Note: Descriptions are shown in the official language in which they were submitted.
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1 20375-644
PR~CESS FOR PROCESSING FISH MEAT
CQNTAMINATED WITH SPOROZOA
BACKGROUND OF THE INVENTION
This invention relates to a process for processing
fish meat or fish flesh. More particularly, it relates to a
process for processing fish meat having a tendency to form jelly
meat or jellied meat due to contamination with sporozoa by
adding a material selected from the group consisting of plasma
protein, serum proteinr serum globulin and mixtures thereof to
the fish meat, whereby it is possible to produce "neriseihin"
~fish meat paste products) having good elasticity from the fish
meat having a tendency to form jelly meat, which otherwise
cannot be used as a raw material for "neriseihin" because of its
lack of gel-forminy capability.
In a fish on which minute sporozoa (mucilaze sporozoa)
belonging to the class of protozoa are parasitic, fish meat
protein is decomposed by a proteolytic enzyme released by the
sporozoa after death of the fish. Particularly, when heating is
carried outr the fish meat is spottily or wholly softened and
~0 liquified in the form of a jelly. This forms so-called jelly
meat. This jelly meat represents a great problem in the fishery
field. When "surimi" (minced meat) is prepared from the fish
meat having a tendency to form jelly meat, the proleolytic
enzyme derived from the sporozoa acts on myosin, i.e., muscle
protein which is a major gel-forming component of "neriseihin"
on heating, and thus decomposes the myosin. Therefore, the raw
fish meat having a tendency to form jelly meat exhibits no gel-
forming capability. The sporozoa to which jelly meat is as-
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cribable belong to the unicapsla genus, ~hloromyxum genus~
Kudoa genus and the like of Myxosporida which belongs to
Cnidosporidae, Sporozoa of Protozoa. These sporozoa are never
parasitic with respect to human beings. Accordingly, when the
sporozoa and fishes on which sporozoa are parasitic are eaten,
there has keen no incidence of health trouble attributable to
sporo~oa. A "neriseihin" which is subjected to heat treatment
presents no problems from the standpoint of food sanitation.
Various processes for solving problems of fish meat
processing having a tendency to form jelly meat have heretofore
been proposed. For example~ U.S. Patent No. 4,207,354 discloses
a process for adding egg white to fish meat having a tendency to
form jellied meat. Further, IJ.S. Patent No. 4,284,653 discloses
a process for adding a substance which inhibits thiol protease
to fish meat haviny a tendency to form jellied meat. Further-
more, Japanese Patent Laid-Open Publication No. 42567/1981
discloses a process for contacting fish meat having a tendency
to form jelly meat with an oxygen acid-type oxidant or SH
reagent. Moreover, Japanese Patent Laid-Open Publication
No. 24872/1988 discloses a process for adding a milk component
of a mammal to fish meat having a tendency to form jelly
meat. Furthermore, Japanese Patent Laid-Open Publication
No. 74446/1988 discloses a process for applyin~ pressure to fish
having tendency to form jelly meat, thereby inhibiting the
formation of jelly meat.
While considerable effects are obtained according
to the prior art processes, such processes are not entirely
satisfactory. We have carried out studies in order to find a
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materlal whereln a small amount of such a materlal can
lnhlblt sporozoa enzyme from actlng on a raw material of
flshes havlng a tendency to form ~elly meat, and whereln good
processed products can be produced therefrom. We have now
found that lncorporatlon of a sultable amount of a materlal
selected from the group con-slstlng of serum proteln, serum
globulln and mlxtures thereof ln flsh meat havlng a tendency
to form ~elly meat due to contamlnatlon wlth sporozoa
lnhlblts proteolytlc enzyme of sporozoa and provldes good
flsh meat processed products such as "surlml" and
"nerlselhln".
SUMMARY OF THE INVENTION
Accordlngly, the process for processlng flsh meat
accordlng to the present lnventlon comprlses addlng a
materlal selected from the group conslstlng of serum proteln,
serum globulln and mlxtures thereof to flsh meat of flshes
havlng a tendency to form ~elly meat due to contamlnatlon
wlth sporozoa.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 ls a graphlcal dlagram showlng the electro-
phoresls patterns of varlous samples obtalned by carrylng out
electrophoresls ln Test Example 2 of the present lnventlon.
