Meat And Meat Products Preservation Methods

The purpose of the container is to prevent foods from spoiling and smelling.

No matter what the degradation is, one of the most important factors causing degradation is microorganisms.

Microorganisms, bacteria, molds and yeasts reproduce easily in conditions suitable for them.

However, in extremely hot-cold, places lacking water and oxygen, they grow very hard in extreme salt and acidic environments.

The main purpose of all preservation methods; It is to make the reproduction and reproduction conditions of microorganisms causing stinking in foods unfavorable.

The main preservation methods applied to fresh meat and some meat products are as follows.

a- Cooling and Freezing

b-Applying heating or heat treatment

c- Drying and concentrating

d- Fermentation

e- Irradiation

f- Using chemicals

Cooling and Freezing

It is one of the most common and effective preservation methods applied to meat and its products.

The freezing point of the meat is between –1.5 C and –1.7 C. Depending on the degree and shape of the freezing, the storage times of the meat can be increased more or less.

Storing meat at temperatures above freezing is called cold storage, and storing at temperatures below freezing.

The mechanical cooling system is created in accordance with a physical law.

Ammonia and other low-boiling refrigerant agents such as gas continuously,

Equipment that can be converted from gas to liquid is called a cooling system.

Besides ammonia, the main refrigerants used in the cooling industry are freon-12, dry ice (C2O) and liquefied nitrogen. They have a boiling point of -20 C, -79 C and -196 C, respectively.

Cooling and Cold Storage

Cooling is applied to meat that will be offered for consumption in a short time. If the meats are cooled and kept cold in accordance with their technique, they do not lose their natural condition of their qualities such as appearance, flavor, color and texture, especially their nutritional values.

For cooling, cattle carcasses are placed in cooling tanks, whose temperature is set at -2 C, and pig and sheep carcasses at -6 and -8 C as quickly as possible, and their doors are tightly closed.

Immediately afterwards, the temperature of the rooms is 12 to 24 hours with automatic control systems at –3 to 0 degrees Celsius, humidity is 88-92%, air currents are 1-3 m / sec for cattle carcasses and 2-3 m / sec for pig and sheep carcasses. It is set.

With the pre-cooling created in this way, the core temperatures of the carcasses can be reduced to +5 C and even lower temperatures in 12 to 24 hours.

The factors to be considered in cooling and preservation of meat, duration of keeping in cold and its effectiveness are as follows;

The number of carcass, the size of the carcass greatly affects the carcass shell oil thickness, the temperature of the cooling chambers, the humidity rate, the air flow and the lighting conditions.

Carcasses with large structure and thick carcass shell oil require pre-cooling for approximately 72 hours.

The cooling capacities of the warehouses should be determined carefully according to their size and the number of carcass to be stored.

Instead of a single large warehouse, several normal cooling units should be built and the sizes of these warehouses to be built should be 18-30 meters long, 7.5-15 meters and 4.8 meters high.

The distance between the hanging hooks on the rails and the floor should be 3.3 meters for cattle carcasses, 2.2 meters for cattle carcasses, 2.7 meters for calves and pigs, and 2 meters for sheep and goats carcasses.

The cooling capacities of the rooms should also be calculated consciously. For this purpose, it should be taken into consideration that 750-880 Kcal / hour energy is required for cooling a normal size carcass (290 kg).

In cooling of the carcasses, it is necessary to control the humidity rate in the environment.

Air flow should be provided in cooling tanks provided that it is not excessive. Air flow is also imperative to speed up cooling. If the air flow is excessive, it causes weight loss (drying).

Salt concentration increases on the surface of the carcasses as a result of excessive drying. In this case, it increases oxidation and formation of methyoglobin, causing the color of the meat to darken and deteriorate quickly.

Even if all conditions are created during cooling, carcass cannot be prevented between 1.5-2%.

Chickens are usually cooled by immersion in cold water as their skins are not skinned. These processes take around 1 hour. However, chickens draw some water during this process and their weight increases. According to the regulation, this weight increase should not exceed the specified limits.

