816
INDUSTRIAL A N D ENGINEERING CHEMISTRY
will probably be of even greater importance to the refineries than in the beet sugar industry, since, among other things, it furnishes a method of controlling the efficiency of the bone black filters. It is possible to tell granulated beet sugar from refined cane sugar by this method. Beet sugar has a surfaqe tension of 62 to 68 dynes, while that of the cane sugar runs from 70 to 74 dynes. It will be necessary to test a large number of samples, however, before this difference can be definitely
Vol. 16, No. 8
established. The enormous sensitiveness of the test is well illustrated by the differences found in granulated sugars of identical appearance and chemical composition. Physical factors have been neglected entirely too much in our sugar laboratories; it is time that colloidal chemistry takes its place beside that of chemical analysis. When this is done it will probably not be long before new and improved methods of purifying the sugar solutions and increasing the extraction will be found.
Double Strength Tincture of Ginger: Its Composition and Analysis’ By B. A. Eden, C. E. Marsh, and H. C. Lythgoe MASSACHUSETTS DEPARTMENT OB PUBLIC HEALTH$BOSTON,
MASS.
INCTURE of ginger A summary is given of previous work and composition of tincture by Street,2 Lythgoe and prepared as described of ginger, together with reasons leading u p to the promulgation of Nurenberg~~ and Harrison in the U. S. PharTreasury Decision 3092 providing for double strength exfract of and Sullivan.4 m a c o pe i a c o n t a i n s the ginger. Samples of ginger powder were qbtained and tinctures were Ginger contains both alcohol-soluble material of water-soluble and alcoholmade with varying concentrations of alcohol and of ginger. A n 200 grams of ginger per liter accurafe method of determining total solids is given and the variance soluble solids. If ginger is in 93 per cent alcohol. The in solids of tincture of ginger made in accordance with the Treasuru extracted with alcohol of term “extract of ginger” is varying concentration, the Decision. applied to the same article solids of the t i n c t u r e s by the Secretary of Agriculwill increase as the strength ture in the definitions and standards promulgated by him for of the extracting alcohol diminishes, owing to the comthe enforcement of the Food and Drugs Act. The term “es- bined extraction of alcohol-soluble and water-soluble sence of ginger” has long been popularly applied to this article. material. The usual examination of tincture of ginger conFor years this substance has been used by many people sists of a determination of the solids and the alcohol, but solely because of its alcohol content, and in order to furnish because of the presence of water-soluble products Street a material more suitable for that purpose it was common recommended the determination of the alcohol-soluble solids. practice to manufacture tincture of ginger with a lower He evaporated the tincture to dryness, weighed the residue, alcoholic content than the U. S.P. variety. These adulterated dissolved it in alcohol, filtered, evaporated the filtrate t o tinctures varied in alcohol between 2 and 75 per cent, but the dryness, and weighed, thus obtaining the alcohol-soluble mean variance was between 35 and 50 per cent. I n most solids. Harrison and Sullivan studied the same phase of instances, such tinctures with an alcoholic content above the question, but instead of alcohol they recommended the 70 per cent were made by extracting ginger with 75 per cent use of absolute ether, because sugar, molasses, glycerol, or stronger alcohol and, except for the low alcohol content, and caramel are to some extent soluble in alcohol but inwere as potent as the U. S. P. variety. The tinctures very soluble in ether and the ether-soluble solids are therefore a low in alcohol were made by diluting the U. 8. P. tincture better index of the ginger content of the tincture than either with water or by dissolving ginger oleoresin in 95 per cent the alcohol-soluble solids or the total solids. The studies of Street and later of Lythgoe and Nurenalcohol and diluting with water. These cloudy, diluted tinctures were then clarified by shaking with magnesia and berg showed that by decreasing the alcohol content of the filtering, and the filtrate was practically free from ginger menstruum the alcohol-soluble solids of the tinctures deresins but possessed a pronounced ginger odor