Benders'dictionary of nutrition and food technology

258sufficient blood to heart muscles; associated with atherosclerosisof coronary arteries.isinglass gelatine prepared from the swim bladder of fish (especiallysturgeon). Used commercially to clear wine and beer, andsometimes in jellies and ice cream. Japanese isinglass is agar.islets of Langerhans The endocrine parts of the pancreas;glucagon is secreted by the α-cells, insulin by the β-cells andgastrin by the γ-cells of the islets.ISO 9000 Quality Standard The international standard for themanagement of quality, widely used in the food industry, cateringand food distribution, but developed originally for the engineeringindustry. ISO 9001 covers the specification for design,manufacture and installation; ISO 9002 the specification for manufactureand installation; ISO 9003 the specification for finalinspection and test.isoacids Obsolete term for isomers of unsaturated fatty acids(including trans-isomers) formed during hydrogenation of oils.isoamylase See debranching enzymes.isoascorbic acid See erythorbic acid.isobaric Processes in which the pressure is held constant andvolume varies with temperature.See also adiabatic; isothermal.isodesmosine See desmosine.isoelectric focusing (electrofocusing) A technique for separatingproteins, etc., by electrophoresis on a support medium that providesa pH gradient, so that each comes to rest at a positiondetermined by its isoelectric point.isoelectric point The pH at which an ionised molecule (e.g. aprotein or amino acid) has no net charge.isoenzymes Enzymes that have the same catalytic activity, butdifferent structures, properties and/or tissue distribution.isoflavones See flavonoids.isohumulones See humulones.isoleucine An essential amino acid, abbr Ile (I), M r 131.2, pK a2.32, 9.76, codons AUA, AUPu. Rarely limiting in food. It is oneof the branched-chain amino acids, together with leucine andvaline.isomalt A bulk sweetener, about half as sweet as sucrose, consistingof a mixture of two disaccharide polyols, glucosorbitoland glucomannitol. About 50% metabolised, yielding 9 kJ(2.4 kcal)/gram.Thought to be less laxative than sorbitol or mannitol,and does not encourage tooth decay, so is used in toothfriendlysweets. It absorbs very little water, so products are lesssticky than those made with sucrose and have a longer shelf-life.isomalto-oligosaccharides See oligosaccharides.