June, 1933
ISDUSTRIAL A S D ESGINEERING CHEIIISTRY
aside from a few erratic deviations, the agreement is excellent, and the constancy of C from substance to substance is better than a t high temperatures. Most of RIills’ data fall on the same line (C = 1.50) as the high-temperature calorimetric data, with the benzene halides forming a second group about 5 per cent below the line. However, a comparison of Mathews’ data ( 1 1 ) a t the boiling point with hlills‘ values (10) shows that the latter are too low, by 4.7 per cent for chlorobenzene and 3.5 for bromobenzene. If the error a t 0 ” C. is of the same nature, most of the discrepancy will disappear, and all Mills’ data fall on a single line. B ~ l o wthe boiling point the value of C apparently tends t o approach 1.70 for all substances, as shown by Mills’ data, or possibly to fall below 1.70, as indicated by the trend of the data of Smith and Taylor for ether. At about room temperature, however, a C value of 1.70 appears to reproduce hlills’ values with considerable accuracy, and is ther(,f ore recommended for the estimation of latent heats in the range from 0 ” to 30” C. ES’rIxiTIox OF T‘OLCMES
i
The principal shortcoming of the present method is the necessity for knowing the value of T 7 g / V l ; hon-ever, as this ratio occurs as the logarithm, it need not be kn0n.n n i t h great accuracy. The method is therefore usable with vapor-pressure data of only fair accuracy, which could not be employed in the Clausius-Clapeyron equation with confidence. Kilson and Bahlke (17) have reviewed the liquid and vapor density data for the paraffin hydrocarbons. Cope, Lewis, and Weber ( I ) recently presented methods of estimating the vapor volumes of the higher hydrocarbons. For the estimation of liquid \rolumes the empirical equation of Saslavsky (14) is useful: V c / V = (1
+ 2.73 dl - O.95T/TC)
(5)
661
Though this obviously cannot hold a t the critical point, it is valid up to a reduced temperature of T/T,= 0.98 without serious error.
L4, B , C d
= =
1’
= = = = =
M P R T
X =
SOTATIOS empirical constants differential operator molecular weight vapor (saturation) pressure gas law constant, in PV = RT abs. temp.; T , = critical temp. molal volume; V I , of liquid; Vz, of vapor; at critical point total latent heat
ITe,
LITERATURE CITED (1) Cope, Lewis, and V e b e r , ISD.ESG.CHEX.,23, 887 (1931). (2) Dana, Jenkins, Burdick, and Timm, Refrigerating Eng., 12, 387 (1926). (3) Dieterici, Ann. Physik, 2 5 , 569 (1908). (4) Griffiths and Marshall, Phil. -\lag., 41, 1 (1896). (5) Hildebrand, J . A m . Chem. Soc., 37, 970 (1916). (6) International Critical Tables, T’ol. 111. p. 245, and Vol. T’, p. 138, McGraw-Hill, 1926. ( 7 ) Kirejev, 2. ccn.org. allgem. C‘hem., 182, 177 (1929).
(6) LeBas, “Molecular T-olumes of Liquid Chemical Compounds,” Longmans, 1915. (9) Lewis and Weber, J. ISD.ESG.CHEX, 14,485 (1922). (10) Marie, Tables Annuelles de Constantes et Donn6es Kumbriques T’ol. I, p. 68, Gauthier-T’illare, Paris, 1910. (11) Mathew, J. H., J . Am. C‘hem. SOC.,48, 562 (1926). (12) McAdams and blorrell, ISD.ESG. CHEY.,16, 375 (1921). (13) Mills, J. E., J . Am. Chem. SOC.,31, 1099 (1909). (14) Saslavsky, Z . physik. Chem., 109, 111 (1924). (15) Taylor and Smith, J . A m . C‘hem. Soc., 44, 2460 (1922). (16) TTatson, IXD. ESG.CHEJI.,23, 360 (1931). (17) Wilson and Bahlke, I b i d . , 16, 115 (1924). ( l b ) Toung, Sydney, Phil. M a g . , 33, 153 (1892). RECEIVED Sovember 4 , 1932.
VitarYlins A and D in Tuna Meal ROGERM‘. TRUESDAIL AND LEE SIIAHINIAS, Truesdail Laboratories, Inc., Los iingeles, Calif.
