Food preservation prevents the growth of microorganisms (such as yeast), or other microorganisms (although some methods work by introducing bacteria or fungi to the food), and slow the oxidation of fat that causes rancidity. Food preservation may also include processes that inhibit visual damage, such as enzymatic browning reactions in apples after being cut during food preparation.
Many processes designed to preserve food involve more than one food preservation method. Preserving the fruit by converting it into jam, for example, involves boiling (to reduce the water content of fruits and killing bacteria, etc.), Sugar (to prevent regrowth) and seal in airtight bottles (to prevent recontamination). Some traditional methods of food preservation have been shown to have lower energy input and carbon footprint, when compared to modern methods.
Some food preservation methods are known to create carcinogens. In 2015, the International Agency for Research on Cancer The World Health Organization classifies processed meats, which are marinated, preserved, fermented and smoked, as "carcinogenic to humans".
Maintaining or creating nutritional value, texture and taste is an important aspect of food preservation.
Video Food preservation
Teknik tradisional
New techniques of food preservation became available to home cooks from early farming to the Industrial Revolution.
Curing
The earliest form of preservation is dehydration or drying, used as early as 12,000 BC. The smoking and marinating technique improves the drying process and adds antimicrobial agents that help with preservation. Smoke stores a number of pyrolysis products into the diet, including phenol syringols, guaiacol and catechols. Salt accelerates the drying process using osmosis and also inhibits the growth of some strains of bacteria. Recently nitrites have been used to heal the flesh, giving it a distinctive pink color.
Cooling
Coolants keep food by slowing the growth and reproduction of microorganisms and the action of enzymes that cause food to decay. The introduction of domestic and commercial refrigerators drastically increases the diet of many people in the Western world by allowing foods like fresh fruit, salads and dairy products to be safely stored for longer periods, especially during warm weather.
Before the era of mechanical cooling, cooling for food storage occurs in the forms of gutter roots and ice boxes. The rural population often cuts their own ice, whereas urban and urban inhabitants often rely on ice trading. Currently, root cell storage is still popular among people who value a variety of purposes, including local food, heritage, traditional home cooking techniques, family farming, frugality, self-sufficiency, organic farming, and so on.
Holds
Freezing is also one of the most commonly used processes, both commercial and domestic, to conserve a variety of foods, including fast food that does not require freezing in an unprepared state. For example, a potato waffle is stored in the freezer, but the potato itself just needs a cool dark place to ensure storage for several months. Cold stores provide long-term and long-term storage for strategic food stocks held in national emergencies in many countries.
Boiling
Boiling liquid food can kill the existing microbes. Milk and water are often boiled to kill harmful microbes that may be in them.
Heating
Heating to temperatures sufficient to kill microorganisms in food is a method used with a lasting stew. Milk is also boiled before it is stored to kill many microorganisms.
Sugaring
The earliest cultures have used sugar as a preservative, and it is common to store fruit in honey. Similar to pickled food, sugar cane is brought to Europe via trade routes. In a sunless northern climate sufficient to dry food, preservatives are made by heating the fruit with sugar. "Sugar tends to take water from microbes (plasmolysis).This process makes the microbial cells dehydrated, thus killing them.This way, the food will remain safe from microbial decay." Sugar is used to preserve fruits, either in antimicrobial syrups with fruits such as apples, pears, peaches, apricots, and plums, or in crystal form where the preserved ingredients are cooked in sugar until the point of crystallization and the resulting product is then kept dry. This method is used for the skin of citrus fruit (candied skin), angelica, and ginger. In addition, sugaring can be used in the production of jam and jelly.
Pickling
Preservation is a method of conserving food in edible antimicrobial fluids. Preservation can be broadly classified into two categories: chemical preservation and fermentation preservation.
In chemical preservation, food is placed in an edible liquid that blocks or kills bacteria and other microorganisms. Common preservatives include salt water (high salt), vinegar, alcohol, and vegetable oil. Many chemical preservation processes also involve heating or boiling so that the preserved food becomes saturated with the curing agent. Commonly acidified foods include cucumber, chilli, corned beef, herring, and eggs, as well as mixed vegetables such as piccalilli.
In fermentation preservation, bacteria in the liquid produce organic acids as a preservative agent, usually by a process that produces lactic acid through the presence of lactobacillales. Fermented pickles include sauerkraut, nukazuke, kimchi, and surstrÃÆ'¶mming.
Lye
Sodium hydroxide (lye) makes the food too alkaline for bacterial growth. Lye will absorb the fat in the diet, which will change the taste and texture. Lutefisk uses alkali in its preparation, as do some olive recipes. Modern recipes for century eggs also call for alkali.
