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Meat processing is the set of methods and techniques used to bring substantial chemical and physical changes in the natural state of meat. These are the methods which are used for making meat and their products attractive, nutritious and marketable as well as for the prolongation of shelf-life. In processing techniques, grinding, chopping, addition of seasoning, alteration techniques for colour, heat treatments etc. are included but cutting, trimming and deboning are not included in processing operations.

History

Meat processing dates back to the prehistoric ages and probably the first processed meat product was sundried meat. Lator it turns to burning of meat over wood fire while salting and smoking of meat was practiced first time in the time of Homer, 850 B.C. In 63B.C.-14 A.D. at the reign of Augustus honey was tried for preservation of meat. Lator various types of cooking such as roasting, smoking, steaming and oven baking came in existance. Salt-preservation was especially common for foods including meat and meat products for warrior and sailor’s diets, until the introduction of canning methods.

Modern food processing technology in the 19th and 20th century was largely developed to serve military needs. In 1809 Nicolus Appert invented a vacuum bottling technique that would supply food for French troops and this contributed to the development of tinning and then canning by Peter Durand in 1810. Although initially expensive and somewhat hazardous due to the lead used in cans. Canned goods would later become a staple around the world. Pasturization discovered by Louis Pasteur in 1862 was a significant advance in ensuring the micro-biological safety of food. In 20^th century, food processing advances with the development of spray drying, freeze drying and the introduction of artificial sweeteners, colouring agents and preservatives such as sodium benzoate. In late 20^th century ready to eat meat food products were introduced to cater the need of consumers.

Ageing of meat is also known as conditioning or tenderising or ripening or maturing and sometime resolution of rigor. It is a process of holding unprocessed meat above freezing point under controlled conditions. By this process we can make muscle soft and pliable thus meat becomes tender. When we keep the meat above freezing point at temperature between 0-3ºC then all those changes occurs which are normally occurs at higher temperature i.e. atmospheric oxidation and enzymatic action of fat, bacterial action etc. When this temperature range becomes below freezing point then it inhibits completely the enzymatic action in the muscles. Ageing is required for marked increase in flavour, juiciness and tenderness of meat. In this process action of enzymes in meat plays key role while bacterial action is not of any importance. Meat tenderness and taste are definitely improved if carcasses or vacuum packed cuts are conditioned after slaughter but paradoxically beef is quite tender just two hours after slaughter and several days of conditioning are required to recover this degree of tenderness.

During the contraction of muscles, thick and thin filaments sliding to each other and decreases the length of sarcomeres. In turn, this decreases the length of fibrils, fibres and the whole muscle. If these muscles remain in contracted length when rigor develops, it causes massive overlap of thick and thin filaments leading to severe meat toughness. It is also necessary to avoid the cooling of meat too rapidly after slaughter, otherwise it cold-shortens and gets tough. If we avoid cold-shortening of muscles during conditioning, it will increase meat tenderness. But with too much conditioning, weight loss, surface spoilage and the cost of refrigerated storage increases.

Ageing of carcasses with little or no fat cover is not recommended by meat specialists. Because these carcasses loose moisture rapidly, loose weight excessively and discolour the meat surface rapidly. In addition, lean meat is also susceptible to deterioration through microbial growth, slime formation by bacteria and mould growth etc. Ageing is important for beef and buffalo meat while pork and lamb do not require ageing because they are slaughtered in the age where they are young and inherently tender. Additionally, the unsaturated fats found in pork fat oxidize during ageing causes rancidity and off flavour. Veal has very little protective fat covering and is high in moisture; thus it does not lend itself to ageing.

Preservation of foods including meat and aquatic foods is a creation of conditions for the food articles in such a way to stop or greatly slow down the activities of micro-organisms, chemical and enzymatic reactions and physical forces to prevent the meat and aquatic foods from spoilage while maintaining its nutritional value and sensory attributes.

Significance of Meat Preservation

1. Meat and aquatic foods are perishable food items and are very prone to spoilage and rancidity development due to high nutrients, moisture and neutral pH.
2. Once meat and aquatic foods is exposed to microbial contamination, chemical and enzymatic reactions then it will be very difficult to attain asepsis.
3. To enhance the keeping quality of meat and aquatic foods so that it will be available for further processing.
4. It protects meat and aquatic foods from shrinkage, sweeting and other physical forces.
5. To protect human health by providing the wholesome meat and aquatic foods to the consumers.
6. By this way we can minimize utilization of energy in processing of meat and aquatic foods.

Fraudulent substitution of meat is the adulteration or mixing of the inferior or cheaper quality meat into superior quality meat. The first case of fraudulent substitution was recorded in thirteenth century A.D. at Florence in Italy. A common fraud in the meat industry in which uninspected meat is substituted for meat that has undergone inspection and been branded as satisfactory. The other frauds are the substitution of meat of another species, e.g. horse for beef especially in Britain and Ireland, beef in kangaroo meat in Australia, cat for chicken or rabbit, goat meat for mutton, mutton for venison, dog meat and cat meat for chevon in other countries including India. As per an estimate about 25-30% of meat sold in India is adulterated. These practices are more common in comminuted meat products. These illegal practices are punishable under PFA act 1955. The choice of method to be applied is depend on the need or condition of meat recovered.

