1% ash, depending on type and species. Structure of meat muscular tissue each fibre is a bundle of tubeshaped cells covered and bound together with a web of white connective tissue, threaded by tiny bloodvessels. The principal attributes of eating quality in meat, for which. For the determination of chemical composition poultry meat and compare values, different poultry species were included. Meat is defined by the codex alimentarius as all parts of an animal that are intended for, or have been judged as safe and suitable for, human consumption. Toward the ends of the muscles the fibres dwindle down till only a firm mass of connective tissue, called tendon, is left. The most abundant chemical in meat is water followed by protein then fat. This page describes what vegetables are, and the different components that go together to form them. In tender meats the collagen is changed by the steam formed from the juices of the meat in the processes of boiling and baking, but a large amount of water must be added to very tough meats to bring about. The composition of poultry meat differs in different commercially available brands which are related to the feed offered, age of slaughter etc.
The shell fish has less fat and more carbohydrate than fin fish. Humans have hunted and killed animals for meat since prehistoric times. Identify meat cuts, grades, and the marketing process. Vanimal productsa meat 3 table 1 the composition of meat proportion % substance composition lean average beef lamb water 75 73 71 protein 18 22 21 fat includes phospholipids, cholesterol and fatsoluble vitamins. Chemical composition and meat quality attributes of. Where the vegetable comes from on the plant affects its postharvest qualities, especially how it changes after harvest. The aim of the study was to compare chemical composition and quality attributes of meat between male long fat tailed sheep n 17 and small east african goats n 17 existing in tanzania. Because of where the cut of meat comes from on the animal, different cuts require different cooking methods, e. Meat with high whc will have a stronger structure and a dry texture. This is an active area of research and many possible orientations have been tested e. Chemical composition of chicken of various commercial brands.
Chemical and physical properties of meat bohat ala. Therefore cuts of meat vary in energy and nutrients, composition, weight and fat level. Meat composition and temperature are the most important factors that determine the generation of mutagens in fried meat. Carbohydrates, minerals and vitamins occur on much smaller amounts but nevertheless are very important metabolically and nutritionally.
Muscle structure, proteins, and meat quality sciencedirect. Meat is defined in the oxford english dictionary as the flesh of animals used as food, now chiefly butchers meat, excluding fish and poultry. But we have meat and we can eat, sae let the lord be thankit. Meat structure and composition a typical cut of meat, such as a tbone steak, is made up primarily of skeletal muscle, connective tissue, fat, bone, and a small. The connective tissue cells are joined together into bundles by two types of connective tissue. Different cuts of meat have different characteristics, e. The composition of meat meat is composed of, in descending order, water, protein, fat, other watersoluble organic material and watersoluble minerals. Meat is composed of water, protein and amino acids, minerals, fats and fatty acids, vitamins and other bioactive components, and small quantities of carbohydrates. Aug 15, 2007 the cla content of meat is affected by several factors, including breed, age and food composition.
Breast meat of soup hens showed a higher fat content 1. Typical processed meat products include bacon, cured ham, corned beef, canned meats, precooked meats, and sausages see meatiindustry. Review article how muscle structure and composition. The narrative part describes the structure offish flesh, the nature and function of the main chemical constituents, their variation with season and their contribution to the. Meat is thought by many to be mainly the muscle parts of the animal, with some fat and connective tissue accepted as part of meat. The chemical composition of the meat from various cuts of poultry obtained from three commercial brands brand i, ii and iii of chicken from different processing plants available in the saudi arabian market. The meat we sell in our shops is derived from skeletal muscle, the muscles that pull on bones of the skeleton to produce body movements. Meat and poultry is composed of muscle, connective tissue, fat and bone. The muscle is approximately 75% water although different cuts may have more or less water and 20% protein with the remaining 5% representing a combination of fat, carbohydrate and minerals. Diet and feeding strategy largely affect meat composition and metabolic properties of muscle, thus affecting meat quality in many ways.
One of the advantages of chicken meat is that the fat is very visible, so if you remove parts such as the skin, the caloric value of the piece will be lower. Composition of meat water, carbohydrates, minerals and. Meat processing, preparation of meat for human consumption. At moderate temperatures below 200 c, a high content of proteins and creatine is necessary for generating, by maillard reaction, the hcas that are responsible for mutagenic activity.
Chemical composition of meat and meat products springerlink. Meat is an important source of amino acids the building blocks of. Secondary structure refers to the shape of a folding protein due exclusively to hydrogen bonding between its backbone amide and carbonyl groups. Structure and composition meat is an excellent source of high nutritional value proteins and a lowcarbohydrate food product associated with a low glycemic index. Shahidi department of biochemistry, memorial university of. Protein composition and structure biology libretexts. Where multiple types of meat have been used you must declare the content of each. Composition of meat meat muscle, which is what we eat, is made of fibres, bound together with connective tissue, that are mainly linked to other groups of muscles or directly to the animals bone structure. Lipids sources of energy, cell membrane structure and function, and metabolic functions vitamins and hormones. Although some epidemiological data has revealed a possible association between its consumption and increased risk of several forms of cancer, cardiovascular and metabolic diseases, meat consumption has been important in human species evolution. Mechanically recovered meat composition is also outlined, due to it is a.
