Additives for frozen surimi

The present invention provides an additive for frozen surimi containing branched dextrins and a surface active agent for food; the frozen surimi into which the additives for surimi of the present invention are added does not give off a fish smell or a bad smell after thawed, and the fish meat product such as kamaboko, chikuwa and the like which is produced from the frozen surimi has a bad smell.

BACKGROUND OF THE INVENTION 
This invention relates to an additive for frozen surimi (ground fish meat) 
for deodorizing or removing the smell. 
Frozen surimi is a product prepared by collecting fish meat from raw fish 
such as wall-eye pollack to give a picked meat, washing the picked meat 
with clean water 2 or 3 times or several times in some cases, if 
necessary, adding a small amount of sodium chloride to the last washing 
water, removing the black skin by a refiner in case of need, dehydrating 
by a screw press, mixing the resultant fish meat with a sugar or sugar 
alcohol and a polyphosphate, packing and freezing the resultant surimi 
followed by storing at -20.degree. C.--30.degree. C. The frozen surimi is 
thawed at use and processed to surimi based products such as kamaboko, 
chikuwa and the like. 
Recently, fishing boats often go far away for catching of fish such as 
walleye pollack because of restriction of fishing grounds. It sometimes 
needs about 10-14 days from fish catch to landing. As the result, the 
commercial value of surimi markedly decreases because the freshness 
becomes remarkably lower and strong smell of walleye pollack is noted. 
Additionally, freshness of the swarming red meat fish (e.g. mackerel, 
sardine or jack mackerel) decreases more swiftly compared with the white 
meat fish such as walleye pollack and bad effects such as remarkably bad 
color tone, lowering of gel formation ability and strong smell of fish are 
recognized when the surimi is prepared because of the higher fat content 
and the more blood-colored meat. The smell of fish is especially so strong 
that the utility for surimi based products is limited. 
As the conventional method for deodorizing or removing the fish smell of 
surimi of fish meat, there are known a masking method adding perfumes or 
alcohol extracts of plants or a deodorizing method utilizing a property 
forming a clathrate compound by cyclodextrin. 
The masking agents such as a perfume and the like have a problem of perfume 
odor or alcohol smell although fish smell disappears. Cyclodextrin is 
expensive and has a disadvantage that the product gives fish smell when 
heated. 
SUMMARY OF THE INVENTION 
The purpose of this invention is to deodorize such an unpleasant fish smell 
of fish meat surimi. 
The unpleasant fish smell of surimi of fish meat can be deodorized by 
adding branched dextrins with a surface active agent for food among the 
starch hydrolyzed products used for controlling freezing denaturation.

DETAILED DESCRIPTION OF THE INVENTION 
This invention relates to an additive for frozen surimi which comprises 
branched dextrins and a surface active agent for food. 
There are preferably used as the branched dextrin, a branched dextrin of 
the mean molecular weight of 3,000-500,000, preferably 5,000-100,000, more 
preferably 10,000-30,000 and a reduced branched dextrin. 
A branched dextrin of the molecular weight of smaller than 3,000 and the 
reduced branched dextrin can't get enough effect controlling fish smell 
and unpleasant smell which is the purpose of this invention. Besides, a 
branched dextrin of the mean molecular weight of more than 500,000 and the 
reduced branched dextrin show the effect controlling the fish smell and 
the unpleasant smell while the use often results in increase of viscosity 
of surimi and properties of surimi become bad. 
The branched dextrins are prepared by separating and removing glucose and 
oligosaccharides of a low molecular size from a hydrolyzed product 
containing straight dextrins, branched dextrins, glucose and 
oligosaccharides of a low molecular weight and purifying and powdering the 
part being rich in branched dextrins. The reduced branched dextrin is 
prepared by hydrogenation of the above branched dextrin. 
As method for hydrolyzing starch there are carried out enzymatic 
decomposition, acid decomposition, thermal decomposition and the like. The 
products are different from each other in decomposition ratio, content of 
branched dextrins and the like depending on the kind of starch (e.g. corn 
starch or rice cake starch), decomposition method, for example, the kind 
of amylase in the enzymatic decomposition (e.g. .alpha.-amylase, 
.beta.-amylase or glucoamylase), action conditions and the like. The 
branched dextrins suited for this invention are prepared by applying 
suitable separation and purification methods to the above products. A 
practical procedure is, for example, disclosed in Jap. Pat. Laying-open 
Pub. No. 205494/1986 or "DENPUN KAGAKU HANDBOOK" (Handbook for Starch 
Chemicals) pp. 64-85 (edited by Jiro Nikuni, published by Asakura Shoten, 
1985). The reduction of the branched dextrin is disclosed in Jap. Pat. 