and flavor. creased while the water-soluble solids increased. Lythgoe This dilute material was frequently put up in very attractive and Nurenberg claimed from the results of their experiments bottles, some of which were labeled “picnic flasks,” and their that tinctures made with 75 per cent alcohol carried about sale was formerly common in Massachusetts towns where as much oleoresin as those made with 95 per cent alcohol. Times have changed and tinctures of ginger with a low the citizens voted not to grant licenses for the sale of intoxicating liquor. Although a number of prosecutions were alcoholic content have practically disappeared from the made for violations of the liquor law by the sale of such market, but the sale of tincture of ginger has greatly increased, articles and convictions were secured in the police and district denoting either a very improbable increase in epigastric courts, all the cases were appealed and, as far as can be ascer- disturbances or a highly probable increase in the use of this tained, were pigeonholed by the various district attorneys, article as an alcoholic stimulant. Since July, 1919, there and none was put on trial in the superior court before a jury. have been repeated convictions in the ,Massachusetts courts These low-strength tinctures of ginger, if not properly for violations of the liquor law by the sale of tincture of ginger labeled, constituted a violation of the food and drug law, and the district attorneys no longer pigeonhole such cases. and the results of researches on their composition, analysis, The Bureau of Internal Revenue, in a laudable but unsuccessand differentiation from the U. S. P. variety were published ful attempt to curtail the use of this preparation for beverage purposes, has promulgated the following decision: 1 Presented under the title “Double Strength Jamaica Ginger Extract:
T
Its Composition and Analysis,” before the Division of Agricultural and Food Chemistry, a t the 65th Meeting of the American Chemical Society, New Haven, Conn., April 10 to 14, 1923.
2 8
6
Conn. Agr. Expt. Sta., Annual Repout, 1810, p. 516. THIS JOURNAL, 3, 910 (1911). Assoc. OBcial Agr. Chem., 1, 506 (1915).
I N D U S T R I A L A N D ESGINEERING CHEMISTRY
August, 1924
(T. D . 3092) Intoxicating liquor-Extract of Ginger Section 94 ( a ) , article 17, Regulations No. 60, revoked TREASURY D E P A R T M E N T Office of Commissioner of Internal Revenue Washington, D. C. T o FEDERALPROHIBITION DIRECTORS AND OTHERSCONCERNED: On and after ninety days from the date hereof U. S. P. tincture of ginger, whether sold as Jamaica ginger, essence of ginger, extract of ginger, or by whatever other name known, is hereby classed as a U. S.P. alcoholic preparation fit for use for beverage purposes, and may be manufactured, sold, transported, and used only in the manner provided for other similarly classed official preparations listed in section 60 ( b ) of Regulations No. 60 and prohibition mimeograph No. 97. Section 94 ( a ) of article 17 of Regulations No. 60 is hereby revoked. An alcoholic extract or tincture of ginger made in accordance with the process described on page 469, ninth revision of the United States Pharmacopeia, will be classed as unfit for use for beverage purposes, provided the quantity of ginger root used is as follows: Jamaica ginger No. 30 powder: 400 grams to make 1000 milliliters. WM.M. WILLIAMS Commissioner of Infernal Revenue Approved: November J6, 1920 S. P. GILBERT,JR. Acting Secretary of the Treasury
Following the promulgation of this decision and the appearance on the market of double strength tincture of ginger, there developed great differences of opinion as to the correct total solids of this new tincture. The writers were of the opinion that the correct figure was from 2 to 2.5 grams per 100 cc., but upon inquiry it was apparent that this might be too high because figures as low as 1.8 and 1.4 grams per 100 cc. were reported as reasonably correct. The samples used by the writers were examined by the A. 0.A. C.5method. For the purpose of assisting a t a proposed prosecution, several samples were submitted to chemists in another laboratory, and it was impossible for the two laboratories to check u p on the same sample. A number of samples of commercial ginger powder were obtained from eight reliable spice-grinders and wholesale dealers and seventy-nine samples of tincture with varying concentration of both alcohol and ginger were prepared. This ginger powder was examined by the methods of the A. 0. A. C.,6 with the results as given in Table I. TABLEI- OMP POSITION VARIETY Jamaica