Canning
Canning involves cooking food, sealing it in sterilized cans or jars, and boiling the container to kill or weaken the remaining bacteria as a form of sterilization. Invented by French confectioner Nicolas Appert. In 1806, this process was used by the French Navy to preserve meat, fruit, vegetables, and even milk. Although Appert has discovered a new way of preservation, it was not understood until 1864 when Louis Pasteur discovered the connection between microorganisms, food decay, and disease.
Foods have varying degrees of natural protection against decay and may require that the last step take place in the pressure cooker. High acid fruits such as strawberries do not require preservatives to be able and only short cycles to boil, while marginal vegetables such as carrots require longer boiling and addition of other acidic elements. Low-acid foods, such as vegetables and meat, require canning pressure. Food preserved with canning or bottling is at risk of being damaged immediately after cans or bottles are opened.
Lack of quality control in the canning process may allow entry of water or micro-organisms. Most of these failures are quickly detected as decomposition in cans causing gas production and cans to swell or break. However, there are some poor examples of underprocessing and hygiene that allow contamination of canned foods by an obligate anaerob Clostridium botulinum , which produces acute toxins in the diet, causing severe illness or death. These organisms do not produce a clear gas or taste and remain undetected by taste or odor. However, the toxin is denatured by cooking. Cooked mushrooms, poorly handled and then canned, can support the growth of Staphylococcus aureus, which produces toxins that are not destroyed by canning or subsequent reheating.
Jellying
Food can be preserved by cooking in a hardened material to form a gel. Such ingredients include gelatin, agar, cornmeal, and garut flour. Some natural foods form protein gel when cooked, such as eels and elvers, and sipunculid worms, which is a delicious meal in Xiamen, in Fujian province of the People's Republic of China. Jellied eels are delicious food in East End of London, where they are eaten with mashed potatoes. Potted meat in aspic (gel made from gelatin and clarified meat broth) was a common way of serving cuts of meat in England until the 1950s. A lot of male meat is also flavored.
The traditional British way of preserving meat (especially shrimp) is to put it in a pot and seal it with a layer of fat. Also common is chicken pot liver; jellying is one step in producing traditional pÃÆ' ¢ tà ©  s.
Jugging
Meat can be preserved by piercing. Jugging is the process of chewing meat (usually a game or fish) in a clay jug or casserole that is covered. Animals to be gouged are usually cut into pieces, put into a tightly sealed jar with salt water or broth, and boiled. The red wine and/or blood of the animal itself is sometimes added to the cooking liquid. Jugging is a popular method for preserving meat until the mid-20th century.
Funeral
Funeral food can preserve it due to various factors: lack of light, lack of oxygen, cold temperatures, pH levels, or desiccants in the soil. Funerals can be combined with other methods such as marinating or fermentation. Most foods can be preserved in very dry and salty soils (such as desiccation) such as sand, or frozen soil.
Many root vegetables are very resistant to decay and require no other preservation than storage in cool, dark conditions, for example with burials on the ground, such as in storage clamps. Century eggs are traditionally made by placing eggs in alkaline slurries (or other alkaline substances), resulting in "inorganic" fermentation by increasing pH, not spoiling. Fermentation retains them and breaks down some complex and less flavorful proteins and fats into simpler, more flavorful. Cabbage is traditionally buried during the fall on northern US farms for conservation. Some methods keep it crisp while other methods produce sauerkraut. A similar process is used in traditional kimchi production. Sometimes meat is buried under conditions that cause preservation. If buried over hot coals or ash, heat can kill pathogens, dry ash can dry out, and the earth can block oxygen and contamination further. If buried where the earth is so cold, the earth acts like a refrigerator. Before burial, meat (pigs/boar) can be fattened. The tallow of the animal is heated and poured onto the meat in a barrel. After the fat hardened the barrel is sealed and buried in the basement or cold ground.
In Orissa, India, it is practical to store rice by burying it underground. This method helps save for three to six months during the dry season.
Butter and similar substances have been preserved as swamp butter in Irish peat swamp for centuries.
Fermentation
Some foods, such as lots of cheese, wine, and beer, use certain micro-organisms that fight the decay of other less benign organisms. These microorganisms keep the pathogens in check by creating a toxic environment for themselves and other micro-organisms by producing acids or alcohols. The fermentation methods include, but are not limited to, novice micro-organisms, salt, hops, controlled (usually cold) temperatures and controlled (usually low) oxygen levels. This method is used to create specific controlled conditions that will support the desired organism that produces food suitable for human consumption.