Pub. No. 18898/1969. 
The branched dextrin used in the additive for surimi of this invention is 
mixed at a ratio of 0.5 weight % or more to fish meat, preferably about 
1-3% by weight. The effect aimed by this invention cannot be sufficiently 
obtained when less than 0.5% by weight is used. The effect is increased by 
using more than 3% by weight, while the viscosity of the surimi often 
increases and the properties of the surimi become bad. 
The branched dextrin on the market sometimes contains impurities and in 
that case it should be compounded in the above range depending on the pure 
content calculated. The branched dextrins in a purity of 85% or more are 
preferably used since too much of impurities which are mainly glucose, 
maltose and other straight oligosaccharides sometimes give other effects 
on surimi. 
The surface active agent for food is not specially limited and there are 
exemplified glycerol fatty acid esters, sucrose fatty acid esters, 
sorbitan fatty acid esters, propylene glycol fatty acid esters, 
polyglycerol fatty acid esters, lecithin, polyoxyethylene sorbitan fatty 
acid esters and their mixture. 
The surface active agent for food used as the additive for surimi of this 
invention is preferably mixed with the fish meat at a ratio of 0.1-1.0% by 
weight, especially 0.1-0.5% by weight. The effect of addition of the 
surface active agent is not recognized when the ratio is less than 0.05%. 
Addition of more than 1.0% by weight is not expected to give a stronger 
effect but there is rather possibility of decrease of elastisity. 
Therefore, the ratio of the branched dextrins and the surface active agent 
for food is suitably 1-20 parts by weight of the latter, preferably 3-20 
parts by weight, based on 100 parts by weight of the former. 
The surface active agent for food may be used alone or as a mixture with 
fats and oil. It is preferred that the total amount of the surface active 
agent for food and the fats and oil is in the above range when fats and 
oil are used. The surface active agent for food and the fats and oil are 
preferably used by dispersing in a sugar or sugar alcohol. As the sugar or 
the sugar alcohol, there are used, for example, glucose, maltose, sucrose, 
lactose, maltitol, sorbitol and the like. 
There are exemplified triglycerides of a fatty acid, esters of a higher 
fatty acid with a higher alcohol as the fats and oil and the former is 
especially preferred. Practically, vegetable fats and oil such as rapeseed 
oil, soybean oil, cotton seed oil, rice barn oil, corn oil, olive oil, 
groundnut oil, palm oil and the like and animal fats and oil such as beef 
oil, lard, fish oil and the like are exemplified. 
Besides, the surface active agent for food and optionally the fats and oil 
may be added, for example, in the emulsified state of O/W or by dissolving 
or dispersing in an edible solvent such as ethanol or propylene glycol, if 
they can be swiftly dispersed into surimi homogeneously. 
The additive for surimi of this invention may be prepared in the form of 
one pack by mixing previously the branched dextrins with the surface 
active agent for food optionally containing the fats and oil or in the 
form of two packs by putting each of the branched dextrins and the surface 
active agent for food optionally containing fats and oil into a separate 
container. Furthermore, it may be prepared in a three pack-form by putting 
the fats and oil alone into a separate container when the surface active 
agent for food contains fats and oil. 
The additive for surimi of this invention may contain a sugar or a sugar 
alcohol when it is used as an additive in a one pack-form, which is rather 
preferred. 
The additive for surimi of this invention in a two pack- or a three 
pack-form may contain a sugar or a sugar alcohol with other components of 
each pack. Furthermore, the sugar or sugar alcohol may be sealed in 
another bag as an independent pack. Besides, the surface active agent for 
food and the fats and oil are preferably used with the sugar or sugar 
alcohol. 
The additive for surimi of this invention is added and mixed before 
preparation of frozen surimi. Adding method, order, timing and mixing 
method are not especially limited and can be used for any of non-salted 
surimi, salted surimi and surimi without phosphorous. 
The additive of this invention is applicable to the fish meat of walleye 
pollack, atka mackerel, sardine, mackerel, Pacific herring, Pacific saury, 
cutlassfish, pike eel, righteye flounder, jack mackerel, melulusa and the 
mixture although it is not limited to these examples. 