Endurance times of chilled meats: First of all, the factors affecting the quality qualities of meat should be known and controlled during cooling and cold storage.

The main of these factors are:

a-The initial degree of contamination of the meat

b-Cold storage temperature, humidity, air flow and light condition

c-Packaging status of carcass or meat

d-Quality grades, sizes and types of carcass or meat

Hygienic conditions during e-cooling processes

The durations of chilled meats vary between 14 and 60 days depending on these conditions.

However, it may not be possible to check them all the time. However, if the atmosphere of the cooling tanks is enriched with carbon dioxide gas, their durability increases even more.

With the widespread use of large markets, chilled meats, especially beef, pork and sheep carcasses were packaged and presented to the customer.

With packaging, meats are protected from contamination of physical, chemical and microbial agents.

Packaging is mostly used for waxed paper, cellophane, PVC and nylon.

Meats packed with these last for 3 weeks without losing much weight.

Fresh meats sold in pieces without packaging can maintain their color for a maximum of 3 days. The partial packaging of fresh meats can partially prevent the formation of oxymyoglobin.

According to the purpose, meat and meat products are packed in various ways, in a vacuumed, vacuumed and controlled atmosphere.

In vacuum packaging, the meats are first placed in durable polyethylene bags, and the air in them is completely emptied and their mouths closed by heating.

In the process of packing in a controlled atmosphere, the meats are placed in the bags as in vacuum packaging and their air is completely taken off. Then a certain amount of nitrogen or carbon dioxide is put into the packages and their mouths are tightly closed.

Ice Cream and Frozen Enclosure

It is one of the most effective preservation methods especially applied to meat and some meat products.

In order for the meat to maintain its quality qualities, the following factors should be considered.

a-Superior quality of carcass, meat and meat products to be frozen and frozen

b-Pre-cooling conditions are created as required, quality of all packaging related elements

c-Realization of freezing conditions, especially freezing speed and degree

d-Frozen storage conditions are within the required limits

Providing e-hygienic conditions

Quality of Carcasses and Meats:

The carcasses to be frozen should be of superior quality and should be obtained from their meat.

Carcasses with sufficient thickness and amount of crust and tallow freeze quickly.

Pre-Cooling and Packaging Conditions:

The first condition in ice cream is the careful pre-cooling of the carcasses.

Beef carcasses are usually taken in ½ and ¼ pieces, and sheep and pork carcasses are either pre-cooled, either wrapped in white cloths or special bags, or without being wrapped, and then frozen.

Freezing Conditions:

Carcasses and meats can be frozen well after pre-cooling,

It depends on providing the freezing speed and degree as required by the method.

If the meat is frozen slowly, their temperature will drop to freezing points after a while, but they will remain at this point for a long time. During this period, a frozen layer forms on the surfaces of the carcasses. This layer delays the carcasses from freezing from outside to inside.

Slow freezing also leads to the formation of pure ice crystals between muscle fibers, outside of the cell. The large ice crystals formed as a result compress the muscle cells and membranes, thereby damaging them, thereby disrupting the physical structure of the muscle.

If the meat is frozen quickly, the defects caused by slow freezing are largely eliminated.

Some researchers consider the internal temperature of the meat cooled to 0 C after pre-cooling, the freezing speed that can be reduced to -4 C in 30 minutes. In freezing technique, this period is called Maximum Crystallization Time or Period.

Freezing Methods:

Freezing in still air

ice cream in containers or trays

Deep freezing in fast air flow

Freezing by immersion in freezing solutions or by spraying these solutions

Quick freezing with cooling agents with very low evaporation temperature

Freezing in Stagnant Air: In this method, the heat transfer medium is air. In this regard, since the freezing process is completely based on the transfer of heat by air, freezing takes place very slowly and for this reason, this method is called stagnant air freezing.

Temperature levels of ice cream tanks are set between -18 C and -29 C. Then the foods to be frozen are placed in the rooms as quickly as necessary. The covers are closed.

