TROWBRIDGE A N D FRANCIS ON GLYCOGEN CONTENT OF BEEF FLESH. CONCLUSIONS.
Emmett and Grindley’s method does not give high enough results for organic phosphorus in cold water extracts of flesh, as the heat of coagulation has changed nearly all of the organic phosphorus to the inorganic form. Barium chloride in slightly ammoniacal solution precipitates the inorganic phosphorus from water extracts of flesh and gives a satisfactorily accurate separation of the inorganic from the organic form. There seems to be a progressive splitting up of the organic phosphorus compounds in beef flesh during the process of cooking so that in well done meats practically all the phosphorus is present in the inorganic form. A study of the tables shows considerable variatioq in the relative amounts of soluble and soluble organic phosphorus in different cuts and in different animals. Extremes will be noted in rib of Jerry (a fat show steer) in which 91-44 per cent. of the soluble phosphorus is organic and in composite of 592 (an extremely emaciated steer) where only 26.02 per cent. or the soluble phosphorus is organic. This subject is being investigated further. COLUMBIA, M o , March 9 , 1910.
-___[CONTRIBUTIOSFROM
DEPARTMENTOF AGRICULTURALCHEMISTRY UNIVERSITYOF MISSOURI]
THE
THE GLYCOGEN CONTENT OF BEEF FLESH. (SECOND PAPER.) B y P. F. TROWBRIDGE AND C K FRANCIS Received February 1 7 , 1910
I n continuing this study1 the following points were especially considered. ( I ) The disappearance or diminution of the glycogen in the flesh of a starving animal. Smith’s “Veterinary P h y ~ i o l o g y ”contains ~ thefollowing: “The glycogen which is stored up in the liver for future use may be made to disappear b y starving and working the animal.” The same author on p. 227 says: “The muscles of well fed animals contain a considerable quantity of glycogen. Ordinarily i t may be stated that the muscles hold as much glycogen as the liver.” ( 2 ) The rapidity with which the glycogen disappears after death. R ~ e h m a n n ,experimenting ~ with dogs, shows that the hydrolysis after death takes place, b u t not so rapidly b u t that the major portion can be recovered a s glycogen in from one-half to two hours after death. Under certain conditions rigor mortis may take place without loss of g l y ~ o g e n . ~ (3) The glycogen in horse flesh ascompared to that in beef. THIS JOURNAL,2, 2
21, (1910). “Manual of Veterinary Physiology,” F . Smith, 3rd E d p 226
a Roehmann, Baochemw, 229, 1908. Ibad , p 236
215
Without indicating the method of analysis, Lebbin’ has reported horse flesh to contain on a n average 0.7 per cent. of glycogen, while Pfluger2 using the alkali method has found from 1 . 5 to 2 . 2 per cent. “Even after nine days’ starvation the musclesof horses have shown a glycogen content of from I to 2.4 per cent. ’ J 3 Among the results published in the previous paper4 we desire to recall to the reader the glycogen determinations on the lean meat from three animals. The percentages of glycogen in these have been averaged and reduced to a moisture- and fat-free condition. Other particulars are indicated in the table below.
l a b . No. 92103 91103 9153
TABLE I.-GLYCOGEN I N LEAN CLOD M ~ S C L E Glycogen in samDle Glycogen calcula’ted in fresh t o fat and sample H n Ofree Condition of percen(, per cent: Kind of animal, animal. 0.697 3.38 Jersey cow Lean 0,663 2.95 Short-horn steer Very fat 0.416 1.82 Hereford steer Emaciated (starving)
Age 6 yca~s. 4 % ws. 23 mos.
While the amount of glycogen in the lean flesh of the Jersey cow is more than that found in the f a t steer, the fact that the cow was in a thrifty condition should be considered. It may be that age is a n important factor, or that the function of the animal in milk production bears somk relation to the storage of glycogen. The thin Hereford steer was not starving in the sense that all food was withheld, but for eleven months he was so fed as to make him lose one-half pound each day. His condition was such at the time of slaughtering that he could not walk steadily b u t could get up of his own accord. Notwithstanding this emaciated condition and the fact that the entire carcass contained no f a t which could bz separated mechanically, the muscle still showed the presence of glycogen in considerable quantity. The following table shows the glycogen content of the liver from a fat Jersey cow, about 7 years old and not in rnilkqfor 1 2 months previous to the date of slaughtering. The animal was killed a t I O : 18 A.M. and the liver received at the laboratory a t I I : 30 A.M. and the first portion placed in alkali at 1 2 : 05. The elapsed time indicates the interval required to remove the organ, grind, weigh and place the sample in the alkali. TABLE II.-GLYCOGEN Lab. No. 91052 z 91052 y 91052 z
Sample. Liver
IN
LIVER OF Cow No. 43. Glycogen. per cent.
Elapsed time.
2.91 3.07 2.83
1 hr. 47 min. 1 hr. 51 min. 1 hr. 57 min.
Table III shows the analysis of the liver from another fat Jersey cow, about 9 years old and not in milk for 1 2 months previous to the date of slaughtering. The animal was killed a t 8:ro A.M. and the liver re12. Nahr-Genussm.. 7,
747. Ibid. 3 Smith’s “Vet. Physl.,” p . 227. 1 L O C . cit. 2
T H E J O U R N A L OF I N D L S T R I A L A N D ENGINEERING C H E M I S T R Y .
216
-
ceived a t the laboratory a t 9:45 portion placed in alkali a t I O : 14.
