Fish Liver and Body Oils Chemical Characteristics, Physical Properties, and Vitamin Content The chemical and physical characteristics and vitamin potency of thirty-nine fish
-4RTHUR D. HOLMES AND FRANCIS TRIPP The E. L. Patch Company, Boston, Mass.
liver and fish body oils have been determined. The chemical and physical characteristics were tested by methods i n the U. S. Pharmacopoeia XI. The vitamin A potency was determined by the Hilger spectrophotometric, the Carr-Price colorimetric, or the U. S. P. XI biological assay method. The vitamin potency of the swordfish liver oils increased with increase i n the amount of unsaponifiable material, but the relation was not entirely consistent. The vitamin A potency of the mackerel liver oils also tended to increase with increase i n the amount of unsaponifiable material but the relation was not consistent. Of the other oils there seemed to be no consistent relation between any of the chemical or physical characteristics and their vitamin potency. Thus, i t is extremely difficult if not impossible to gain information concerning the vitamin potency of a fish liver or body oil by the determination of its chemical and physical characteristics.
G. HOWARD SATTERFIELD University of North Carolina, Raleigh, N. C.
The chemical and physical characteristics were determined by the U. s. P. XI method (63). A11 vitamin D a s s a y of the oils were made by the U. S. P. XI biological method. The vitamin A values were determined by either the U. S.P. XI biological method (63) the Carr-Price antimony trichloride colorimetric method (12) as described in the British Pharmacopoeia (9),or by the Hilger vitameter (39, 68). While t'he biological assay is the official method for determining the vitamin A content of fish liver oil, i t is costly and time consuming. Therefore colorimetric and spectrophotometric methods have been devised for the estimation of vitamin A, and thousands of gallons of fish liver oils are annually purchased and sold on the basis of results so obtained. Xany English concerns still express vitamin A potency in terms of blue units. I n an earlier study (89)the authors obtained by bot'h the Hilger vitameter method and the antimony trichloride colorimetric method results of the same order for t'he vitamin A potency of thirty-two samples of cod liver oil. The Bssociation of Official Agricultural Chemists (SO) studied the value of the vitameter for assaying cod liver oil and found that results obtained by different laboratories varied from 18 to 32 per cent. The Vitamin Assay Committee of the American Drug Manufacturers Association (26), in an extensive study of the reliability of the vitameter for determining the vitamin A potency of fish liver oils and concentrates, found a tendency for certain samples to react peculiarly. However, they concluded that the Hilger vitameter mas well suited for rapid routine assays of the approxime.te vitamin A content of fish liver oils. Since in the present study it was not feasible to assay all of the oils by the biological method, many of them were assayed either by the antimony trichloride colorimetric method as described in the British Pharmacopoeia or by the Hilger spectrophotometric method. The properties of the oils and the results of the vitamin -4 and D assays are reported in Table I.
D
URIXG recent years research studies have shown that the liver and body oils from many species of fish are rich natural sources of vitamins A and D, and some of these oils have become commercially important. I n view of the present scarcity of cod liver oil and the future uncertainty of the cod liver oil market, the pharmaceutical and medical professions are turning to new natural sources of vitamins A and D. The chemical and physical characteristics vary for different fish liver and body oils and thus serve to identify an oil. The properties usually considered are specific gravity, refractive index, saponification value, iodine number, free fatty acid, and unsaponifiable matter. An early publication (27) from this laboratory reported the characteristics of over one hundred samples of cod liver oil of known origin, and the U. S. pharmacopoeia (53) definitely specifies the chemical and physical characteristics of cod liver oil; but a review of the literature revealed only limited data concerning these characteristics of other fish liver or body oils which are being used or may be considered as sources of vitamins A and D. Consequently a study was made of a series of seven halibut liver oils, five swordfish liver oils, seven tuna liver oils, three mackerel liver oils, and the liver or body oil from seventeen other species of fish.
Halibut Liver Oils Emmett, Bird, Nielsen, and Cannon (17) found the specific gravity of halibut liver oil (Hippoglossus hippoglossus L.) to be practically constant a t 0.928, the saponification numbers to vary from 179.0 to 193.0, the iodine numbers from 118 to 126, and the unsaponifiable matter from 7.44 to 7 90 per cent. Brocklesby and Denstedt (IO) studied the chemical characteristics of halibut liver oil made from British Columbia fish and found iodine values from 139.0 to 141.3, saponification values from 169.5 to 176.0, and unsaponifiable matter from 7.5 to 7.6 per cent. In a more recent study 944
July, 1941
.
