Physical Characteristics of a Beef Marker

Chemical Properties of Meat

Chemical Composition:

Water                                    56-72%

Protein                                  fifteen-22%

Fats                                         v-34%

Not-protein substances     3.v%

Properties:

• H2o:

Water contributes to many of the characteristics of meat products.
Approximately 65% of the weight of fresh meat is from h2o which is directly related to the poly peptide content of meat. There is a constant relationship of virtually iii.7 to one betwixt h2o and protein content in fresh meat.

In all living animals, water contributes to cellular integrity, pregnant it provides the internal pressure level to keep cells from collapsing on themselves. Water as well provides lubrication for musculus fibers, assuasive smooth contraction and release of muscle tissue.

Protein binds with water in the cell considering of a polar attraction between water and protein molecules. When an fauna is slaughtered, the ability of the muscle to retain water is reduced. Postmortem changes will affect water loss in fresh meat. Several techniques are applied afterward slaughter to reduce water loss.

Postmortem is a term used to describe the state of the animal after it has been slaughtered. Once an creature has been slaughtered, rigor mortis, or the stiffening of body joints due to contraction of the musculus tissue, begins after a few hours. Rigor mortis occurs in a expressionless body because of the trunk's inability to keep calcium ions out of the musculus cells.

Calcium ions promote the linking of actin and myosin, two types of muscle fibers, which brainstorm to contract and are unable to release. The muscles will stay contracted until the muscle tissue begins to decompose, approximately 72 hours later death. Refrigeration and rapid cooling can filibuster the onset of rigor mortis, but the process will occur upon the thawing of the carcass. Meat is mostly considered to be more tender if prepared subsequently rigor mortis has passed.

Virtually of the reduction in water holding chapters of muscle is due to a decrease in the pH of the musculus. pH is a measurement of the acidity or alkalinity of a substance. The final water-binding ability depends on the charge per unit and extent of the pH drop. When the pH drops quickly during the conversion of muscle to meat (slaughtering), a lower h2o-binding capacity results.

The lowered pH is due to an accumulation of lactic acid, a product of glycogen metabolism, in the muscle of the animal. The lactic acrid becomes concentrated in the musculus because the circulatory system, inactive afterwards slaughtering, is unable to remove information technology.

• Proteins:

As a source of protein, meat protein is the second largest component afterwards the water one. Muscle protein is divided into 3 groups based on their solubility properties; firstly, sarcoplasmic protein (30%), myofibril protein (55%) and stromal poly peptide or musculus tissue (fifteen%).

Sarcoplasmic proteins are soluble in water and dilute salt solution contained in the sarcoplasmic. Myofibril protein is a poly peptide-containing structures myofibril and is soluble in saline solution with a concentration of 1.5% or more. Stromal proteins are main elective of connective tissue that is not soluble in salt solutions just soluble in brine or acid treatment.Sarcoplasmic proteins include glyceraldehyde, aldose, enolase, creatine kinase, lactate dehydrogenase, pyruvate kinase, phosphorilase, myoglobin, calpain, chatepsin, extracellular proteins and membrane poly peptide. Proteins are equanimous of myosin, actin, troponin, tropomyosin, M-poly peptide, C-protein, Titin, Nebulin and Desmin. Myosin is the largest component in myofibril and dissolves into the solution with high ionic force (greater than 0.3 M). Myosin has an of import functional properties in meat, namely (a) is an enzyme with ATP-ase activity, (b) myosin class a circuitous with actin and (c) myosin grade aggregate with each other to form filaments.

Stromal proteins include collagen, elastin and reticuline. This protein directly affects meat quality past:

1. Lowering the tenderness of meat and it depends on the number of stromal protein and the degree of cross-linking other stromal proteins.
2. Influencing meat emulsion capacity due to this protein is not soluble in water.
3. Lowering H2o Binding Capacity of meat considering of the low content of hydrophilic and charged amino acids.
4. Lowering meat nutritional value.

