S

585 A4

S 585 A

1926-1927

BUREAU OF CHEMISTRY,

Respectfully,

The Bureau of Chemistry is authorized to investigate problems in the field of agricultural chemistry and to enforce certain regulatory statutes controlling the purity and truthful labeling of foods, drugs, tea, and naval stores.

In the field of agricultural chemistry the work of this bureau is largely concerned with crop chemistry, especially with that part of crop chemistry which includes the study of the composition and utilization of farm products.

CROP CHEMISTRY

Experimental work conducted during the year has shown that the highprotein wheat resulting from the application of sodium nitrate to the soil at the time of heading yields as much flour as normal wheat raised under the same conditions and that this flour gives a bread having superior qualities. In a field-plot study of the practicability of increasing the protein of wheat by fertilizer applications attention was directed to the quantity of sodium nitrate to be applied to produce the optimum effect, to the possibility of replacing the sodium nitrate by other nitrogenous fertilizers, such as ammonium sulphate, and to the practicability of spacing the rows of wheat so as to permit heading-time applications on a large scale. The best time for applying the fertilizer had been determined in previous years.

Work was done on the possibility of increasing the iron content of green vegetables by applying iron

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C. A. BROWNE, Chief.

pounds to the soil or by changing the soil reaction, but the results thus far obtained are inconclusive. Some experiments were carried on to determine the effect of soil reaction on the yield and composition of certain crops.

A paper on Soil Reaction in Relation to Horticulture was published to meet the widespread interest in the subject of soil reaction and its effect on plant growth. Such related subjects as the correlation between soil reaction and nitrogen content and the composition of the ash of air plants were studied to obtain information as to the mineral constituents available to plants from atmospheric sources. CONSTITUENTS OF THE COTTON PLANT

producing centers. One of the pressing problems of fruit and vegetable growers is to find more profitable outlets for the culls and for the surplus which can not, for one reason or another, be marketed profitably in the fresh state through the regular channels of commerce. The bureau has been working for a number of years on the development of technological processes for manufacturing usable substances from cull and surplus

fruits and vegetables to aid in the solution of this problem. The development of such processes not only brings greater returns to the growers but creates new manufacturing industries, which give profitable employment to capital and labor.

The development of new processes for utilizing fruits and vegetables is slow and tedious work, requiring extensive and patient research. The composition of fruits and vegetables as a rule is very complex, and the various chemical substances contained in these products can only be determined by laborious and extended research. After the chemical composition in detail has been determined there remains the experimental work to develop practical processes and devices for manufacturing profitably on a commercial scale the various substances which the researches have shown may be produced. Although progress in both research and development work is often slow, the results are in the long run highly profitable to the growers of fruits and vegetables, as well as to the manufacturing industries. It has been found in this and other countries that the basic research and experimental work must be done by the Government, but that the application of the results may be left to private capital and individual initiative. The returns from the basic research work are often so long delayed that it can not well be financed by individuals, who must ordinarily expect a return upon their investment within a reasonable time.

The report of the chemist for 1925 outlined the steady growth of the commercial application of methods worked out in the bureau for the utilization of cull and surplus oranges and lemons, particularly in California. Several commercial concerns are now manufacturing on a profitable scale numerous marketable products from large quantities of cull oranges and lemons which would otherwise go to waste. The research work begun in the Bureau of Chemistry laboratory at Los Angeles about 12 years ago is now

proving most profitable to the citrusfruit industries of California.

The basic research work of the Los Angeles laboratory was continued during the year. A chemical study is being made to ascertain the exact composition of orange and lemon oils for the purpose of determining whether the inability to manufacture satisfactory terpeneless oils from the California citrus fruit is due to some fundamental chemical difference between these oils and those made from European oranges and lemons or to variations in the processes of manufacture. The results of this research should show the relative values of the oils for certain uses, such as the manufacture of ice creams, hard candies, cake icings, perfumery, and beverages. By means of an improved machine to press the oil from orange peel and lemon peel developed during the year at least 5 pounds of oil can be extracted from the peels of a ton of lemons. One concern in Los Angeles uses 60 tons of citrus fruit a day in making juice by means of a revolving burr-type machine. As citrus oils are worth approximately $2.50 a pound, the extraction and utilization of the oil would mean an additional return of $12.50 for each ton of cull fruit or, on the output of this one plant, a gross additional income of $750 a day. More work must be done to perfect the machine and the process for extracting the oil before this possible additional return can be realized. It is believed that research work now under way on the detailed chemical composition of the oils from orange and lemon peel will develop information that will enable California manufacturing concerns to utilize these oils for all purposes for which the European product can now be used.

Work was continued on the utilization of pomegranates, the production of which is increasing rapidly in California. Pomegranates must be carefully graded for the market, with the result that large quantities of culls are available. A satisfactory concentrated juice and jelly have been experimentally manufactured in the Los Angeles laboratory. One commercial concern is now producing juice and may shortly take up the manufacture of this product in concentrated form. The development of juice manufacture is retarded by marketing problems. Other concerns are considering the manufacture of concentrated juice and jelly from pomegranates. An improved press devised for extracting pomegranate juice in experimental