C

FISHERIES AND MARINE SERVICE

Translation Series No. 2971

The protection of marine products from deterioration due to the oil oxidation - XIV. Application of citrus fruit

terpenes to fish products

by Kenzo Toyama, Koji Anzai, and Keizo Kikuchi

Original title: Suisanbutauno Aburayake Boshi ni kansuru Kenkyu-XIV Kankitsurui terupen no suisankako eno riyo ni tsuite

From: Nihon Suisangakukai shi (Bulletin of the Japanese Society of Scientific Fisheries), 39(8) : 891-898, 1973

Translated by the Translation Bureau( HH/PS) Multilingual Services Division

Department of the Secretary of State of Canada

Department of the Environment Fisheries and Marine Service

Halifax, Laboratory Halifax, N.S.

1974

17 pages typescript

Fee e9`71 SECRÉTARIAT D'ÉTAT

BUREAU DES TRADUCTIONS

I 31

DEPARTMENT OF THE SECRETARY OF STATE

TRANSLATION BUREAU

MULTILINGUAL SERVICES -vààe DIVISION DES SERVICES CANADA

INTO - EN TRANSLATED FROM - TRADUCTION DE

English Japanese

DEMANDÉ PAR

MAR 1 1 1974 Allan T. Reid PERSON REQUESTING ------- ----

DIVISION MULTILINGUES

AUTFIOR - AUTEUR

Kenzo Toyama, Koji Anzai and Keizo Kikuchi

TITLE IN ENGLISH - TITRE ANGLAIS

Protection of Marine Products from Deterioration due to Oil Oxidation-XIV

Application of citrus fruit terpenes to fish products

TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANG2RE (TRANSCRIRE EN CARACTÈRES ROMAINS)

Suisanbutauno Aburayake Boshi ni kansuru Kenkyu-XIV Kankitsurui terupen no

suisankako eno riyo ni tsuite REFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE ,FOREIGN CHARACTERS.

RÉFÉRENCE EN LANGUE ÉTRANGÉRE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÈRES ROMAINS. •

Nihon Suisangakukai shi

REFERENCE IN ENGLISH - RÉFÉRENCE EN ANGLAIS

Bulletin of the Japanese Society of Scientific Fisheries

PUBLISHER - ÉDITEUR DATE OF PUBLICATION DATE DE PUBLICATION

PAGE NUMBERS IN ORIGINAL NUMÉROS DES PAGES DANS

L'ORIGINAL

891-898 VOLUME

YEAR ANNE.E

ISSUE NO. NUMÉRO PLACE OF PUBLICATION

LIEU DE PUBLICATION

8 39 1973

TRANSLATION BUREAU NO. --- - NOTRE DOSSIER NCI

NUMBER OF TYPED PAGES NOMBRE DE PAGES

DACTYLOGRAPHIÉES

17

165673 REQUESTING DEPARTMENT MINISTÉRE-CLIENT Environment

BRANCH OR DIVISION Fisheries Service TRANSLATOR (IN(TIALS)

• DIRECTION OU DIVISION TRADUCTEUR (INITIALES) 1TH /P

YOUR NUMBER VOTRE DOSSIER N 0

05-02-74 DATE DE LA DEMANDE

SOS•200•10.6 (REV. 2/68) 71330-21-029 4533 3

UNEDITED TRANSIATI Far information nr,I -

TRADUCTION NON (VISE Information seulement DATE OF REQUEST

£19 . DEPARTMENT OF THE SECRETARY OF STATE

•-• TRANSLATION BUREAU

MULTILINGUAL SERVICES

DIVISION

SECRÉTARIAT D'ÉTAT

BUREAU DES TRADUCTIONS

DIVISION DES SERVICES

MULTILINGUES

tu

tr. 141, Ce 0 " E , o •c

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CLIENT'S NO. DEPARTMENT DI vIS I ON/BRANCH CITY

NO DU CLIENT MINISTÉRE DIVISION/DIRECTION VILLE

Environment Fisheries Service Ottawa, Ont.

