June, 1924
INDUSTRIAL AND ENGIhTEERING CHEMISTRY
beaker. The liquid is heated to effect solution of the crystals as far as possible, and then filtered through purified asbestos. The filtrate is allowed to cool over night in a porcelain evaporating dish, and the crystals are separated from the mother liquor t)y filtering through asbestos. They are then dried a t room tomperature for 24 hours and a t 100’ C. for 2 hours. The oxalate is made from these purified compounds in the following manner: Two hundred and fifty grams of the oxalic acid are dissolved in about 500 cc. of hot distilled water in a large beaker, and a solution of 70 grams of the permanganate is added slowly and cautiously, the oxalic acid solution being kept near the boiling point. The permanganate color is quickly destroyed after each addition, and finally manganous oxalate begins to settle out. Towards the end the permanganate must be added very slowly. When all the permanganate has been added and the manganous oxalate has settled, the supernatant liquid is decanted without cooling the solution. The manganous oxalate is washed by decantation with cold water until free from the excess of oxalic acid, brought) onto a Biichner funnel, and sucked as dry as possible. The crystals, which should be pure white without the least
609
pink tint, are spread out on filter paper to dry in the air. They may be further dried a t room temperature in a current of dry air. The salt so obtained is bottled, and will keep indefinitely under ordinary conditions. If the oxalic acid solution is allowed to become too cold some trihydrate will form. I n this case the manganese oxalate, after having been filtered, is heated with water to about 90’ C. until no pink tinge is perceptible. The crystals are then again brought onto a filter and washed and dried as outlined. The use of the salt in practice is exceedingly simple. The desired quantity is weighed on a watch glass (1 gram of MnCz04.2Hz0 is equal to 0.3069 gram Mn) and transferred to a beaker or flask. Evaporation to fumes with sulfuric acid will form manganous sulfate for use with Volhard’s method, or treatment with concentrated nitric acid will give a solution of manganous nitrate for the chlorate or bismuthate method. ACKNOWLEDGMENT The author desires to express his thanks to J. A. Holladay for assistance in the preparation of the manuscript, and to T. W. B. Welsh for the photomicrographs.
Starch in Sorghum Sirup’” By J. J. Willaman and F. R. Davison DIVISION O F AGRICULTURAL BIOCHEMISTRY, UNIVSRSITY
ORGHUM sirup is typically rather viscous, and OCcasionally the viscosity is so great as to cause a semisolid consistency of the sirup. I n 1920 the writers received from several scattered sources samples of sirup that were jelly-like in consistency, like a soft and stringy fruit jelly. This was so marked, and the output of one Minnesota sirup factory during this season was so consistently of this character, that it was decided to investigate the cause of the condition. The writers have been negligent in publishing the results, however, and meanwhile Sherwood has published two papers on the same ~ u b j e c t . ~Since the writers used methods in their work somewhat different from those used by Sherwood, it was thought desirable to publish their results as well. The first suggestion was that starch was the cause of the jellying, and Sherwood found this to be the case. He has reviewed the previous work ’on the occurrence of starch in sorghum juice. He found by analysis from 0.14 to 0.85 per cent of starch in various samples of sorghum juice, with an average of 0.33 per cent. By treatment of the heated juice with malt diastase he could remove the starch entirely, and the resultant sirups were free from sliminess and gelatinous properties. Added starch could be circumvented in the same way. He concluded that starch was responsible for the jelly-like nature of some samples of sorghum sirup.
S
MATERIAL AND METHODS Several samples of jellied sorghum sirup, from various sources and made from unknown varieties, were obtained, as well as some samples made from Minnesota Early Amber grown in M i n n e ~ o t a . ~ 1 Presented under the title “The Gums of Sorghum Sirup” before the Division of Sugar Chemistry a t the 66th Meeting of the American Chemical Society, Milwaukee, Wis., September 10 to 14,1923. 2 Published with the approval of the Director, as Paper 419, Journal Series, Minnesota Agricultural Experiment Station. * THISJOURNAL, 15, 727, 780 (1923). 4 Thanks are due to the Waconia Sorghum Mills, Inc., Waconia, Minn., for many large samples of sirup.