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Pugsley (44) found the iodine numbers of eleven samples of halibut liver oils t o be between 96.3 and 159.2. The unsaponifiable matter for eleven samples varied from 5.1 to 15.8 per cent. Simons, Buxton, and Colman (49) found that the iodine value of halibut liver oil varied from 130 t o 145. The seven samples of halibut liver oil were prepared from fish caught off the New England and Nova Scotia coasts during the summer and fall. The oil was obtained from the livers by the procedure described in detail in a patent (96). The chemical analyses varied as shown in Table I. As early as 1929 Schmidt-Nielsen and Schmidt-Nielsen (47) reported that the liver oil obtained from the halibut gave a strong color reaction with antimony trichloride. I n 1932 Emmet et al. (17) published a report on the vitamin potency and the physical characteristics of halibut liver oil. They found the vitamin A content to vary from 37,500 to 62,500 International units per gram while the antirachitic potency varied from 2000 to 3333 International vitamin D units per gram. Other early investigations concerning the vitamin A and D potency of halibut liver oil are reported by Lovern et al. (33, 34). Bills and co-workers (6) studied the seasonal variations of halibut liver oil and found that the potency varied between 35,000 and 240,000 I. U. of vitamin A and between 900 and 1400 I. U. of vitamin D per gram. In a later publication Bills et al. (6) reported the potency of halibut liver oil rendered from fish caught on the Pacific Coast as 41,000 I. U. of vitamin A and 1400 I. U. of vitamin D. Black et al. (7) found in a series of twenty-seven oils that the vitamin A potency of halibut liver oils varied from 8000 to 202,000 U. S. P. X I units. According to Pugsley (4.4) the vitamin D potency of halibut liver oils assayed by him varied from 1100 to 5200 I. U. and the vitamin A, from 4400 to 80,000 blue units per gram. The vitamin A content of the seven halibut liver oil samples assayed in this study varied from 4440 to 135,000 and the vitamin D potency ranged from 550 to 20,000 U. S. P. XI units per gram. No consistent relation was found b e tween the unsaponifiable matter and the vitamin A and D contents of the oils. The oil with the smallest amount of unsaponifiable matter contained the smallest amount of vitamins A and D, but the oil which contained the largest amount of unsaponifiable matter was not the most potent source of vitamins. Furthermore, Table I shows that there is no definite relation between any of the chemical and physical characteristics and the vitamin A and D potencies of halibut liver oils.
Swordfish Liver Oils I n a study of the utilization of swordfish livers, Harrison et al. (84) determined the properties of the swordfish liver oil (Xiphias gladius L.) manufactured by several methods. They found that refractive indices varied from 1.4730 to 1.4913, iodine values from 128.4 to 168.6, saponification numbers from 148.8 to 184.5, free fatty acid from 23.9 to 46.1 per cent, and unsaponifiable matter from 2.5 to 14.7 per cent. Simons e2 al. (49) reported that the iodine values of swordfish liver oils vary from 130.0 to 145.0. Four samples of swordfish liver oil were prepared from fish taken from the Atlantic Ocean off northeastern United States during June, July, and August. The oil was separated and recovered from the livers by the procedure used for the halibut liver oils (86). The variation in the chemical properties is shown in Table I. Harrison and co-workers (24) reported that the vitamin potency of swordfish liver oil was as high as 300,000 U. S. P. vitamin A and 9500 U. S. P. vitamin D units per gram. Bills (4) found a swordfish liver oil that contained 10,000 I. U. of vitamin D and later ( 6 ) stated that swordfish liver oil made from 2806 kg. of livers had a potency of 250,000 I. U. of
945
vitamin A and 14,000 I. U. of vitamin D. Black et al. reported 96,700 and 236,000 U. s. P. X I vitamin A units for two samples of swordfish liver oil (7), and found that the vitamin D content of a series of swordfish liver oils ranged from 4050 to 10,300 I. U. per gram (8). The vitamin A potency of samples 8 to 12 (Table I) varied from 19,600 to 328,000 units with an average of 165,720 units per gram. The vitamin D potency of the three oils assayed varied from 1550 units for the Japanese oil to 25,000 units for a lot of swordfish liver oil procured from a Massachusetts producer. There was little correlation between the chemical and physical characteristics and the vitamin potency of the swordfish liver oils. It was obviously a mere coincidence that the unsaponifiable content for the oil having the highest vitamin A potency (328,000 units) was 21.03 per cent, the highest value obtained for any of the swordfish liver oils.
Tuna 'Liver Oils A survey of the literature revealed practically no data concerning the chemical and physical characteristics of tuna liver oil. Davies and Field (14) reported an iodine value of 109 for a sample of blue-fin tuna oil obtained from Australian fish. The seven samples of oil were prepared from livers of several species of tuna, including Japanese ( T h u n n u s orientalis), New England (Thunnus secundodorsalis Storer), Hawaiian striped (Katsuwonus pelamis), and albacore ( T h u n n u s g e r m ) . The New England tuna liver oil was manufactured a t Gloucester, Mass., from fish caught in adjacent waters. The oil was removed from the livers by a patented process (86). The oil from the Hawaiian striped tuna was prepared by ether extraction of the livers under laboratory conditions. The other five oils were obtained from the trade and are believed to be typical of commercial tuna liver oils. The chemical properties are given in Table I. There was a wide divergence in the amount of fatty acids present in the oils. The smallest amount found was 0.35 per cent, while the Hawaiian striped tuna liver oil had a free fatty acid content of 77.70, with an average of 16.71 per cent for all the samples under consideration. However, if the exceptionally high values are excluded, the average becomes 0.42 per cent. It was reported that the Hawaiian tuna livers were shipped frozen from Honolulu and the oil which contained 77.70 per cent free fatty acid was extracted from the livers with ether. Oil 16 was made in this laboratory from Japanese blue-fin tuna livers by extraction with ethyl ether and contained 37.15 per cent free fatty acid. These high fatty acid values indicate that the livers had not been stored under satisfactory conditions. Black et al. (7)found that the vitamin A potency of a series of ten samples of tuna liver oils varied from 32,400 to 131,000 U. S. P. XI units per gram. Bills (4) reported a value of 40,000 I. U. of vitamin D for blue-fin tuna liver oil, and in a later study (6) found 80,000 I. U. of vitamin A and 16,000 I. U. of vitamin D for blue-fin tuna liver oil from New England fish; 36,000 and 61,000 for Japanese blue-fin tuna liver oil; 18,000 and 41,000 for albacore liver oil; 48,000 and 13,000 for yellow-fin tuna liver oil; and 43,000 and 58,000 for striped tuna liver oil. The highest vitamin A potency obtained for oils 13 to 19 was found in the sample of New England tuna liver oil which contained 148,000 U. S. P. X I vitamin A units per gram; the lowest was 20,000 for an oil of unknown origin. The highest vitamin D potency was 70,000 U. S. P. XI vitamin D units for a Japanese blue-fin and a Japanese albacore liver oil. The Hawaiian striped tuna liver oil had the lowest vitamin D value obtained.