Fermentation is the conversion of starch microbial and sugar into alcohol. Not only can it produce alcoholic fermentation, but it can also be a valuable preservation technique. Fermentation can also make food more nutritious and tasty. For example, drinking water in the Middle Ages is dangerous because it often contains pathogens that can spread the disease. When water is made into beer, boiling during the brewing process kills bacteria in the water that can make people sick. In addition, water now has nutrients from barley and other ingredients, and microorganisms can also produce vitamins as they ferment.
Maps Food preservation
Modern industrial engineering
Food preservation techniques are developed in research laboratories for commercial applications.
Pasteurization
Pasteurization is a process for the preservation of liquid food. It was originally applied to combat the contamination of young local wine. Today, this process is mainly applied to dairy products. In this method, the milk is heated to about 70 ° C (158 ° F) for 15-30 seconds to kill the bacteria inside it and cool it rapidly to 10 ° C (50 ° F) to prevent residual bacteria from grow. The milk is then stored in a bottle or a sterile bag in cold places. This method was invented by Louis Pasteur, a French chemist, in 1862.
Hollow packing
Vacuum packing stores food in a vacuum environment, usually in an airtight bag or bottle. The vacuum environment of the bacterial strip of oxygen needed to survive. Vacuum packaging is commonly used to store nuts to reduce the loss of taste from oxidation. The main drawback to vacuum packaging, at the consumer level, is that vacuum sealing can damage the contents and rob a particular food, such as cheese, from the taste.
Food additives made
Preservative additives can be antimicrobial - which inhibits bacterial or fungal growth, including fungi - or antioxidants , such as oxygen absorber, which inhibits the oxidation of food constituents.. Common antimicrobial preservatives include calcium propionate, sodium nitrate, sodium nitrite, sulfites (sulfur dioxide, sodium bisulfite, potassium hydrogen sulfite, etc.), and EDTA. Antioxidants include butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Other preservatives include formaldehyde (usually in solution), glutaraldehyde (insecticide), ethanol, and methylcloroisothiazolinone.
Irradiation
Food irradiation is food exposure to ionizing radiation. Several types of ionizing radiation can be used, including beta particles (high-energy electrons) and gamma rays (emitted from radioactive sources such as cobalt-60 or cesium-137). Irradiation can kill bacteria, fungi, and insect pests, reduce maturation and damage the fruits, and at higher doses cause infertility. This technology can be compared with pasteurization; sometimes called "cold pasteurization", because the product is not heated. Irradiation allows low-quality or contaminated food to be sold.
National and international experts have declared food irradiation as "healthy"; UN organizations, such as the World Health Organization and Food and Agriculture Organization, support food exposure. Consumers may have a negative view of irradiated food based on a misconception that the food is radioactive; In fact, irradiated foods do not and can not become radioactive. The activists also oppose the exposure of food for other reasons, for example, on the grounds that irradiation can be used to sterilize contaminated food without solving the underlying causes of contamination. An international rule on whether food can be irradiated or not varies worldwide from no regulation to full prohibition.
Approximately 500,000 tons of food is irradiated annually worldwide in more than 40 countries. This is primarily spices and herbs, with increasing segments of fresh fruit being irradiated to quarantine fruit flies.
Pulsed electric field electroporation
Pulsed electric field electroporation (PEF) is a method for processing cells by using short pulses of a strong electric field. PEF has potential as a type of low-temperature alternative pasteurization process to sterilize food products. In PEF processing, a substance is placed between two electrodes, then a pulse electric field is applied. The electric field enlarges the pores of the cell membrane, which kills the cell and releases its contents. PEF for food processing is a growing technology that is still being studied. There is already a PEF processing industry application limited to pasteurization of fruit juice. To date, some of the processed PEF juice is available in the European market. Furthermore, for several years the application of juice pasteurization in the US has been using PEF. For the purpose of cell disintegration, especially potato processers showed great interest in PEF technology as an efficient alternative to their preheaters. Potato applications are already in operation in the US and Canada. There are also commercial PEF potato applications in various countries in Europe, as well as in Australia, India, and China.
Modified mood
Modifying the atmosphere is a way to preserve food by operating in the surrounding atmosphere. The famous salad vegetable is hard to preserve now being packed in a closed bag with a modified atmosphere to reduce the oxygen concentration (O 2 ) and increase the carbon dioxide (CO 2 ) concentration. There are concerns that, although salad vegetables maintain their appearance and texture under these conditions, this preservation method may not retain nutrients, especially vitamins. There are two methods to conserve grains with carbon dioxide. One method is to place a dry ice block at the bottom and fill the can with wheat. Another method is to clean the container from the bottom with carbon dioxide gas from a cylindrical tube or bulk supply.
Carbon dioxide prevents insects and, depending on the concentration, fungi and oxidation from damaging the grain. Grains stored in this way can remain edible for about five years.
