CA1053066A

CA1053066A - Method for the production of fish meat powder retaining functional characteristics of fresh fish meat

Info

Publication number: CA1053066A
Application number: CA260,061A
Authority: CA
Inventors: Fumindo Kai; Eitaro Kumazawa; Yozo Ishioka; Kazuyoshi Ishida
Original assignee: Snow Brand Milk Products Co Ltd
Current assignee: Snow Brand Milk Products Co Ltd
Priority date: 1975-09-04
Filing date: 1976-08-27
Publication date: 1979-04-24
Also published as: JPS5540023B2; JPS5231863A; SU716513A3; ZA765029B; AR214299A1; NO763007L; NO142985C; NO142985B

Abstract

METHOD FOR THE PRODUCTION OF
FISH MEAT POWDER RETAINING
FUNCTIONAL CHARACTERISTICS OF FRESH FISH MEAT

Abstract of the Disclosure A fish meat powder retaining the functional characteristics of fresh fish meat is obtained by mincing fresh fish meat or frozen SURIMI (frozen ground fish meat) to from a sol having fine air bubbles uniformly distributed therein, foaming the resultant fish meat sol under a vacuum and drying the fish meat foam in the form of a thin sheet at low temperatures. This method enables fish meat powder to be obtained by a process which does not involve excessive energy utilization and which does not result in the distruction of the useful characteristics found in the fish starting material.

Description

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FIELD OF THE INVENTION:

This invention relates to a method of producing a : . .
fish meat powder from fresh fish meat or frozen SURIMI, which powder retains the functional characteristics of the starting material. The term "frozen SURIMI" as used herein means the product obtained by freezing fresh fish meat with a poly-,~ phosphate, sorbitol, sugar, etc.(as described, for example, ln U.~. Patent No. 3,955,011).
BACKGROUND OF T~IE INVENTION:
In recent years, in consequence of an increase in the demand for fish meat as a source of protein, as need has arisen for the establishment of a method which permits fish meat stock to be preserved in a state in which it has the - functional characteristics of fresh fish meat and in which it can retain these characteristics intact for a long period of time.
A known preservation method comprises the steps of slicing meat from the fish body, washing the meat slices with water, grinding the washed meat slices with a polyphosphate and a saccharide or sugar alcohol and freezing the resultant ground meat mixture, namely a method whereby the fish meat is preserved in the form of frozen SURIMI. This method is effective in preventing the fish meat from losing the functional characteristics of fresh fish meat during the period of frozen storage and in preventing the fish meat from being degraded owing to the freezing thereof. Nevertheless, with this method it is essential that the fish meat be stored in - a frozen state with the consequent disadvantage that it is expensive to freeze the meat and to keep it frozen during - 30 storage and distribution to the market outlets.
` With a view to ensuring simple handling during .; ' ,~

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distribution to market outlets, a method has been proposed for producing a fish meat powder which retains the functional characteristics oE the fresh fish meat used as the starting material by preparing fresh fish meat or Erozen SURIMI in the form of sol and subsequently spray drying the Eish meat sol to form a powder. According to this method, however, the fish meat prepared in the form of sol must be diluted wlth water to a solids content of about 10 percent so as to be sultable for the spray drying operation. This addition of extra water brings about the disadvantage that the energy spent -'n the dehydration of the sol by spray drying is increased.
Means such as spray drying, freeze drying and vacuum drying, are generally used for the drying of foodstuffs depending upon the attributes and form of each particular ;
foodstuff. In the case of fish meat, because of peculiar ;~
properties such as the high susceptibility of fish meat proteins to denaturization and the high molecular weights `
of the fish meat proteins compared with those of other food-stuffs, it is considered extremely difficult from the practical point OI view to dry fish meat in such way that the ;
functional characteristics of the fresh fish meat will be ~t;lined intact throughout the drying treatment. Fish meat ~; powder ret~nlng the aforementioned characteristics can be produced by the use of a freeze drying process which entails little denaturization of the fish meat proteins, but the -~ fish meat used as the starting material is generally first frozen and then subjected to heat~drying in a vacuum. This process, therefore, has the disadvantage that energy expenditure is required in two separate steps i.e. the freezing and drying. Furthermore, since this process is usually carried : '

