On an Attempt to Preserve Whale Meat Freshness with
5-Nitrofurfuriden Aminoguanidine from Decay

BY
SHICHIRO AKIYA, OTOMATSU HOSHINO,andN OBUO MOTOHASHI(Receiver June 15, 1952)

With latest improvement of food situation the demand for whale
meat is decreasing in Japan. It seems chiefly due to the easy decay offreshness of whale meat that this tend is seen, in spite of high nutritive
value of it which is practically equal to that of general edible meats.
Freshness decay is inevitable in coastal whaling, particularly insummer, for the reasons of air injection into whale body to float it
after death and of tugging whales to land stations for a considerably
long time. The purpose of our present study is to preserve whale
meat freshness from decay by injection and .circulation of a germicide
which is attached at the head of the harpoon. As a germicide, 5nitrofurfuriden aminoguanidine hydrochloride (Guanofracin in commercialname, abbreviated G.F. in this report), one of nitrofuran group, which
was lately discovered, was adopted for our experiment, from the following view points: 1. mighty sterilizing power 2. harmless as foodand 3. very soluble in water etc. This is yellow powder, soluble inabout 100 parts of cold water and in about 30 parts of warm water(60°C). Although sterilizing power depends upon species of bacteria,
G.F. is thought sufficiently effective at the concentration of 1/10,000100,000 for our purpose. If whales caught in the adjacent waters toJapan are assumed to be 20 tons in average body weight and quantityof their blood is assumed to be 1/13 of body weight, viz., 1.5 tons,
about 15 gr. of G.F. would be necessary for keeping G.F. at a concentration of 1/100,000 in such a quantity of blood. On the basis of thisassumption 10-20 gr. of G.F. per whale was used in the present experiments. The experiments were carried on at Akkeshi, Hokkaido in
September 1950 and in August 1951 and at Ayukawa, Miyagi prefecture,in November 1950. Successful injection on sei whales and sperm whales
could be at Akkeshi but no successful results could be obtained at Ayukawa due to bad weather and end of the whaling season.
In order to compare the freshness change between G.F. injectedwhales and a control whale, pH of aqueous extract of their meat andG.F. concentration in their blood were measured. In 1951, a -·glass

s. AKIYA, 6. HOSHINO and N. MOTOHASHi

24

Table 1.

Results of Experiments in 1950.
I EstimatedG.F.
attached i concentrationof G.F. inharpoon
bloodISp.

SexI

No. 1

Sperm Female

4023.00 hrs.

No. 2

11Male3722.00

IINo. 3

IIII

3822.00

IINo. 4Sei

II4424.00

IINo. 5IIII4324.00

II13 g/340 cc
II physiologicalsalt solution
5g/300cc-"
water
15g/300 cc
water
20 g/300 cc
water

hit

0.5mg%

IItracepierced
II2;3 of G.F. quantity was lost due to the shock of the failed first harpooning.

-><Table 2.

N o.

S P·No.
6.
Se 1

Results ofDate of 1 Lapse of I Water!'!
i GF
B 0 dY Da t e 0 f
treattimetern1Locality 1 • •I
le~gthcaptured
nt
betweenerat[Wea-1ofi' attachS exm! meP. ther Ied
f t D
T'T'capture and ture I
I. capture'lhar p 00n___::__ ~ ime ~ ime fiensing
1ID

Maleoc[Aug.
IAug.
44 1 7 6.30
8 14.00--1--1-131.30hrs.

"I[SSE135°[ not;;0.31 B Akkeshi[ used--1-1'

1No.
7IIII

44I 10 12.00[1 10I

N3.

IIII

21.30

1122.0III

18.oofi11r:;:1-e47

Cl,

SE/S

I

uso I usedII

1_ _ [II10.00

16.00

II22.0 r--------------1--N~.

11-----

I
48 I

9.30

15 10.001 16

10.30

14.30

11----

21.0 jI_ __c I ~~7~ i! SSE
F : 850--1::II/1I1iNo.
10IIMale44fl11.00

II

1.00

14,00

IIIISSE21.0 I F i 350

II-------1--1~~· Sperm !:1-e
No12.

