GIFSQ — Global Institute for Food Safety & Quality 1. Principle In this method, the butter sample is melted in hot water, and the chlorides present in the mixture are titrated with a solution of silver nitrate using potassium chromate as indicator. Reaction AgNO₃ + NaCl → AgCl + NaNO₃ 2AgNO₃ + K₂CrO₄ → Ag₂CrO₄ […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applicable to all dairy products. 1. Principle When milk powder is ignited at high temperature in a muffle furnace, organic matter is burnt out and mineral and other inorganic matter remains in the ash. 2. Apparatus a. Platinum or silica crucible: about […]

GIFSQ — Global Institute for Food Safety & Quality Scope Whole milk powder, skimmed milk powder, partially skimmed milk powder, infant milk food, infant formula, milk cereal weaning food and processed cereal based weaning food fall under this category. 1. Preparation of sample of milk powder Make the sample homogeneous either by mixing or shaking, […]

GIFSQ — Global Institute for Food Safety & Quality 1. Preparation of sample of paneer Grate the paneer sample quickly through a suitable grater. Mix the grated sample thoroughly. Transfer the grated sample to an air-tight container to await analysis, which should be carried as soon as possible after grinding. Keep the sample in an […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applicable to all varieties of cheese. 1. Principle The fat in cheese is in the form of an emulsion. This emulsion is broken with sulphuric acid and fat separation is facilitated by amyl alcohol. 2. Apparatus a. Gerber centrifuge b. Gerber cheese […]

GIFSQ — Global Institute for Food Safety & Quality 1. Preparation of sample of cheese Prior to analysis, remove the rind or smear or mouldy surface layer of the cheese, in such a way as to provide a sample representative of the cheese as it is usually consumed. Grind or grate the sample by means […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applicable for testing the presence of vanaspati ghee in butter and ghee. 1. Principle The development of a permanent pink colour in a sample of butter with furfural solution in the presence of hydrochloric acid indicates the presence of sesame oil, and […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle Several dyes and colours like azo-dyes, annatto or other vegetable colour, and gallate antioxidants in butter give characteristic colour upon treatment with alkali or acid. 2. Apparatus a. Balance b. Test tubes c. Pipettes Qualitative test tubes — GIFSQ illustration 3. Chemicals a. Ethyl […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle When sulphuric acid is added to butter, the proteins will be digested, thus destroying the membrane of the fat globules. The free fat is then released. The fat remains in liquid due to heat produced, and during centrifugation the fat, being lighter, will be […]

GIFSQ — Global Institute for Food Safety & Quality 1. Preparation of sample of butter Warm the sample in an airtight container with the lid screwed down tightly, or with the glass stopper, in an oven or water bath maintained at 37 ± 2°C. Shake vigorously to obtain a homogeneous fluid emulsion free from un-softened […]

GIFSQ — Global Institute for Food Safety & Quality 1. Preparation of sample In order to keep the sample homogeneous, it is better to allow it to melt at room temperature rather than to heat it. Mix thoroughly by stirring or by pouring bulk and further one vessel to another. If the sample contains milk […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applicable to milk and milk products. 1. Principle Protein in milk and milk products is digested with concentrated sulphuric acid in the presence of a catalyst containing a mixture of sodium or potassium sulphate and copper sulphate, in a digestion chamber. During […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle The sample is treated with ammonia and ethyl alcohol; the former to dissolve the protein and the latter to help precipitate the proteins. Fat is extracted with diethyl ether and petroleum ether. Mixed ethers are evaporated and the residue weighed. This method is considered […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applicable to all types of milk powders. 1. Principle The Gerber method for determination of fat in milk and milk products depends on the liberation of the fat by the action of sulphuric acid on milk or milk products in specifically shaped, […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applied to milk and milk products. 1. Principle The principle involves clarifying the sample with the help of zinc acetate and potassium ferrocyanide, inverting a part of the sample using hydrochloric acid, and determining the reducing sugars content in both inverted and […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applicable to all dairy products and food and food products such as sweetened condensed milk, skim condensed milk as well as other food products. 1. Principle When sulfuric acid is added to the milk, the protein will be digested, thus destroying the […]

GIFSQ — Global Institute for Food Safety & Quality 1. Preparation of sample Temper the unopened can in a water bath at 30–35°C until warm ↓ Open, transfer to a beaker large enough to permit stirring thoroughly, scrape out all milk adhering to the interior of the can, and mix until the whole mass is […]

GIFSQ — Global Institute for Food Safety & Quality 1. Reagents Chromotropic acid reagent: prepare a saturated solution of 1,8-dihydroxynaphthalene-3,6-disulfonic acid by stirring 0.5 g of the acid in 100 mL of 72% H₂SO₄. The solution is pale yellow in color. Prepare 72% H₂SO₄ by taking 150 mL of concentrated H₂SO₄ and mixing with 100 […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle In cultured dairy products such as dahi or yoghurt, total solids are determined after neutralization of developed acidity with alkali. In this procedure, NaOH is used for neutralization of developed acidity, followed by determination of total solids by evaporation at 100 ± 2°C. 2. […]

GIFSQ — Global Institute for Food Safety & Quality 1. Preparation of sample of Dahi To get a representative sample, particularly in case of a thick-set product, it may be necessary to pour out the whole of the contents in a mortar and mix it thoroughly until the mass is homogeneous. Aliquots are weighed out […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method is applicable to fluid milk, powder milk and other milk products. 1. Principle The method is based on the titration of the sample with sodium hydroxide to a phenolphthalein end point, and by comparing the colour with the colour obtained by mixing rosaniline […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle The sample is titrated with sodium hydroxide to a phenolphthalein end point, using milk containing rosaniline as a comparison standard. 2. Apparatus a. 100 mL porcelain basin b. Burette Titration apparatus — GIFSQ illustration 3. Reagents a. 0.1 N NaOH solution b. Rosaniline acetate […]

GIFSQ — Global Institute for Food Safety & Quality Scope This method prescribes the procedure for the determination of fat in whole milk, evaporated milk, and standardized milk, toned milk, double toned milk, separated milk, skimmed milk, buttermilk, condensed milk and homogenized milk by the Gerber method. Sampling and sample preparation If the sample is […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle Neutralizers (NaOH, Na₂CO₃ and NaHCO₃) are added to milk to neutralize the developed acidity in milk. The rosalic acid method can be used for the detection of the presence of these neutralizers in milk. There are two variants of this method; both variants are […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle The presence of extraneously added sodium chloride in milk can be detected by silver nitrate and potassium chromate reagent. 2. Reagents a. Silver nitrate (AgNO₃) solution: 0.1 N, aqueous b. Potassium chromate (K₂CrO₄) solution: 10% (w/v), aqueous 3. Procedure Take 5.0 mL of milk […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle Urea is a natural constituent of milk and it forms a major part of the non-protein nitrogen of milk. Urea concentration in milk is variable within a herd. Urea content in natural milk varies from 20 mg/100 mL to 70 mg/100 mL. However, urea […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle Starch molecules form a blue colored complex with iodine. Incorporation of starch in milk can be detected by adding iodine solution to it. 2. Reagents a. Iodine solution: dissolve 2.6 g of iodine and 3 g of potassium iodide in a sufficient quantity of […]

GIFSQ — Global Institute for Food Safety & Quality 1. Principle Fructose in cane sugar (sucrose) reacts with resorcinol in HCl to give red colour. 2. Reagents a. Resorcinol solution (0.5%): weigh 0.5 g of resorcinol in about 40 mL of distilled water. Add 35 mL of concentrated HCl (12 N) to it and make […]