DETAILED DESCRIPTION OF THE INVENTION
Flshes whereln ~elly meat ls llkely to be formed
because of parasltlsm of sporozoa lnclude North Paclflc hake
(Merlucclus productus), Chllean hake (Merlucclus gayl) and
Argentlnean hake (Merlucclus hubbsl) of Merlucclus; flatflsh,
bastard hallbut, tuna, marlln, baracuda, salmon, common sea
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bass, flylng flsh and common dolphln. Flshes whlch can be
processed accordlng to the present lnvention are not llmlted
to the klnd of flshes llsted above.
Sporozoa cannot be lntrlnslcally observed by the
naked eye. When the degree of parasitlsm ls lncreased, a
number of sporozoa are clustered to form a bag-shaped matter
generally called a cyst, and a sporozoan cyst havlng a slze
vlslble to the naked eye ls formed. In the case of North
Paclflc hake, a cyst ln the form of black halr ls observed at
the flllet surface when the percentage of parasltlsm of
sporozoa ls hlgh. In the case of Peruvlan hake, a black or
whlte cyst ls observed and the percentage of parasitlsm can
be from 14 to 40% dependlng upon the slze of a flsh body and
the place where lt was caught. Flsh meat on which sporozoa
havlng a hlgh concentratlon are parasltlc can be used as a
raw material ln the present lnvention.
In the present invention, a material selected from
the group conslsting of serum proteln, serum globulln and
mlxtures thereof ls added to fish havlng a tendency to form
~elly meat due to contamlnatlon with sporozoa. As ls well
known, plasma protein is a proteln component ln a llquld
component obtalned by removing visible components such as
leukocyte, erythrocyte and thrombocyte from blood. A
materlal remalnlng after flbrlnogen present ln the plasma
proteln ls coagulated and deposlted ls serum proteln.
Albumln, globulln and the llke are contalned ln the serum
proteln. It ls observed that a substance present ln the
serum protein which particularly effectlvely acts as a
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substance whlch inhlbits protease ln the present lnventlon ls
globulln.
Serum proteln and serum globulin as used hereln are
generally prepared from blood of varlous domestlc anlmals and
flshes. For example, a powder obtalned by sampllng blood
from domestlc anlmals such as cattle, plgs, horses, sheep,
goats, chlckens and ducks, and flshes such as sea breams and
young yellowtalls ls used, separatlng a predetermlned
component from the blood, and drylng lt. Of these, serum
proteln of cattle and plgs ls preferably used. The serum
proteln ls generally avallable at low cost.
An example of a process for separatlng blood
components wlll now be descrlbed. Sodlum cltrate ls added to
sampled blood to prevent coagulatlon. When the centrlfuged
supernatant ls drled, a sllghtly llghtly yellowlsh brown
powder of plasma proteln is obtalned. After blood sampllng,
the blood ls allowed to stand at 5~C, and mass-shaped
aggregate of blood cell and flbrln ls centrlfuged to remove
them to obtain an amber supernatant. Thls supernatant ls
lyophlllzed to obtaln llghtly yellow powdered serum proteln.
The serum ls sub~ected to saltlng out by a 50% saturated
ammonlum sulfate solutlon and thereafter centrlfuged to
collect the same. The centrlfuged serum ls dlalyzed by a
O.lM sodlum chlorlde solutlon, and the dlalyzate ls
lyophlllzed to obtaln a sllghtly graylsh whlte powder of
serum globulln.
In general, when "surlml" or "nerlselhln" ls
prepared, flsh meat ls sub~ected to debonlng, leachlng and
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dehydratlon, and ad~uvants such as sugars and polyphosphates
are added to the dehydrated meat. The resulting mlxture is
kneaded and thereafter formed into fresh "surimi" or further
frozen to form a frozen "surimi". To this fresh "surimi", or
"surimi" which has been thawed ln the case of the frozen
"surlmi", are added additlves such as starch, salt and
seasoning. The resulting mixture ls ground, kneaded, formed
into a specific product, and heated to obtain a fish meat
"neriselhln".