BUREAU NO. LANGUAGE TRANSLATOR (INITIALS)

NO DU BUREAU LANGUE TRADUCTEUR (INITIALES)

165673 Japanese HH / PS MAR 11 1974

Bulletin of the Japanese Society, of

Scientific Fisheries

Vol. 39, No. 8, 1973

PROTECTION OF MARINE PRODUCTS FROM DETERIORATION DUE

TO OIL OXIDATION - XIV

APPLICATION OF CTTRUS FRUIT TERPFNES TO FISH PRODUCTS

(Received April 19, 1973)

Kenzo TOYAMA,* EDii ANZAI,** and KEizo KIKUCHI***

Citrus fruit oils, which contain more than 90% terpents, have been known . to prevent

flavor reversion in soybean oil and spoilage in fish sausaae. The authors attempted the

application of these substances to the protection of fish products from deterioration due to

oil oxidation while noting at the same time, the effect cf added citrus flavor on fish products.

Six citrus oils clifferina in the raw citrus source and the method of preparation were

tested for their antioxidative effect on fish oil. Thouah hardly effective when tested under

such severe conditions as those of the Active •Oxyzen Method, they were fairly effective

under such milder test conditions as those of the oven test at 37'C and the storage test at

room temperature. Aniong these citrus oils, lemon terpene was found lo be most practical as it is less ex-

pensive as ‘vell as satisfactorily effective. When it was applied to salted dried saury and

Shiokara, a product of half-autolysed skip jack gut with 30% salt, the lemon flavor im-

proved the impression of the products, although the antioxidative effect was not as significant

as that of BHA.

*Tokyo Univ. Fish., Konan 4, Minato-ku, Tokyo,Japan **Kyokuto Kagaku Sangyo Co., Jingumae 1, Shibuya -ky, Tokyo, Japan ***Taiyo Sangyo Co., Nishikata kamite, Koshigaya city, Saitama, Japan.

SOS-200-10-31

R,r1.= I noqq.7

to

2.

Synthetic antioxidants, which have been used widely to prevent

deterioration from oxidation of oils in fish products, as well as other

food additives have recently been considered for re-examination with

respect to their toxicity. Consequently, the replacement of those

synthetic antioxidants by natural products presenting relatively little

danger of poisoning has received increased attention. In the previous

reportl) Toyoma et al..examined the applicability of natural tocopherol

mixtures. The efficacy of the substance was higher than expected. It

was also recognized that when it was used at relatively higher concen-

trations, one obtained almost the same efficacy as with synthetic pre-

servatives. But they stated that the price was relatively high and this

factor created some difficulties in the actual application.

Generally, the flavor of citrus fruits is favored by Japanese

people. To mask fishy odors, juice and peels of citrus,fruits are often

used. When lemon peels and juice were added to soybean oil, it was

noticed2) not only that the flavor was improved but also that the oxida-

tion of unsaturated fatty acid was contained as well. In this case,

in addition to improving the smell, terpenes such as limonene and citral

are claimed to contribute to the prevention of oxidation. Also, there

is antiseptic effect in orange oil and d-limonene3'4) and they are

proven to be effective as preservatives for fish sausages.5). This

action is assumed to be the result of the oxidative products of d-limonene.

In the present experiment, we applied citrus fruits oil and p.892

its major component terpene to processed fish products in the hope that

they might prevent oxidation as well as add flavor, and we decided to

evaluate their potential uses.

Since there were only few reports on the antioxidant effects of

I

citrus fruits oils and terpenes, this éffect of these substances was

examined first with respect to fish oil. It was found out that when the

environmental conditions were relatively mild, some terpenes had a definite

efficacy. Consequently, their applications to dried salted saury and

to other fish.product were examined. The feasibility was recognized

for practical application and the results are summarized as follows.

EXPERIMENT

Refined citrus fruits oil and terpene samples:

Refined citrus fruits oils and terpenes used in this experiment

are all products from the Soda Spice Co. Six kinds different by their

raw materials and by their extraction methods, were used. The names

and the composition are'as follows. Orange (or lemon) oil:

Oil extracted by pressing orange (or lèmon) peels. More than

90% is terpenes, but most is d-limonene. Both oils are similar, but

orange oil contains linallol and lemon oil contains citral: As it con-

tains terpene aldehyde (major aromatic constituent), it is relatively.

expensive. It is a light yellôw liquid having An orange (or lemon) aroma.

Orange (or lemon) oil B:

This is obtained after the orange (or lemon) oil is treated with

60-70% alcohol at room temperature and after the major aromatic con-

stituent (terpene aldehyde) is removed. It is about 96% of the original

oil. Sesquiterpenes and others exist as 'components of terpenes, while they

are not found. in oils obtained by distillation. It is a*light yellow-

ish green transparent iiquid having an orange (or lemon) aroma.