Freezing in Containers or Trays: In this method, the heat transfer medium is containers or trays. The containers used for this purpose are made with double walls in order to circulate the cooling agent in them. In the system, this is also called indirect ice cream, since the meat is frozen not directly with the cooler, but by contact with the containers cooled by them. In the containers, the temperature can be adjusted between -10 and -30 C, and at these temperatures, more meat can be frozen in a very short time, packed with steak, steak, cutlet and chopped meat.

In this method, packaged beef, sheep, chicken and fish meat, which are 4-5 cm thick, can be frozen within a short period of 1-2 hours.

If the meats are placed unpacked, frost is formed on the sides that touch the surface.

The flavor and nutritious values of the meats that have freezing burns are low and their color turns into dark brown.

Freezing in Fast Cold Air Flow: It is the most widely used method in the meat industry today. For this purpose, specially prepared warehouses or tunnels are used. In these tunnels, the rapid cold air flow is provided by powerful fans located in certain areas. The transfer rate of heat is greatly increased and the freezing time is greatly reduced by the rapid cold air flow created.

In systems, the speed of the air is adjusted between 10 and 15 m / s and the temperature is between -30 -45 C.

The most economical freezing conditions are provided by adjusting the air flow rate to 12 m / sec and -30 C.

Freezing with Solutions: The method of dipping into the freezing solution or spraying this solution is used for freezing chicken carcasses and, if necessary, some red meat and fish.

The solution used should not be toxic first.

In this method, NaCl and CaCl solutions are mostly used as solutions.

In addition, glycerin and propylene glycol have been used recently.

Meats to be frozen are usually placed in solid plastic bags and after their mouths are closed, they are frozen in solution tanks that have a temperature between approximately -20 C and -30 C, by special baskets for a certain period of time. Freezing with Freezing Agents with Very Low Freezing Point: Using very strong freezers, foods are frozen in tanks cooled by dipping, spraying or their vapors.

For this purpose, liquid and / or vapor nitrogen and carbon dioxide are used most commonly from freezing agents.

Although ice cream is expensive in this way, it is still used in the freezing of quality pieces of meat such as steak, steak, chops and fish.

Determination of Freezing in Meats

Some applications are used to determine whether the meat is frozen. Some of these are those.

Cutting the carcasses from the thickest part with the saw: in this application, if the meat is completely frozen, it is easily cut to the end. The sectional face is quite smooth. If freezing is not complete, it will be difficult to cut the meat.

Drilling carcasses from their thick places: In this method, fully frozen meat is easily drilled. Less frozen meat is drilled hard.

Striking the carcasses with an iron stick: When a fully frozen carcass is hit with an iron stick, a hard sound is obtained, and in those who are not fully frozen, a low and full sound is obtained.

Frozen Storage Conditions and Duration

The quality of frozen meat affects the quality of the meat after cutting and before freezing, the method of freezing, storage conditions after freezing and freezing.

If carcasses and meats are to be exported, they are pre-cooled for a certain period of time, and then frozen at -18 C or lower. Then, they should be packed with suitable packing material and shipped with transport trolleys of -10 or less.

If the meat is to be taken into a short-term preservation after freezing, it should be placed directly in warehouses set at -12 C and should be consumed within 4-5 months at the latest.

Carcasses and meats that will be preserved for a long time; After freezing, it should be stored at a temperature of at least -18 C or less.

All necessary precautions must be taken during the frozen storage, especially in order to keep the temperature unchanged. Ice crystals can form during temperature rise and fall, causing physical deterioration.

If the carcasses and meats to be kept frozen are not wrapped or packaged in accordance with the technique, the storage times are considerably shorter.

Freezing and storage time also affect the animal's species. Cattle carcasses can be stored at low temperatures (-24) for up to about 1 year, whereas pig, sheep and chicken carcasses can be stored for a less time.

The main disorders that occur during frozen preservation and imported frozen meat are abnormal odor, color distortion in colors ranging from dark brown to greenish and even yellow depending on the conditions, freezing burn.

Thawing Frozen Meat

If the thawing is not done in a known manner, it may cause more damage to the meat than freezing.