- 2 -~53~66 ..out batchwise9 the production efriciency thereof is too low to ,;, render the process practicable.
SUMMARY OF THE INVENTION: :
In view of the state of affairs described above, we made a study in search of a method for the production of a flsh meat powder substantially retaining the functional characterlstics of raw :Eish meat, which method does not require large energy costs for drying and can be practised in a continuous operation According to the invention there is provided a ;~
method of producing a fish meat powder substantially retaining the functional charac.teristics of fresh fish meat, comprising mincing and kneading fresh fish meat or frozen SURIMI at a `
temperature of not more than 30C in such way as to form a fish meat sol having fine air bubbles uniformly distributed therein, then foaming the fish meat sol thus obtained under a vacuum to convert said sol into a porous mass and drying ~., said porous mass in the form of a thin sheet at a temperature of not more than 30C.
In the process of the present invention, the energy cost required for the final drying is very low, the operation of. drying can be accomplished in a continuous manner at a high rate and the aforementioned functional characteristics are substantially retained in the final product because :
the conversion of the fish meat into the sol is effected without the addit.ion of water. .
DETAILED DESCRIPTION 0~ THE PREFERRED EMBODIMENTS OF THE INVENTION-, . ., . _ _ , The fish meat which is used as the raw material in the present invention can be fresh fish meat or frozen SURIMI ..
:, obtained from any white-meat fish which has a comparatively low oil content and has an ability to form KAMABOKO (boiled fish .
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meat cake). Examples of the fisll which satisfy this requirement and are suitable for this purpose include Alaska pollack, komai, flatfish, warazuka9 lockington, saurida, nibea mitsukuria, ' merluza, halibut and tilapia. The fish meat to be used as the raw material should be as fresh as possible, for the KAMABOKO-Eorming property of the fish meat increases with the degree o~ freshness of flsh meat. The term "functional characteristics of fresh fish meat" as used herein means the K~MABOKO-forming property (preponderantly the binding ability), the water-holding property (representative of the affinity for water) and other similar properties which are `~
inherently possessed by fresh fish meat. These functional ~ ' ' characteristics are very important from the standpoint of the utilization of the fish meat in food processing. The functional characteristics decrease proportionally as the ' ' denaturization of the fish meat protein advances. For this reason it is preferable to incorporate saccharides such as `~ sucrose, glucose, maltose and lactose and sugar alcohols such as sorbitol, xylitol and mannitol into the fish meat ~; 20 because these substances possess the ability to prevent ' denaturization of proteins due to dehydration. Where frozen SURIMI is used as the raw material, however, the incorporation of such additives is not particularly necessary because frozen SURIMI usually already incorporates these substances in conjunction with polyphosphates to serve as agents for prevention of denaturlzation due to freezing.
The fish meat satisfying the aforementioned requirements is minced and kneaded in a suitable kneading machine, such as a colloid mill, while the meat is held at a temperature of not more than 30C so as to form a fish meat sol having fine air bubbles uniformly contained therein.
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- Addition to the fish meat of a soLuble polysaccharide such as dextrin, a soluble protein such as whey protein or egg white, a natural gum such as tragacanth gum or a synthetic stabilizer such as carboxymethyl cellulose (CMC), preparatory to the formation oE the fish meat sol, enables the fine air bubbles produced in the aforementioned step of kneading to be stably contained ln the resultant meat sol. Further, the aEorementloned mincing and kneading treatment is preferably carrled out qulckly at a low temperature in the range of 0 to 5C. ~t temperatures in this range, the meat is prevented from freezing, whilst on the other hand, the meat temperature is held well below 30~C. All precautions should be exerclsed to keep the meat temperature below 30C, for if the meat temperature rises above 30C, there is a possibility ~ i that the flsh meat proteins would undergo denaturization in the course of the treatment and consequently the functional characteristics of the fish meat powder would be impalred.
The formation of a fish meat sol having fine air bubbles uniformly distributed therein may satisfactorily be carried out by mlncing and kneading the fish meat in a -colloid mill operated at a rate of about 1,000 to 5,000 rpm.
