March, 1929
INDUSTRIAL A N D ENGINEERING CHEMISTRY
281
The Antirachitic Factor in Burbot-Liver Oil’ Bertha Glow and Abby Marlatt HOMEECONOMICS DEPARTMENT, UNIVERSITY
H E increasing popularity of the use of the oil from the liver of the cod as a preventive of rickets and as a stimulus to the maintenance of health has increased tremendously the sales of all the preparations of cod-liver oil. The nearest fresh-water relative of the cod, the burbot fish, often called Yawyer fish” or “eel pout,” is found in all our large inland waters, such as the Great Lakes and the streams leading into them. The U. S. Commissioner of Fisheries reported in 1928 that in the total annual catch of fish in Lake Erie 170 tons of burbot were taken. As these fish are seldom used for human food, they were either thrown away or used for fertilizer. The annual catch as indicated by the commissioner is 200 tons a year from the Great Lakes. Some of the nearby states have made efforts to destroy the burbot in the streams and ponds where they feed upon the young fry of trout. I n the waters of Lake Winnebago in Wisconsin 25 tons were thus removed in 1925-26. The average weight of the burbot fish is about 3 pounds, but the liver is reported to be a t least six times as large as that of any other &h in these waters. One of the livers used in this study weighed 275 grams (0.55 pound). The percentage of oil secured from the liver has been found to vary from 36 to 56, possibly depending on the waters from which the fish was taken and the age of the fish.
T
Oil ration
O F WISCONSIN,
MADISON, WIS.
inch cubes, weighed, and blanched in one-third its weight in water. The liver and the boiling blanching water were packed in cans, approximately 200 grams of liver and 66 cc. of water in each half-pint jar. These were cooked in a pressure cooker a t 15 pounds (1 atmos.) for 20 minutes. By this process the oil rose to the top of the can and later was removed with a medicine dropper and used in the feeding experiments. Experimental The recovery method was used throughout this investigation. In this method young rats were placed on a ricketsproducing ration for 21 to 23 days and a t the end of that time the recovery or test diet was given for 10 additional days. At the end of the tenth day the rats were chloroformed and the wrist end of the radii and ulnae removed and covered with a 10 per cent formalin solution. After standing 24 hours or more the modified “line test” technic according to Steenbock’s method was used to determine the degree of recovery. Seventeen litters and 76 rats were used. Each rat weighed approximately 60 grams when the rickets-producing ration was started. The age of the rats a t this date ranged from 23 to 35 days. Ration 2965 was the rickets-producing r a t i ~ n . ~
Comparison of Antirachitic Properties of Burbot- a n d Cod-Liver Oils 2% 1% 0.5% 0.25% 0.125% 0.06%
0.03%
0.015%
0.007%
BURBOT-LIVER OIL
Number of rats 2 Oil consumed during 10 days, grams: Average for group 1.47 Variation within group l+,~t;\,+58 “Line test”
5 0.67 0,.,5,7;0+84
5
4
0.326 0,.,2,9;0,.39
5
0.185 O++lZj;O.205
0.094
D,;o,S;O,.
5 11
0.041
5
0,+023J-0.044
0.021 O+,O+l9-0.022
10 0.011 0,i010-0.013
2
0.004
p n e
COD-LIVER OIL
Number of rats 4 4 4 4 5 6 5 Oil consumed during 10 days, grams: Average for group 1.44 0.69 0.386 0.185 0.097 0.049 0.023 Variation within group 54 0,.L%;O. 81 0,;3,5;0.41 0,.,1,63-0.210 OiO$O-O. 103 0.047-0.053 0.018+-0.026 “Line test” + t o ++ 0 to Explanation of “line test” results: + + * + + +Complete healing-very narrow metaphysis and a heavy line + + Fair healing-wide metaphysis and a narrow line + + + + + Practically complete healing-narrow metaphysis and a heavy line Signs of healing-wide metaphysis and a slight line + * + +Very good healing-medium metaphysis and a heavy line 0 No healing + + + Good healing-medium metaphysis and a medium line
l+.2232:.