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
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Vol. 33, No. 7
TABLE I. CHEMICAL ANALYSIS AND VITAMIN POTENCY OF FISHLIVERAND BODYOILS Sample NO. 1 2 3 4
5 6
7
Species Halibut liver Halibut liver Halibut liver Halibut liver Halibut liver Halibut liver Halibut liver Average
Sp. Gr.
Refractive Index
0.922 0,927 0.916 0.916 0.925 0.918 0.925 0.921
1.4864 1.4948 1.4859 1 ,4859 1.4850 1.4831 1.4846 1,4865
8 9 10 11 12
Swordfish liver Swordfish liver Swordfish liver Swordfish liver Swordfish liver J a o . Average
0.913 0.919 0.918 0.905 0.914 0.914
1.4974 1.4930 1.4869 1.4825 1.4772 1.4874
13 14 15 16 17
T u n a liver N . E. T u n a liver Jap. blue fin T u n a liver J a p . T u n a liver Jap. blue fin T u n a liver Hawaiian striped T u n a liver Jap. albacore T u n a liver Average
0.917 0.907 0.926 0.917 0.866 0.915 0.966 0.916
1.4889 1.4886 1.4886 1 ,4870 1.4660 1.4839 1.4848 1.4839
18
19
20 21 22
23 24 25 26 27 28 29 30 31 32 33 34
Mackerel liver Mackerel liver Mackerel liver Average
0,969 0,028 0.931 0.942
1 ,4969 1.4810 1.4811 1.4863
Dog salmon liver Perch liver Bonito liver White sea bass liver Pike liver Burbot liver Ling cod liver Whiting oil Turbot liver Dogfish liver Shark liver R a y liver
0,936 0.821 0.915 0.906 0.856 0,919 0.922 0 . Q17 0.917 0.905 0.919 0.926
1.4841 1.4777 1.4830 1.4749 1.4750 1 ,4820 1.4823 1.4811 1.4748 1.4755 1.4803 1.4857
Saponification Iodine NO. Value Halibut Liver Oils
Swordfish Liver Oils 163.4 162.2 162.0 141.6 164.9 141.9 170.0 131.9 182.1 130.8 168.5 141.7 T u n a Liver Oils
Nackerel Liver Oils 166.8 l58,2 177.6 129.1 177.0 155.5 173.8 147.6 Miscellaneous Liver Oils
c -
Free Fatty Acids, yo
Mackerel Liver Oils The mackerel liver oils (Scomber scombrus L.) were prepared from California fish under laboratory conditions by Morgan, Kimmel, and Davison (58). The properties varied as shown in Table I. Bills (4) found that lirer oil from Boston mackerel contained 750 I. 'c. of vitamin D per gram, and later (6) reported a vitamin A potency of 88,000 I. U. and a vitamin D potency of 1400 I. U. for liver oil from California mackerel. Black and Sassaman ( 8 ) found the vitamin D content of Japanese mackerel liver oil t o vary from 5000 to 6000 I. U. per gram. The two oils with the smaller amounts of unsaponifiable material (Table I) had vitamin A potencies of 30,000 and 76,000 units per gram while the mackerel with the largest amount of unsaponifiable material had a vitamin A potency of 211,000 units. Morgan et al. (58) obtained 5400 units of vitamin D per gram for mackerel liver oil 20. They also found 2700 and 75 units of vitamin D per gram for other mackerel liver oils prepared under similar conditions. Miscellaneous Liver Oils DOG SALMON LIVER OIL (Oncorhynchus keta). The oil was extracted in the laboratory with petroleum ether from livers taken from Alaskan fish. The livers were frozen while
...
0.26 1.71 0.43 0.31 1.40 0.34 1.73 0.88
11.11 17.95 11.90 12.76 12.40 10.93 4.56 11.66
0.45 0.25 1.43 0.37
164.00
4.83
21.03 13.78 9.34 7.24 7.68 11.81
0.40 0.45 0.44 37.15 77,70 0.45 0.36 16.71
9.75 8.37 2.18 6.96 4.73 5.16 3.55 5.81
74,OO 61.00 55.60 21.00
36.80 24.30 30.82 30.64
15.63 8.37 5.78 9.93
...