Meat is an animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat but it may also describe other edible tissues such as organs, livers, skin, brains, bone marrow, kidneys or lungs. Meat is highly nutritious food because it contains protein, fat and carbohydrates in relative proportion, supply energy as required by the human body, posses ability to build or replace tissues and the substances present in meat are easily absorbed by the human body. Meat is also a good source of B-complex vitamins but fat soluble vitamins are low in meat. It is a good source of phosphorous, zinc and iron but low in calcium. Meat also contains significant amount of copper, sodium, potassium and magnesium but low in carbohydrate contents. Carbohydrate is found mainly in form of glycogen which disappears completely after completion of rigor mortis. In general lean red meat is particularly good source of protein, niacin, vitamin B6, vitamin B12, phosphorus, zinc and iron. About 100g of meat can provide more than 25% RDI of these nutrients. It also provides more than 10% RDI of riboflavin, pantothenic acid and selenium. Of the four meats, mutton is particularly nutrient-dense and the richest source of thiamine.

Conversion of muscle to meat is a complex process in which several physical and chemical changes takes place over a period of several hours or even days. The major changes which take place during this process include fall in muscle pH and temperature as well as muscle shortening which further leads to proteolysis or ageing. These changes during conversion of muscles to meat are variable and have great effect on meat quality (tenderness, juiciness, flavour, colour etc.) and also on certain processing characteristics like emulsification, binding properties and yield of the products. To know this complex process it is necessary to understand the process of energy production and metabolic pathway shifting in live animals.

Pre Slaughter

In the living animal, aerobic metabolism is used to obtain energy. The source of energy at this stage is either free fatty acids or blood glucose or muscle glycogen. In this process total 38 ATP molecules are produced from single glucose or glycogen molecule by the complex processes known as glycolysis, oxidative decarboxylation and oxidative phosphorylation. However, under stressful situations, anaerobic metabolism may be used and lactic acid is produced. Lactic acid is usually transported from the muscles to the liver, where it is re-synthesized into glucose and glycogen, or to the heart, where it is metabolized to carbon dioxide and water.

The word meat comes from the old english word mete, which referred to food in general. Most often this means the skeletal muscle and associated fat but it may also describe other edible tissues such as organs, livers, skin, brains, bone marrow, kidneys and lungs etc. In other words we can say meat is those animal tissues which are suitable for use as food by the man. It is composed of numerous types of tissues like muscle tissues, epithelial tissues and nervous tissues but the major component of meat is muscle. Particularly skeletal muscle is the principal source of muscle tissue in meat while smooth muscle contributes little to meat. The muscle and connective tissues are the major compositional components and contributes towards qualitative and quantitative characteristics of meat. Broadly muscle can be classified into striated and smooth muscles. Striated muscles have transverse band pattern as seen in skeletal and cardiac muscle. However, smooth muscles do not show such pattern and mainly found as a component of blood vessels.

In spite of big potential of the largest livestock population in the world, meat industry in India is still in nascent stage. It is a business of those who are not trained and very much literate. The industry is primarily based on the raw material that is not reared for meat purpose but serves the secondary role after passing their viable life in primary field. The industry is also facing problem of social prejudice and meat is taboo for certain communities. But scenario is now changing and people are coming forward to organise the sector. Now the society is accepting the facts that meat is an only source of cheap and nutritious food to million of people in India and the good source of animal protein for large segment of Indian population, particularly landless, small and marginal farmers.

India ranks fifth in the world meat production with the annual meat production of about 6.3 million tones which is 2.21% percent of world meat production. In the last two decades meat industry in India has grown @ 4.5% whereas, during the last five years, this segment has been growing very fast at the rate of 27% annually. It has a good future if given proper attention by the Government and Private Entrepreneurs. In total meat production, share of cattle is 17.34%, buffalo 23.3%, sheep 4.6%, goat 9.4%, pigs 5.3%, poultry 36.6% and others 3.4%. The share of various meat types in total Indian meat production accounts buffalo meat 1.5 million tones, beef 1.28 million tones, mutton 0.24 million tones, chevon 0.53 million tones, pork 0.50 million tones, chicken meat 2.20 million tones and duck meat 0.07 million tones. To produce the above quantities, the extraction or slaughter rates in cattle are about 7.9%, buffaloes 11.1%, sheep 47.9%, goat 37.9%, pigs 88.9% and poultry 73.6%. In the world total meat production Indian cattle meat shares 13.1%, buffalo meat 55.8%, mutton 5.7% and chevon 14.9%. However, India is having world’s 15.0% (210 million) cattle, 57.0 %( 111 million) buffaloes, 7.0 %( 74 million) sheep, 17.0 %( 154 million) goat and 1.5% pigs. Overall contribution of meat sector in total output of Livestock sector was Rs 25984 crores in the year 2004-2005.