Investigation as to the present use of these fish and the livers has shown that fishermen often take the livers home as a delicacy and that along the wharves on the shore of Lake Michigan the women often come to the fishing boats to buy the fish livers for use. However, they are not placed upon our markets, though the fish itself is very satisfactory eating and the livers can be made into many very appetizing dishes as demonstrated in studies made in this laboratory in 1923-24 when they were acceptably fed as part of a luncheon to the American Bankers Association. The preliminary study by McCollum and co-workers2 indicated that the oil from the burbot liver contains the antirachitic vitamin. Because of this and because of the prevalence of the burbot in Wisconsin waters, in 1926-27 the Home Economics Department of the University of Wisconsin made a detailed study of the relative antirachitic potency of burbot-liver oil. Through the courtesy of the assistant superintendent of fisheries in Wisconsin, the burbot fish livers were removed from the catch and shipped packed in ice within 24 hours. The gall bladder was removed and the liver cut into 1 Received September 5, 1928. Published with the permission of the Director of the Wisconsin Agricultural Station, Madison, Wis. 2 McCollum et al., J. Bzol. Chem., 53, 293 (1922).
Filtered burbot-liver oil or cod-liver oil (Meade-Johnson) was added directly to the ration a t the end of the depletion period. I n all rations in which the oil was below 1 per cent, a 1 per cent ration was first made and the lower percentages were made from it by the dilution method. For example, to obtain the 0.25 per cent ration 25 grams of the 1 per cent ration were made up to 100 grams with ration 2965. Individual food-consumption records were kept during the recovery period, and from this the number of grams of oil consumed could be calculated. Discussion Comparison of the results on the two kinds of fish-liver oil rations (Table 1) showed that the 2 per cent cod-liver oil ration was necessary for practically complete healing while with the burbot-liver oil ration the healing was practically complete on a ration as low as 0.125 per cent. The 0.5 per cent cod-liver oil ration gave very good healing while the 0.06 per cent burbot-liver oil also gave very good healing. With 0.03 per cent cod-liver oil there was no healing in three cases and only very slight evidences in the other two cases, while McCollum et al., J. Biol. Chem., 64, 263 (1925).
I N D U S T R I A L A N D ENGINEERING CHEMISTRY
282
the same percentage of burbot-liver oil gave good signs of healing. With as low as 0.015 per cent burbot-liver oil addition to the ration there were still considerable signs of healing. The two rats on the 0.007 per cent burbot-liver oil were probably comparable to the 0.06 per cent cod-liver oil addition. There seems t o be no doubt that the samples of cod- and burbot-liver oil studied showed a marked difference in antirachitic potency. A quantitative estimation of the comparison revealed that the burbot-liver oil is eight times as potent as the cod-liver oil. For instance, the 0.06 per cent burbot-liver oil and the 0.5 per cent pod-liver oil rations give healing (see table) and the latter has practically eight times the amount of oil addition; 0.03 per cent burbot-liver oil and 0.25 cod-liver oil give healing, etc. Whether or not this difference in antirachitic potency is ++++
VOl. 21, N o . 3
due to the inherent property of the oils or to a variation from one sample t o another is not known. Hess, Bills, Weinstock, Honeywell, and Riokin4 have reported a wide variation in the potency of cod-liver oil. They report that the antirachitic potency of the liver of the cod is in inverse ratio to its content of oil. Tests of the ether extract of livers, very small and poor in fat, showed them to be exceptionally potent-"far exceeding in potency any oil which has been heretofore reported." In the light of this work by Hess and his co-workers, perhaps too much emphasis may be placed on the relative potency of burbot- and cod-liver oils. At least, we probably can assume that burbot-liver oil may be classed with cod-liver oil as an excellent source of the antirachitic vitamin.
+ + +
4
Hess e t al., Proc. SOC.Ezptl. Biol. Med., 26, 653 (May, 1928)
Inversion of Sucrose in Beet-House Sirups' R. J. Brown and H. W. Dahlberg GREATWESTERN
S C C A R COMPANY,
DENVBB, COLO.