Additionally, the additive for frozen surimi of this invention may be 
compounded with other improving agents, for example, a freezing 
denaturation preventing agent (e.g. polyphosphate) and an elastisity 
improving agent (e.g. gluten, soybean protein, egg protein, milk protein 
or blood plasma). 
This invention is further explained in detail with examples. 
EXAMPLE 1 
Dehydrated fish meat was prepared from walleye pollack landed 12 days after 
the catching and after being made to contain water to a certain amount by 
previous mixing, the meat (5 kg) in each group was mixed with the additive 
in Table 1 and blended to be homogeneous by a small silent cutter for 5 
minutes. The resultant surimi (2.5 kg) each was put into a bag made of 
polyethylene film, frozen at -30.degree. C. overnight by an air-blast 
freezer to give frozen surimi and then stored at -30.degree. C. 
Three months after from the freezing the frozen surimi (2.5 kg) in each 
group were taken out and thawed naturally by leaving in a room overnight. 
The surimi (2 kg) was put into a small silent cutter, blended with 3 
weight % of sodium chloride and 5 weight % of potato starch for 13 
minutes, packed into a polychlorovinylidene film and then heated in a hot 
water of 90.degree. C. to give kamaboko. 
A sensory test (observation of the state and smell of the surimi) and 
measurement of Hunter whiteness were carried out with the surimi and the 
kamaboko. Besides, Hunter whiteness was measured by a color difference 
meter in ND-101DP type (available from Nihon Denshoku Kogyo). 
TABLE 1 
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Hunter 
Additive (weight %) Whiteness State 
Test Poly Degree (%) 
of Smell 
No. Sugar 
*1 
*2 
*3 
Phosphate 
Surimi 
Kamaboko 
Surimi Surimi 
Kamaboko 
__________________________________________________________________________ 
1 Ref. 
6 0 0 0 0.3 18.0 
48.0 Skin is coarse 
Fish smell 
Fish smell 
Ex. and dark 
is strong, 
is strong, 
Unpleasant 
Unpleasant 
smell is 
smell is 
strong 
strong 
2 Ref. 
4 2 0 0 0.3 19.4 
49.8 Skin is fine and 
Fish smell 
Fish smell 
Ex. white with 
is present, 
is present, 
transparency 
Unpleasant 
Unpleasant 
smell is 
smell is 
present 
present 
3 Ref. 
4 0 0 2 0.167 20.1 
50.1 Skin is fine and 
Fish smell 
Fish smell 
Ex. light white 
is present, 
is present, 
Unpleasant 
Unpleasant 
smell is 
smell is 
present 
present 
4 Ex. 
2 2 0 2 0.167 21.2 
51.5 Skin is fine and 
Fish smell 
Fish smell 
light white with 
is little, 
is little, 
transparency 
Unpleasant 
Unpleasant 
smell is not 
smell is 
present 
not present 
5 Ex. 
2 0 2 2 0.167 21.4 
51.8 Skin is fine and 
Fish smell 
Fish smell 
light white with 
is little, 
is little, 
transparency 
Unpleasant 
Unpleasant 
smell is not 
smell is 
present 
not present 
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*1 Branched dextrin (mean molecular weight 10,000, containing ratio 
85-90%) (product of Sanmatsu Co., & Ltd) 
*2 Reduced Branched dextrin, the hydrogenated product of *1 
*3 Composition, powder consisting of 83.3% sorbit 10% a glycerol fatty 
acid ester (monoglyceride from cotton seed oil and 6.7% polyphosphate) 
Ref. Ex. indicates a comparative example. 
Ex. indicates an example of the present invention. 
From the results in Table 1, the following effects are recognized. The 
product of this invention hardly has smell of walleye pollack and 
unpleasant smell is not noted. The surimi has fine skin and is light white 
with transparency and gloss. The quality of the surimi is markedly 
improved. Furthermore, the kamaboko prepared from the surimi hardly has 
smell of walleye pollack and unpleasant smell has disappeared. The skin is 
fine and light white with gloss. On the other hand, the surimi in 
Reference Example 1 has strong smell of walleye pollack and strong 
unpleasant smell is noted. The color tone is dark. The skin of the 
kamaboko is a little coarse and dark white without gloss. 