OF
MINNESOTA, ST.
PAUL,
MINX.
Analysis for “crude gum” was made by diluting the sirup with five volumes of water, precipitating with two volumes of 95 per cent alcohol, filtering, drying, and weighing the precipitate. Starch was determined by analyzing the crude gum, with or without drying, by the diastase method. Dry matter in the sirup was determined by an Abbe refractometer. EXPERIMENTAL RESULTS Table I gives the analyses of twelve samples of sirup for total solids, crude gum, and starch. One sample of cornstalk sirup is included for comparison, since this sirup contains no starch. It will be noted that the jellying property is not dependent on the density of the sirup. I n general, the jellying is proportional to the amount of crude gum present, although the last column shows that the percentage of starch in the crude gum is of more importance than the total amount of gum. Furthermore, the data show that any sirup having 1.3 per cent or more starch is likely to be more or less jellylike. T A R II-ANALYSGS ,~ OF SORGHUM A N D CORNSTALK SIRUPS Solids
7 .-” 84.0
3.10 0.80 6.92
1.17 0.32
37.8 40.7
1.39 4.95
0.0
0.0
..
4.30
0.70
16.3
.. .. ..
4.30
0.80
18.6
3.54
1.33
37.8
3.56
1.90
53.4
4.23
0.79
18.7
4.01
1.18
28.7
.
8 9 10
11
Normal, hiinn., September 11, 1921 Moderately jelly-like, Minn,, Septemher 12 1921 Moderately jelly!-li ke , Minn ., October 10 1921 Nqcmal,_. I d n n . , October 11, l t l i s l
12
Normal,
Minn.,
12, 1921
October
Starch Starch in in Crude Sirup Gum
7 ,0 3.36
SamDle DESCRIPTION 7 .”n 1 Very jelly-like Minn. 1920 8 2 . 5 2 Moderately jeliy-like, Ihinn., 1m n 77.6 3 N;r-&k, Minn., 1920 80.7 4 Very jelly-like, Ohio, 1920 . 5 Cornstalk sirup 1921 and 1922 (average; 75.0 6 Very jelly-like, Wis., 1920 68.0 Normal, Minn., September 7
10 1921
Crude Giim
.. ..
41,
4.00
.. ..
.. ..
I N D U S T R I A L A N D ENGINEERING CHEMISTRY
610
In order to see whether nitrogenous compounds play any part in the consistency of the sirups, the crude gum, precipitated before and after dialyzing the diluted sirup, was analyzed for nitrogen, with the results shown in Table 11. There is very little nitrogen present in the crude gum, and the amount varies erratically with the dialyzing treatment, Therefore, it is unlikely that nitrogen compounds have anything t o do with the jellying property of the sirups. The data in Table I1 show that the quantity of crude gum present is always less in the dialyzed sirups, and that the decrease is proportionately about the same in all cases. This is interpreted to mean, not that alcohol-precipitable material is dialyzed away, but that during the precipitation of the gum a great deal of dialyzable material is occluded. This is no doubt why the crude gum analyses as shown in Table I do not vary proportionately with the jellying property of the sirups. In Sample 1, however, there is some indication of loss of starch by dialysis, since the starch percentage is 3.36 and the alcohol precipitate after dialysis is 1.32. '
TABLE 11-RELATION OF DIALYSIS AND
OF NITROGEN CONTENT TO CONSIRUPS CRUDEGunr NITROGSN IN GUM Before After Before After Dialysis Dialysis Dialysis Dialysis
SISTENCY OF
Sample
1 2 3 4 6
DESCRIPTION Very jelly-like, Minn.,
1920
Moderately jelly-like, Minn., 1920 Normal. Minn.. 1920 Very jelly-like; Ohio,
1920 Cornstalk sirup, 19211922 (average)
%
%
%
4.00
1.32
0.099
0.068
1.20 0.29
0.101) 0.142
0.269 0.534
6.92
1.67
0.260
0.190
1.39
0.35
0.943
0.724
It was then thought desirable to add to a sirup gelatinized starch in varying quantities and note the consistencies produced, The sirup used was one that had been diluted, freed from gum with alcohol, and the filtrate reevaporated to a sirup. The results are shown in Table 111. Apparently, 1.6 per cent or more of starch produces a jellied sirup. This agrees fairly well with the figure of 1.3 per cent deduced from Table I. NATUR OF~THE GUM The foregoing data show that apparently most of the gummy matter or alcohol precipitate in sorghum sirup is starch, A few additional tests were made to see if any further constituents could be identified. Pentosans were found to be absent in both dialyzed and nondialyzed samples. After removal of the starch by diastase, precipitation of the gum with alcohol, and then hydrolysis with 3 per cent sulfuric acid, a strong test for galactose was obtained by means of the mucic acid reaction. TABLE III-EsE=~cT
ADDEDSTARCH ON THE CONSISTENCY OF SORGHUM SIRUPS ~. . Starch Added Viscosity Sample Per cent Centipoises
TABLE1%'-GUM
CONCLUSION From this work it may be concluded that the major portion of the alcohol-precipitable material in sorghum sirup, exclusive of occluded material, is starch, but that some true gum containing galactan is also present, as well as the calcium salts of citric acid. These results corroborate and extend the work of Sherwood.