A satisfactory method for the determination of the quantity of copper reinvert sugar in beet-factory sirups has been given. duced by a given quantity of adoption of p H conIt has been shown that the invert-sugar content of invert sugar by this method trol in beet-sugar low-purity beet products cannot be taken as a measure varies with the temperature factory operations, replacing of previous inversion of sucrose, owing to the destruca t the boiling point, which the former control by alkation of invert sugar in such products. In the range a t high altitudes is lowered linity, the problem of inverof 6 to 9 pH the rate of destruction of invert sugar was sufficiently to cause a decided sion of sugar has become imfound to depend on the concentration of impurities, decrease in reduced copper. portant. the H- or OH-ion concentration showing no measurable After studying various proSince the published data on effect. cedures, many of which had rates of inversion of sucrose The effect of various factors on the rate of loss of been proposed by p r e v i o u s i n s i r u p s conflict in some sucrose in beet sirups was roughly determined. Deinvestigators, the f o 11owing cases, a brief investigation of creasing the pH of the sirup from 8 to 6 increased the method was adopted as one the inversion p r o b l e m w a s rate of loss of sucrose about ten times. Decreasing which would give concordant made for the purpose of dethe purity from 100 to 60 per cent decreased the rate of results: t e r m i n i n g the approximate loss of sucrose about 40 per cent. A 10"C. temperature rate of destruction of sucrose Transfer a quantity of sirup rise increased the rate from two to three times. Variaunder conditions met in pracrepresenting 11.0 grams of dry tions in concentration of solutions, in the range of tice. The field covered insubstance t o a 200-ml. flask, 10 to 80 per cent dry substance, produced no marked cluded the development of a clarify with the minimum quaneffect on the rate. The rate of loss of sucrose in beet tity of neutral lead acetate, and satisfactory method for defilter. Delead 100 ml. of the sirups from different sources was found to be constant, termination of invert sugar in filtrate with 10 ml. of a solution under constant conditions. The rate of loss of subeet-sugar products, the ascontaining 5 grams each of socrose in sirups of 90 per cent purity at 6 pH and 80 certaining of the suitability dium oxalate and d i s o d i u m per cent dry substance heated at 80" C. was almost p h o s p h a t e per 100 ml., and of the invert sugar determinafilter. Transfer 50 ml. of this double that calculated by Spengler a'nd Todt on the tion as a measure of sucrose filtrate to a 250-1111, Erlenmeyer basis of the inversion constant of sucrose in hydrod e s t r o y e d , and the deterflask, add 50 ml. of mixed Fehlchloric acid found by Jackson and Gillis. m i n a t i o n of t h e r a t e a t ing's solution (Quisumbing and Thomas modification2), cover which sucrose was destroyed. These three phases of the problem will be considered sepa- with a watch glass, and heat in a water bath a t 80' C. for 30 minutes. Filter the reduced copper through asbestos in a rately. Gooch crucible and determine copper by the iodine m e t h ~ d . ~
ITH t h e g e n e r a l
Determination of Invert Sugar in Beet Sirups
The difficulty in making the invert sugar determination in low-grade beet products arises from their low invert-sugar content, usually less than 1 per cent on dry substance. I n the ordinary method, where 50 ml. of clarified solution, representing 10 grams of sirup dry substance, are boiled with 50 ml. of Fehling's solution for 2 minutes, the cuprous oxide precipitate is frequently very unsatisfactory, and duplicate analyses often fail to give concordant results. Furthermore, 1 Presented before the Division of Sugar Chemistry at the 76th Meeting of the American Chemical Society, Swampscott, Mass., September 10 to 14, 1928.
Calculate invert sugar from the Quisumbing and Thomas tables, making corrections for effect of sucrose.
The Quisumbing and Thomas method of copper reduction was adopted because their temperature of heating could be reproduced, and because rather extensive tables were available. The covered Erlenmeyer flask was used since it was found that the exclusion of air during the heating period was the determining factor in preventing the formation of a highly dispersed copper precipitate. Since the concentration of sirup impurities is also a factor in determining the degree of 2
8
Quisumbing and Thomas, J. Am. Chcm. Soc., 48,1503 (1921). Assocn. O5cial Agr. Chem., Methods, p. 191 (1925).
