What is the function of metabisulfite?

Abstract. Sodium metabisulphite is used as an antioxidant agent in many pharmaceutical formulations. It is extensively used as a food preservative and disinfectant. It has been demonstrated that sulphite exposure can affect some organs.

How does sodium metabisulfite work as a preservative?

SMBS is a sulfur-containing preservative that inhibits the oxidase in the food, and also can block the normal physiological oxidation process of microorganisms and thus inhibit the reproduction of microorganisms in food preservation.

What is metabisulfite made of?

Sodium metabisulfite can be produced by crystallizing a solution of sodium bisulfite. Sodium bisulfite results from introducing sulfur dioxide into a solution of sodium sulfite. Sodium sulfite, in turn, can be produced by introducing sulfur dioxide into sodium hydroxide.

What happens when sodium metabisulphite is dissolved in water?

When introduced to water, sodium metabisulfite liberates sulfur dioxide gas which has a very pungent and unpleasant odour. This gas can also lead to respiratory problems in humans.

What is the pH of sodium metabisulfite?

4.6
Sodium Metabisulfite Solution (SMBS) is made by dissolving solid sodium metabisulfite into water and has a pH of 4.6 at 1.0 % (by weight) solution strength.

Is metabisulphite Sulphur dioxide?

SMBS is not permitted in several countries for use in meat products. Chemically, SMBS contains 67% sulphur dioxide (SO2). When SMBS is applied to a meat product, the SMBS instantly reacts with water and, as a rule of thumb, around 50–55% added SMBS can be found analytically in the meat product as SO2.

What is SMBS chemical?

​Sodium Metabisulphite (SMBS) is a white/creamy chemical which is soluble in water. Its chemical formula is Na2S2O5, an inorganic compound made up of sodium, sulfur and oxygen, and used in many industries such as food, textile, mining, water treatment, construction chemicals and paper.

Is potassium a metabisulfite?

Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent odour. It is mainly used as an antioxidant or chemical sterilant. As a disulfite, it is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably.

Is sodium metabisulfite an acid or base?

A corrosive acid when mixed with water.

What is the pH of potassium metabisulfite?

It is also known as E224. Added to wine and cider at the pH range of between 3.6 and 4.4 it prohibits the growth of wild yeasts, bacteria and fungi giving effective prevention of biological spoilage.

What is the difference between sodium metabisulfite and potassium metabisulfite?

The only difference between sodium metabisulfite and potassium metabisulfite is that they will leave a residual trace of either sodium or potassium. Some brewers prefer potassium metabisulfite as they deem it to have a more neutral flavour, the amounts being used however are very small so I tend not to worry.