A.M.
and the first
TABLEIII.-GLYCOGEN I N LIVEBOF Cow h'o. 4 Lab. No. 9102 z 9102 y 9102 z
Sample. Liver
Glycogen, per cent. 3.09 3.18 3.12
Elapsed time. 6 min. 2 hrs. 13 min. 2 hrs. 2 1 min.
2 hrs.
The remaining portion of the above sample was placed in cold storage for one week, the temperature remaining about 6.5 ' C. Triplicate determinations were then made which gave results indicated in Table iV. TABLEIT'.-GLYCOGEN I N LIVER OF Cow No. 4 AFTER ONE WEEK. Glycogen. Lab. X o . Sample. per cent. Elapsed time. Condition of sample. 9102 x x 9102 y y 9102 zz
Liver
2.78 2.66 2.57
1 week 1 week
1 week
Fresh Fresh Fresh
The remaining portion of the sample mas returned to the cold storage and the same temperature maintained for another week. When removed on the 14th day the sample appeared to be in about the same condition, so i t was decided to expose i t in a sealed bottle to atmospheric temperature before analyzing. The results of the analysis after that time are shown in Table V. TABLEV.-GLYCOGEN Lab. No. 9102 X Z X 9102 YYY 9102 zzz
IX LIVEROF COW NO. 4 AFTER 15 DAYS.
Glycogen, Sample. per cent. Liver
2.06 2.32
Condition Elapsed time. 15 days
of sample.
Lab. No.
time passed after the death. of the horse before the sample was placed in alkali. The temperatures mentioned are those to which the sample was subjected for the period given previous to the analysis. The above results show that horse flesh is subject to an enzymatic hydrolysis similar to that of beef. At the end of 2 2 hours the loss of glycogen was equal to 51.4 per cent. and a t the end of 3 days to 91.1 per cent. SUMMARY AND CONCLUSIONS. I . The glycogen content of beef muscle and beef liver varies from 0.1 to 0.7 and 0 . 2 to 3.8 per cent. respectively. 2 . Starvation or extreme debility does not cause entire removal of glycogen from the muscle or liver. 3. The glycogen of beef liver and muscle slowly decreases, but does not entirely disappear, when kept a t a temperature of 6.5' C. for over two weeks. Glycogen may be present even when liver has become unfit for food. 4. Horse flesh is subject to an enzymatic hydrolysis of the glycogen similar to that of beef. The glycogen decreases slowly when the sample is exposed to temperatures of about 20-25 '. 5. The glycogen content cannot be said to offer an absolute or even approximate basis for distinguishing beef from horse flesh. COLUMBIA, Mo.. Feb.. 1910.
Slightly spoiled.
2.36
ADDRESSES.
Portion 9102 xxx was intentionally removed from the bottle without its being mixed with the remainder of the sample, as i t showed evidence of decomposition, being covered with mold. The results were somewhat higher than we expected after the sample had been exposed for eighteen hours to the temperature of the air. Upon obtaining the records from the local weather bureau a rather interesting fact became apparent : the average temperature for the eighteen hours was 6.6'C. As we have previously demonstrated that low temperatures check the hydrolysis of glycogen, no great change could be expected in this instance. Exfieriments with Horse Flesh.-A horse thin but not in starving condition, about twenty years old, was killed and a portion of lean muscle from low in the neck used for the glycogen determination. I n the tables below the elapsed time indicates the
91 190 Z 91190 Y 91190 z 91190 x x 91190 YY 91190 x x x 91190 YYY 91190 zzz
TABLEVI.-GLYCOGEK IN HORSE FLESH Condition Glycogen, Elapsed time. Temperature. of sample. per cent. 30 min. 20'-25' Fresh 0,183 0,122 37 /' 41 " 0.133 22 hrs 200 Fresh 0.066 22 " 0.077 0.014 0.015
0.010
3 days 3 'I 3 *'
May, 1910
20'
Slightly decomposed
VEGETABLE TANNING MATERIALS.* By
JOHN
H. Y O C U M , Ladew and Yocum Tanneries, Newark, N. J ,
When in the time that our tanners had the virgin forest t o depend upon, hemlock and oak bark were the only vegetable tanning materials in use in this country, and they yet remain the source of greatest supply of tannin. The yearly cut of *hemlock bark is between 800,000 and goo,ooo tons, and oak bark from ~ o o , o o c ~ ~ o o ,tons. o o o The peel of helmock has decreased about one-third in the last ten years, while the peel of oak bark has remained nearly stationary. Because of increased production of leather during this period and because of the decrease in the peel of hemlock bark, it has become necessary to reach other sources of tannin supply. The first development to meet these conditions was the making of chestnut wood extract, which has now reached a very important stage, from ~ ~ o , o o o - ~ o o , obbls. o o being produced yearly. I n addition chestnut wood is being used at many southern tanneries directly in the leaches. Tanners have found that the liquors obtained by this method are insufficient in strength for their purposes, so some of them have added evaporating plants to their leach houses to concentrate their liquors to a sufficient strength for their use. A barrel of chestnut extract is practically equal to a ton or cord of either oak or hemlock bark, and while the yield from various extract factories differ, generally a cord af wood (128 cubic feet) yields a barrel of the 2 5 per cent. tannin chestnut extract. Quebracho extract is made from quebracho wood, a product Address before S e w York Section, American Symposium on Leather.
Chemical Society