49,90 9.34 0.31 7.76 17.68 3.84 0.77 2.62 3.89 0.56 0.30 9.68
11.36 5.64 5.24 4.71 4.29 1.34 5.71 3.32 8.27 14.84 4.55 1 81
20.64
Miscellaneous Body Oils 1.4760 0.31 191.8 109.1 1.4850 0.23 190.1 181 .o 1.4779 4.24 182.0 135.1 1.4811 2.13 191.3 154 0 1,4778 0.63 180.6 117 8 method of Black et ai. (7), using a factor of 2000.
Eel body 0.919 35 Sardine body 0.928 36 Herring body 0.916 37 Menhaden body 0.924 38 Rosefish oil 0.915 39 a Calculitted from Hilger vitameter E values b y b Biological test. C Reported in a previous publication b y Morgan et al. (58).
UqsaHilger ponifiable vitameter M a t t e r , yo E value
1.21 0.60 1.92 1. 0 5
2.66
54: 00 53.00 3i'oo
... .
I
.
7S:OO 45.00 9 80
...
14:oo
...
...
...
... I
.
.
... ...
7.00
...
7.20 1.90 17 20 10,oo
...
...
15.40 0.14
...
0.25 0 17 0.17 1 79
Vitamin Potency-----. .U. S. P. XI Units/Gram Vitamin A5 Vitamin Db 135,000b 112,000b 108,000 106,000 90,000b 62 000 4:440b
.....
4,000 4.000f 2,500
2,500 20,000 1,500 550
....
....
328,000 235,000b 156,000 90,000 19,600
25,000 20,000
.....
.... 1,550 .,..
148,000 122,000 111,200 42,O0Oc 33,000 28,000 20,000b
30,000 70,000 45,000 40,000 27,0000 70,000 60,000
.....
211,000~ 76,000; 30,000
.....
5,8OOc 10,000b 14,000
70,000~
14,400 3,800 34,400 20,000 10,OOOb 2,300b 30,800 280
1,500-b 500 340 340 3,580
....
5,4000
.... ....
....
475c 750 20,000 1,400C 500 400 700 l.OOO+
400
....
100
....
200-
....
100
50f
50
-
in transit from Alaska. The chemical and physical characteristics are given in Table I. The value of 49.90 per cent for free fatty acid is unusually high; it is exceeded only by 77.70 per cent for the Hawaiian striped tuna liver oil and indicated unsatisfactory handling of the livers from which the oil was produced. Harrison et al. (11)found about 300 units of vitamin D per gram for oils from sockeye and silver salmon waste, and 150400 units of vitamin D and 4000-8000 vitamin A units for three Chinook liver oils. Bailey ( 2 ) found 50 and 67 units, respectively, of vitamin D per gram and a small amount of vitamin A in the oil of canned British Columbia sockeye and pink salmon. Bills (4) reported 1300 I. U. of vitamin D for Chinook salmon liver oil and 400 I. U. for dog salmon liver oil. Black et al. (7) reported a vitamin A potency of 150,000 U. S. P. XI units for two samples of salmon liver oil. Lavern and coworkers (53) found that salmon liver oil was vastly richer in vitamin iithan cod liver oil. Davies and Field (IQ), in a study of Australian fish livers, found that the vitamin A content of five lots of salmon liver oil varied more than 300. per cent. Lee and Tolle (32) studied the physical and chemical characteristics of oil prepared from salmon taken from the Columbia River, Puget Sound, and Fraser River area, and found that salmon liver oils are approximately five t o twenty times as potent in vitamin A and two to three times
July, 1941
INDUSTRIAL AND ENGINEERING CHEMISTRY
as potent in vitamin D as cod liver oil. Harrison et al. (22) determined the physical and chemical characteristics and vitamin content of Pacific salmon oil from cannery trimmiegs and of oils prepared from various portions of the fish. They found wide variations, from 6500 to 13,000 Lovibond blue units of vitamin A per gram for Chinook liver oil. Brocklesby and Denstedt (IO)found that the chemical and physical characteristics of commercial salmon oil varied over a considerable range, depending upon the nature of the raw material and the species. Tolle and Nelson (50) reported that salmon oil can be produced which is equal to good grades of cod liver oil in vitamin A content and approximately twice as potent as cod liver oil in vitamin D. Morgan et al. (58) found a potency of 57,600 U. S. P. XI vitamin A and 570 U. S. P. XI vitamin D units for a sample of solvent-extracted silver salmon liver oil. Morgan et al. (38) found 5800 U. S. P. vitamin A and 475 U. S. P. vitamin D units per gram in dog salmon liver oil 23 (Table I). This oil had a high vitamin potency in spite of its exceedingly high fatty acid content. PERCH LIVEROIL (Aplodinotus grunniens). Oil 24 (Table I) was prepared in this laboratory from livers removed from fish obtained in October from Lake Erie. The oil was extracted with ethyl ether. It was biologically assayed and found to contain 10,000 U. S. P. XI units of vitamin A and 750 U. S. P. XI units of vitamin D per gram. The latter value greatly exceeds 11 I. U. of vitamin D per gram reported by Bills (4) for Ohio perch oil prepared from the mesentery of the fish. BONITOLIVEROIL (Gymnosurda pelamis L.). The oil was manufactured under commercial conditions (25) from livers obtained from South America. It was represented as being typical of medicinal oil obtained from this species of fish. Bills et al. (6) found California bonito liver oil had a potency of 120,000 I. U. of vitamin A and 50,000 I. U. of vitamin D per gram. Assay of oil 25 (Table I) showed it to have a potency of 14,000 U. S. P. XI vitamin A units and 20,000 U. 5. p. XI vitamin D units per gram. The unsaponifiable content of oil 25 was 5.24 per cent whereas a tuna liver oil containing 5.16 per cent unsaponifiable material had a vitamin potency of 28,000 vitamin A units and 70,000 vitamin D units per gram. WHITE SEABASS OIL (Cynoscion nobilis). The sample was made from livers from Southern California fish. The livers were received frozen and were extracted with ether (58). The vitamin content of oil 26 (Table I) was determined by Morgan et