Pelatihan dan persiapan calon calon guru yg dilatih di asrama guru Pati Jawa tengah

FOOD AND DRUGS 505 ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS Food and Drugs Relation Between the Specific Conductivity and the Age of Hens' Eggs. W. Rudolph. (2. Unters. Lebensm., 1938, 75, 428430.)-Numerous methods have been suggested for the determination of the age of eggs, e.g. the determination of the increase of inorganic phosphorus in the white (Janke and Jirak, Biochem. Z., 1934, 271, 309) and determination of the ammonia-content of the whole egg (Folin, 2. Physiol. Chem., 1902, 37, 161; Griinhut, 2. Unters. Lebensm., 1929, 37, 304; Rudolph, 2. Chem. Apfiarat, 1937, 24, 364). Since during ageing the yolk absorbs water and at the same time gives up water-soluble substances to the white, variations must occur in the conductivity of the white. The total phosphorus-content of fresh eggs, and of others which had been stored in air at 0" C. for five months, was determined, and the variation in this figure was compared with the variation in the specific conductivity of the white, measured at 20" C. For the fresh eggs the specific conductivity was 7-42 x and the phosphorus- content 23.7 mg. per 100 g. ; for the stored eggs the specific conductivity was 8.29 x An increase of 4-6 mg. of phosphorus per 100 g. thus corresponds with a loss of resistance of 5.0 ohms. Experiments with eggs stored under suitable conditions for 7 months showed that there was no relation between the inorganic phosphorus-content of the white or the ammonia-content of the egg and the specific conductivity. Since the total phosphoric acid undergoes iar greater variation with age than the inorganic phosphoric acid, it is more directly comparable with changes in the specific conductivity. It is also possible that changes in the chloride-content play an important part. Pine (J. Assoc. Of. Agric. Chem., 1924, 8, 57) has found, besides small amounts of inorganic phosphates, larger amounts of glycerophosphoric acid in the white of ageing eggs. The conjecture that the increase of phosphorus in the white of ageing eggs is due to decomposition of the shell appears less probable than that glycerophosphoric acid is liberated from the lecithin of the yolk and diffuses into the white where it undergoes gradual hydrolysis. Variation in the Sodium-content of Milk During the Lactation Period. M. Vuk and 2. v. Siindor. (2. Unters. Lebensm., 1938, 75, 312- 316.)-The method of Reichard (2. Unters. Lebensm., 1936, 71, 501) for the determination of sodium in wine by means of the precipitate formed with magnesium uranyl acetate was adapted to the determination of sodium in milk. The milk (100 ml.) was evaporated to dryness, charred and extracted with hot water, and the residue was completely ignited. The ash was moistened with 0.5 ml. of hydrochloric acid (sp.gr. 1-19), united with the aqueous extract and evaporated to dryness. The residue was again moistened with hydrochloric acid, dissolved in water, filtered and washed into a 100-ml. flask. Milk of lime was added, and the solution was made up to 100ml. with cold water and allowed to stand for an hour with frequent shaking. A portion of the mixture (75ml.) was filtered and and the phosphorus-content 28.3 mg. per 100 g. A. 0. J. Published on 01 January 1938. Downloaded on 25/10/2014 17:28:53. View Article Online / Journal Homepage / Table of Contents for this issue

Pelatihan dan persiapan calon calon guru yg dilatih di asrama guru Pati Jawa tengah

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