METHOD FOR DETERMINATION OF SORPTION CAPACITY OF BREAD CONTAINING PECTIN Russian patent published in 2012 - IPC G01N33/02 

FIELD: food industry.

SUBSTANCE: method involves pectin-containing bread sampling in an amount of no less than 100 g whereof one prepares solution in the form of bread mess. The mixture is left for 1-2 minutes and then filtered. One determines Pb-pectates in the settled filtrate. A sample of the filtrate is taken, treated with standard plumbum solution to produce volumetric sediment of Pb-pectates. The produced sediment is separated by filtration through a paper filter. The sediment on the filter is repeatedly washed with distilled water till Pb²⁺-ion disappearance in wash waters with subsequent washing with 96% ethyl alcohol solution in an amount of 50-100 ml. The separated sediment is slightly dried. Then the sediment is treated with a combustion agent solution containing concentrated nitric acid and 30% solution of hydrogen peroxide at a ratio of 3:1. The sediment combustion is performed by the mixture boiling on hot sand during 2-3 hours till complete transparency of the solution boiled out till volume is 30-40 ml. The produced solution containing plumbum is mixed with standard disodium dihydrogen ethylenediaminetetraacetate solution, preliminarily produced, in an amount of 60-70 ml, 15 ml of ammonia buffer solution and no more than 1 ml of "eriochrome black T" indicator. Then mixture is titrated with standard solution of zinc sulphate. Titration termination is determined by disappearance of the indicator blue colour and its transition into lilac. One determines the volume of zinc sulphate solution spent for titration. One calculates normality of the solution containing plumbum, plumbum weight in the solution after wet combustion and sorption capacity of pectin-containing bread.

EFFECT: enhancement of determination informativity and reliability.

2 tbl