Meats can be thawed mainly in the following ways;

1) In cold weather, for example, in cooling rooms or refrigerators

2) at room temperature

3) in water

4) directly during cooking

If the meats are not packaged, they should be wrapped in wet cloth and, if possible, thawed in a container.

The main factors affecting the dissolution of meat are:

1) Heat of frozen meat

2) Heat capacity of the meat to be melted

3) The size of the meat

4) Way of Thawing

5) The state of heat and air flow in the dissolution medium

Dissolving at room temperature is recommended for meats. But microbial growth occurs more at room temperature. Because of this fact, meats should be cooked as quickly as possible. Or they can be cooked frozen or partially thawed.

Heat Treatment

Food preservation by the heat treatment was initiated by Appert in the 19th century. Appert managed to keep the meat for a long time by putting the lids in tightly closed cans or containers after cooking the meat. Pasteur clarified that microorganisms died with this heat treatment. As a result, the canning industry has reached the current level.

Heat treatment is applied to kill highly toxic microorganisms that cause spoilage and stinking in meat and meat products and to inactivate enzymes that accelerate the stinging reactions. In other words, microorganisms can be completely destroyed with this method.

Heat treatment is generally applied in 2 levels in the storage of the meat.

Moderate heating process, in which foods are heated up to about 58-75 C. This is mainly used in cooking processed meat products. At these temperatures, only some of the microorganisms can be destroyed, and the rest become inactive.

Excessive heat application system or sterilization, in which the temperature can be increased to 100 degrees Celsius and above. With this application, all the stinking microorganisms are killed and damaged in such a way that they cannot be reproduced. These can be stored for a very long time. Heat Transfer Types: In all heat treatments, generally heat is transferred by conduction, convection and / or radiation.

Conduction is the transfer of heat directly between the product's own molecules or particles.

Convection, on the other hand, is the transfer of heat to the product with the massive movements of intermediary substances such as heated water, air or steam.

Radiation is the transfer of heat energy to the product through radiation.

Meat products are quite different from each other in terms of fat content, water content, degree of darkness and homogeneity. In this respect, separate heat treatment programs should be prepared in terms of their qualities.

Heat Resistance of Microorganisms: The resistance of microorganisms and spores to heat is quite different from each other.

If meat products contain a large number of microorganisms and spores, a lot of heat energy is needed to kill them.

The resistance of microorganisms to heat is generally explained by the term “heat death time” (İÖZ = thermal death time (TDT)).

To produce canned meat at the level of commercial sterility, it is imperative to know the following.

Heat curve of heat-resistant microorganisms and spores that may be present in the product

Heating heat, heat transmittance and cooling curves of the product to be applied to heat treatment

Dimensions and shape of canned food boxes

Pasteurization degrees are generally applied for pork and canned beef.

To sterilize meat products, special autoclaves are used, which can create pressure in them. For this, the boxed meat products are placed in autoclaves and then the covers of the autoclaves can be raised to 120 C with the help of water vapor.

Drying

The purpose of preservation with drying is to reduce the water activities of meat and products and to stop microbial growth in them.

Some meat products such as bacon, dry and semi-dry sausages are completely or partially air-dried during their maturation.

Generally, hot air and freeze drying methods are used in drying and preserving meat and products.

Fermentation

This method is especially used in the production of fermented sausages in the meat industry. The method is based on anaerobic metabolism created in carbohydrates in meats by acid-forming bacteria that are naturally found in meat or added to meat later.

As a result of this metabolism, carbohydrates turn into lactic acid. Accordingly, acidity increases and pH decreases in sausages.

Irradiation

One of the methods of preserving meat is the application of ionizing radiation. For this purpose, mostly radioactive cobalt and X-rays are used.

When these rays are applied to meat and meat products in certain doses, they stop microbial growth in them.

Protection with Chemicals

While the meat is processed into the products, for example, it is smoked, dried, cooked and sausage is mixed with many additives and the durations are tried to be increased even more.

For this purpose, additives such as sodium chloride, nitrate, nitrite, sodium ascorbate, ascorbic acid, erythrobat are used.

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Meat And Meat Products Preservation Methods

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