Orange (or lemon) terpenes:

This is a portion obtained by reduo.ed pressure distillation (5--10mip)

4.

of orange (or lemon) oil at 50-600 C. It is about 90% of the original

oil and it contained hardly any aromatic constituents (terpene aldehyde).

It is a colorless and transparent liquid with an orange (or lemon) aroma.

As for the terpene component, the amount of lemonene is extremely large

and contains more monoterpene derivatives.

Antioxidant additive sample:

To compare and confirm the efficacy of the antioxidant virtue

of citrus fruits terpenes, BHA (butyl hydroxyanisole, produced by

Nikki Universal Co., "Sasuten", counaercial name), and which is known

as a typical :synthetic antioxidant in fish products, was used.

Fish oil sample:

Flatfish oil, produced in a fish meal factory ship of the north

sea was refined by treating it with alkali, after adding 5% of active

alumina, and by reduced pressure heating (Hg: lower than 5mm; filtered

at 230oC, after 30m stirring). It is used when the peroxide value

is_lower than 0.51 meq/kg , and the.acid value lower than 0.5.

Method of measuring the efficiency of antioxidant action with respect

to fish oil:

1. AOM (Active Oxygen Method):

The equipment used was constructed according to the study

report6)

given by the experts commission of the American Oil Chemists'

Society. All conditions for determination followed the recommendations

made in the report. The heating temperature at 97.8+0.2°C and the

cleaning air flow at 2.33 ml/sec were strictly observed. Although the

sample oils and terpenes (or BEA) were added to the refined flatfish

oil as alcohol solution, following the method described by MOORE et

*It is expressed by the milligram equivalent of peroxide oxygen in lkg of fat.

5.

in order to minimize the effect of alcohol addition, the concentration

of additives was adjusted so that the amount of additives was kept

at 1 ml per sample. For control, only the same amount of alcohol was

added. According to the RIEMENSCHNEIDER'S method,8)

about 0.1g of

samples from the sanie test tube was taken at one hour intervals, and the

AOM value was determined by the time required by the peroxide value

(measured by simple LEA'S method 9) ) to reach 125 meq/kg*. The protec-

tion factor (antioxidant coefficient) was then obtained by comparing

this value to the value of a control solution to which no terpenes or

BHA had been added.

2. Oven test:

The sample oils were prepared by adding an ether solution which

contained a calculated amount of refined sample oils and terpenes (or

BHA), to refined flatfish oil samples, Using the LEA'S method9) , about

2.2g of prepared sample oils were taken into small cylindrical cups

(lcmxlcm). More than ten from each section were prepared. The change _

of peroxide value9) was studied while storing them in a constant temper- p.893

ature bath at 37+ 1°C. In the case of very volatile additive material,

to avoid the possibility of reaction among substances while storing,10)

ail the samples were stored in a large petri dish, separately by section.

3. Experiment of storing at room temperature.

50 ml of the same sample oil used in the oven test was taken into

a beaker and left at room temperature (average 23°C) avoiding direct sun-

light. The peroxide va1ue9)

and oxidized acid va 1ue11) were determined

at appropriate intervals. To minimize errors by selectiveness, the sample

oil was mixed thoroughly every time when it was taken for determination.

*Refer to the footnote on the previous page.

1

Color

Odor

6.

Prearation of dried salted samples and experimental method:

As in the previous report,1)

using a 16 hour soaking method,

dried salted materials were prepared from fresh frozen saury, Calobis

sira (BREVOORT). After cutting off the heads, the fish bodies were

open flat, and most of the guts and bones were removed and washed by

water. They were soaked for 16 hours in 7% salt water. A calculated amount

of terpenes (or BHA) was dissolved in alcohol. Each 2m1 of it were

added to 11 of previously described salt water, while stirring. This

was used as dispersion solution. After the completion of soaking, the

samples were washed briefly and dried under the sun for two days (total

drying time was 13 hours). They were analyzed when the water content was

about 50% and stored at room temperature. With one portion of the samples,

instead of adding terpenes to the salt solution, a 10% terpene alcohol

solution was gently sprayed on the surface of the samples before they

dried, to evaluate the effect.