at. (38) and found to contain 70,000 vitamin A and 1400 vitamin D units per gram. Bills et al. (6) reported that liver oil from white sea bass taken off the Southern California coast had a potency of 55,000 I. U. of vitamin A and 6000 I. U. of vitamin D per gram. PIKELIVER OIL (Esor musquinongy). The oil was obtained by ethyl ether extraction of fresh yellow pike livers obtained from Manitoba, Canada. Analysis (Table I) showed it to have a free fatty acid content of 17.68 per cent. Ordinarily this figure would indicate that the oil was made from old or improperly stored livers, but in this instance the livers arrived from Manitoba well iced and in good condition. Lovern et al. (33) reported that pike liver oil contains about double the quantity of vitamin A found in cod liver oil. However, the vitamin A and D potencies of oil 27 (Table I) are several times those specified by the U. S. P. XI for cod liver oil. BURBOTLIVEROIL (Lotu masulosa). The sample assayed in this investigation was purchased on the open market. The oil was manufactured under commercial conditions from livers obtained from Lake Michigan burbot. Nelson, Tolle, and Jamieson (42) found that burbot liver oil was four to ten
947
times as potent in vitamin A and three t o four times as potent in vitamin D as good grades of medicinal cod liver oil. As early as 1922 McCollum et al. (55) reported that the oil of the burbot possessed antirachitic properties. Clow and Marlatt (15)stated that burbot liver oil may be classed with cod liver oil as an excellent source of the antirachitic vitamin. While the unsaponifiable content of oil 29 (Table I) was the lowest of any of the liver oils considered in this investigation, the vitamin content of 3800 vitamin A and 400 vitamin D units is not so low as that of some of the other oils. LINGCODLIVEROIL (Ophiedon elongatus). Sample 29 was supplied by the Seattle, Wash., laboratory of the United States Bureau of Fisheries. Brocklesby and Denstedt (IO) found a high vitamin A value by colorimetric tests for liver oil obtained from the ling cod. In an early study Bailey ( 1 ) also showed that ling cod liver oil was a rich source of vitamins A and D. In a more recent publication Pugsley (46) found this oil to be a good source of vitamin A. Bills (4) reported a vitamin D potency of 1300 I. U. for ling cod liver oil, and later (6) found an extremely high potency of 160,000 I. U. of vitamin A and 840 I. U. of vitamin D for a commercial ling cod liver oil. While the vitamin A value of oil 29 (34,400 I. U.) is much lower than that reported by Bills et al. (6), the vitamin D value is similar. WHITINGLIVER OIL (Merluccius bilineuris). Oil 30 was obtained from fish caught along the Massachusetts coast,. It was removed from the livers by solvent extraction. The properties given in Table I are somewhat similar to those for U. S. P. cod liver oil, except that the free fatty acid and unsaponifiable contents are three times that to be expected in medicinal cod liver oil. Lovern et al. (53) found that the vitamin A content of whiting liver oil slightly exceeded that of the haddock and considered the oil inferior in vitamin A potency to average cod liver oil. Assays of oil 30 (Table I) showed vitamin A and D potencies considerably in excess of those specified for medicinal cod liver oil. TURBOT LIVEROIL (Reinhardtius hippoglossoides). A sample of steam-rendered oil was obtained from a commercial producer in Newfoundland. The iodine number, 110.4 (Table I), was the lowest of any of the liver oils, which would indicate that this oil had a lower degree of unsaturation than the other liver oils studied. Bills (4) reported 260 I. U. of vitamin D for a sample of turbot liver oil. Lovern et al. (35) found this oil to be vastly richer in vitamin A than cod liver oil. While the amount of unsaponifiable matter in sample 31 (Table I) is several times that of medicinal cod liver oil, its vitamin content is not correspondingly higher than that of cod liver oil. DOGFISHLIVER OIL (Squalus acanthias L.). Since an earlier investigation in this laboratory (28) showed that dogfish liver oil contained significant amounts of vitamin A, a typical oil was obtained for investigation. This oil was manufactured on a commercial basis from livers taken from fish caught along New England shores. It is assumed that the unusually high unsaponifiable matter of oil 32 (Table I) was due in a large measure to squalene, a highly unsaturated hydrocarbon, found in the liver oils from various members of the shark family. Guha, Hilditch, and Lovern (18) found that the unsaponifiable content of dogfish liver oil varied from 4.0 t o 32.9 per cent. Holmes and Pigott (28) reported that a composite oil from five dogfish livers had the following characteristics: specific gravity 0.9153, refractive index 1.4762, saponification value 169.3, iodine number 145.8, and free fatty acid 0.2641 per cent. Bills et al. (6) found that the liver oil from Pacific Ocean dogfish contained 23,000 I. U. of vitamin A and 16 I. U. of
948
INDUSTRIAL AND ENGINEERING CHEMISTRY
