Samples.
Total ash.
1........
2. . . . . . . . 3.., . , , . . 4. ....... 5........ 6........ 7. . . . . . . . 8.. . . . . . . 9.. . . . . . . 10... . . . . . 11.. ...... 12.. . . . .
6.90 3.37 6.88 9.35 3.44 3.50 3.53 3.88 4.75 2.52 3.50 4.15
TABLE III.-PERCENTAGES. NonWater Ash in- Volavolatile sol. tile ether ether sol. ash. in HC1. ext. ext. 1.34 0.92 0.78 0.86 1.28 0.85 1.19 1.32 1.05 0.09 1.08 1.34
2.64 0.90 .2.80 6.11 0.43 1.03 0.49 0.31 1.54 0.15 0.45 0.64
1.44 1 .83 1 .68 1.81 0.67 1.58 0.93 1 .03 1.40 0.59 0.72 0.63
2.85 3.89 3.80 3.40 1.88 3.80 2.01 2.88 3.01 1.92 1.42 1.91
Alcohol ext. 10 68 6 28 6 28 6.80 7.i6 8 .08 7.66 6.i4 7 .i6 8.46 6.04 7 .88
Crude fiber. 36.88 28.88 31.14 29.10 23.40 25.06 24.30 26.96 23.34 27.16 23.74 26.49
does not practice blending to work in dirty material, but because blending is necessary to obtain the desired flavor that is demanded by the trade. LABORATORY WEIKEL& SMITHSPICECo.. PHILADELPHIA, Pa.
THE RIPENING OF HOPS. By
c. E.
BRADLEY AND H.
v.
TARTAR
Received April 22, 1912.
The changes which take place in the chemical composition of the hop cone during the ripening period are of interest both from the scientific and from the technical standpoint. Although the composition of the bitter principles of the hop has been known for a long time, their chemical constitution is a perplexing subject which has in recent times engaged the attention of a number of investigators. From their studies, i t appears t h a t some of the constituents of the hop cone are closely related in chemical composition, and it is quite possible that changes take place during the ripening period in which one constituent passes over into the form of another. If this does occur, a study of the composition of the hop cone a t different stages of ripeness might be valuable in throwing light on the chemical constitution of the different bitter principles. Prom the technical standpoint, it is important that hops should be picked a t the degree of ripeness when they possess the maximum brewing value. Recent C O A l P O I l l‘ION O F
HOP CONES
AT
the cones fully ripened. As a result, the hop growers who desire to produce a product of high quality are a t a loss to know just when to gather their crops. Because of the nature of the literature on the chemical composition of the hop, it may be well t o state, b y way of explanation, t h a t investigators are agreed t h a t the principal constituents of the hop cone are’ a volatile oil, a hard resin commonly designated as the “gamma” resin, two soft bitter resins designated as the “alpha” and “beta” resins, a wax, and a tannin. The constituents designated as resins are not true resins, but owing to the common use of the term in this connection, the authors have continued its use. The recent work of Sillerr indicates that the gamnia resin may be composed of two different substances, but the work is hardly conclusive and we believe needs further study. E X P ER 1 M E N T ii L PA RT . In August, 1910, a study was begun a t this laboratory of the composition of the hop cone a t different stages of the ripening period. The samples were gathered approximately five days apart, the first being picked August r ~ t hthe , last September 26th, and all taken from the yard of the Seavy Hop Company, near Corvallis, Oregon. In collecting, representative cones of various sizes were taken from the upper and outer portion of the vines, which was well exposed t o the sun. On August I I t h , two samples were secured, one being of the smaller and the other of the larger and more fully developed cones. Very soon after the samples were gathered they were spread out and allowed t o dry in the shade at room temperature. When the drying operation was complete, the hops were bagged, great care being taken not to crush the cones and to avoid loss of the lupulin through sifting. I n the analytical work, the method of the authors2 for the determination of the hard, total, and soft (bitter) resins was employed. The separation of the alpha and beta bitter resins was carried out according to the method outlined by Siller.3 Chapman’s4
DIFFERENT STAGES
OF THE
RIPRNING PERIOD.
Composition of Dry Matter (Percentages). 7
Sample NO.