Nitrogen gas (N 2 ) at a concentration of 98% or higher is also used effectively to kill insects in seeds through hypoxia. However, carbon dioxide has an advantage in this regard, because it kills organisms through hypercarbia and hypoxia (depending on concentration), but requires concentrations above 35%, or more. This makes carbon dioxide better for fumigation in situations where airtight seals can not be maintained.
Controlled Atmospheric Storage (CA): CA storage is a non-chemical process The level of oxygen in a confined space is reduced, usually by the infusion of nitrogen gas, from an estimated 21 percent in the air we breathe up to 1 percent or 2 percent Temperatures are stored at 0- 2 Â ° C constant (32-36 Â ° F) Moisture is maintained at 95% and carbon dioxide levels are also controlled.An appropriate condition indoors is arranged according to apple varieties, developing specific regimens for each variety to achieve the best quality. keeping the conditions constant. "" East of Washington, where most of the Washington apples grew, had enough storage space for 181 million boxes of fruit, according to a report made in 1997 by managers for the Washington State Department's Department of Agriculture Service Division. storage capacity shows that 67 percent of that space - enough for 121008,000 apple boxes - is CA storage. "
Storage of airtight grain (sometimes called hermetic storage) depends on the respiration of grains, insects, and fungi that can modify the enclosed atmosphere enough to control insect pests. This is a great ancient method, and has a modern equivalent. The success of the method depends on having the correct mixture of sealing, grain moisture, and temperature.
The patented process uses fuel cells to dispose and automatically maintains oxygen fatigue in the shipping container, containing, for example, fresh fish.
Plasma nonthermal
This process subjects food surfaces to "flame" ionized gas molecules, such as helium or nitrogen. This causes the micro-organisms to die on the surface.
High-pressure food preservation
High pressure food preservation or post-mediation refers to the use of food preservation techniques that utilize high pressure. "Pressed inside a vessel that uses 70,000 pounds per square inch (480 MPa) or more, the food can be processed so as to maintain the fresh appearance, taste, texture and nutrition while paralyzing harmful microorganisms and slowing down the damage." In 2005, this process was used for products ranging from orange juice to guacamole to deli meat and sold widely.
Biopreservation
Biopreservation is the use of natural microbiota or microbiota or antimicrobials that are controlled as a means of preserving food and extending its shelf life. The beneficial bacteria or fermentation products produced by these bacteria are used in biopreservation to control decay and make the pathogens inactive in food. This is a benign ecological approach that gets increased attention.
What is interesting is the lactic acid bacteria (LAB). Lactic acid bacteria have antagonistic properties that make them very useful as biopreservatives. When LAB competes for nutrients, their metabolites often include active antimicrobials such as lactic acid, acetic acid, hydrogen peroxide, and peptide bacteriocin. Some LABs produce antimicrobial nisin, which is a very effective preservative.
These days, bacteriocin LAB is used as an integral part of obstacle technology. Using them in combination with other preservative techniques can effectively control bacterial decay and other pathogens, and may inhibit the activity of a broad spectrum of organisms, including inherently resistant Gram-negative bacteria.
Technology obstacles
Obstacle technology is a method of ensuring that pathogens in food products can be eliminated or controlled by combining more than one approach. These approaches can be considered as "obstacles" pathogens must go through if they are to remain active in food. The proper combination of obstacles can ensure all pathogens are removed or rendered harmless in the final product.
Obstacle technology has been defined by Leistner (2000) as an intelligent combination of obstacles that secure the safety and stability of microbes as well as organoleptic and nutritional qualities and economic viability of food products. Organoleptic quality of food refers to its sensory properties, namely appearance, taste, smell, and texture.
Examples of obstacles in the food system are high temperatures during processing, low temperatures during storage, increased acidity, decreased water activity or redox potential, and preservative or biopreservative presence. According to the types of pathogens and how risky they are, the intensity of the obstacles can be tailored individually to meet consumer preferences in an economical way, without compromising product safety.
See also
Note
References
Further reading
- Marx de Salcedo, Anastacia (2015). The kitchen is ready for combat: How the US military shapes the way you eat . New York: Current/Penguin. ISBN: 9781101601648.
External links
- A ca. 1894 Gustav Hammer & amp; Co. catalog of commercial cooking machines.
- Preserve food ~ from the Clemson House Home and Garden Information Center
- National Center for Home Food Conservation
- BBC News Online - US soldier food... just add urine
- House Archive Economics: Tradition, Research, History (HEART)
The e-book collection of over 1,000 classic books on the home economy spanning the years 1850 to 1950, created by the Cornell University Mann Library.
Source of the article : Wikipedia
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