Musculus protein solubility is one of the factors influencing properties of water retention in the muscles and eventually affects meat quality. Physical and chemic bonding in muscle protein affects structural and texture muscle protein. In that location is a correlation between protein structure and solubility, and is related to tenderness or hardness of meat during processing and storage.

• Fats:

Other chemic components that are important in meat are fats. Although relatively few in amount, it is the tertiary largest chemic component in the flesh. Fat in meat has both beneficial and detrimental roles. One of the disadvantages is the oxidation. It affects meat processing. Fatty is an of import free energy source considering of the amount of free energy produced tin can be doubled from that generated past proteins and carbohydrates. Fat in meat is by and large in triglycerides course. The limerick of triglycerides significantly determines meat tenderness and roughness. Fatty acid composition in each species is dissimilar and it is likewise has different effect on fat properties in each species. Total saturated fat acids in sheep, cattle and pigs respectively 53%, 45% and 40%, while the unsaturated fatty acids respectively were 47%, 55% and 60%.

• Soluble Non-Protein Organic Substances:

These substances fall into two categories: nitrogen-based substances such equally free amino acids and vitamins, and carbohydrates such equally lactic acrid and glucose.

• Inorganic Substances:

The major minerals consist of phosphorous and potassium together with small amounts of sodium, magnesium, calcium, zinc, and other trace metals. Thus meat is a good source of essential amino acids, minerals and vitamins, and a adept source of energy (on average, beefiness yields 510 kJ and lamb yields 630 kJ per 100 chiliad). All the essential amino acids required for life are present and highly bioavailable in raw muscle tissue. Iron, phosphorous and potassium (together with the sodium nowadays in cured meats) are of import minerals. Pork has a high vitamin B content, while liver is rich in a considerable number of vitamins, specially vitamin A. Meat is an important dietary source of both vitamins B1 (thiamin) and B2 (riboflavin).

Physical Properties of Meat

• Water
• Water Activity Water Belongings Capacity
• Meat Texture
• Wet
• Firmness
• Odour And Flavor
• PH
• Appearance

Water:

• Principal component of meat.
• estimated close to 70 –75% (muscle is 65 to 85 %)
• Well-nigh variable component
• About of the meats water is in the costless state.
• Affects juiciness.

Water activity (Aw):

• H2o activity (a_{due west} ) is the term for the corporeality of free (not chemically or physically bound) water, which is available for the growth of microorganisms.
• This information is particularly important, as college amounts of costless water favour the growth of microorganisms, while lower amounts (drier products) result in less microbial growth.
• Bacteria usually require at to the lowest degree aw 0.91 and fungi at to the lowest degree aw 0.7
• This belongings affects odor, colour, season, texture and shelf-life.
• The Aw is measured using a h2o activity meter.

Water Activity meter

• Typical a_westward in Meat Products

Product	awest Range
Fresh meat	0.99 (0.99 to 0.98)
Raw-cooked sausages	0.97 (0.98 to 0.93)
Liver sausages	0.96 (0.97 to 0.95)
Stale meat	0.lxx (0.xc to 0.sixty)

Water Holding Capacity:

• The meats ability (myofibril protein) of retaining its water or added water, during the application of external forces such every bit cut, grinding or pressing.
• Importance due to its influence on:
  • Color
  • Texture and firmness of raw meat
  • Palatability characteristics
  • Juiciness and tenderness of cooked meat
• Meat with loftier WHC will take a stronger structure and a dry texture.
• Conversely, if WHC is low then flesh is soft, moist texture/ watery and toughness of meat is lost.
• The nearly widely employed method for its conclusion is the filter-paper press technique.