- __,______,___ l__ !____ I
I
isE1; E i - 2
19 16.ooi 20 15.00 23.00 II
23.51 B I ll0° i
II37i-----------1-I**

IIII37I'III

14 • oor·II'
I___ \__16 • 00

26.00 ,.,rI

1/ 2 E:
24 • O II B i/ SE
1050
IIIThe 2nd harpoon which had seemed misfired, was found fired when the whale25Attempt to Preserve Whale Meat Freshness

electrode pH meter which was carried as far as to Akkeshi was used,
as well as pH test paper.
By the results of qualitative and quantitative analysis applied tofracin group, it was found that G.F. turns reddish orange with caustic
alkali like some of 5-nitrofran derivatives. On the basis of the resultof the preliminary test, therefore, colorimetric determination of G.F.
in whale blood was made. In the same concentration, colorimetric valueof G.F. in blood was considerably smaller than that of G.F. in water.
This may be due to the loss in the treatment to remove protein fromblood. Injected G.F. presented in blood at an extremely small concentration, so sample had to be concentrated if necessary.
Table 1 shows the results of the five cases at Akkeshi in 1950 (2sei whales and 3 sperm whales). Among them, one was for control andthe successful G.F. injection was seen only in 2 cases (on sperm whales)
Experiments in 1951.
iAmountl Estimated\of G.F. concentra·injected tion of G.F.
in whale\ lstG.F. \ 2ndG.F.
3rdG.F.
toblood1harpoon amount1harpoon amountharpoon amount whaleI.

IINote!

IIIhit20 grhit

0hit

20 gr

I!

"

.
0 [misfired I 20
" pierced".
d0 II pierce

20

I0 I

15""

I"

I-·

I

4.0gr

0000ihit20"

I 20 gr

0.4mg%trace

"

2020

pierced20

0was flensed.

G .F. sufficiently
circulated during
10 or so minutes
l.2mg% between 3rd harpooning and deathof the whale.

II0G.F. did not circulated so well
due to a shortinterval between
2nd harpooning
and death of thewhale.
G.F. concentration in blood wasvery small due toinstant death ofthe whale.

26

S. AKIYA, 0. HoSHiNO and N. MoTOB'.ASHt

and the rest were failed due to misfire or piercing of harpoon andinstant death of whale.
Table 2 shows the results of the seven cases at Akkeshi in 1951
(5 sei whales and 2 sperm whales). Among them, one was for control
and successful G.F. injection was seen in 2 cases (sei whales) and therest was not successful. pH curves for each experiment in Tables 1and 2 are shown in Figs. 1-4. Fig. 1 indicates pH values which weremeasured with pH test paper (Toyo Filter Paper Co. Ltd., made) on acontrol whale and two G.F. injected whales in 1950. Figs. 2-4 indicate
those which were measured with a glass electrode pH meter on a control
whale and two G.F. injected whales in 1951. Time when the whale
was completely caught is shown by 0 and the oblique lined part covers
time when the whale was being flensed on the land stations. After
flensing was finished, the sample meat was kept at 30°C in the thermostat.
In 1950, both of the two successfully injected whales were sperm
whales. The whale No. 1 was injected 13 gr. of G.F., which was
acknowledged to preserve freshness a little from decay on the basis of
pH curve and odor and appearance of meat. The concentration of G.F.
in blood was at a level of 1/200,000. The remarkable difference in pH
curve was not seen between the whale No. 2 and the control whale,because 2/3 parts of G.F. prepared were lost due to the shock of thefailed first harpooning and the rest was injected with the second harpoon. In this case, a trace of G.F. was only seen in blood.
In 1951 successfully injected whales were both sei whales and thewhale No. 7 was injected twice 20 gr. of G.F. each, 40 gr. in total,
No 1 Sperm wl1ales

No3

9.

6No 2'o (control)~ 6-4-~ 6·215;;

48

Fig. 1.

54--50-~66--=12

Attempt to Preserve Whale Meat F'reshness

21

which indicated the concentration of G.F. in blood enough to restrain
the growth of bacteria. pH curve in this case showed that G.F. injection could preserve freshness of meat from decay. The whale No.
10 was injected 20 gr. of G.F. but died immediately after hit, so theconcentration of G.F. in blood was less than 1/200,000, which seemed
to preserve freshness from decay to some extent.
No. 77·80

Se1 whnles'o G.F 40g

o G. F none

No. 6

7·60

'7·40

no7-006·60,lO'c

6-60.]O'c.., l>-40
: 620
G>

~ 600~ 580i;-*560

Fig.

2.