The stage of adding the thus obtained serum or
serum globulin to the fish meat having ~elly meat ln the
present lnventlon may be any step ln the "suriml" production
process and may be any step before heatlng in the case of the
fish meat "neriselhln" production process. It is preferable
that the serum proteln or serum globulin be added when the
flsh meat is sub~ected to leaching in producing "suriml", or
when ad~uvants are incorporated ln the dehydrated meat or
when kneadlng is carrled out in processing "neriseihin".
The amounts of the serum protein and/or serum
globulln added to fish meat having ~elly meat ln the present
lnventlon are as follows. The amount of the serum proteln
added ls from 0.01 to 10 parts (preferably from 0.5 to 3
parts) (on a dry basls) based on 100 parts of raw flsh meat.
The amount of the serum globulln added ls from 0.001 to 10
parts based on 100 parts of raw fish meat. Small amounts of
these components are sufficient.
If the amount of the serum protein or serum
globulln fraction added ls less than the lower llmlt, the
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actlvity of sporozoa enzyme cannot be lnhlbited, and a raw
materlal for "nerlseihln" havlng sufflclent gel elastlclty
cannot be prepared. If the amount added ls greater than the
upper llmlt, blood odor wlll be lncreased, the degree of
coloration wlll be lncreased and the flavor and taste of the
fish meat product wlll be lowered.
The following examples lllustrate preferred
embodiments of the present invention as well as similar
processes. Plasma proteln, serum proteln and serum globulin
descrlbed herelnafter are prepared from bovlne blood. Parts
and percentages are by welght. In the following examples,
the ~elly, strength representlng a physlcal property of a gel
formlng abllity ls expressed as J.S. (g-cm) obtalned by
multiplylng the rupture strength (W value (g)) measured by
uslng a 5 mm-dlameter plunger wlth a round end by food
checkers by the dlstance of the concave up to rupture (L
value (cm)).
Organoleptlc evaluatlon of a "kamaboko"-shaped gel
was carrled out uslng the followlng 10-stage evaluatlon.
("kamaboko" ls a paste plled up on a thln rectangular wooden
board).
Foldlng Test
The speclmens used were cut lnto round sllces
havlng a thlckness of 3 mllllmetres and folded between thumb
and lndex flnger.
Score 10: when the specimen is folded into quarters and
strongly pushed, no crack occurs;
9 when the speclmen is folded lnto quarters and
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strongly pushed, cracks are formed;
8: when the speclmen ls folded lnto quarters and
sllghtly pushed, cracks are formed;
7: when speclmen ls folded lnto quarters and the whole
ls caused to contact together, cracks are formed;
6: when the speclmen ls folded lnto quarters and the
whole ls llghtly put together; crack~ are
lmmedlately formed;
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5: when the specimen is folded into two halves and the
whole is put together, cracks are formed within the
one-half portion;
4: when the specimen is folded into two halves and
the whole is put together, cracks are formed in the
whole;
3: when the specimen is folded into two halves and
the whole is liyhtly put together, cracks are
immediately formed;
2: when the specimen is pushed with the finger, it
is breakable; and
1: the specimen does not cohere.
Biting Feel Test
The specimens used were cut into round slices having a
thickness of 5 milimeters. Firmne,s,s and sensory were scored by
the bite test.
Score 10: extremely strong and flexible;
9: very strong and flexible;
8: considerably strong;
7: slightly strong;
6: the strength is generally good;
5: while t,he strength is generally good, the specimen is
slightly brittle;
4: slightly weak and considerably brittle;
3: weak and brittle;
2: extremely weak, and
1: the specimen does not cohere.
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1a 20375-644
Test Example l
As a raw material, North Pacific hake was used. It
had an average body weight of 520 grams, wherein about 16~ of a
cyst in the form of black hair exhibiting likelihood to form
jelly meat due to contamination with sporozoa was observed. The
hake was subjected to deboning, leaching and dehydrated. Sugar
and a phosphate were added to the dehydrated hake. The mixture
was frozen to prepare a frozen "surimi" of North Pacific hake.