vitamin D, and that Atlantic dogfish liver oil (4) contained only 3 I. U. of vitamin D. Pugsley (43) studied the vitamin A potency of 130 grayfish (dogfish) liver oils from the British Columbia region and found E values varying from 0.29 to 19.23 for different lots of oil. He also found the vitamin D potency of three samples of grayfish liver oil to be 4, 6, and 7 I. U., respectively. Other earlier investigators reported vitamin values of dogfish liver oil (10, 11, 16). It is evident that dogfish liver oil is a poor source of vitamin D. The biological assay of oil 32 for vitamin A showed a potency of 2300 U. S. P. X I units, which is one tenth that reported by Bills et al. (6) for Pacific dogfish liver oil. SHARELIVEROIL (Carcharias taurus). The sample was prepared under commercial conditions from sand sharks captured in Florida waters. While the unsaponifiable content of this oil (4.55 per cent) greatly exceeds that of cod liver oil and similar edible fishes, it is only about one third that (14.84 per cent) obtained for dogfish liver oil 32. In a previous study Jones and Christiansen (31) found the unsaponifiable content to vary from 1.69 to 12.40 per cent, the free fatty acid from 0.059 t o 0.840 per cent, and a sample of liver oil from sand sharks had an unsaponifiable content of 9.60 and a free fatty acid content of 0.16 per cent. Brocklesby and Denstedt (IO)reported that the liver oil of an Arctic shark contained 10.2 per cent of unsaponifiable material. Simons et al. (4.9) found the iodine value of shark oils to vary from 110 to 135. Bills (4) reported that shark liver oil contained 50 I. U. of vitamin D. Jones and Christiansen (SI) found the vitamin A potency of various shark liver oils to vary from 168-6000 units. They also obtained a vitamin A potency of 200 units for liver oil from sand sharks. Rusoff and Mehrhof (46) reported that Florida shark liver oil contains approximately 9000 U. S. P. X I vitamin A units per gram. Simons et al. (49) stated that shark liver oils examined by them had a potency as high as 26,100 vitamin A units per gram. The shark liver oil studied in this investigation contained 30,800 vitamin A and 100 U. S. P. X I vitamin D units per gram. The relation between the unsaponifiable matter and the vitamin potency is not the same for the two species of shark, as the dogfish liver oil had an unsaponifiable content of 14.84 per cent and a vitamin A potency of 2300 units, while the shark liver oil with an unsaponifiable content of 4.55 per cent had a vitamin A potency of 30,800 units per gram. RAYLIVEROIL (Manta birostris). The oil was prepared from the liver of a ray that weighed approximately 1500 pounds and was captured off the Florida coast. The iodine number (196.9) for oil 34 (Table I) was higher than that of any other oil studied and indicates that it is highly unsaturated. The free fatty acid content of 0.68 per cent compares favorably with that of edible cod liver oil. Also the specific gravity (0.926) and saponification value (179.8) are similar to those of good cod liver oil. A review of the literature revealed no data concerning the vitamin content of ray liver oil. Assay of oil 34 for vitamin A by the vitameter gave an E value of 0.14. Applying the usual conversion factor of 2000, it was computed that this oil contained about 280 U. S. P. X I vitamin A units per gram.
Miscellaneous Body Oils EEL BODYOIL (Leptocephalus conger L.). The oil was prepared in this laboratory by steam extraction of a supply of eels purchased from a local fish market. Oil 35 had a light yellow color, a somewhat fishy odor, and resembled cod liver oil in general appearance and viscosity. The low iodine value of 109.1 (Table I) indicates a well saturated oil. The free fatty acid content of 0.31 per cent and an unsaponifiable value of 1.21 per cent were similar to those of cod liver oil.
Vol. 33, No. 7
Edisbury, Lovern, and Morton (16) found that substantial quantities of vitamins A and D occur not only in the liver but in other tissues of eel. They also found that the oil obtained from the nonliver tissues was similar in vitamin A content t o that of cod liver oil. The same investigators (33) found considerable vitamin A in the liver oil of the conger eel. Shorland and McIntosh (48) studied the vitamin content of New Zealand eel body and liver oils, and found the liver oil to be extremely rich in vitamin A. Biological assay of oil 35 showed less than 1500 vitamin A and 200 vitamin D units per gram. While these values compare favorably with the potency of medicinal cod liver oil, the yield of oil and the relatively limited supply of eels indicate that eel body oil cannot be considered as a commercial source of vitamins A and D. SARDINEBODYOIL (Sardinia caerulea). Sample 36 was taken from a commercial lot of several thousand gallons of oil manufactured from Pacific Coast fish and was typical of sardine oil used for poultry feeding. The free fatty acid (0.23 per cent) and the unsaponifiable content (0.60 per cent) were lower than any of the other oils examined. Brocklesby and Denstedt (10) reported 0.52 t o 0.86 per cent for the unsaponifiable content of sardine body oil. Bills and co-workers (6) reported that sardine oil prepared from Pacific Ocean fish contained 2700 I. U. of vitamin A and 110 I. U. of vitamin D per gram. Trueadail and Culbertson (61) found that sardine oil contained nearly as much vitamin D as cod liver oil, while Nelson and Manning (41) stated that sardine oil was equal t o or a little better than cod liver oil as a source of vitamin D and was only about one tenth as potent in vitamin A as cod liver oil. nilussehl and Ackerson (40) found sufficient vitamin D in sardine oil to promote good calcification in chicks when their ration contained 0.5 per cent of the oil. Brocklesby and Denstedt (10) found the vitamin D potency of commercial sardine (pilchard) oil to be