Sample A
B
C
D E
F G
H
African Cochin AVERAGE
I J
A to H
GINGERPOWDER Cold Water Alcohol Moisture Extract Extract Per cent Per cent Per cent 13.63 11.30 4.28 11.33 13.60 4.50 ' 12.93 12.50 3.26 13.57 10.26 3.15 12.97 12.25 3.55 12.28 11.86 3.80 12.86 11.79 2.49 13.55 13.00 5.20 11.51 5.92 12.05 11.80 11.63 3.67 12.89 12.07 3.78 OF
These samples gave an unusually low alcohol extract. Winton reports eighteen samples varying between 2.42 and 5.48 per cent, average 4.10 per cent, while Harrison and Sullivan report eleven samples varying between 4.29 and 7.00 per cent, average 5.36 per cent. The variance in this figure may be due to faulty drying. All the tinctures were prepared by percolation and the procedure outlined in the U. S. Pharmacopeia was carefully followed. Forty-five tinctures were prepared using 400 grams of ginger per liter of finished product and 95, 90, 85, 80, 75, and 70 per cent alcohol. Using 95 per cent alcohol, forty-two tinctures were prepared from 100, 200, 250, 300, 350, and 400 grams of ginger per liter of finished product. Considerable difficulty was encountered in developing a satisfactory method for the determination of solids. Heating in an electrically heated oven a t 100" C. in a flat-bottomed 6 6
Assoc. Official Agr. Chem., Methods, 1919, p. 206. I b i d 1919, p. 257. ~
817
platinum dish gave unsatisfactory results, owing possibly to variation in temperature in different parts of the oven. The use of sand or asbestos was of no advantage, and drying in a vacuum desiccator over sulfuric acid was not satisfactory. Heating i n vacuo a t 60" C. over sulfuric acid gave low results owing to loss of volatile material, as shown by discoloration of the acid, but similar treatment a t 40" C. resulted in no discoloration of the acid and gave results comparable with the method finally adopted. TABLE 11-COMPOSITION
O F TINCTURE OF GINGER MADEFROM DIFFERENT SAMPLES AND VARYING AMOUNTS OF GINGSR (Alcohol used: 95.27 per cent by volume, 92 78 per cent by weight) Total Solids PER CENT ALCOHOL Ginger Specific Grams/ By Used Gravity BY Weight X'ARIETY Samule G./Liter 15'/15' C. 100 Cc. Volume 90.14 0,8005 93.39 Jamaica A 200 0.8224 2.50 89.96 1.000 93.26 0.8229 _.. 89.62 1.220 93.00 0.8238 300 89.12 1.413 92.63 0.8251 350 88.24 1.631 91.96 0.8273 400 90.21 0.9026 93.44 0,8222 Jamaica B 200 89.96 1.178 93.26 250 0.8229 92.89 89.46 1.381 300 0.8242 92.60 89.08 1.607 0.8252 350 92.18 88.52 1.822 0,8266 400 93.87 W.82 0.8205 0.748 Jamaica C 200 93.14 89.81 0.890 250 0.8233 1.150 93.11 89.77" 0.8234 300 92.74 89.27 0,8247 1.294 350 88.72: 1.460 92.33 0.8261 400 89.62: 0,9002 93.00 Jamaica D 200 0,8238 89.46. 1.120 92.89 0,8242 250 88.bZ 1.320 92.18 0.8266 300 88.36 1.590 92.05 0.8270 360 87.81 1.708 91.63 0.8284 400 93.75 Jamaica E 200 0.8210 0.7050 93.20 250 0.8231 0.9051 0,8246 1.160 92.77 300 0.8261 1.373 92.33 350 1,596 92.08 400 0.8269 0,8228 1,128 93.29 Jamaica F 200 0.8239 1.405 92.97 250 92.67 1.640 0.8253 300 1.889 92.21 0.8265 350 2.232 91.72 0.8281 400 91.39 0.591 94.28 African 0,8189 I 100 90.07 1.163 93.34 0,8226 200 91.23 87.27 0.8298 2.393 400 94.31 91.43 0.397 Cochin J 100 0.8188 90.46 0,739 93.62 200 0.8215 91.17 87.19 0,8300 1.862 400 0.545 94.08 91.11 Jamaica 0.8197 H 100
METHODSOF ANALYSIS TOTAL SOLIDS-Place a flat-bottomed platinum milk dish on a tray upon the top of a steam bath, measure 10 CG. of the tincture into the dish; when the contents appear to be dry, place the dish over the live steam and dry for 10 hours. Cool in a desiccator and weigh. Express results as grams per 100 cc. After drying 10 hours the weights were practically constant; there is but little change between the ninth and the tenth hours. ALcoHoL-Determine the specific gravity and compute the alcohol by means of a standard alcohol table. Hehner's table was used in this work. The specific gravity of ginger oleoresin is so near that of water that the error in the alcohol percentage is not more than 0.20 with the samples made. This error is less than that arising from the ordinary method of diluting the samples with four volumes of water, filtering with magnesia, distilling the filtrate, and multiplying the per cent of alcohol in the distillate by the necessary factor. The results of the analyses of these figures are given in Tables 11, 111, and IV.
