:Molecular Distillation of Fin \ Vhale Liver oil
Aiji Kaneko
Introduction.
The author carried on molecular distillation of fin whale liver oil,examined the distillate with special emphasis on vitamin A and tried
to determine its characteristics. That is, it has been pointed out that
although whale liver oil shows a vitamin A color reaction it has little
biological effect. Nakamiya1) explained it with absorption spectrum andhas reported that the peak has moved from 328 m,u. Furthermore, N. D.
Embree~) reports that the peak of absorption spectrum exist at four places
and called it cyclized vitamin A. It has already been discovered that
this does not have any effect in accelerating growth. The absorption
spectra of these are very similar to those of vitamin A itself, and anotherimportant fact is that, at 200cC, vitamin A is transformed into cyclised
vitamin A type due to the presence of an unsaturated acid such as oleic
acid. Therefore, it is assumed that vitamin A is cyclized by unsaturated
acid in the liver oil and thus lose its growth effect. A substance called
kitol was discovered recently (3), kitol, was obtained from the unsaponifiable
matter in whale liver oil by molecular distillation and crystalyzing wassuccessful (4) but its structure was not determined, although experimentally, it is just two times that of vitamin A. It ·resembles carotene verymuch and is ColLio02, the peak of absorption being 286 mµ.
The kitol
also does not possess growth accelerating effect but its color reaction isthe same as that of vitamin A.
In order to solve these problems, experiment was carried on as an attempt to discover cyclized viatmin A other than vitamin A coloring substancewas concentrated by molecular distillation, following which, attempts weremade to obtain crystals of these, but as explained later, obtaining pure crys.
tals was not successful.
No. 1. Molecular distillation of fin whale liver oil.
As explained in the introduction, molecular distillation of liver oil wascarried on, but distillation of the sample was carried on as it is, without
pre-treatment. That is, the object was to detect the range through which
vitamin A will distil and, at the same time, to find out to what extent

IIMolecular distillation of Finback whale Liver oil47

molecular distillation can be used as a possible means of refining oils andfats industrially.
Molecular distillation was carried on with sai;iples which was not deodorized or neutralized in order to determine its deodorizing and neutralizing
capacity. It was intended to crystalyze the concentrated vitamin A distillate
by the Hamano Method4 l.
1. Sample.
Sample used was Antarctic fin whale liver oil obtained from fin whale
caught by the Taiyo Fishery Co., Ltd., in 1946 and its chemical constantsare as follows :Appearance (15°C) Yellowish white, semi-solid
Refractive Index (18°C) 1.4950
178.0
Saponification Value
Vitamin A (C. L. O. U.) 50
Iodine Value (Wijs)
141.0
Unsaponifiable matter
1.7%
Also, the vitamin A determination during the experiment was made by
the Oshima method6 ).
2. Apparatus.
Molecular distillation apparatus used by the author was of all-glass typeand its capacity is 1.5 kg., the area of the evaporation surface is about
200 cm\ the distance to the condensation surface 5 mm and speed of circulation is 10 c.c. per minute. Pressure in the apparatus was determined byGeisler tube and was about 10-~mm Hg.
For heating, parafin oil was placed in the cylinder of the evaporation
surface and heated electrically, and the distilling temperature was the temperature of the bath so it is somewhat higher than the true temperatureof the oil.
Experimental result and observation.
600 g of the liver oil sample was charged into the above apparatus,
degasified at room temperatures, and further degasified after about twohours while carrying on circulation.
The circulation was carried on while working the diffusion pump andAs
degasification continued, temperature raised gradually and distilled.
the liver oil sample was not saponified, the distillation temperature wasgenerally high and the first distillate began at 220cC. Temperature range
3.

Aiji Kaneko

48

was divided into four parts. Chemical constants of the distillates \Vere as
follows : General Characteristic of distillates of fin whale liver oil bymolecular distillation.
--·- ·---------- ------Distilla- - I - - -·-· - · ·Unsaponi- Ition Tern-' Quantity Appearance
n1S
Add ! Iodine
fiable !Y· A. (C. OrderDistillate 1 peraturej of Distil-,D
Value j Value f matter L. 0. U.) /(°C/10- 2 latel(15°C)
I(%)
mm Hg)'-. 1 - .. -- _I... - ----- ---- ----- - - - 1
I (g) (%) :Yellowish whiSample
3.050
1.4950
141.0
1.7
++
600
I te semi-solid!
+++(1)
-220
3 0.5
43.6
133
1.5180124.5
5.8
R<d liquid+++!
Goldencolor('.;)
220-260
32 5 3
29.0
115.0
800
1.51686.1+++·liquid
1 Yello"'. w~ite_(3)260-29064 102.1
97.5
154
2.8
1.4995
1+++
71 sem1-sohd
Yellowwhite(4)280-300
95 15 81.5
94.5
1.48959.8
50 I' -'-, -'-,
semi-solidLight brown 1.4930
Residue
395
1.1
130.7
1.4
3 II +[ liquidI
I-- -------------