EXAMPLE 2 
Frozen surimi in the composition shown in Table 2 was prepared in the same 
manner as in Example 1 and kamaboko was prepared in the same manner as in 
Example 1 using the surimi after keeping at -30.degree. C. for 3 months. 
Besides, the composition was prepared by homogeneously dispersing each of 
monoglyceride of cotton seed oil, sorbitan monooleate, a sucrose fatty 
acid ester (HLB15) and polyethylene glycol monooleate in melted sorbitol 
by a mixer, cooling to cake, crystallizing and then grinding. It comprises 
90% of sorbitol and 10% of each surface active agent. The composition 
comprising 90% of sorbitol, 4% of monoglyceride of cotton seed oil, 3% of 
sorbitan monooleate and 3% cotton seed oil was prepared in the same manner 
as noted above. 
The results concerning the surimi and the kamaboko are shown in Table 2. 
The methods for measurement are the same as in Example 1. 
TABLE 2 
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Kind of Additive (weight %) 
Test Surface Active Poly Smell 
No. Agent Sugar 
*1 
*2 
*3 
Phosphate 
Surimi 
Kamaboko 
__________________________________________________________________________ 
1 Ref. 6 0 0 0 0.3 Fish smell 
Fish smell 
Ex. is strong, 
is strong, 
Unpleasant 
Unpleasant 
smell is 
smell is 
strong 
strong 
2 Ex. 
Monoglyceride of 
2 2 0 2 0.3 Fish smell 
Fish smell 
is little, 
is little, 
Unpleasant 
Unpleasant 
smell is not 
smell is not 
present 
present 
3 Ex. 
Sorbitan monooleate 
2 2 0 2 0.3 Fish smell 
Fish smell 
is little, 
is little, 
Unpleasant 
Unpleasant 
smell is not 
smell is not 
present 
present 
4 Ex. 
Sucrose fatty acid 
2 2 0 2 0.3 Fish smell 
Fish smell 
ester is little, 
is little, 
Unpleasant 
Unpleasant 
smell is not 
smell is not 
present 
present 
5 Ex. 
Propylene glycol 
2 2 0 2 0.3 Fish smell 
Fish smell 
is little, 
is little, 
Unpleasant 
Unpleasant 
smell is not 
smell is not 
present 
present 
6 Ex. 
Monoglyceride of cotton 
2 2 0 2 0.3 Fish smell 
Fish smell 
Seed oil is little, 
is little, 
Sorbitan monooleate Unpleasant 
Unpleasant 
Cotton Seed Oil smell is not 
smell is not 
present 
present 
7 Ex. 
Monoglyceride of 
2 0 2 2 0.3 Fish smell 
Fish smell 
Cotton Seed oil is little, 
is little, 
Unpleasant 
Unpleasant 
smell is not 
smell is not 
present 
present 
__________________________________________________________________________ 
*1 Branched dextrin (mean molecular weight 10,000, containing ratio 
85-90%) (Product of Sanmatsu Kogyo Co., & Ltd) 
*2 Reduced Branched dextrin, the hydrated product of *1 
*3 Composition 
Ref. Ex. indicates a comparative example. 
Ex. indicates an example of the present invention. 
As shown in Table 2, it is recognized in the groups (Nos. 2-6) of this 
invention that smell of walleye pollack in the surimi and kamaboko is 
hardly present and unpleasant smell is not felt when the branched dextrin 
and each of the surface active agent are used together. Additionally, the 
color tone of each of the surimi in the groups (Nos. 2-6) of this 
invention is light white with transparency. The effect improving quality 
of surimi is notable. Among the surface active agents, monoglyceride of 
cotton seed oil gives good effect followed by sorbitan monooleate. 
EXAMPLE 3 
Frozen surimi having the composition shown in Table 3 was prepared in the 
same manner as in Example 1 and Kamaboko was prepared in the same manner 
as in Example 1 using the surimi after storage at -30.degree. C. for 3 
months. 
Besides, the composition is prepared by dispersing homogeneously a glycerol 
fatty acid ester (monoglyceride from cotton seed oil) in melted sorbitol 
by a mixer, cooling to cake, crystallizing and then grinding. It consists 
of 90% of sorbitol and 10% of a glycerol fatty acid ester. The results 
concerning the surimi are shown in Table 3. The evaluation standard in the 
sensory test concerning surimi and kamaboko is as follows: 
A: Smell of walleye pollack and unpleasant smell are hardly present, 
B: Smell of walleye pollack and unpleasant smell become weak. 