The results of the experiment aiming at determining the efficacy

of terpenes on the samples were evaluated in a sensory fashion and by

peroxide value 9) of oil extracted by ether (16 hours of extraction by

Soxhlet method) as done in the previous report. Although the standard for

sensory evaluation is exactly the sanie as in the previous report, it is shown

in Table 1.

Table 1. A conventional rule proposed for expressing the orranoleptically appraised grade

of deterioration as integer* for fish products.

3 4 5 6

Normal Slichtly Yellow . Sornevshat Reddish. Reddish yillow reddish yellow brown

Normal Slightly Rancid Stroncly — — - ranciii rancid ,

** The greater the integer indicating the deterioration grade, the higher the decree of rancidity

and rustinc.

7.

ration of "shiokara"(salted fish guts)and experimental method:

The internal organs of bonito were .cut open. Undigested food

residues were removed and 30% of salt added after washing. After leaving

it.overnight, the sample was prepared by chopping with an electric chopper,

after the water was removed. 300g at a time of this sample was put in a

500m1 conical flask, and cured by leaving it at room temperature (20°C) avoid-

ing direct sun light. A calculated amount of the sample terpene was added

to the immediate material and was mixed by shaking, prior to the procedure

described previously. While curing, once every day during the first week,

then once in a while, the material was stirred by -shaking the flask. The

efficacy of terpene_on the sample material was evaluated in a sensory way,

for its taste and flavor. At the same time, the peroxide value and

oxidized acid value 11) of the ether extraction (after an addition and mixing

of anhydrous sodium sulfate to the samp?e, at the rate of-6 times its

quantity, the extraction by Soxhlet method was conducted for 16 hours) were

determined and examined.

Method of determining the solubility of antioxidants in terpenes:

This was done according to the method applied by Toyama et al. 12)

for the solvent. First a terpene sample was placed in a large test tube.

Excess antioxidants were added and dissolved thoroughly by stirring at room

temperature for 30 minutes. After leaving it for five minutes, a part of

supernatant was filtered quickly. Then the antioxidant was quantitatively

determined by diluting that part in alcohol of a certain quantity. BI-IA.

was determined by the 2.6-dichloroquinone chloroimide method,l3) and BHT

was determined by the 2-2'7dipyridyl method.14) In these cases, it was

confirmed prior to the analytical procedure that there was hardly any

effect on the determination, caused by a minute amount of coexisting

terpe.nes.

8.

RESULTS AND DISCUSSION

Assa of the antioxidant efficacy of refined oils and of terpenes on

fish oil;

Prior to application of refined citrus fruits oils and terpenes to

fish processed products, the efficacy of these substances on fish oil was

assayed.

1. Evaluation by AOM.

The effectiveness of the addition of citrus fruits oils, oil B

and terpenes to refined flatfish oil was tested by AOM, adding low con-

centration (0.02%) and high concentration (0.10%) respectively. The

results are shown in Table 2. ..A,gainst the expectation, in every case,

Table 2. Antioxidative efficacy of citrus fruit oils and terpenes in refined flat fish oil (evaluated by Active Oxyten Method).

Sample No.

Citrus fruit terpenes and oils Protection Kind Concentration stabilities factor

1 Control 2 .. • Orange oil -

3 u e

4 Orange oil B* 5

6 Orange terpene

7 ii

8 Lemon oil 9

10 Lemon oil B*

11 u y

12 Lemon terpene 13

hr. 0 5.3 1.0 0.10 - 53 - 1.0 0.02 5.6 1.1 0.10 5.3 1.0 0.02 5.6 1.1 0.10 5.0 0.9 0.02 5.3 1.0 0.10 • 5.2 1.0 0.02 - 5.2 1.0 0.10 5.7 1.1 0.02 - 5.1 1.0 0.10 5.0 0.9 0.02 5. 2 1.0

* Oil B is the residaal frac:ion of citrus oil after its essential components were removed with dilute.d alcohol.

hardly any effect was recognized. The kinds of raw material or the method

of preparation seemed to have no relation to their effectiveness. Also

there was no relation between the results and the difference in concentra-

tion of the substances. In some cases, a lower concentration seemed to

9.

have more effect but the difference was very small and no significant re-

lation could be found.

This fact shows that the major aromatic constituents (terpene

aldehyde etc.) which exist in relatively large amount in orange (or lemon)

oil and other substances (hydrocarbons and totopherol and so on) do not

have any more antioxidant effect or helpful effect to antioxidant action

than terpenes do. In addition to the above fact, as the price of the oils

is more than ten times that of oil B and of terpenes, these refined citrus

fruits oils themselves are eliminated by the following experiments.