1
2 3 4 5 6 I
8 9
10
Date of picking. Aug. 1 1 (cones smaller size). Aug. 1 1 (cones larger size). , Aug 16. . . . . . . . . . . . . . . . . . . Aug. 2 1 . . . . . . . . . . . . . . . . . . . Aug. 2 6 . . . . . . . . . . . . . . . . . . Aug. 3 1 . . . . . . . . . . . . . . . . . Sept. S . . . . . . . . . . . . . . . . . . Sept. 1 1 . . . . . . . . . . . . . . . . . . Sept. 19 . . . . . . . . . . . . . . . . . . Sept. 2 6 . . . . . . . . . . . . . . . . .
Moisture Dry matter percentages. 8.07 7.32 7.71 10.67 10.12 9.31 8.60 9.42 8.87 7.30
91.93 92.68 92.29 59.33 89.88 90.69 91.40 90.58 91.13 92.70
Wax. 0.52 0.57 0.37 0.55 0.34 0.46 0.35 0.32
0.38 0.33
investigations show that the major part of the actual brewing value of hops lies in the content of soft bitter resins, and hence the amount of these constituents in the hop cone a t different stages of ripeness is of prime importance. At present, manv brewers. regardless of intrinsic value, insist that hops should be picked somewhat green while others prefer t o have
A
Total resins.
Total soft bitter resins.
10.39 12.20 14.07 15.00 16.24 16.48 18.39 20.48 20.57 20.67
8.44 10.76 12.56 13.76 14.51 15.17 16.79 18.24 18.41 19.41
Alpha resin. 1.88 2.74 3.53 3.84 3.92 4.52 6.27 7.07 8.47 8.40
Beta resin. 6.56 8.02 9.03 9.92 10.59 10.35 10.52 11.17 9.94 11.01
Gamma resin.
Tannin
1.95 1.44 1.51 1.24 1.73 1.31 1.60 2.24 2.16 1.26
3.48 2.92 2.98 2.59 2.88 3.06 2.81 3.36 3.28 2.76
method was used for the determination of tannin. Moisture was estimated by drying iut vacuo over sulfuric acid a t room temperature. The determination of the wax was made incident t o securing the solutions
*
Z l g . Umtersuch. N a h r u n o - G e n u s s . . 18, 241. JOURNAL, 4 3 209 (1912). Z t g . Untersuch. N a h r u n g - G e n u s s . , 18, 241.
4
J
lnsf. B , . ~ ~13, . , 646 (1907); 15, 360 (1909)
592
T H E JOCRAY.4L OF I?\'DUSTRIAL
necessary t o the determination of the total resins. The extract obtained from extracting the hops with ether was taken up with alcohol, and the wax, insoluble in this solvent, was collected on a tared filter, washed with alcohol, dried at room temperature and weighed. Owing t o the exceedingly small amount of volatile oil present and the consequent difficulty of making a quantitative estimation, the determination of this constituent was omitted. The results of the analyses are given in the preceding table. In order to afford a n accurate comparison, the amounts of wax, tannin, and the different resins have been calculated t o dry matter. The results show t h a t there is a continuous increase in the amount of soft bitter resins throughout the ripening period. The riper the hop, the richer it is in these substances and if high soft bitter resin content is a criterion of brewing value, the fully ripened hop is much t o be preferred. The ratio of the amount of alpha bitter resin to the amount of beta bitter resin is of interest. On August 11th, the ratio was I : 3.48, while on September 26th, i t was I : 1.30. Between the first picking and the last, the amount of alpha bitter resin increased 450.5 per cent., while the beta bitter resin increased but 167.8 per cent. There seems t o be no marked change during the ripening period in the amount of gamma resin, wax and tannin. From the analytical data, there is also no evidence that one constituent changes to the form of another during the process of ripening. 1
AGRICULTURAL EXPERIMENT STATION, CORVALLIS,OREGON.
ANALYSESOF SOME FATS OF THE AMERICAN BUFFALO (BISON). B y ALBERTH. SCHMIDT. Received March 1 , 1912.