DISCUSSION These tinctures contain alcohol, practically all the alcoholsoluble solids of the ginger used, some of the water-soluble solids of the ginger, and considerable of the water present in the ginger. It is therefore to be expected that the watelcontent of the tinctures made with the same concentration of alcohol will increase with increasing quantities of ginger.
INDUSTRIAL AND ENGINEERING CHEiMIXTRY
818
Using the average results of the thirty-seven tinctures made from 95 per cent alcohol and 200, 280, 300, 350, and 400 grams of Jamaica ginger, the coplputed water content as grams per 100 cc. is 7.60, 7.75, 7.95, 8.07, and 8.31, respectively. With increasing quantities of ginger and constant alcoholic content of the menstruum, there is an increase in solids in the tinctures directly proportional to the quantity of ginger used, together with a decrease in the alcoholic content and a simultaneous increase in the specific gravity and the refractive index. With constant quantities of ginger and decreasing alcoholic content of the menstruum, the tinctures will have increasing solids (due to increase in watersoluble solids), increasing specific gravity, and increasing refractive indexes. TABLE III-COMPOSITION
TINCTURE O F GINGERMADE
DIFFERENT SAMPLES OF JAMAICA GINGER AND VARYING CONCENTRATION OF ALCOHOL (Amount of ginger used, 400 grams per liter) PERCENT ALCOHOL Totdl PER CEST ALCOHOL U3ED Specific Solids FOUND BY BY Gravity Grams/ By By Volume Weight Sample 15'/1.5OC. 100 Cc. Volume Weight 0 8273 1.631 A 91.96 88.24 92 78 95 27 1,822 0 8266 92.1s 88.52 R 1.460 0.8261 92.33 88.72 C 1.780 0.8284 91.63 87.81 D 0.8269 1 596 92.08 88.40 E 2,232 91.72 0.8281 87.92 F 92.71 0,8248 1 386 89.23 G 2 068 87.73 91.57 0.8286 H 1.795 A 0 8408 87.91 83.00 85 88 90 17 1.630 0.8393 88.37 83.58 R 1,470 0,8395 88.31 C 53.50 1.990 0.8408 87.91 D 83.00 1.840 0.8405 83.12 88.00 E 2.295 0.8410 82.92 F 87.85 0.8394 1,560 88.34 83.54 G 79.84 A 0.8529 1.900 83.98 78.16 85 36 A 0,8545 2.140 83.43 77.50 OF
$E F
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:ig g:: g:0.8548 i: 2.028 83.32
0.8561 0.8533 0,8670 0,8698 0.8678 0,8724 0.8680 0.8687 0.8653 o,8797 0.8837 0,8831 0,8840
~
:
0.8838 0.8979 0,8973 0,8953 0.5981 0,8961 0.8961 o.s966
2.397 1.750 2.261 2.655 2.145 2,707 2.048 2.416 2.145 2,460 2.780 2.290 2.742
:;$: ~
2.278 2.590 2.860 2.330 2.815 2.462 2.510 2.500
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82.86 83.85 78.73 77.71 78.44 76.80 78.36 78.11 78.25 74,05 72.50 72.73 72.42
$
72.46 66.74 66.99 67.81 66.65 67.49 67.49 67.28
:; i:
7 7 , ~ 76.83 78.00 72.09 70.92 71.75 69.88 71.67 71.38 71.54 66,83 65.13 65.38 65.04
~ g;:;:
65.08 59.00 59.26 60.13 58.91 59.78 59.78
59.57
Vol. 16, No. 8
properly made should be within these limits. The average solids of those made with 95 per cent of alcohol is 1.738 and the median obtained from the probability series plot is 1.68 grams per 100 cc. Fifty per cent of the solids vary between 1.49 and 1.86 grams per 100 cc.