The Chemical Division of the United States Tariff Commission' By C. R. DeLong UNIWD
STATE9 TARIFF COMMISSIO~,WASHINGTON, D. C.
NDER the so-called flexible tariff provision of the Tariff Act of 1922, the Tariff Commission has continued its investigations of production costs and other factors in the competitive situation as regards various commodities. While the facts collected were originally for the use of Congress in fixing rates of duty and later for use by the President in revising these rates, the Commission's reports have found a much wider use in the chemical industry. The information is of interest to the development departments of the various chemical companies, in deciding whether or not the companies shall enter into the manufacture of any given product, and, if they do enter a new manufacturing field, the scale of manufacturing operations to be adopted. It should also be of assistance to manufacturers in planning their schedules of production and sales policies. The surveys of industries involve the compilation of cost data and trade secrets of individual manufacturers, which are held in strict confidence by the Commission. The facts are used only in preparing summaries which, without disclosing individual data, give general information that could not have been obtained except by the codperation of the individuals and corporations who profit most from it. 1 Abstract of paper presented before the Division of Industrial and Engineering Chemistry at the 67th Meeting of the American Chemical Society, Washington, D.C., April 21 to 26, 1924.
OF
OBTAINED F R O M 300 GRAMS OF SORGHUM S I R U P IN 1200 CS. OB WATER
Volumes of Alcohol Used 1
2 3
in alcohol of the strength used, but more insoluble in stronger alcohol. Accordingly, 300 grams of sirup were diluted with 1200 cc. of water, and the gums fractionally precipitated with 1, 2, and 3 volumes of alcohol. The results are shown in Table IV. Most of the precipitate is obtained in the first fraction, but the ash content in the latter fractions is much greater, approaching the CaO content of the calcium salts of citric and tartaric acids (33 and 30 per cent, respectively). Quantitative tests showed the ash to be largely calcium.
%
3.10 0.80
Vol. 16, No. 6
Gum Obtained Grams
Ash in Gum Per cent
13.5 1.5 0.7
10.6 21.9 26.0
Two samples of gum were next analyzed for citric acid, and 9.4and 11.4 per cent, calculated as the free acid, were obtained. This indicated that possibly the crude gum contains considerable calcium citrate, which is somewhat insoluble
Increase Duty on Barium Dioxide On May 20, President Coolidge issued a proclamation ordering that after thirty days the duty on imported barium djoxide be increased from 4 to 6 cents a pound. This increase is the maximum permissible under the flexible provisions of the Tariff Act of 1922. The Tariff Commission made an exhaustive study of the production costs of this substance in this country, England, France, and Germany, and recently submitted a report of its investigation to the President. This report brought out the fact that Germany is the principal competing country, with England and France, respectively, second and third, and that production costs in Germany are very much less than in this country. Barium dioxide was not produced in. the United States prior t o the World War. The largest domestic production amounted to $5,000,000, in 1917. Investigations into the differences in production costs in this country and abroad of a number of other chemical products have been completed by the Commission and reports are to be made to the President shortly. It is understood that the facts developed call for increases in the duty.