No. 9 Sei whales ~ G.F. none
No. 10 Sei whales ~ G.F. 20 g
7.60
7,40.
7 201.00
680
6 60~ 640

§ 6-20g~~6.0o~ 5 80!"',0IZ

18243036-Hours

Fig. 3.

42485460

72

s. AKi.YA:, 0; HosntNo and N. MOTOHA:SHI

288 20.

~. No

II8·00f

No

12 Sperm wha!c:, -1

Sperm whcle6<;' G f 20g'
G. F none

7·80 ~

760 ~ .

I

74017 20 ~

700r
680
660r

r

~ 640 l~ 6 201~No Ii

I 600t! 5·80 Il GO [__--;6c--~1~2-----=1s-~24-L-L~J~O~-----:i7-43---5.i
5~HoursFig.

606672

4.

As these experiments depend much upon the external conditions,such as sea condition and whaling technique etc., we could not obtain
only a few successful results. Nevertheless G.F. injected whale showedslow spoilage and injected G.F. was completely circulated although it
was diluted to less than calculated value in concentration with permeatedsea water and oozed humours in the course of tugging.
The conclusion might be therefore that G. F. can presserve freshness of whale meat from decay to some extent, if more than 20-40 gr.
of G. F. are injected to a suitable point and G. F. is absorbed over 1/5100,000 in concentration in blood.
We wish . to express our sincere thanks to Mr. T. Nakai, Whales
Research Institute for kind advice, to Toyama Chemical Co. Ltd., for
supply of reagent, to Taiyo Fishing Co. Ltd., for various facilities inexperiments and to Mr._ T. Niwaguchi for cooperation. We owed apart of expenses to the Experimental Research Fund of the Ministryof Education, for which we wish to express our gratitude.
Experimental part

1. Attachment of G. F.
A grenade of the whaling harpoon is cylindrical and has a space ofabout 900 cc in it. - An explosive compound and a fuse occupy most of
the space, leaving about 300 cc for G. F. attachment. So, a tin or aAttempt to Preserve Whale Me::it F'rmhness

29

gum made ice bag, in which 15-20 gr of G. F. and about 300 cc of wateror physiological salt solution were mixed, was prepared.
In the beginning, the ice bag was used as a container, which wasbroken due to the shock of discharge and wet powder led often to misfire. In the later stage of the . experiments, therefore, the tin wasused instead of it. . As any of the authors did not get aboard thecatcher boat in 1950, detailed information on harpoon hitting was regretably not obtained. In 1951, they could get a chance to observe
hitting of the harpoon on whales by aboarding the catcher boat.
2.

Measurement of pH 1)

Some 5 gr. blocks of meat taken from dorsal part of the whale bypossible germ free operation were left at 30°C in the sterilized Petri's
scale in the thermostat.
At intervals of a certain hours they were ground well with qualtz
sand in the mortar. To those which were placed in a 150-200 cc flask,
100 cc of distilled water was added and stirred well for ten minutes.
After standing, pH of the supernatant was measured with pH testpaper (Toyo Filter Paper Co. Ltd. made) and with the glass electrode
pH meter.
3.

Measurement of G. F. concentration in blood

As the blood of the whale was diluted with sea water and humours,a certain quantity of comparatively dense blood was prefered, and after
acidifying it with acetic acid, protein in it was coagulated by boiling.
The filtrate was condensed again if necessary and cooled and filtered toremove the precipitate. G. F. concentration of this filtrate after alkalizing it with caustic alkali, were determined (Presence of G. F. turns
the color to yellowish orange) with Duboscq colorimeter in 1950 andwith Beckmann's spectrophotometer at 400-410 mµ in 1951 (cf. Akiya
and Sawamura: reported separately).
For control a fundamental experiment was preliminary made with
G. F. aqueous solution.
Summary

An attempt to preserve the .whale meat freshness from decay by
circulation of G.F. in whale blood which was attached in the head of
the whaling harpoon, before its death, was tried in 1950 and 1951 atAkkeshi, Hokkaido. Successful injection was made on 2 sperm whalesand 2 sei whales. The results of the measurement of pH of the meats. AKIYA, o. HOSHINO and N. MOTOHASHI

30

extract from them and concentration of G. F. in their blood showedthat G. F. injected whales could preserve their freshness from decay,
when compared with a control whale.
Literature1) Shichiro Akiya:

Japanese Jour. of Legal Medicine 4 187, (1950).

(Pharmaceutical Department, the Faculty of Medicine, University of Tokyo)