Chemical studies on the Freshness of \iVhale l\lleat. II.
On comparison between whale meat and beef
on deteioration of freshness and autolysis.

Tadashi Nakai
In the previous paper (this bulletin, p. 17) the author reported thatthe freshness of whale meat can be evaluted by determining the volatilebasic nitrogen, i. e. ammonia nitrogen, or formol titrating nitrogen, as
various workers have done on other kinds of meat. Although it cannot be
said that the freshness of whale meat and that of other kinds of meat canbe compared by the absolute quantity of these nitrogen in a definite quantityof meat, yet taking into consideration the fact that the volatile basic substances and the formol titrating sudstances are products in every stage ofdeterioration of freshness or putrefaction, the author believes that a comparison of the readiness of deteriorution of freshness or putrefaction in whaleand other meat can be made by comparing the condition of increase in theamounts of the two kinds of nitrogen with lapse of time. For this purpose,
Fig. 1.
a piece of flesh of sei-whale (I waPH mg,shi-kujira; Balaenoptera borealis).9.0 900
and a piece of beef were stoodat room temperature in summer
and changes in the amount ofvofatile basic nitrogen, formoltitrating nitrogen and a change inpH value with lapse of time weredetermined. Results obtained arelisted in Table I and summarized in Fig. 1. As shown in Fig.
1, the amounts of these nitrogen,especially that of volatile basic
nitrogen, makes a greater increase during the course of the•whale meatx beefvolatile basic N.
deterioration of freshness in seiformol titrating N.
whale than in beef. Formal titra-·-·--·- pH28

Tadashi Nakaiting nitrogen in sei-whale meat was far greater than beef in absolute quantity
but the rate of increase in beef was slightly above that of sei-whale meat.
Increase of pH value was more rapid in sei-whale meat than in beef.
This may be due to a large production of volatile basic substances insei-whale meat.
Fig. 2
From these results, it can be said thatmg.
the freshness of sei-whale meat is more
140,,,,"""x
readily deteriorated than that of beef, pro120
vided that the kind of bacteria attacking---·--------~/-- ..
,100 _. . . -.,,...

--,,.,, . .

meat is not brought into question.
,,/,/x'
At the same time, autolysis which plays 80/,'a part in the deterioration of freshness incompany with bacterial action was compared in both meat. The results obtained
are shown in Table II and summarized inFig. 2.
048_1:w hrs.
Increase in the amount of nitrogen• whale meatx beefresulting frorri autolysis was found to bevolatile basic N.
formol titrating N.
very small compared to that found whenin united action with bacteria which mentioned above. Increase of bothkinds of nitrogen was found to be greater in beef than in sei-whale meat
during the process of autolysis.

::(/t::

Experimentala)

Deterioration of freshness at room temperature.
A piece of sei-whale meat preserved in an ice chamber for three days

after dissection and a piece of beef stored in a refrigerator by a butcher
were used as materials in the present experiments.
Each material was divided about equally into several Petri' dishes andlet stood at room temperature in August. Every 24 hrs. the content of adish for each material was minced and thoroughly pounded in a mortar.
4 g of each meat thus treated was weighed into a test-tube and 6 cc ofabsolute alcoholic 0.01 N H2S04 was added to prevent subsequent decay.
Samples thus obtained were put to the determination of volatile basic nitrogen and formol titrating nitrogen as mentioned in the previous report.
The determination of pH value was made as follows : 2 g of mincedChemical Studies on the Freshness of Whale Meat. II.

29material was pounded in a mortar with 10 cc of distilled water, allowed tostand for a short time, and the pH value of the supernatant liquid wasdetermined with Toyo pH test-paper (methyl red and phenol red) and its
standard table of change of colour which had been corrected with buffer.
Results obtained were as follows :Table I.

IFormol tittating N*

Volatile basic N*Time (hrs.) ! S . he1-w ae1
Beef
meat
0
24
48
72

16.5
128493
776

I

21.3
64.4
250
392i

pHII

Sei-whale
meatI

102
211616521233451i

IIIIII(*Beefi Sei-whale
meat

5.9
6.5
7.4
7.9

IBeef
6.0
6.2
7.1
7.1

in mg/100 g)b) Autolysis.
Materials used were the same as in a).
Each material was minced, thoroughly pounded in a mortar, and several
samples of 2 g each were placed in glass bottles.
These bottles were corked after the addition of 18 cc each of distilledwater saturated with chloroform, and allowed to stand at room temperature.
At start and after 48 and 120 hrs., 30 cc each of absolute alcoholic 0.01 N
HsS04 were added in each bottle to prevent subsequent progress of autolysis.
·Samples obtained in this manner were put to the determination of the twokinds of nitrogen.
Formol titrating nitrogen.- The sample was transferred to a beaker,
heated in a gently boiling water bath for about 15 min., and the supernatantclear liquid was filtered into an Erlenmeyer's flask. 10 cc of distilled water
was added to the meat residue in the beaker, heated in a water bath for
5 min., and filtered as before. After the washing of the precipitate wasrepeated twice more, 1 cc of 20 % sulfosalic acid was added to the combined filtrate and washings in the flask, The mixture was allowed to standovernight, and filtered into a 50 cc volumetric flask. The residue on thefilter was washed, and the combined filtrate and washings were diluted tothe marking. 20 cc of the solution thus obtained was put to the formaltitration.

Volatile basic nitrogen.- 20 cc of the solution obtained above wassubjected to the aeration method as described in the previous report.

Tadashi Nakai

30

Results obtained were as follows :Table II,
Volatile basic N*

Formol titrating N*

Time (Hrs.)
048120Sei-whale meatBeefSei-whale meat

Beef

22.8
25.4
28.l

23.9
32.0
42.0

10111812452.l
82.2
138(* in mg/100 g)
In concluding this report, the author wishes to express his deepest
gratitude to Dr. Tsutomu Maruyama for his kind guidance throughout theexperiment and to Prof. Dr. Shichiro Akiya for his kind advices given
during the work. Further, the author wishes to thank Mr. T. Tawara andMr. R. Fukazaaw who helped him in the exi:eriment, and to Mr. R. Nag2ura and Mr. T. Nishihara for their assistance in providing the opportunitiesfor obtaining materials for the present experiment.

(Feb. 10, 1948)