March, 1945
INDUSTRIAL A N D ENGINEERING CHEMISTRY
This Month OOD, its quality and flavor, starts the March issue in a tasty F w a y Four articles form a symposium on the subject and are a tribute to Harvey W. Wiley and they come from the memorial symposium to him held by the Division of Agriculture and Food Chemistry during the recent Korth Jersey Meeting. Harvey W. Wiley, as one will find in reading the articles, is the father of the pure food and drug legislation and as such gave great impetus to the scientific control of food in all its aspects. Thus Ernest C. Thompson of the Borden Company in his article on quality control in the dairy industry states that Wiley’s “sound basic principles of quality control as related in particular to adulteration and the use of preservatives opened the way to recognizing that all foods should be pure and clean, that their keeping qualities should not rest upon the use of preservatives”. Thompson then proceeds to describe the practical results of two prominent accomplishments in dairy products quality controlremoval of diseased cattle from milk producing herds, and the education and supervision of personnel. He states that since 1917, the number of cattle showing positive reactions to tuberculin tests has decreased from 3.2% to 0.7%. An old art is slowly yielding to the organizing power of chemistry and E. C. Crocker of Arthur D. Little, Inc., points the way in his study of the volatile constituents of food flavors. He treats flavoring materials as organic chemicals possessing vapor pressures, boiling points, and other characteristic properties. In his article there is a table of 240 typical flavors arranged in 14 classes according to vapor pressures. The range in volatility from groilp to group ranges not more than two to one yet over the 14 groups the variation in vapor pressure is some three thousand fold-from one millimeter to less than one-thousandth of a millimeter. Suggestions for the use of the table are included. Number three of the Wiley symposium is from H. E. Robinson and H. C. Black, Swift and Company, on flavors in food fats. The quantity of food fats used in our diet is not appreciated, say the authors, and the number of these materials they list is impressive. The authors delve into the chemical facts behind flavors in fats, and explain some of the things that happen to an oil before it gets to your table. Quality in meat and meat products may seem quite theoretical during the present shortage but 0. G. Hankins of the U. S. Department of Agriculture has much to say about the subject. Many factors beginning a t the life of the animal right down through the find processing effect the quality of the meat. A second symposium on cellulose and cellulose plastics brings six papers to our readers. Recent progress in the field is the subject of the first paper by three authors from Polytechnic Institute of Brooltlyn. Weather resistance of cellulose ester plastic compounds IS reported by L. W. A. Meyer and W. AI. Gear. hart of the Tennessee Eastman Corporation. They report on the appearance and physical properties of a number of cellulose acetate butyrate and cellulose acetate plastics that were exposed for two years to the weather in Arizona, Florida, and Tennessee. They found that resistance to weathering is improved somewhat
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by the proper choice of plasticizer but the major improvement came by adding small amounts of an ultraviolet light inhibitor such as phenyl salicylate. The temperature of the injection cylinder is the most important variable on tensile and impact values of cellulose plastics according to R. H. Ball, C. E. Leyes, and A. A. Melriychuk of the Celanese Corporation of America. In their article on cellulosic molding compounds, the authors state that an increased injection cylinder temperature gives greater impact strength, reduces tensile strength, and increases elongation a t the break point. Two important papers for the agricultural and fertilizer field follow in this issue. The first is by Shaw, Parker, and Ezekiel, the second by MehPing. All authors are with the U. S. Department of Agriculture. The first paper comes to the conclusion that the percentage of nitrogen in fertilizer is a ratio between the prices of nitrogen and phosphate and potash. They also conclude that a drop of 20% in nitrogen price plus a corresponding increase of 20% in plant-food content would have meant, on a 1937 basis, over a million tons of additional fertilizer for farmers with no increase in expenditure. Rlehring in his article places the gradual rise of nitrogen consump tion and states that the factors effecting fertilizer nitrogen consumption are cash, farm income, and cost per unit of nitrogen in various competing forms. He also says that consumption of plant nutrients including nitrogen is increasing independent of farm income or price and not the least factor affecting this increase is education and sales promotion.
Next Month
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will be featured by an extensive symposium of six papers on catalysts and catalytic methods in the petroleum field. The subject is greatly important to our present war effort and to the future welfare of our country, for the chemist is responsible for the fuels to power our machines. No single technique holds more promise than that of catalytic chemistry and we are planning much on that subject for next month. The meeting of two new arts will be seen in an article “Emulsion Polymerization of Acrylic Esters” with the newer synthetic detergents. Cholesterol can be separated from degras by solvent extraction as n-e will see next month, along with other articles on the production of hydrogen sulfide from sulfur and hydrocarbon and an article on red lead-alkyd resin reaction. Orange juice is still giving a lot of trouble when it comes to canning commercially but chemistry is still working on the problem as we shall see when April comes around. Then too we shall have something on acetylation of castor oil, the effect of humidity on synthetic rubber, and a study on naphthene pyrolysis for producing butadiene, And that is As We See It. PRIL