2. Evaluation by oven test.

The evaluation of the effectiveness of antioxidants by AOM does

not necessarily agree with the results of actual storing trials, because

under such severe experimental conditions as high temperatures ventilation,

oxidation develops rather quickly in samples with higher degrees of un-

saturation such as in the case of the fish oil. In the previous paragraph,

there was hardly any antioxidant power recognized in.citrus fruits oils

and terpenes. It was considered that on account of such experiment con-

ditions, no clear results were shown,asthe antioxidant power of terpenes

was relatively weak. Therefore the effectiveness of antioxidant power of

oil B and of terpenes on refined flatfish oil was examined by oven test

which represents relatively mild experimental conditions when compared with

AOM. The results are shown in Figure 1.

In this case also, there was hardly any effect shown by oil B and

terpenes, even by BHA, for a period of up to one week of storage, jun gp in

the control samples. Hereafter, effects gradually started to appear, and about

two weeks later, marked effects were finally recognized. .

10.

Pib. 1. Antioxidativic efficacy of citrasfruit oils and terpenès in refined flat

fish oil (evaluated by oven test ae37`C), \\'here, O Can:rol (No. 1^), _-,Le,non oil 13 0.101,0 (No. 15), t. ier•ionterpene 0.10;; (No. 16). M. Orangeoil B 0.10% (No. 17), G Orange ter-penc 0.10% (No. 18), E? Orange :er-pene 0.02% (No. 19), and © BKA I0.02% (No. 20).

But the effects were inferior to thoseof BHA. The effect of oil

B was inferior to that of its corresponding terpenes. These results in-

dicate that the antioxidant power of citrus fruits terpenes is weaker

than expected.

3. Evaluation under room temperature storage.

The antioxidant power of oil•B and terpenes was fairly recognizable in

the oven test. Even with this method the experimental conditions are more

rigorous than actual storing conditions. Therefore there is a risk of mis-

calculating the correct evaluation when fish oil is the substrate. There- p.895

fore one portion of the sample oil prepared for oven test was stored at x'oom."

temperature and the antioxidant power of added terpenes was examined. The

Kind

21 Control 22 Orange oil B 23 Orange terpene 24 Lemon oil B 25 Lemon terpene 26 Orange terpcne 27 BHA

0 0.10 0.10 0.10 0.10 0.02 0.02

Sample No.

Additives After 5 days

Conc. (Pffi/) meg/kg 16.51

After 6 days

Conc. Method Ôdor c°1°r* 150V Odor Color* pov I II , I II

meg/kg meg/kg 3 1 214.65 4 6 2 249.93 2 1 29.56 2 4-5, 1-2 45.07 2 1 197.84 3 5 1-2 330.66 2 1 190.66 1** 5 1-2 202.52

2 1 28.89 1** 4-5 1 34.36

2 1 144.31 1** 5 2 164.04

Antioxidative treatment ..Before storane Sample •

No. Kind

o 28 Control 0 I/ 1

1 1**

. 1**

1** 1**

0.01 0.02 0.20 0.011 0.20j

29 BHA 30 Lemon terpene 31 "

32 f BHA t Lemon terpene

33 Lernon terpene

immening I/

/I

sprayed

11. results are shown in Table 3.

Table 3. Antioxidative efficacies of citrus fruit terpenes in refined fiat fish oil when allowed

to stand in room temperature.

After Alter 16 davs 24 days (POV) (POV) mea/kn meq/kg 68.71- 97.84 45.10 76.99 40.20 66.56 46.75 73.07 45. 1 0 72.17 58.80 • 79.13 59.06 86.48

Alter 38 days

(POV) (0A*) meq/kg % 401.17 3.89 186.60 1.46 165.93 1.43 174.74 1.72 176.26 1.52 301.40 2.84 123.35 0.91

After 45 dvas (P0V) meg/kg 504.03 281.61 177.22 259.23 250.65 384.90 151.75

Aftu 52 days

(POV) (0A*) meq/kg % 577.81 7.70 380.21 4.07 4'01.70 4.39 351.83 3.77 343.99 3.48 491.08 4.13 257.77 2.62

* Oxidized acid.