C
OSSIDERABLE data have been published upon the pended on fish meal or other related marine products, suitable for the of ~ man andl beast,~ as has been completed on nutritive of fish meals as pointed out by ~ ~ cod ~ dietary of the science of nutrition would liver oil,i our knowledge
and McCollum ( I ) . Little of this concerns the vitamin be much It is only to be hoped that the future contents of such meals. Malcohi (4, 6)found a destruction n-ill Drovide such data. of v i t a m i n A when fresh fish and oysters were dried. Several A representatire sample of meal prepared The w o r k of K’elson a n d i n v e s t i g a t o r s (7, 8, 10) rehlannillg (’) and Of this laborschiefly from the dark meat of the tuna has been port varying vitamin D values tory (12) has indicated tuna oil for different fish meals. It is tested for its Titamin A and content. The to be an excellent source of vitaapparent that q u a n t i t a t i v e tuna meal prored to be a good source Of ritamin min D but inferior in its vitamin v i t a m i n studies of fish meals A , containing more than 14 Sherman units per A content. The canned white have been fern. l l a n n i n g (6) gram. It is an excellent Source of vitamin D, meat of the tuna has assumed a has stated this position a s assaying more than 62 units (A. D. AI. A.) of definite place in the American follows: dietary, and substantial quantifhisfactor per gram. ties of tuna meal, produced priU n f o r t u n a t e l y n e possess If is suggested that canned funa, which is the marily from the dark tunameat, f a r too meager a Of knou-lwhite luna meat, may protide these two factors are used in animal and poultry edge concerning the v i t a m i n potency of fish meal and related f o r the human dietary. The citamin confent rations, although it has been reof canned tuna should be inziestigafed. ported as a source of food for marine p r o d u c t s , except in the case of cod liver oil where concertain groups of people. This siderable scientific i n f o r m a t i o n sideration should be given tuna meal as a source investigation undertaken to is a v a i l a b l e . Needless to say, of vitamins A and D f o r animal and poultry ,jetermine the tuna meal content If a corresponding amount of scientific research had been exrations. of vitamins A and D.
con-
662
INDUSTRIAL AND ENGINEERING CHEMISTRY
SOURCEOF MATERIAL The fresh tuna meal’ investigated was a representative sample of this vacuum-dried product. Daniels and McCollum ( 1 ) in their studies of fish meals indicate the three different manufactmuringmethods and conclude: “In every case the vacuum- and steam-dried meals were found to produce greater growth responses than the flame-dried products.” The tuna (Neothunnus macropterus) are caught off the coast of Mexico or Central America. They are immediately packed in ice and delivered to the cannery 15 to 35 days after the catch.
Vol. 25, No. 5
D COSTEXT The vitamin D content of the tuna meal was determined quantitatively by the method proposed by the Vitamin Assay Committee of the American Drug Manufacturers’ Association (3) for cod liver oil assays. The vitamin D content of the tuna meal may be expressed in units per gram of meal, where a unit of vitamin D (3) is defined as the minimum average daily amount of tuna meal required to produce a continuous narrow line across the metaphysis of the leg bones in four out of six rats under the experimental conditions of this method. This continuous narrow line corresponds to a 2+ degree of healing. Table I1 gives a summary of the results. J-ITAMIX
TABLE11. DEGREEOF HEALING ATTAINED ON GRADED DAILY AMOUNTSOF TUNAMEAL DAILYSUPPLEMENT ( 8 days) Me.
