Air, water, and food from a sanitary standpoint . e weight remainsconstant within 2 or 3 milligrams. During the process of heat-ing stir the butter frequently to hasten evaporation of the water. Determination of -Directions.—Weigh 10 grams of butter in a small beaker, add 30 of hot water, and when the fat is completely melted transfer the whole to a separately funnel. Shake the mixture thoroughly, allow the fat to rise to the top, and draw off the water, taking care that none of the fat-globules pass the stopcock. Repeat the operation four times, using 30 of water each time. M
Air, water, and food from a sanitary standpoint . e weight remainsconstant within 2 or 3 milligrams. During the process of heat-ing stir the butter frequently to hasten evaporation of the water. Determination of -Directions.—Weigh 10 grams of butter in a small beaker, add 30 of hot water, and when the fat is completely melted transfer the whole to a separately funnel. Shake the mixture thoroughly, allow the fat to rise to the top, and draw off the water, taking care that none of the fat-globules pass the stopcock. Repeat the operation four times, using 30 of water each time. Make the washings up to 250 , mix thoroughly, and titrate 25 in a six-inch porcelain dish, using — silver nitrate with potassium chromate as an indicator. Complete Analysis of Butter in One Sample.—Direc-tions.—Weigh about 2 grams of butter into a platinumGooch crucible, half-filled with ignited fibrous asbestos, anddry it at ioo° C. to constant weight. The loss in weight isthe amount of water. Then treat the crucible repeatedly. A. Butter X 30. C. Oleomargarine X 30. B. Beef-fat X 30,D. Lard X 30. food: analytical methods: butter. 205 with small portions of petroleum ether, using- gentle suction,and again dry it to constant weight. The difference betweenthis and the preceding weight will be the amount of carefully heat the crucible over a sma1l flame or in amuffle until a light grayish ash is obtained. The loss inweight is the amount of curd, and the residual increase inweight over that of the crucible and asbestos is the ash. If de-sired, the salt may be washed out of the ash and determinedby titration with silver nitrate after neutralizing the solutionwith calcium carbonate. FLOUR, PREPARED CEREALS, ETC. This class of foodstuffs is usually in a dry form and notliable to rapid change by micro-organisms, and the examina-tion consists in the determination of their food value. Thismay require a simple analytical process, as in the case of thequantity of
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