‘Prunes’ is prepared from peach.

Arrak” liquor is prepared from date palm.

Hayane” variety of date palm suitable for juice making.

Kanji” is made from black carrot.

Kirschwascer” a wine prepared from cherry.

Shahi” variety of Litchi suitable for canning.

New Technique of Food Preservation

1. High Pressure Processing (HPP)

High Pressure Processing (HPP) is a method of food processing where food is subjected to elevated pressures (up to 87,000 pounds per square inch or approximately 6,000 atmospheres), with or without the addition of heat, to achieve microbial inactivation or to alter the food attributes in order to achieve consumer-desired qualities. Pressure inactivates most vegetative bacteria at pressures above 60,000 pounds per square inch. HPP retains food quality, maintains natural freshness, and extends microbiological shelf life. The process is also known as high hydrostatic pressure processing (HHP) and ultra high-pressure processing (UHP).

Quality Standards and Laws

Quality is how well a product or service satisfies the needs of the customer. This includes all aspects related to the needs of the customer such as quality specifications, safetgy, delivery method or date, price etc. Quality can be interpreted in several ways as conformance to the standards, meeting customers’ preference/ satisfaction for desired quality attributes, degree of excellence and zero defect products etc. Because of education and consequent greater understanding of implications of poor quality commodities in recent years, consumers have become quality conscious and this fact is also applicable to food and food products. In order to strengthen competitiveness, quality must be incorporated throughout the value added chains right from the harvesting, handling, manufacturing, processing, packaging, storage, marketing and distribution stages, especially in the case of food and food products.

Food Safety and Standard Authority of India (FSSAI) has adopted the standards of Fruit Product Order (FPO).

Chutney

It is a product prepared by cooking the fruit pulp with added salt, sugar, spices, acetic acid and fruit to a suitable consistency so that it contains TSS not less than 50% and fruit part not less than 40% as per FSSAI specification. Sugar, salt, spices, acetic acid all act as partial preservatives. Preservatives may also be added in chutney for increasing its storability. Generally no artificial colour and flavor are required to be added.

Sauce

Sauce is a product similar to ketchup, prepared from pulps of tomato or other fruit/vegetable, having TSS not less than 15% and cooked to a suitable consistency with added sugar, salt, spices and vinegar. Sugar, salt, spices, acetic acid all act as partial preservatives. According to FSSAI specification fruit sauce should have minimum of 15% TSS and 1.2% acidity. Preservatives and colours may also be added for increasing of appearance and storability.

Preserves (Murabbas) are prepared from whole fruits and vegetables or their segments by addition of sugar followed by evaporation to a point where microbial spoilage cannot occur. The final soluble solids concentration is reached to about 70 per cent. The finished product can be stored with or without hermetic sealing and refrigeration.

Jam is prepared by boiling the fruit pulp with required quantity of sugar to thick consistency, firm enough to hold fruit tissues in position. It should contain not less than 68.5 per cent soluble solids. Jam may be made from a single fruit (apple, strawberry, banana, pineapple etc.) or from combination of two or more fruits. Jam contains 0.5-0.6% acid and invert sugar should not be more than 40%.

The preservation of food in common salt or in vinegar is known as pickling. It is one of the most ancient methods of preserving fruits and vegetables. Pickles are good appetizers and add to the palatability of a meal. They stimulate the flow of gastric juice and thus help in digestion. They are prepared with salt, vinegar, oil or with a mixture of salt, oil, spices and vinegar.

A dilute solution of acetic acid produced by a two-stage fermentation process in the first stage, fermentable sugars is converted into ethanol by the action of yeasts and in the second stage, bacteria of the genus Acetobacter oxidize the ethanol to acetic acid.

Vinegar is a liquid produced from the fermentation of ethanol in a process that yields its key ingredient, acetic acid. The acetic acid concentration ranges typically from 4 to 8 percent by volume for table vinegar (typically 5%) and higher concentrations for pickling (up to 18%). Natural vinegars also contain smaller amounts of tartaric acid, citric acid, and other acids.

Fruit juices which do not undergo alcoholic fermentation are termed as unfermented beverages. They include natural and sweetened juices, RTS, nectar, cordial, squash, crush, syrup, fruit juice concentrate and fruit juice powder. Barley waters and carbonated beverages are also included in this group.

Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions.

Freezing is one of the easiest and least time consuming methods of food preservation. The freezing process is a combination of the beneficial effects of low temperatures at which microorganisms cannot grow, chemical reactions are reduced, and cellular metabolic reactions are delayed.

Methods of Freezing

1. Sharp freezing (slew freezing)

In sharp freezing commodities are exposed at -15 to -29⁰C. It required 3-72 hrs. Here the thawed tissue cannot regain its original water content. The ice crystals formed are large and rupture the cells. The thawed tissue cannot regain its original H₂O content.