Meat Texture:

• Texture is a degree of meat fineness or coarseness.
• Texture measurement tin be visually, touched or chewed.
• Texture, hardness and structure of meat are influenced past several factors, including the WHC, rigor status, marbling fat, connective tissue content in meat and muscle packet size.
• Meat with high WHC will have a stronger structure and a dry texture. Conversely, if WHC is low then flesh is soft, moist texture/ watery and toughness of meat is lost.
• Meat in pre rigor land has long sarcomere. When rigor, sarcomere shortened and peak rigor state, sarcomere lenght is very short. (The curt sarcomere indicates that sarcomerer contract to class the actomyosin or cross bridge bail. The formation of this bond, meat becomes harder and stronger).
• The presence of fatty marbling gives a soft texture. Low marbling content in meat marbling cause meat looks rough and dry out. Even so, if excessive marbling produce meat with watery texture and information technology is also not good, Meat become soft and less rigid.
• Likewise a role in texture, marbling fat also influence the aroma and juiceness meat. Fatty marbling will requite the distinctive olfactory property of meat and usually preferred by consumers.
• The proportion of loftier connective tissue that causes the coarse-textured meat and feels more hard and non soft.

Muscle Firmness or Wetness:

• Muscle compactness or wetness can be described as soft and exudative (SE), firm and normal (FN), or house and dry (FD).
• Soft and exudative means that the meat does not hold its shape and that moisture drips from the meat. Soft and exudative meat is frequently drier and tougher when cooked, then it is less desirable to consumers; it does not work very well for processing into sausage products.
  Soft and exudative meat is oftentimes associated with pale colored meat; this is known equally PSE, or pale, soft and exudative meat.
• Both firm and normal and firm and dry meat are considered acceptable in the meat manufacture and to consumers.

Scent and Flavor:

• Meat olfactory property and season depends on animal historic period, sexual practice, the amount of fatty tissue and the nature of its distribution.
• Meat of previously sick, scraggy animal will always taste worse.
• Flavour of fresh meat is specific, somewhat sweetish.

pH:

• The pH of meat tin range from v.ii to 7.0.
• The highest quality products tend to fall in the pH range of 5.7 to vi.0.

Appearance:

• External appearance is characterized by overall appearance of a product or carcass meat.
• attention is paid to presence of mould on the surface, extraneous inserts and drawing of a cut (of products), drying of carcass meat.
• Bruising, clots, residues of pare and the internal organs not only impairs commercial appearance of meat but also decreases its durability for storing.

Color:

• Dependent on
  • Paint content
  • Ultimate pH and rate of pH turn down postmortem
  • Nature of group attached to the fe and the state of the iron
  • Ingredients, processing, packaging
• Pigments
  • Two main pigments: myoglobin and hemoglobin
  • Majority of colour is due to myoglobin
• Amount of myoglobin in the muscle
  • Historic period: Veal<Calf<Immature beef<Quondam beefiness
  • Looses affinity for oxygen as age increases
  • Species: <Lamb<Beef
  • Type: Support<Locomotive

Factors Affecting Meat Colour

• Chemical State of Myoglobin
  • Ferrous (Fe++)
    • H_iiO→ Purple → Deoxymyoglobin
    • O_ii → Blood-red →  Oxymyoglobin
    • NO → Unstable pink →  Nitric oxide myobglobin
    • CO → Ruby-red →   Carboxymyoglobin

• Vitamin E feeding of cattle
  • Prevents oxidation; retards conversion of myoglobin to metmyoglobin

• Leaner
  • Produce metmyoglobin, choleglobin, and sulfmyoglobin pigments
• Curing
  • Nitrosylhemochromogen is the stable cured meat pigment

As well Study:

• Preservation of Meat by Salting
• Irradiation of Raw Meat
• What is Canning of Meat and Process of Canning Meat
• What is Curing of Meat and Meat Curing Methods
• Chilling of Meat
• Smoking of Meat and Smoking of Meat Process

References :

https://animalscience-info.blogspot.com/2011/04/meat-texture.html

grossmanshapid.blogspot.com

Source: https://bohatala.com/chemical-and-physical-properties-of-meat/

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