Preservatives sulfites

Photography. Sodium sulfite is useful as a reducing agent in certain photographic fixing baths, developers, hardeners, and intensifiers (334). However, the principal use is as a film preservative and discoloration preventative (see Photography). 

Sulfur dioxide, sulfites, and metabisulfites have had extensive use as antimicrobial preservatives in the food industry. In pharmaceuticals they have had a dual role, acting as preservatives and antioxidants. The sulfa dmgs, or sulfonamides, the first effective chemotherapeutic agents to be employed... 

The slight excess of sulfite can be left to use as a kind of preservative or be destroyed using oxidizing agents like hydrogen peroxide. One has to be careful in leaving oxidants or reductants in the product. There might be some difficulties when the sulfosuccinate comes in contact with dyes. 

Potassium sulfite is commonly used as a food preservative, because the sulfite anion undergoes reactions that release sulfur dioxide, an effective preservative. Determine the concentrations of the ionic species present in a solution of potassium sulfite that is 0.075 M. 

The incorporation of certain excipients in products is deemed to be undesirable. Examples are the inclusion of mercurial preservatives, the inclusion of benzyl alcohol in parenteral products for use in children, the use of benzoic acid esters in injections, and the inclusion of sulfites and metabisulfites in products in general. If it is intended to use any of these materials, then a full justification will be required. 

Sulfur dioxide is an economically important gas that is used as a refrigerant, disinfectant, and reducing atmosphere for preserving food. Although it is also used in the manufacture of many other sulfur compounds, the most important use of S02 is as a precursor in producing sulfuric acid. It can be obtained by burning sulfur, but it is also produced in numerous other reactions. Sulfites react with acids by liberating so2. 

The most important methods commonly used in produce preservation are low temperature, aw reduction, low acidity, and preservatives (e.g. organic acids and sulfite). The microbial stability and the sensory quality of most foods are based on passing over a combination of hurdles. 

Kubeck and Naylor [2] tested four chemical preservatives (formaline, sulfite, bisulfite and a mixture of formaline/sulfite) by analysing NPEOs in river water over a period of 4 weeks. The sulfite- and bisulfite-preserved samples deteriorated drastically beginning after the first week, dropping 60-80% in NPEO concentration after four weeks. Formaline maintained the NPEO concentration within 10% of the original through at least two weeks. Formaline/sulfite mixture showed 25% loss after four weeks. 

Sodium hydrogen sulfite, NaHS03, is a preservative that is used to prevent the discolouration of dried fruit. In aqueous solution, the hydrogen sulfite ion can act as either an acid or a base. Predict whether NaHSOs dissolves to form an acidic solution or a basic solution. (Refer to Appendix E for ionization data.)... 

Uses Manufacture of acrylonitrile, hydrazine hydrate, hydrogen cyanide, nitric acid, sodium carbonate, urethane, explosives, synthetic fibers, fertilizers refrigerant condensation catalyst dyeing neutralizing agent synthetic fibers latex preservative fuel cells, rocket fuel nitrocellulose nitroparaffins ethylenediamine, melamine sulfite cooking liquors developing diazo films yeast nutrient. 

Sodium sulfite (Na SO ) is an antioxidant, used as a preservative except with meats. It is also used for water treatment and in photography and textile bleaching. 

Uses. Intermediate in the manufacture of sulfuric acid and sulfite pulp casting of non-ferrous metal used in the food industry as a biocide and a preservative... 

Sulfites Preservative Antioxidants used to reduce spoilage can produce allergic reactions, especially in asthmatics... 

Contraindications Ophthalmic solutions (both strengths) of phenylephrine HCl are contraindicated in patients with anatomically narrow angles or narrow-angle glaucoma, severe arteriosclerotic cardiovascular or cerebrovascular disease, use during intraocular operative procedures when the corneal epithelial barrier has been disturbed, and in persons with a known sensitivity to phenylephrine, sulfites, or any of its components including preservatives. The 10% solution is contraindicated in patients with aneurysms. 

There are different kinds of chemical preservatives commonly used in foods which either inhibit the activity of bacteria or kill the bacteria. These chemicals include benzoates (such as sodium benzoate), nitrites (such as sodium nitrite), sulfites (such as sulfur dioxide) and sorbic acid. 

Coulometric titration of sulfite in wine.36 Sulfur dioxide is added to many foods as a preservative. In aqueous solution, the following species are in equilibrium ... 

Preservatives. Most preservatives do not kill microorganisms present in food. Rather, they prevent further growth and proliferation of anything that is present by either lowering the water activity or increasing the pH of the foods in which they are used. Preservatives include benzoates, sorbates. propionates, organic acids, sulfur dioxide and sulfites, parabens. sodium nitrate and sodium nitrites, and natamycin and ntsin. See also Preservative. 

Preservatives. Sulfur compounds, such as sulfur dioxide and sodium bisulfite, are used commercially to preserve the color of various food products, such as orange juice, dehydiated fruits and vegetables, such as apricots, carrots, peaches, pears, potatoes, and many odiers. Concentrated sulfur dioxide is used in wine-making to destroy certain bacteria. The color preservation of canned green beans and peas is enhanced by dipping the produce in a sulfite solution prior to canning. In 1986, some of these compounds and uses were put under closer regulation in the United States. 

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