2.7r
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1x1 ALCOHOL,
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P€RCENVT BY b'&/GnT.
RELATION BETWEBN SOLIDS A N D ALCOHOL IN TINCTURE OF GINGER
Tinctures of ginger made in accordance with Treasury Decision 3092 should vary in solids determined as described herein between 1.38 and 2.25 grams per 100 cc. and the alcohol content should be about 90 per cent by volume. The refractive index is of little value other than to show the presence or absence of methanol. A year has elapsed since this investigation was begun, and this method for solids in tincture of ginger has been in use in this department, and has proved satisfactory. Many successful prosecutions have been carried out, and the analyses of sealed duplicate samples by commercial chemists have checked almost perfectly with the figures obtained by the writers.
CONCLUSIONS Unless great care is taken, erroneous results will be obtained in determining the total solids of double strength tinctures of ginger, the figures being too high. Commercial double strength tincture of ginger should be expected to have total solids between 1.4 and 2.0 grams per 100 cc.; if less than 1.4 the sam'ple is open to suspicion, if less than 1.3 the sample is not double strength, if above 2.0 the solids may have been reinforced by substances other than ginger. If the total solids of commercial samples fall between the limits set for pure, double-strength tincture of ginger, it is advisable to determine the alcohol-soluble or other soluble solids in order that the purity of the article may be more nearly established.
The curve shows the variance in the total solids of tinctures made with varying concentrations of alcohol. It represents the maxima and minima and averages from forty-two tinctures. It should be understood that the alcohol-soluble solids and the ether-soluble solids would show a decrease with decrease in the alcohol concentration. The total solids in double strength tinctures made from different samples of ginger vary considerably. The figures obtained from eight samples made with 95 per cent alcohol and seven samples made with 90 per cent alcohol each form a probability series and the variance in commercial samples TABLE IV-SUMMARY Ginger Used G./L. 200 250 300 350 400 400 400 400 400 400
PER CENT ALCOHOL USED BY BY. Volume Weight Samole 95.27 92.78 8 92.78 7 95.27 7 95.27 92.78 92.78 7 95.27 92.78 8 95.27 90.17 S5,88 7 7 85.36 79.84 so. 19 7 3 , 7 5 7 7 68.21 75.30 62.36 7 69.92
SPECIFIC GRAVITY 15=/150 c. Min. Max. Av. 0,8205 0.8238 0,8222 0 8228 0.8242 0.8233 0,8234 0.8266 0.8246 0.8246 0,8270 0.8256 0.8248 0,8286 0.8271 0.8393 0.8410 0.8402 0.8529 0.8561 0.8546 0.8670 0.8724 0.8689 0.8797 0.8840 0.8829 0.8953 0.8981 0.8968
I
TOTAL SOLIDS GRAMWOOCc. Min. Max. Av. 0,702 1.128 0.866 1.057 0.890 1.405 1.048 1,640 1.274 1.489 1.255 1.889 1.386 2.232 1.738 2,295 1.799 1.470 2.397 2.026 1.750 2.707 2.338 2.048 2.458 2.240 2.780 2.581 2.330 2.860
---By Min. 93.00 92.89 92.1s 92.05 91.57 87.85 82.86 76. S O 72.42 66.65
PERCENT ALCOHOLFOUND Volume-----By Weight--Max. Av. Min. Max. Av. 93.87 93.45 90.82 89.62 93.29 93.14 90.00 89.46 93.11 92.78 89.77 88.52 92.48 92.77 89.31 88.36 92.02 92.71 89.23 87.73 88.37 88.10 83.58 82.92 83.39 83.98 78.16 76.83 78.73 72.09 69.88 78.06 72.90 74.05 66.83 65.04 67.21 67.81 60.13 58.91
