GIFSQ — Global Institute for Food Safety & Quality Principle The chloride in the water-soluble ash is determined by argentometric titration: silver nitrate precipitates the chloride, and the end point is shown by the red-brown colour of silver chromate with potassium chromate indicator, or by the Volhard back-titration. The result is expressed as sodium chloride […]

GIFSQ — Global Institute for Food Safety & Quality Principle Salt (as sodium chloride) in the pickle sample is determined by either of two methods: the procedure given for salt in Chapter 9 of this book, or the indirect (Volhard) method. Procedure Determine the salt content of the composite pickle sample by the procedure given […]

GIFSQ — Global Institute for Food Safety & Quality Principle The strength of a brine is determined from its density with a hydrometer. The Baumé hydrometer was earlier calibrated in per cent salt by weight; at present the Baumé scale indicates less concentration than the true per cent of salt. The most common hydrometers are […]

GIFSQ — Global Institute for Food Safety & Quality Principle This is a colorimetric limit test for sodium ferrocyanide, added to brine to modify salt crystal growth. Ferrous sulphate and sulphuric acid develop a blue colour with ferrocyanide; the colour of the sample solution is compared in comparator tubes with a control containing a known […]

GIFSQ — Global Institute for Food Safety & Quality Principle This is a limit test for the common metallic impurities that are coloured by hydrogen sulphide (Ag, As, Bi, Cd, Cu, Hg, Pb, Sb and Sn). The colour developed by the test solution on adding hydrogen sulphide is compared with that of a standard lead […]

GIFSQ — Global Institute for Food Safety & Quality Principle The alkalinity of the salt, expressed as sodium carbonate, is determined by titrating an aliquot of the water-insoluble-matter filtrate against standard hydrochloric acid with methyl orange as the indicator. Apparatus required Burette (for the hydrochloric acid titration) Reagents a. 0.1 N hydrochloric acid, HCl, standard […]

GIFSQ — Global Institute for Food Safety & Quality Principle Sulphate is determined gravimetrically as barium sulphate: the soluble sulphate is precipitated from the boiling acidified solution with barium chloride, the granular precipitate is collected, washed free of chlorides and dried to constant weight. Apparatus required Tared sintered glass crucible (G No. 4) or Gooch […]

GIFSQ — Global Institute for Food Safety & Quality Principle Water-soluble calcium and magnesium are determined by complexometric titration with standard EDTA solution. The combined calcium and magnesium are titrated at pH 10 with Eriochrome Black T indicator (wine-red to pure blue end point); calcium alone is titrated in alkaline medium with murexide or calcein […]

GIFSQ — Global Institute for Food Safety & Quality Principle The water-soluble impurities other than sodium chloride are obtained by a stepwise accounting of the determined constituents: carbonates, calcium, sulphate, magnesium and potassium are combined with their radicals in a fixed order, and the water-soluble matter other than sodium chloride is then calculated from the […]

GIFSQ — Global Institute for Food Safety & Quality Principle The salt is dissolved in water and the insoluble residue is collected on a prepared Gooch crucible, washed, dried to constant weight and weighed gravimetrically. The increase in weight is the water-insoluble matter, reported on a moisture-free basis. Apparatus required Gooch crucible with asbestos mat […]

GIFSQ — Global Institute for Food Safety & Quality Principle This is a precipitation titration: the chloride in the dissolved sample is titrated with standard silver nitrate, using potassium chromate as the indicator; the end point is the first persistent reddish-brown tinge after brisk shaking. Apparatus required Conical flask Burette (for the silver nitrate titration) […]

GIFSQ — Global Institute for Food Safety & Quality Principle The chlorides in the product are precipitated by an excess of silver nitrate, and the organic matter is then oxidised with potassium permanganate in acid solution. The excess permanganate is decomposed by sucrose, and the unused silver nitrate is determined by titration with thiocyanate. The […]

GIFSQ — Global Institute for Food Safety & Quality Principle This is a Volhard back-titration. The chloride in the salt is precipitated with a measured excess of silver nitrate; the unused silver nitrate is titrated with standard ammonium thiocyanate, using ferric ammonium sulphate as the indicator (first appearance of a red-brown colour). The sodium chloride […]

GIFSQ — Global Institute for Food Safety & Quality Principle Moisture is determined gravimetrically: the salt sample is heated and the loss in weight, brought to constant weight by repeated heating and weighing, is reported as the moisture content. Apparatus required Tared 250-ml conical flask Small funnel Oven (capable of 250°C) Analytical balance Sample preparation […]

GIFSQ — Global Institute for Food Safety & Quality Principle The salt sample is ground to a defined particle-size range and mixed by quartering so that every weighed portion taken for the determinations is representative of the bulk. Apparatus required Grinder or mortar Sieve No. 20 Sieve No. 80 Sample preparation Grind the sample so […]

GIFSQ — Global Institute for Food Safety & Quality Principle Determination of water-soluble matter other than sodium chloride is done after determination of the parameters sodium chloride percentage and water insoluble matter percentage on the dry basis. Calculation % water soluble matter other than sodium chloride = 100 − (NaCl % + % water insoluble […]