808 EXPERIMENT STATION RECORD. 



wheats of the Bluestem, Red Russian, Turkey Red, Fife, Dale, Little Club, 

 Galgalos varieties, and of hybrids cultivated at the Washington Station. 



Summarizing results it would seem that " gluten as it is ordinarily pre- 

 pared has a variable nitrogen, ash, starch, and moisture content. The pecul- 

 iar copper reduction resulting from adding the filtered extract from hydrolized 

 gluten by acid is undoubtedly due to some other substance than starch or sugar. 

 An average of about 75 per cent of the total nitrogen of flour enters into the 

 crude gluten. Glutens obtained from low-protein flours are not necessarily any 

 richer in nitrogen, more free from ash, etc., than glutens derived from medium- 

 or high-protein flours. The reason why low-protein flours yield much lower 

 percentages of gluten than medium- or high-protein flours may be attributed to 

 the scattering of such glutens, resulting in mechanical loss. Blending such 

 flours with strong gluten flours results in yields comparable to those obtained 

 for medium- and high-protein flours." 



Contribution to the examination of flour, E. Kohn (Chem. Ztg., 36 (1912), 

 No. IJf, pp. 121-123). — For detecting foreign substances in flour, i. e., by- 

 products, the author utilized the following method : 



One-half gm. of flour ia well shaken with 10 cc. of ether in a test tube and 

 poured in a comparatively flat, large, porcelain dish. Bran, plant hairs, and 

 wheat particles are removed from the surface of the liquid upon which they 

 float or the ether is allowed to evaporate and the particles removed from the 

 residue by means of a preparation needle. The particles are then washed with 

 a little water to remove the adhering starch grains and examined in chloral 

 hydrate. An optional qualitative method is also given. 



To detect wheat, bean, or barley flour in rye flour, the author allows diastase 

 to act on flours in an acid medium and then determines the density or the sugar 

 content of the hydrolized mixture. The figures obtained are greatest for rye 

 flour, least for bean flour, and greater for wheat flour than barley flour. 



The Watkins test for determining the cause of sliminess in bread, H. 

 KiJHL {Chem. Ztg., 35 (1911). No. 1J,3, pp. 1321. 7322).— There are two methods 

 which may be used for detecting the presence of the organisms which produce 

 sliminess in bread, namely, the baking test in which 450 gm. flour and 240 cc. 

 of water at from 40 to 42° C. are employed, and the "Watkins test," which is 

 based on the fact that the bacteria producing the viscousness contain spores 

 which resist temperatures varying between 80 and 100°, whereas spore-free 

 bacteria are thermolabile. The latter method is of particular value where 

 only small quantities of flour are available for the test, and it can also be 

 employed for obtaining pure cultures of slime-producing bacteria. Some experi- 

 ments with the method are reported. 



The chemical differentiation of fermentation vinegar and vinegar essence, 

 with particular reference to their formic acid content, H. Fincke {Dent. 

 Essigindus., 15 {1911), No. 19, pp. l.'i5-14S). — This is a discussion of work 

 previously noted (E. S. R., 25. p. 311: 26, p. 208). 



Standards for malt vinegar, A. C. Chapman {Pharm. Jour. [London], J/, 

 ser., 3.'t {1912), No. 2527, p. 3.9//). — The author maintains -that malt vinegar 

 complying with the requirements set down by the U. S. Department of Agri- 

 culture as regards methods of manufacture may give analytical results well 

 outside of the standards laid down. 



" Thus, it is shown that in cases where fermentation has been very com- 

 pletely effected the malt vinegar may have a levorotatoi*y instead of a dex- 

 trorotatory action on polarized light, owing to the disappearance of the dextro- 

 rotatory carbohydi'ate matters, and to the presence of levorotatory proteins. 



"Jour. Soc. Chem. Indus., 25 (1906), No. 8, pp. 350-357. 



