Total Sulphite Assay Kit (Colorimetric) (ab211102) provides
a simple and sensitive assay to detect small concentrations of sulphite present
in a variety of food and beverage samples such as wine, juices, dairy, canned
products, juices or dried fruit. This assay is based on the oxidation of
sulphite to sulfate, which reacts with the enzyme mix to produce a stable
signal that can be detected at OD = 570 nm, and that is directly proportional
to the amount of sulphite present in the sample. This assay is very sensitive
and can detect as low as 20 µM of sulphite in a variety of samples. This
product is manufactured by BioVision, an Abcam company and was previously
called K699 Total Sulfite Assay Kit (Colorimetric). K699-100 is the same size
as the 100 test size of ab211102. Sulphites (also known as sulfites) are
substances that occur naturally in the human body as by-products of the
metabolism of amino acids containing sulfur side chains. They are readily
oxidized to sulfates via several enzymatic reactions and excreted in urine at
the rate of 1000 mg/day. The term sulphite is used for all sulphite-derived
molecules: bisulphites, metasulphites, and SO . Total sulphite is defined as
the sum of bound and free sulphite. Sulphites are often considered as allergens
due to the adverse symptoms observed in asthmatic patients. Exogenous sources
of sulphites include polluted air, and food and beverages containing sulphur
dioxide (SO ). SO is a molecule that easily reacts with several small compounds
including aldehydes, ketones, anthocyanins, cobalamine, thiamine, NAD and
flavins. SO also interacts with cysteine residues in proteins and promotes
cross-linking. Sulphites are also used as regulated food
preservatives/additives/enhancers in dried fruits, wine and beer. They are
considered as GRAS (Generally Recognized as Safe) in food and beverages. In
wine, SO reacts with sugars, aldehydes and anthocyanins.