equal to medicinal cod liver oil. Milne, Rudolph, and McFarlane (37) reported 202 I. U. of vitamin A for pilchard oil. Morgan and collaborators (38) found that commercial sardine oils contained negligible amounts of vitamin A, and only one of fourteen oils met the vitamin D standard for U. S. P. cod liver oil. The unusually low unsaponifiable value for sardine oil 36 (Table I) is accompanied by a low vitamin A potency. HERRINGBODYOIL (Culpea harengus L.). The oil was obtained from Iceland and is believed t o be typical of oil from that source. The saponification value of 182.0 (Table I) is similar t o that of cod liver oil. The free fatty acid content of 4.24 per cent is approximately three times the maximum limit for cod liver oil and probably indicates that the stock from which the oil was made was not strictly fresh. A review of the literature revealed no data concerning the chemical and physical characteristics of herring body oil. Bills (3) found a sample of Newfoundland herring oil t o have a vitamin D potency equal to that of cod liver oil. Nelson and Manning (41) reported that Alaska herring oil was about one tenth as potent in vitamin A as cod liver oil, while the oil from Maine herring contained only about half as much vitamin A as that from the Alaska herring. The vitamin D potency of the Maine herring oil was found to be only 15 per cent that of cod liver oil, while the Alaska herring oil was about 30 per cent as efficient. While the vitamin D content of oil 37 (Table I) meets the U. S. P. specifications for cod liver oil, the vitamin A value is only a little more than one third that specified for edible cod liver oil. MENHADEN BODYOIL (Brevoortia tyrannus). Sample 38 was prepared by a modern commercial process from the entire bodies of menhaden caught off the coast of the middle Atlantic states.
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INDUSTRIAL AND ENGINEERING CHEMISTRY
Harrison and Pottinger (23) reported that the free fatty acid content of menhaden oil prepared by different methods ranged from 0.28 to 5.30 per cent. Brocklesby and Dens k d t (10) found the unsaponifiable content to vary from 1.60 to 2.20 per cent, and the iodine value from 139.0 to 173.0. Nelson and Manning (41) were unable to demonstrate any vitamin A in biological assays of menhaden oil, but the vitamin D potency was about three quarters that of medicine1 cod liver oil. BiUs (4)found that a sample of menhaden oil contained 50 I. U. of vitamin D per gram, and an oil from the Chesapeake Bay region (3) was about 75 per cent as potent in vitamin D as cod liver oil. Harrison (20)published an extensive report which deals with many phases of the menhaden oil industry. Manning, Nelson, and Tolle (36‘) in a study of the manufacture of menhaden oil tested eleven samples prepared by different methods. Four of them were equal to medicinal cod liver oil in vitamin D, while the others were about 75 per cent as efficient. Halverson and eo-workers (19) reported that 1 per cent of a good quality menhaden oil in a mash would supply ample vitamin D for the prevention of rickets in chicks. It is evident from the data (Table I) that menhaden oil, even when prepared and stored under approved conditions, fails to be equivalent to cod liver oil as a source of vitamins A and D. ROSEFISHBODYOIL (Sebastes marinus L.). A review of the literature revealed no data concerning the chemical and physical characteristics or the vitamin potency of oil prepared from whole rosefish. A sample was obtained from a supply of oil which had been manufactured under commercial conditions by an alkali-refining process from rosefish caught off the Massachusetts coast. Biological assay of oil 39 (Table I) for its vitamin D content a t 50- and 150-unit levels showed that it contained very little if any antirachitic value.
Acknowledgment The authors gratefully acknowledge the helpful services of William Wallace who assayed some of the oils under consideration. The authors also wish to express appreciation to the U. S. Bureau of Fisheries, Massachusetts Fisheries Association, A. F. Morgan, Eastern States Farmers’ Exchange, Gorton-Pew Fisheries Company, Ltd., Shark Industries, Inc., Rowland Marine Products Company, W. A. Munn & Company, Kishman Fish Company, Manitoba Cold Storage Company, Ltd., and Atlantic Coast Fisheries Corporation, who kindly supplied some of the samples of oils studied in this investigation.
Literature Cited Bailey, B. E., Canadian Biol. Fish., 7, 1-8 (1933). Bailey, B. E., J. Biol.Board Can., 2,431 (1936). Bills, C.E., J. Biol. Chem., 72,751 (1927). Bills, C.E., Physiol. Rev., 15, 1 (1935). Bills, C. E., Imboden, M., and Wallenmeyer, J. C., J. BWZ. Chem. Proc. 105, X (1934). Bills, C. E., Massengale, 0. N., Imboden, M., and Hall, H., J . Nutrition, 13,435 (1937). Black, A., Greene, R. D., Sassaman, H. L., and Sabo, C., J . A m . Pharm. Assoc., 27, 199 (1938). Black, A., and Sassaman, H. L., A m . J . Pharm., 108,237(1936). British PharmacoDoeia. London. Constable and Co.. 1932. Brocklesby, H. N., and Denstedt, 0. F., Biol. Board Can., BuU. 37, 1-150 (1933). Callow, R. K., and Fischmann, C. F., Biochem. J., 25, 1464 (1931). Cirr, F. H., and Price, E. A,, Ibid., 20, 497 (1926). Clow, B., and Marlatt, A., IND.ENQ.CHEM.,21, 281 (1929). Davies, W., and Field, D. J., Bwchem. J., 31, 248 (1937). Drummond, J. C.,and Hilditch, T. P., “Relative Values of Cod Liver Oils from Various Sources”, London, H. M. Stationery Office, 1930.