This "surimi" was thawed7 and thereafter 3% of salt, 3% of
potato starch
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and 1% of a powder of plasma protein, serum protein or
serum globulin were added to the "surimi". The mixture
was kneaded. A polyvinylidene chloride tube was filled
with the kneaded mixture. The mixture was heated for 40
5 minutes at 90~C and cooled. Its jelly strength was
measured. A gel containing no plasma protein, serum
protein or serum globulin was prepared as a control, and
its jelly strength was measured.
The results are shown in Table 1.
TABLE 1
Amount Jelly
No. Additive added strength Folding F lg
(%) (g-cm)
1 none 0 142 2 2
2bovine plasma 1 930 10 10
protein
3bovine serum 1 990 10 10
protein
4bovine serum 1 1300 10 10
globulin
In the case of the gel containing no plasma protein,
serum protein or serum globulin, the jelly strength is
25 very low (i.e., 142 g cm), cracks are easily formed in
twofold condition and the gel exhibits an inferior mouth
feel. On the other hand, gels containing plasma protein,
serum protein or serum globulin exhibit a jelly strength
of at least 900 g-cm. Thus, such gels exhibit good gel
30 physical properties.
Test Example 2
A frozen "surimi" of North Pacific hake contaminated
with sporozoa used in Test Example 1 was thawed.
Thereafter, 3% of salt, 3% of potato starch and from 0.5
35 to 3~ of bovine plasma protein were added thereto. The
resulting mixture was kneaded and a polyvinylidene
chloride tube was filled with the mixture. The mixture
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was heated for 40 minutes at 90~C and cooled. The jelly
strength of this "surimi" processed product and the
pattern of sodium dodecyl sulfate-polyacrylamide gel
electrophoresis (hereinafter referred to as SDS-PAGE)
5 were measured. The measurement of the SDS-PAGE pattern
makes it possible to observe how the molecular shape
of "surimi" protein varies in producing a "surimi"
processed product. The SDS-PAGE method was carried out
according to a Weber-Osborne's method using 10%
10 acrylamide gel-0.1% SDS. The solubilization of
a "kamaboko" gel was carried out by mincing
the "kamaboko" gel by means of a Potter hand homogenizer,
and adding 2% SDS, 8M urea, 0.1M Tris-glycine and 5 mM ~-
mercaptoethanol as solubilizing agents to prepare a
15 sample for electrophoresis. After electrophoresis,
dyeing of protein was carried out by using Coomassie
Brilliant Blue.
TABLE 2
Amount of Jelly
No bovine plasma strength Folding Biting
protein added Feel
(%) (g-cm)
1 none 199 2 2
2 0.5 718 9 9
3 1.0 949 10 10
4 2.0 996 10 10
3.0 1190 10 10
With at least 0.5% of bovine plasma protein, good
gel strength was obtained. The obtained electrophoresis
patterns are shown in FIG. 1. Pattern (1) shows a
pattern of North Pacific hake "surimi" without heating;
3 and Patterns (2) through (6) show electrophoresis
patterns of "kamaboko-like" gels of Nos. 1 through 5 of
Table 2, respectively.
zoa~
As can be seen from electrophoresis Pattern (2), in
the case of sample No. 1 containing no bovine plasma
protein, myosin, i.e., major protein of the North Pacific
hake "surimi" is decomposed by protease derived from
5 sporozoa contained in the "surimi" to form small pieces.
This corresponds well to the fact that the jelly strength
is very low, i.e., 199 g cm. As can be seen from
SDS-PAGE Patterns (3) through (6) of "kamaboko" gels
containing from 0.5% to 3% of bovine plasma protein, the
10 extent of decomposition of myosin is reduced with
increase in the amount of plasma protein added. In the
case of Pattern (6), substantially no myosin is
decomposed. The extent of decomposition of myosin
observed in SDS-PAGE Patterns (3) through (6) corresponds
15 well to their jelly strength.
That is, the bovine plasma protein acts as an
inhibitor for protease of sporozoa, and the decomposition
of "surimi" protein by protease of sporozoa in producing
and processing "surimi" is inhibited. Thus, Test Example
20 2 demonstrates that "surimi" processed products having
good gel physical properties can be produced from
the "surimi" of North Pacific hake.
EXAMPLE 1
North Pacific hake contaminated with sporozoa used
25 in Test Example 1 was dressed, and deboning was carried
out. The North Pacific hake was subjected to mincing
treatment to form a material in the form of ground meat.
