What are the different types of chemical food preservation?

Food chemical protection has been practiced since one first started to store food for later use. Food storage has increased the problem of creeping, usually caused by microorganisms such as bacteria, fungi and yeast. In addition to drawing food inedible or unacceptable, microbial activity could lead to potentially fatal food poisoning. Through history, a wide range of chemicals has been used to prevent food being prevented, and their use data since the first suspicion of microorganisms was suspicious. These chemicals range from naturally occurring substances such as salt, sugar, salty and spices, to modern food ingredients such as benzoate, sorbates and sulphuries. To achieve the desired effect, it is necessary to use approximately six times as much sugar as salt, but both should be used in relatively large quantities to be effective, and this obviously limits their use because they give the food a strong taste, especially in the case of salt. Are therefore an employeeOna where their tastes supplement food, so salt is used for meat and sugar for fruit. Many herbs and spices contain chemicals that can kill microorganisms, which were also used as preservatives. Garlic, onions, spices and oregano are particularly effective in killing bacteria.

Sodium and potassium nitrate, also known as a salty machine, have been used for centuries to preserve and treatment of meat and are still used to this day. The bacteria reduce nitrates (not _{3 -) to nitrites (not 2 -}

) and then to nitrate oxide (not) that destroys enzyme ferredoxin, which uses their energy such as clortridium th. For this reason, nitrates or nitrites are considered necessary in treatedMeat products such as ham, bacon and sausages. However, this form of chemical food preservation is controversial; Nitrites can respond with chemicals in the meat to form nitrosamins that are carcinogenic. Nitrates and nitrites are not effective against microorganisms that do not use ferredoxin - for example Salmonella .

Methods of preservation of chemical food introduced in the 20th century include the use of salts of some organic acids such as benzoic, propionoic and sorbic acids - for example, sodium benzoate, sodium propionate and potassium sorbat. After absorbing into microbial cells, these chemicals disrupt the cell transport system, which allows the absorption of nutrient cell membranes, which prevents growth. Are effective against a wide range of bacteria and molds at low concentrations and usually do not affect the taste of food; However, usually work best at a relatively low pH so they are best suited for use in sour foods such as fruit juice, carbonated drinks andsalad jersey. Parabens - esters of hydroxyparabenzoic acid - are effective in a wider pH extent.

sulfits and metabisulphites release sulfur dioxide, which is dissolved in water to form sulfuric acid. It seems to work similarly to organic acids and is particularly effective against yeast and molds, including mushrooms that produce afflatoxins. These preservatives are often used in dried fruits and wine; However, their use is not allowed in the meat because they turn red and can disguise the odor of the decay, so the spoiled meat is fresh. Some suffering are very sensitive to sulfur dioxide and its derivatives and must avoid food and drink containing relatively high levels of sulfurry.

The use of antibiotics for preservation of chemical food is not allowed in most countries, as this can lead to the creation of bacteria tribes resistant to antibiotics. However, nisin bacteriocin is sometimes used because - unlike most bacteriocins - is effective against a wide range of micrOorganisms. It is added to some processed cheese products and some canned foods.

food and food containers are sometimes treated with certain chemicals before wrapping, unlike the addition of preservatives. For example, fruit is often fumigated by ethylene and propylene oxides for mold inhibition. Various flavors and antioxidants added to food can also help keep it.