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(16) Edisbury, J. R., Lovern, J. A., and Morton, R. A., Biocham. J., 31,416 (1937). (17) Emmett, A. D., Bird, 0. D., Nielsen, C., and Cannon, H. J.. I S D . ENQ.CHElbf., 24, 1073 (1932). (18) Guha, K. D.. Hilditch, T. P., and Lovern. J. A., Biochem. J.. 24, 266 (1930). (19) Halvereon, J. O., Smith, F. H., Sherwood, F. W., and Dearstyne R. S., N. C. State Coll. Agr. Expt. Sta., Tech. Bull. 57, 1-31 11938). - -, (20) Harrison, R. W.,U. S. Bur. Fisheries, Investigational Rept. 1, 1-113 (1931). (21) . . Harrison. R. W., Anderson. A. W.. Holmes. A. D.. and Pinott. - . M. G., Ibid., 36, 1-8 (1937). (22) Harrison, R. W.,Anderson, A. W., Pottinger, 8. R., and Lee, C.F., Ibid., 40, 1-21 (1939). (23) Harrison, R. W.,and Pottinger, S. R., Ibid., 4, 1-11 (1931). (24) Harrison, R. W.,Pottinger, 8. R., Lee, C. F., and Anderson, A. W.. Ibid.. 28. 1-10 (1935). (25) Hempel, H. (to Gorton-Pew Fisheries Go., Ltd.), U. 8. Patent 2,156,985(May 2, 1939). (26) Holmes, A. D., Black, A., Eckler, C. R., Emmett, A. D., Heyl, F. W., Nielsen, C., and Quinn, E. J., J . Am. Pharm. Assoc., 26,525 (1937). (27) Holmes, A. D., and Clough, W. Z., Oil & Fat Industries, 4, 403 (1927). (28) Holmea, A. D.,and Pigott, M. G., IND. ENO.CHEM.,17, 310 (1925). (29) Holmes, A. D.,Tripp, F., and Satterfield, G. H., IND.ENG. CHEM.,Anal. Ed., 9,456 (1937). (30) Irish, I. J., Rept. of Associate Referee on Vitamin A to A. 0. A. C., Nov. 11, 1935. (31) Jones, W. S.,and Christiansen, W. G., J . A m . Phurm. Assoc., 24, 295 (1935). (32) Lee, C. F.,and Tolle, C. D,, IND. ENQ.CHmd., 26,446(1934). (33) Lovern, J. A., Edisburv, J. R., and Morton, R. A., Biochem. J., 27, 1461 (1933). (34) Lovern, J. A., and Sharp, J. G., Ibid., 27,1470 (1933). (35) McCollum, E. V.,Simmonds, N., Becker, J. E., and Shipley, P. G., J . Biol. Chem., 53,293 (1922). (36) Manning, J. R., Nelson, E. M., and Tolle, C. D., U. S. Bur. Fisheries. Investiuutional Revt. 3. 1-5 (1931). (37) Milne, H.I., Rudolph, L., and MoFarlane, W. D., Poultry Sci., 16,383 (1937). (38) Morgan, A. F., Kimmel, L., and Davison, H. G., Food Reseurch. 4, 145 (1939). (39) Morton, R.A.. “Application of Absorption Spectra to Study of Vitamins and Hormones”, pp. 1-70, London, Adam Hilger, Ltd., 1935. (40) Mussehl, F. E.,and Ackerson, C. W., Poultry Sci., 12,31 (1933). (41) Nelson, E.M., and Manning, J. R., IND. ENO.CHEM.,22, 1361 (1930). (42) Nelson, E. M., Tolle, C. D., and Jamieson, G. S., U. S. Bur. Fisheries, Investigational Rept. 12, 1-6 (1932). (43) Pugsley, L. I., J . Fish. Research Board Can., 4, 312 (1939). (44) Ibid., 4, 396 (1939). (45) Ibid., 4, 472 (1940). (46) Rusoff, L. L., and Mehrhof, N. R., Poultry Sci., 18, 339 (1939). (47) Schmidt-Nielsen, Signe, and Schmidt-Nielsen, Sigval, Biochem. J., 23,73 (1929). (48) Shorland, F. B., and McIntosh, I. G., Ibid., 30, 1775 (1936). (49) Simons, E. J., Buxton, L. O., and Colman, H. B., IND.ENQ. CHEM.,32, 706 (1940). (50) Tolle, C. D., and Nelson, E. M., Ibid., 23, 1066 (1931). (51) Truesdail, R.W.,and Culbertson, H. J., Ibid., 25,563 (1933). (52) Twyman, F., and Allsopp, C. B. “Practice of Absorption Speotrophotometry with Hilger Instruments”, 2nd ed., pp. 1-140, London, Adam Hilger, Ltd., 1934. (53) U. S. Pharmacopoeia XI, Easton, Penna., Mack Printing Co. 1936.
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