C: Smell of walleye pollack and unpleasant smell become a little weak. 
D: Smell of walleye pollack and unpleasant smell are strong. 
TABLE 3 
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Test. Additive (Weight %) 
Smell 
No. *1 *3 Sugar *4 Surimi 
Kamaboko 
______________________________________ 
1 Ref. Ex. 0 6 D D 
2 " 0.5 5.5 D D 
3 " 0 1 5 0.3 D D 
4 " 2 4 D D 
5 " 3 3 D D 
6 Ref. Ex. 0 5.5 D D 
7 " 0.5 5 D D 
8 Ex. 0.5 1 4.5 0.3 C C 
9 " 2 3.5 B B 
10 " 3 2.5 B B 
11 Ref. Ex. 0 5 D D 
12 Ex. 0.5 4.5 C C 
13 " 1 1 4 0.3 B B 
14 " 2 3 B B 
15 " 3 2 A A 
16 Ref. Ex. 0 4 D D 
17 Ex. 0.5 3.5 B B 
18 " 2 1 3 0.3 B B 
19 " 2 2 A A 
20 " 3 1 A A 
21 Ref. Ex. 0 3 D D 
22 Ex. 0.5 2.5 B B 
23 " 3 1 2 0.3 A A 
24 " 2 1 A A 
25 " 3 0 A A 
______________________________________ 
*1 Branched dextrin 
*3 Composition 
*4 Polyphosphate 
Ref. Ex. indicates a comparative example 
Ex. indicates an example of the present invention 
The evaluation concerning the results shown in Table 3 is arranged in 
relation to each addition amount of the branched dextrin and the 
composition. The result is shown in Table 4. 
TABLE 4 
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Blanched Dextrin 
Composition 0 0.5 1 2 3 
______________________________________ 
0 D D D D D 
0.5 D D C B B 
1 D C B B A 
2 D B B A A 
3 D B A A A 
______________________________________ 
It is recognized from Table 3 that the smell of walleye pollack and the 
unpleasant smell disappear by using a branched dextrin and a composition 
of a glycerol fatty acid ester together. 
Additionally it is recognized from Table 4 that use of 0.5% by weight or 
more of a branched dextrin together with 1% by weight or more of a 
composition or 1% by weight of a branched dextrin together with 0.5% by 
weight or more of a composition makes smell of walleye pollack and 
unpleasant smell disappear. 
EXAMPLE 4 
Frozen surimi having the composition shown in Table 5 was prepared in the 
same manner as in Example 3 and kamaboko was prepared in the same manner 
as in Example 1 by using the surimi after storage at -30.degree. C. for 3 
months. Evaluation was carried out in the same manner as in Example 3. 
As the result, the reduced branched dextrin was recognized to give a little 
stronger deodorizing effect than the branched dextrin. 
TABLE 5 
______________________________________ 
Test. Additive (Weight %) 
Smell 
No. *2 *3 Sugar *4 Surimi 
Kamaboko 
______________________________________ 
1 Ref. Ex. 0 6 D D 
2 " 0.5 5.5 D D 
3 " 0 1 5 0.3 D D 
4 " 2 4 D D 
5 " 3 3 D D 
6 Ref. Ex. 0 5.5 D D 
7 " 0.5 5 D D 
8 Ex. 0.5 1 4.5 0.3 C C 
9 " 2 3.5 B B 
10 " 3 2.5 A A 
11 Ref. Ex. 0 5 D D 
12 Ex. 0.5 4.5 B B 
13 " 1 1 4 0.3 B B 
14 " 2 3 A A 
15 " 3 2 A A 
16 Ref. Ex. 0 4 D D 
17 Ex. 0.5 3.5 B B 
18 " 2 1 3 0.3 A A 
19 " 2 2 A A 
20 " 3 1 A A 
21 Ref. Ex. 0 3 D D 
22 Ex. 0.5 2.5 A A 
23 " 3 1 2 0.3 A A 
24 " 2 1 A A 
25 " 3 0 A A 
______________________________________ 
*2 Reduced branched dextrin 
*3 Composition 
*4 Polyphosphate 
Ref. Ex. indicates a comparative example. 
Ex. indicates an example of the present invention.