Benders'dictionary of nutrition and food technology

30gies) may be due to the production of antibodies against specificfood proteins. Chemically the antibodies form a class of proteinsknown as the γ-globulins or immunoglobulins; there are fivetypes, classified as IgA, IgD, IgE, IgG and IgM.A monoclonal antibody consists of a single protein species.They are produced by fusing sensitised B-lymphocytes from thespleen of an animal immunised with the antigen with myelomacells, in vitro.The hybrid cells are selected by use of appropriateculture media, diluted so that individual colonies can be raisedfrom a single cell, and therefore produce a single antibody. Theoreticallypermits very much more specific immunoassay thanmixed antisera raised in vivo, which are polyclonal antibodies.anticaking agents Substances added in small amounts to powderedfoodstuffs such as salt, icing sugar and baking powder toprevent caking, e.g. polyphosphates (E-544, 545), aluminiumcalcium silicate (E-556), calcium silicate (E-552), magnesium carbonate(E-504), calcium carbonate (E-170).anticoagulants Compounds that prevent or slow the process ofblood clotting or coagulation, either in samples of blood takenfor analysis or in the body. One of the most commonly used isheparin, which is formed in the lungs and liver. People at risk ofthrombosis are often treated with warfarin and similar compoundsas an anticoagulant, to reduce the risk of intravenousblood clotting. These act as antagonists of vitamin k in thesynthesis of blood clotting proteins. Oxalate and citrate functionas anticoagulants in vitro because they remove calcium fromthe blood clotting system; hirudin (from leeches) inactivatesprothrombin.See also blood clotting.antidiarrhoeal agents Two groups of compounds are used to treatdiarrhoea: adsorbants such as attapulgite (hydrated aluminiummagnesium silicate) and kaolin (hydrated aluminium silicate),and compounds that decrease intestinal motility, such as codeine,diphenoxylate and loperamide.See also antimotility agents.antidiuretic Drug used to reduce the excretion of urine and soconserve fluid in the body.See also water balance.antidiuretic hormone (ADH) See vasopressin.antiemetics A variety of compounds used to treat persistent vomiting,including dopamine, serotonin and muscarinic cholinergicantagonists, antihistamines, cannabinoids, corticosteroids andsome of the neuroleptic agents.antienzymes Substances that specifically inhibit the action ofenzymes. Many specifically inhibit digestive enzymes and are