Chemical food preservation

Common sequestering agents are disodium EDTAcitric acid and citratestartaric acidand lecithin.

Food Preservatives Photo by: Ziablik Most foods contain enzymes or natural chemicals, such as acids or alcohols, that cause them to begin to lose desirable characteristics almost immediately after harvest or preparation.

In addition, a host of environmental factors, such as heat and the presence of microorganisms, acts to change foodstuffs in ways that may harm the food product. Food preservation traditionally has three goals: Traditional methods of preservation usually aim to exclude air, moisture, and microorganisms, or to provide environments in which organisms that might cause spoilage cannot survive.

Ancient peoples are known to have had dried fruits, vegetables, and meats. The pemmican of Native Americans and the jerky consumed by present-day campers and hikers are both prepared by drying. The drying process can include smoking, which may actually add antibacterial agents. The processes of dehydration and freeze-drying, used today to produce such foods as powdered coffee and soup, are variations of drying.

Among the earliest preservatives were sugar and salt NaClwhich produced food environments of high osmotic pressure that denied bacteria the aqueous surroundings they needed to live and reproduce. Jams and jellies are preserved as solutions of high sugar content, and Chemical food preservation meats e.

Unlike other microorganisms, molds can often withstand the effects of high salt or sugar concentrations in foods.

Fortunately, they seldom cause illness. Early methods of air removal included the sealing of foods inside containers such as jarsor the covering of food surfaces with hot paraffin.

The invention of canning by Nicolas Appert enabled commercial preparations of foodstuffs. His process was used commercially in by Peter Durand in England, using metal cans. During the earliest days of canning, some persons including some Arctic explorers probably died as a result of exposure to the lead that was once used to solder cans.

Modern techniques of air removal include vacuum sealing and the use of plastic wrappings. Along with cooking, which kills most bacteria, freezing stops or slows bacterial growth as well as changes in foods brought about by enzymes present in the foods.

Unlike the slower freezing of foods in homes, quick freezing in commercial processing enables foods to retain more of their natural appearance and taste.

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Chemical preservatives include free radical scavengers also known as antioxidantssuch as vitamin C and compounds such as BHA butylated hydroxyanisoleand bacterial growth inhibitors, such as benzoic acid, sulfur dioxide, and sodium nitrite NaNO 2. Some chemical preservatives may be harmful: Sulfur dioxide often used to preserve wines is irritating to the bronchial tubes of persons who have asthma, and nitrites have been implicated as carcinogens.

After Louis Pasteur proved that it was the presence of bacteria that caused food to spoil, there was a tendency to consider all microorganisms harmful. But in fact, microbial action is responsible for the production and preservation of some foods.

The action of microbes is a part of the production of cheese and some flavoring agents. Sauerkraut is both processed Nitrates are a common preservative in luncheon meats.

The irradiation of foods has the advantage of enabling food packaging and preparation in which there is less person-to-food contact, thus decreasing the possibility of contamination and decreasing the need for chemical preservatives, some of which may be harmful.

The ionizing radiation that is used to irradiate foods, wherein the foods are exposed to bursts of high-intensity x rays or streams of electrons, disrupts bacterial DNA. Some persons have objected to the irradiation of foods because of an unfounded fear of radioactivity.

As pathogens such as virulent strains of coliform bacteria have caused food poisoning, the irradiation of animal carcasses and, in particular, of hamburger during its preparation has become more desirable.

Food Preservation

Irradiation currently extends the shelf lives of foods such as strawberries. Irradiation does not make foods radioactive, but may cause changes in food color or texture.Food preservation - Food irradiation: Food irradiation involves the use of either high-speed electron beams or high-energy radiation with wavelengths smaller than nanometres, or angstroms (e.g., X-rays and gamma rays).

These rays contain sufficient energy to break chemical bonds and ionize molecules that lie in their path. .

Chemical Cuisine | Center for Science in the Public Interest

IN A PICKLE! TYPES OF FOOD PRESERVATION IN THE 19 TH CENTURY Virginia Mescher [Author’s Note: This article is only meant to offer an overview of food preservation methods used in the. Preservation of food products containing chemical food preservatives is usually based on the combined or synergistic activity of several additives, intrinsic product parameters (e.g.

composition, acidity, water activity) and extrinsic factors (e.g. processing temperature, storage atmosphere and temperature). Before huge multinational corporations did it for us, humans had to figure out how to turn raw, unrefined formerly-living things into food that could be.

Learn about different food preservatives like natural food preservatives, artificial food preservatives and chemical food preservatives. Also learn the harmful preservatives in food and some common preservatives food and preservatives food .

Different Methods of Food Preservation. Food preservation is known “as the science which deals with the process of prevention of decay or spoilage of food thus allowing it to be stored in a fit condition for future use”.

Preservation ensures that the quality, edibility and the nutritive value of the food remains intact.