Composition, essential nutrients in meat and poultry meat. Meat and meat products encyclopedia of life support. Jul 20, 20 composition and structure of meat meat is the flesh of an animal used for food according to the little oxford dictionary. Meat and meat products encyclopedia of life support systems. This note gives the chemical composition, in simplified form, of commercially important species of fish landed in britain or imported in quantity. Chemical composition of meat and meat products request pdf. Although there are these variations, retail cuts of meat are influenced by the structure and composition of the carcase, e. Meat is generally eaten cooked, but many recipes call for raw beef, veal or fish. Mechanically separated meat msm mechanically separated meat is the product obtained by removing meat from bones after boning, or from poultry carcases, using mechanical methods that cause the muscle fibre structure to be lost or changed. Some have meat and cannot eat, some cannot eat that want it. To show the structure of animal tissues so that students can understand postmortem events that occur in muscles and how they affect meat properties.
Secondary structure does not include bonding between the rgroups of amino acids, hydrophobic interactions, or other interactions associated with tertiary structure. This section begins with the nutritional composition of red meat, and then focuses on the key nutrients delivered through the consumption of red meat in the context of the australian diet. Reviewarticle how muscle structure and composition influence meat and flesh quality annelistrat,1,2 benedictelebret,3,4 isabellelouveau,3,4 thierryastruc,5 murielbonnet,1,2. Fat is an important energy source because of the amount of energy produced can be doubled from that generated by proteins and carbohydrates. In meat and sh esh, these qualities are in uenced by many in vivo and postmortem pm factors such as species, genotypes, nutritional and environmental factors,slaughteringconditions,andpmprocessing. May 24, 2017 texture, hardness and structure of meat are influenced by several factors, including the whc, rigor status, marbling fat, connective tissue content in meat and muscle bundle size. Composition and structurecomposition and structure muscle tissue consist of three major components. Meat structure and composition a typical cut of meat, such as a tbone steak, is made up primarily of skeletal muscle, connective tissue, fat, bone, and a small amount of smooth muscle such as arteries and veins. The structure, composition and preservation of meat. This eventually led to their use in meat production on an industrial scale with the aid of slaughterhouses meat is mainly composed of water, protein, and fat.
Request pdf chemical composition of meat and meat products meat is the flesh of certain animal species that is used as food by humans and includes many tissues and edible parts although the. A typical cut of meat, such as a tbone steak, is made up primarily of skeletal muscle, connective tissue, fat, bone, and a small amount of smooth muscle such as arteries and. Water 75% protein 20% fat up to 5% carbohydrates small quantities. A study of the structure and composition of lean meat. The composition of fish varies to a large extent and depends on its fat content. Other kinds of meat are marinated and barbecued, or simply boiled, roasted, or fried. Identify the pigments in meat and the changes that occur during heating and cutting. The process of conversion of muscle to meat involves a series of complex chemical reactions including structural changes of muscle, protein degradation, and breakdown of highenergy compounds. This chapter gives a description of the chemical composition of the coconut, which will form a basis for understanding chemical processes in the following chapters. Meat is a concentrated nutrient source, previously considered essential to optimal human growth and development higgs, 2000. Chemical composition of meat meat nutrition free 30day. The advent of civilization allowed the domestication of animals such as chickens, sheep, rabbits, pigs and cattle. Pdf how muscle structure and composition influence meat and.
Consumers prefer lean meat of reduced content of fat and high protein. Meats are often classified by the type of animal from which they are taken. Feb 12, 2017 meat composition meat composition varies with. To add to the complexity, legislation relating to meat and meat products varies from country to country. Myoglobin and related compounds discuss the factors determining meat quality. Muscle fibers are bound together in bundles by connective tissue. The coconuts composition is dependent on several factors such as age and varieties. The harder and tougher the connective tissues of the meat, the longer the time which will be required in cooking to change them to gelatine. The structure and muscle composition, the kinetics of pm changes, and the additional meat use and processing methods that are applied e. Chemical composition of chicken of various commercial brands available in market.
Texture, hardness and structure of meat are influenced by several factors, including the whc, rigor status, marbling fat, connective tissue content in. The double helix structure showed the importance of elucidating a biological molecules structure when attempting to understand its. Composition and properties of meat chemical animal science. Composition of meat meat cutting and processing for food. The definition of quality can be described readily when the product is a simple substance such as sodium chloride, used for curing meat.
Chemical composition of chicken of various commercial. Nutritive value of various fish is given in table carbohydrate. Composition and structure of meat meat is the flesh of an animal used for food according to the little oxford dictionary. How muscle structure and composition influence meat and flesh. Meat is the common term used to describe the edible portion of animal tissues and any processed or manufactured products prepared from these tissues. Review article how muscle structure and composition influence. The coconut, scientifically known as cocos nucifera, is a fibrous drupe. Because these factors also in uence the structure and composition of skeletal muscle, their e ect on meat quality could largely. The fat portion includes some fatsoluble substances, including some vitamins. White and yellow connective tissue, the white connective tissues are called collagen, is found in all the muscles of the. Like meat, fish contain some glycogen in muscle tissues.
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