Calcium bisulfite (calcium bisulphite) is an inorganic compound which is the salt of a calcium cation and a bisulfite anion. It may be prepared by reacting lime with an excess of sulfurous acid, essentially a mixture of sulfur dioxide and water. It is a weak reducing agent, as is sulfur dioxide, sulfites, and any other compound containing sulfur in the +4 oxidation state. As a food additive it is used as a preservative under the E number E227. Calcium bisulfite is an acid salt and behaves like an acid in aqueous solution.
Calcium hydrogen sulfite
3D model (JSmol)
|E number||E227 (preservatives)|
|Molar mass||202.22 g/mol|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
The International Numbering System for Food Additives (INS) is a European-based naming system for food additives, aimed at providing a short designation of what may be a lengthy actual name. It is defined by Codex Alimentarius, the international food standards organisation of the World Health Organization (WHO) and Food and Agriculture Organization (FAO) of the United Nations (UN). The information is published in the document Class Names and the International Numbering System for Food Additives, first published in 1989, with revisions in 2008 and 2011. The INS is an open list, "subject to the inclusion of additional additives or removal of existing ones on an ongoing basis".List of food additives
Food additives are substances added to food to preserve flavor or enhance its taste, appearance, or other qualities.Potassium bisulfite
Potassium hydrogen sulfite or potassium bisulfite is a chemical compound with the chemical formula KHSO3. It is used during the production of alcoholic beverages as a sterilising agent. This additive is classified as E number E228 under the current EU approved food additive.Pulp (paper)
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fiber crops, waste paper, or rags. Many kinds of paper are made from wood with nothing else mixed into them. This includes newspapers, magazines and even toilet paper. Pulp is one of the most abundant raw materials .Sodium bisulfite
Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical compound with the chemical formula NaHSO3. Sodium bisulfite is a food additive with E number E222. This salt of bisulfite can be prepared by bubbling sulfur dioxide in a solution of sodium carbonate in water. Sodium bisulfite in contact with chlorine bleach (aqueous solution of sodium hypochlorite) will generate heat and form sodium bisulfate and sodium chloride.Sulfite process
The sulfite process produces wood pulp which is almost pure cellulose fibers by using various salts of sulfurous acid to extract the lignin from wood chips in large pressure vessels called digesters. The salts used in the pulping process are either sulfites (SO32−), or bisulfites (HSO3−), depending on the pH. The counter ion can be sodium (Na+), calcium (Ca2+), potassium (K+), magnesium (Mg2+) or ammonium (NH4+).