As expected, it was proven that oil B and terpenes showed distinctive

power as antioxidant when used at relatively high concentration and at

room temperature. Although there was no difference in effectiveness be-

tween oil B and terpenes, from the viewpoint of the extracting method

terpenes have less possibilities of containing tocopherol and other sub-

stances than oil B, and the effectiveness was slightly better for lemon

terpene. Thus only lemon terpene was used in the following experiments.

The efficacy of lemon terpene on dried salted saury.

According to the results in Table 3, the efficacy of lemon terpene

is good enough to be used with fish products although it is inferior to

that of BHA. The experiment was conducted to prevent deterioration from

oxidation of oil in dried salted saury, using lemon terpene. The results

are shown in Table 4. Table 4. Protective efficacies of lemon terpene %:ith or without BHA for fat-oxydative

deterioration of salted-and-dried saury.

I: Abdominal cavity wand. II: Ventral tin. ** Having lemonish odor.

12.

At the end of the preparation, the control sample was already

orange yellow in the wall area of the abdominal cavity. Samples treated

with lemon terpene were light yellow in color as the samples with BHA,

and a good lemon flavor was also detected. But when oil was extracted, the

peroxide value was higher than expected, although it was generally lower

than that of the control sample and no effective antioxidant power such

as in BHA was recognized. After six days of storage, the control sample

showed general oil burn signs caused by oil oxidation, but the samples

with lemon terpene were in relatively good condition although • less

well preserved than the samples treated with BHA. Although these results

are similar in trend to the results of the experiment with flatfish oil

at room temperature, the addition of lemon flavor definitely improved the

quality impression of the product and therefore yielded results beyond

expectation. As the samples treated with both BHA and lemon terpene showed

a better appearance and state of oil than the samples treated with BHA only, p.896

the possibility of combined use of these two substances was expected. Al- —

though the concentration of the additive was relatively high, the samples

treated with lemon terpene by spraying, showed good result. Therefore, it

is considered that the use of citrus fruits terpenes with processed fish

products is hopeful enough.

The efficacy of lemon terpene on "shiokara". (salted fish guts)

It has been reported15)

that in the production of "shiokara", when

fish gut rich in oil was used, to keep its flavor and color, oxidation must

be controlled, and the strong efficacy of BHA has been recognized. When

"shiokara" is uncooked, it is considered16)

that prevention of poisonous

peroxide formation is more important than with other processed fish pro-

ducts. At present, the law does not allow the use of synthetic antioxidant.

As their odor is so strong and distinctive, peels of "yuzu" (e P.nd of

citrus fruit)* are often added in some homes. When these matters are

considered, "shiokara" is most suitable among other fish products to be

cons idered for lemon terpene application. The actual application of

lemon terpene on "shiokara" made from bonito gut was examined. The re:- _

sults are shown in Table 5.

Table 5. Antioxidative efficacies of lemon terpcne on the Shin Icara.* .

Sm le C.one. of After 10 days After 30 days After 50 days After 30 days lemon No. tcrpene Odor • POV OA** POV OA** POV OA** POV OA** Odor - ------ Taste -

% meg/kg ./ /0 meq/kg % .meq/kg . % mcq/kg % ----- - ---

34 0 Fishy 22.84 1.02 12.19 1.56 8.68 1.62 4.36 2.41 Fishy Wild .

35 0.1 Slightly 21.86 0.76 18.68 • 1.55 5.93 • 1.53 6.06 j..26 Slightly Mild fishy fishy • -

• 36

0.2 Slightly 33.67 0.79 9.44 1.85 6.2.8 1.15 6.42 j .85 Slightly Slightly lemonish lemouish harsh

. . ...,„ .,, .

37 0.5 Lemonish 24.27 0.49 10.24 1.49 6.20. 0.66 4.44 1,13 Letnopish Slightly .' - • astringent •

38 1.0 Strongly 14.2$ 0.57 . 6.65 1.51 5.44 1.30 3.31 0,72 f.,empmish . /".striageut lemonish ' •

* Partly autolysed skipjack gut with 30% of salt.

** Oxidized acid. •

Although the efficacy of lemon terpene with respect tp eontrol

of oxidation in oil was very clear, there were questions about the improver

ment of flavor, depending on the amount of terpene used.