To this material were added 2% of salt, 5% of potato
starch, 2% of sugar, 0.5~ of seasoning and 1% of a bovine
30 plasma protein powder. The mixture was lightly kneaded
and formed into balls. These balls were boiled for 10
minutes at 100~C. Fish balls containing no bovine plasma
protein powder were prepared as a control. The fish
balls containing no bovine plasma protein formed "tumire"
(a spongy product), and the resulting product exhibited a
significantly inferior mouth feel. The fish balls
containing bovine plasma protein had such physical
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properties that there was good sensory resistance to the
teeth when bitten, it was noticed that the effects of the
bovine plasma protein were remarkable.
EXAMPLE 2
Chilean merluccius (Merluccius gayi) having an
average body weight of 623 grams and contaminated with
sporozoa was used as a raw material. It was subjected to
deboning, leaching and dehydration. To this dehydrated
meat were added 7% of sugar, 0.2% of a polyphosphate and
2% of bovine plasma protein. The resulting mixture was
kneaded, and frozen to form a frozen "surimi". A
frozen "surimi" containing no bovine plasma protein was
prepared as a control. The "surimis" were stored for 4
months at -25~C and thereafter an "itazukemushi-kamaboko"
(a steamed paste piled up on a thin rectangular wooden
board) was prepared therefrom. The "itazukemushi-
kamaboko" was prepared as follows. 100 Kg of
frozen "surimi" was thawed and thereafter 3 kg of salt, 5
kg of "mirin" ("mirin" being a kind of wine used as
seasoning in Japan), 5 kg of corn starch, 60 kg of water,
and 1.4 kg of seasoning were added thereto. The mixture
was kneaded by means of a silent cutter and formed into
an "itazuke-shaped kamaboko". This was heated for one
hour in a steamer. While "kamaboko" obtained by using
the frozen "surimi" containing bovine plasma protein
exhibited a mouth feel similar to that of "itazuke-shaped
kamaboko" obtained by using a conventional Alaska pollack
"surimi", the "surimi" containing no bovine plasma
protein formed "tumire" and "kamaboko" was not produced.
EXAMPLE 3
As a raw material, L-size yellowfin-sole was used.
It had a parasism percentage of 18% wherein sites on
which sporozoa were parasite were dissolved and removed
in the form of spots when the flatfish was heated. The
flatfish was dressed, and its skin was removed by means
of a peeling machine. The treated flatfish was subjected
to deboning by means of a deboner, leaching and
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dehydration. To this dehydrated meat were added 5% of
sugar, 0.2% of a polyphosphate and 3% of a bovine serum
protein dried powder. These materials were mixed, and
the mixture was frozen to form a frozen "surimi". A
5 frozen "surimi" containing no bovine serum protein dried
powder was prepared as a control. These frozen "surimis"
were stored for 6 months at -25~C. These were thawed,
and 3% of salt and 3% of potato starch were added
thereto. The resulting mixtures were kneaded, and
10 polyvinylidene chloride tubes were filled with the
kneaded mixtures. The mixtures were boiled for 40
minutes at 90~C and cooled. Their jelly strength was
measured. Their mouth feel and flavor and taste were
examined.
TABLE 3
Amount of
plasma Y Biting . M th Flavor
No. strength Foldlng and
protein Feel feel
(g cm) taste
added
(%)
1none (O) 136 2 2 poor good
2 3 865 9 9 good good
25It was apparent that, even if the bovine serum
protein is previously added to the "surimi" and frozen,
this serum protein exerts superior effects, its biting
property and mouth feel are superior to those of the
product containing no bovine serum protein and that its
30 flavor and taste are comparable to those of the product
containing no bovine serum protein. ~-
When the plasma protein, serum protein or serum
globulin is added to the fish meat having jelly meat due
to contamination with sporozoa, and the fish meat is
35 treated therewith according to the present invention, its
plasma protein and the like inhibit the protease of the
sporozoa, and thus a good "neriseihin" having gel-forming
200~244
capability can be produced. Further, the plasma protein
and the like used are obtained at low cost, and are
effective in a small amount. Accordingly, the desired
products can be economically produced and thus the
5 process of the present invention is extremely effective
for such products.