I.. ·- -II'-- ... -i

I· I

In the above table, in regards to odor, it was fortunate that the original
sample had considerable odor and so it was used for determining the odorof each distillate tested on eight healthy girls. Needless to say, it is difficult to indicate odor quantitatively and the result is based on general smelling senes.
Odor of residue oil was very slight, acid value low, little p~lymerizationand it was observed that is was suitable for edible use.
Vitamin A was concentrated into this fraction. Therefore, if liver oil
which has been deodorized by pre-treatment was used, it can be used asvitamin A for addition in margarine.
A greater part of the free fatty acid was distilled over at 22o~c.
4. Summary.
The following conclusion was drawn from the above molecular distillation, from the point of view of refining oils and fats :( 1 ) Sample should be completely dehydrated and degasified.
( 2 ) In regards to apparatus, the pump should be powerfull and circulating apparatus be absolutely secure.
( 3 ) Neutralization is almost complete by molecular distillation.
( 4) It is possible to obtain concentrated solution of vitamin A 16 times
that of the sample, and if it has been deodorized by pre-treatment, it
is possible to use it for addition to margarine.
( 5 ) Odor will accumulate to the same fraction as vitamin A but since itwill distill over in the second fraction after neutralization, it is believed

Molecular distillation of Finback whale Liver oil49

that the molecular weight is somewhat larger than the free acid.
( 6 ) There is little polymerization of the residue oil so it is suiable asedible oil.
No. 2. Derivation vitamin A crystals.
Attempts were made to derive crystals from the vitamin A distillate
concentrated by the method described in the previous report, by the· Hamano
Method5\ but pure crystals could not be obtained because the quantityof the starting sample was too small. In Hamano Method, anhydrous maleic
acid is made to condense directly on vitamin A ester and crystals obtained.
Next it is saponified and the acid portion of its ester is also determined.
30 g of the above concentrated liver oil is dissolved in 100 g of anhydrous benzol and anhydrous maleic acid is dissolved at the same time, carbon
dioxide gas is sealed into the tube and made to react by heating at l00°C.
After 48 hours, Carr-Price reaction is absolutely absent so it is assumed
that condensation was completed at this point. In the inner surface ofthe sealed tube, a small quantity of white, amorphous crystals app=ared.
After the reaction, benzol was distilled off at reduced pressure, theviscous liquid poured into 3 liters of anhydrous p=troleum ether and allowed
to crystalize. After standing for one day, about 0.48 g of white, powderlike
crystals, were obtained at the bottom of the container. The melting "pointof this crystal was 189°C and since recrystalization could not be obtained
at 220cC, as referred to in reference (5) it was continued to the next procedure. That is 0.48 g of the crystal was saponified with 10 c.c. of 0.1 N
KOH.C~H"OH and acidified with HCL At this stage, only oily substance wasfreed and crystalline substance could not be obtained. This oily substancewas extracted with anhydrous petroleum ether and the soluble part was awhite crystal with a melting point of 37"C. This is the acid portion ofvitamin A, but since the quantity of the sample was too small to confirm
it, it was discontinued.
The oily substance insoluble in petroleum ether was recrytalized threetimes with benzol-ether, but the melting points were not constant. That is,
it was only observed that it began to melt at l60°C, become a brownviscous substance ill the vicinity of 220°C and finished melting into reddish
brown at 280°C. This is very similar so the behavior of anhydrous maleic
acid mixture of carotene referred to in Nakamiya's thesis7> observationof the experimental result.

50Aili Kaneko

( 1)
( 2)

The derivation of vitamin A crystals was by Hamano's method.
Anhydrous maleic acid additive was obtained, but on acidifying withHCl, only an oily substance was produced and no crystals were obtained.
( 3 ) The melting point of the sbustance, assumed to be the petroleum
ether soluble acid component, was 37°C.
( 4 ) The petroleum ether soluble portion was recrystalized with C6H.·(C2H5)20 but the melting point was not clear and it was observed that'the behavior resembled that of anhydrous maleic acid mixture ofcarotene.
As indicated above, the research on crystal derivation by anhydrous
maleic acid mixture· was unsuccessful, but it is concluded that besides vitamin A, a higher molecular substance resembling carotene, is also present inwhale liver oil. Because of this, it was thought that it did not crystalize out
but only formed an oily substance and also, the melting point was notclear. At present other methods for determining this is being studied.
The above reserch was carried on in the chemistry laboratory of theTokyo University of Literature and Science and gratitude is expressed to Dr.
Ishikawa, Dr. Mitsuwa and Omote, master of science, for their instructioJ,1.
Also, . deep appreciation is expressed to the Taiyo Fishery Co., Ltd., andSakuma, Manager of plant, for supplying the sample.
Reference
1) Nakamiya, Kojima, Kawakami:

Scie. Pap. Inst. Phys. Chem. Res. 20 (1941) 576-528,2) Embree, N. D.: J. Biol. Chem. 128 (1939) 187, Gilman:

Biochem. J. 32 (1938) 1252.

3) Embree, N. D. Shantz E. M.: J. A 0. C. 65 (1943) 910-13.
4) Claugh; E. B. Kashev, H. N., Roberson, C. D. Baxter, J. K.:
5)

Hamano : I. P. C.R. 549 (1934) 85.

Science 105 (1947) 436.

'6) Oshima : J. Jap. Agri. Chem. Soc. 15 (1939) 53-62.
7) Nakamiya, Jiro: Scie. Pap. Inst. Phys. Chem. Res. 15 (1939) 286.