With respect to the condition of extracted oil, although some

changes in the quantities of oxidized acid were observed during the curing

period, this quantity was generally lower in the portion treated with lemon

terpene than in the control portion. The antioxidant effect pf lemon

terpene was clear. The peroxide value was low in every case eyen in the

,control portion to which no lemon terpene had been added, and Phe çoncenr

tration did not rise enough to be considered poisonous. During the pro- , -

cess of curing, the value even seemed rather to decrease. This wap the

*Bracket is a translator's note.

14.

result of enzyme action during the curing process. Already Fulcuda15) re-

ported that the peroxide value of oil obtained from "s.hiokara "(made

from viscera of "buri", Seliola quinqûéndiâ.ta) by extraction after dis-

tillating and drying while heating, was about 30 meq/kg after 30 days of

curing, regardless of the application of antioxidants and that it decreased

after that time. This tendency agrees with the results of.this experiment,

Accordingly, if consideration is given only to the formation of peroxides,

the preventing effect in "shiokara" becomes less meaningful, but the

fluctuation of peroxide value between curing and consumption should yet

be examined.

As shown by the results of sensory examination concerning the

flavor of "shiokara" after curing, as the concentration of lemon terpene

used increaseq,the lemon flavbr remains strong and the smell of raw fish

fades; generally the flavor creates a soft impression: At.higher concen-

tration, however, the impression was not always satisfactory. The taste

of the portion (No. 35) treated with a low concentration was good, but in

the portion with a higher concentration, an astringent taste increased-with

the concentration and it was not considered satisfactory. The portion (No.

38) with highest concentration particularly had an irritating aftertaste and

showed the unsatisfactory effect of overuse. By reviewing this experiment,

fairly good results were obtained from the portion with an addition of 0.1%.

in actual application, the best results may be expected when a 0.1% or a

l.ower concentration of lemon terpene is added.

Solubility'of antioxidants in citrus fruits'terpèiies

It was accidentally confirmed in this experiment that BHA and BHT

dissolved easily in citrus fruits terpenes. Therefore the sQlubility of

these antioxidants in lemon terpene was determined. The solubility of BHA

p.898

15,

was 14.05 at 21.0°C and that of BHT was 45.82 at 19.3 °C. As already

described, citrus fruits terpenes are natural and considered haLuiless.

This character shows great possibilities for use as carrier and solvent

when adding BHA and BHT which are employed widely at present for fish

processed products.

CONCLUSION

From the results of the experiments described above, it was

confirmed that citrus fruits terpenea have efficacy in preventing oxida-

tion, and whey they are used they also add a distinctively pleasant

flavor to the products. Although it was not recognized in this experi-

ment, it was reported that d-limonene, its major constituent had an an-

tibiotic power, So in the future, the selection of the products for whiCh

it should be used and other problems of practical application must be con-

sidered.

Recently, the components of refined citrus fruits oils have been

examined in detail, and it has been reported they they contain traces of

many kinds of terpenes, sesquiterpenes and oxygen containing compounds. In

the present report, although the refined oils and their fractions pro-

duced commercially were used as •such, in the future, the effect of theee

substances coexisting in relatively small amounts and the confirmation of

their antioxidant power should be examined.

SUMARY

The use of refined citrus fruits oils and terpenes with fish pr9 -

cessed products was considered. Six samples, varying in materials and

tracting methods were examined with respect to their antioxidant power, first

on fish oil. Although no efficacy was recognized under severe environmental

16.

conditions as in AOM, fairly distinctive results were recognized in the

oven test at 370 C and in the room temperature storage test. Lemon ter-

pene was selected for its composition and price, and applied on dried

salted saury and "shiolcara" made from bonito gut. The antioxidant power

was relatively weak, but it gave a lemon flavor to the products and improved

their appearance.

We would like to express our thanks to Kyokuto Kagaku Sangyo Co.

for their assistance, to the Nikki Universal Co. for donating BHA, to.Mr.

Hisamitsu Ashida, fruits essence research director of the Soda Spices Co.

for donating citrus fruits terpenes and giving knowledge about them, to

Mr. Toyokazu Niimi of the Ninben Co. for donating "shiokara" material and

for giving advice, and to Mr. Toshi Wada, studeizt at the Tokyo University of

Fisheries for helping with the sensory test of "shiokara".

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2) Kumazawa Co. of Oil Refinery: Document for Patent Application, 1968-

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17.

13) J. H. tvlAtioN and R. A. à1APMAN: Anal Chem., 23, 1120:1123 (19 -51).

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