During the month of December, 1905, there was sold in the Union Stock Yards a mixed car lot of stock, consisting of some cattle, a few so-called Cattaloes2 cross between cattle and buffalo-and one pure bred specimen of the buffalo, or American bison. I obtained five different kinds of the fats of this particular animal and analyzed them. Having gone over all the available literature on fats and oils and found no reference to previous analyses of buffalo fats, I believe i t may be of interest t o place on record the analyses of various fats of a n animal that is now almost extinct on our continent. For comparison, I also obtained samples of the corresponding fats from a lot of native steers ranging in age from two to four years. These fats as well as the buffalo fats were rendered in the laboratory. The one striking point is the'difference in the kidney fats of the cattle as compared with the buffalo. This is no doubt due to the difference in size of the kidneys of the buffalo, as compared with cattle. The buffalo kidney is about one-half the size of the cattle kidney and is surrounded by a compact and comparatively small amount of fatty tissue, whereas the cattle kidney is large, and in native cattle is surrounded by a large mass of fatty tissue which is much softer and less
ANALYSES OF BUFFALO FATS.
Name of fat. Caul f a t . . . . . . . . Kidney f a t . , , , . . Ruffle f a t . . . . . . , Paunch f a t . . . . . . Chip fat. . . . . . . . ANALYSES
OF
Sp. gr. at 15O.
Free fatty acids.
0.9263 0.9346 0.9364 0.9244 0.9344
0.90% 1.657r 1.90% 1 .SO% 1.25%
FATSO F NATIVESTEERS.
Sp. gr. Name of fat. at 15'. Caul f a t . . . . . . . . . 0 . 9 3 7 Kidney fat ... , . , . 0 , 9 3 3 Ruffle f a t . . . . , . . . 0 . 9 3 2 Paunch f a t . . . , . , 0 . 9 3 4 Chip f a t . . . , . , . . . 0 . 9 3 7
.
Titer. 50.1OC. 52.2OC. 51 . O o C. 4 7 . 4 ' C. 4 9 . 6 ' C.
Iodine No.'
Saponification No.
33.23 29.45 32.50 34.92 35.16
200.6 199.3 199.4 204.2 199.5
FOURYEARS OLD. SaponiIodine fication Free fatty acids. Titer. No.' No. 0.30% 48.8O C. 36.10 203.0 0.60yo 42.85O C. 4 8 . 8 6 196.0 0.25% 0.20% 0.25%
T W O TO
48.6OC. 43.8O C. 43.4OC.
36.13 46.04 47.20
199.0 201.3 196.8
firm than the fatty tissue of this particular buffalo. This anatomical difference in size of the buffalo kidney as compared with its close relative, the cattle, is not readily explained. I n its wild state the buffalo was often without water for three or four days when roaming over our semi-arid plains. What bearing this may have on the size of the kidneys of animals living under such conditions is open t o question. The hindquarters of the buffalo are far lighter than those of cattle and, therefore, it is logical to assume that the organs in the posterior part of the buffalo would be smaller than the corresponding organs of cattle. I a m not able t o account for the high percentage of free fatty acid in the buffalo fats, as they were rendered when comparatively fresh and in the same nianner as the cattle fats. I had no record of the age of this buffalo bull a t the time of slaughter, but was told t h a t it was about seven or eight years old. LABORATORY OF SULZBEQGER & SONSCOMPANY, CHICAGO.
THE DETERMINATION OF EUCALYPTOL (CINEOL) IN ESSENTIAL OILS.* ny FRANCIS D. DODGE. Received May 1 5 , 1912.
The methods so far suggested for the determination of eucalyptol in essential oils have proved rather unsatisfactory, for, although eucalyptol possesses t o a n unusual degree the capacity of forming molecular compounds with a variety of other substances, these compounds are not, in general, easily purified, nor stable enough to be utilized for analytical purposes. The hydrochloride, hydrobromide, phosphate, arsenate, oxalate and ferrocyanide have been described, as well as the compounds with iodol beta-naphthol, and resorcinol, but the attempts t o make any of these the basis of a n assay method have not been very successful. After much fruitless experiment alovg this line, I was compelled to abandon the compounds of eucalyptol, and endeavored to utilize another property, namely, its stability to cold permanganate solution. Eucalyptol, being a saturated cyclic compound, of considerable stability to alkaline reagents, is practi1 2
Iodine numbers determined by Wijs' method. Read before N. Y . Sec. Am. Chem. Soc., April 8, 1910.