R.4TS O N SCPPLEMENT
16 20
15 14
40 Controls (preliminary) Controls (eyptl.)
2 5
5
DEGREEOF HEALINQ (Av. line test) 1 + 2.5+ 3 + Severe rickets No healing
DISCUSSION OF RESULTS Figure 1 indicates that the sample of tuna meal tested is a good source of vitamin A. Even the smallest daily supplement (0.075 gram of tuna meal) is more than adequate for unit growth, actually producing growth above that of reported FIGURE 1. AVERAGE GROWTH CURVESOF RATSRECEIVING standard albino rats (2). Unit growth, according to Sherman, is an average weekly gain of 3 grams. Thus definite evaluaGRADEDDAILYTUNAMEALSUPPLEMENTS tion of the meal in terms of vitamin A is not possible, other After cleaning, the fish are cooked from 2.25 to 6 hours, than that the sample tested contained considerably more than depending on the size of the fish, in direct steam cookers a t a 14 units of vitamin A per gram, making it comparable to temperature of 105’ C. After cooling, the white and dark butter, carrots, and dried whole milk as a source of this factor. The data in Table I1 indicate that the meal contains more meat is separated. The white meat is canned for human consumption, and the dark meat and the off-color white meat than 62 A. D. M. A. units of vitamin D per gram. It is an are immediately placed in a direct steam cooker a t 125’ C. excellent source of this factor and apparently would compare This heated mass is pressed through a continuous screw press favorably with the poorer medicinal grades of cod liver oil, to extract oil and water, after which the fish is dried in a since the Vitamin Assay Committee states (3): “Cod liver oil steam-jacket vacuum drier a t 115’ C. for 3.5 to 6 hours. shall be assayed for its vitamin D content by the following depending upon the moisture content. Grinding and screen- method, When so assayed the oil shall contain a t least 100 vitamin D units per gram.” ing are the final manufacturing operations. The favorable vitamins A and D content of the dried dark A chemical analysis of this sample indicated the following meat of the tuna fish suggests that canned tuna, comprised composition: protein (N X 6.25), 62.09 per cent; ash, 18.24 wholly of the white meat, may be an important source of per cent; moisture, 8.61 per cent; fat (ether extract), 8.04 per these two factors in the human dietary. This appears to cent; free fatty acid, 0.97 per cent; and crude fiber, 0.50 warrant further investigations as to the vitamin content of per cent. canned tuna. Tuna meal, which has been used primarily as a source of protein in animal and poultry rations, should also be VITAMIXA COXTENT The general technic of Sherman and Munsell (11) was given consideration as an effective source of both vitamins A D. employed in determining the vitamin A content of tuna meal, with the exception that vitamin D was supplied by LITERATURE CITED irradiating a n adequate quantity of the yeast in the basal Daniels and McCollum, Bur. Fisheries, Investigation Rept. I , ration. No. 2 (1932). Donaldson, “ T h e R a t , ” 2nd ed., Wistar Institute, 1924. Table I contains the average rat-growth records made by Holmes, J. Am. Pharm. Assoc., 20, 588 (1931). groups of animals receiving different daily amounts of the New Zealand Inst., 57, 879 (1926). Malcolm, Trans. PTOC. tuna meal, on the basis of a 7-day week, for 8 weeks. Ibid., 58, 167 (1926). TABLEI. AVERAGE GROWTHO F RATS RECEIVINGGR.4DED AMOUNTS OF TUNAMEAL DAILY Tux4 MEAL SUPPLEMENT RATS
AVERAGE WEIGHT Start of meal supplement
28-29 days
Drams
Drams
AVERAGE AVERAQE WEEKLY FOOD GAIN EATEN Grams Grams 12.7 563 11.1 632 10.9 657
4 41 100 12 41 118 16 44 128 0 12‘“ 47 142 a,Control animals: average weight at, death, 112 grams: average survival period, 23 days. These average gains in weight are represented by curves in Figure 1. 1.0 0.1 0.075
1
..
Oliver’s Brand, American Fisheries’Company, San Diego, Calif.
...
Manning, Bur. Fisheries, Fisheries Doc. 1090, 371 (1930). Am. SOC.Animal Production, 1927, Maynard and Miller, PTOC. 226. McFarlane, Graham, and Richardson, Biochem. J., 25, 358 (1931). Selson and Manning, I N D .ENQ. CHEX.,22, 1361 (1930). Scheunert, Resohke, and Schakir, 2. Tierzucht. Zuchtungsbiol. Tierernuhr., 15, 273 (1929). Sherman and hIunsell, J . Am. Chem. SOC.,47, 1639 (1925). EXG.CHEM.,25, 563 (1933). Truesdail and Culbertson, IND. RECEIVED November 8, 1932. Presented before the joint meeting of the Divisions of Agricultural and Food and of Biological Chemistry a t the 84th Meeting of the American Chemical Society, Denver, Colo., Auguat 22 to 26, 1932.