Once the fish meat sol having fine air bubbles unlformly distributed therein is formed, the foaming by the vacuum treatment and the subsequent drylng step can be carried out ~ ;
very effectively. The flsh meat sol offers no hindrance to -' the drylng treatment since the viscosity of the sol is below ` about 2,000 poise. The method of the present invention, therefore, proves to be advantageous over the conventional methods which r~ rely for the productlon of flsh meat powder upon the known art of spray drying.
The fish meat sol obtained as described above is ':; :
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quickly foamed under a vacuum, preferably a vacuum in the range of from 4.6 to 30 Torr, to give a spongy mass having a foamed texture. Subsequently, the spongy mass is spread in the form of a thin sheet on a surface, e.g. the surface of a drying belt made of steel, and the thin sheet is dried e.g.
by means of radiant heat or heat conducted through the medium o~ the belt or by a combination of the two means of heat appllcation. If the fish meat sol is kept under a vacuum of less than 4.6 Torr, there is a possibility that the sol will freeze. If it is kept under a vacuum of more than 30 Torr, however, the temperature of the sol rises and consequently the functional characteristics of the fresh fish meat are degraded and the stability of the cells in the foamed mass is impaired to such an extent that the solid may be converted back into a liquid state. Use of a vacuum outside the stated range of 4.6 to 30 Torr, therefore, proves to be disadvantageous. If the drying treatment is performed on the ;
fish meat sol which has assumed a liquid state, then a dry film is formed on the surface of the sol which impedes the escape of further water from inside the sol, therefore, even if the interior of the system is kept under a low degree of vacuum, the temperatura of the material being treated rises in the course of the drying treatment, with the result that `
the functional characteristics will be degraded.
When the fish meat sol is foamed to produce a spongy texture and then subjected to drying as described above, the water present in the sol is readily diffusible in conjunction with the air bubbles and, at the same time, the vaporization `
area is very large because of the porosity of the substance.
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Consequently, the drying can be rapidly accomplished even by a small temperature gradient. According to the present . i ~.
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S3~;6 invention, therefore, the drying of the fish meat sol can be accomplished while the temperature of the sol is held below 30C, i.e. the highest temperature at which the fish meat proteins can be prevented from denaturizing. By the drying method described above, the water content of the finally produced fish meat powdercan be decreased to below 6 percent.
SLnce the method lnvolves the conversion of fish meat into a sol wlthout necessarily requiring the addition of water, the concentration of solids in the resultant sol is in the neighborhood of 20 percent, even when the raw material is in the form of fish meat slices. In the drying step, therefore, the energy required for obtaining a fish meat powder having a water content of not more than 6 percent is notably low as compared with the spray drying treatment (in which the solids content of the sol must be lowered to the neighborhood of 10 percent).
The fish meat powder which is obtained by the drying treatment is preferably immediately packed into an airtight ` ;
container by a vacuum packaging method and put into storage ;
at low temperatures of the order of O to 10C.
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As illustrated in one of the Examples cited hereinafter, a test specimen prepared by kneading a fish meat powder :. . :
obtained in accordance with the present invention in conjunction - with a suitable amoune of water and about 3 percent oi sodium chloride, subjecting the resultant mix to further kneading in conjunction with added starch and heating the final mix by following the procedure employed in the production of - KAMABOKO, with necessary modifications, was found by test to have a jelly strength of about 6~0 g, a value comparab].e with the jelly strength of a test specimen prepared by subjecting raw SURIMI from fresh fish meat to the same treatment. This - ~5 6~ :
indicates that the fish meat powller has a jelly strength (namely, a KAMABOKO-forming property) and a water-holding property (namely, the ability to reconstitute on the addition of water) similar to that of fresh fish meat. ~
; As described above, the present invention enables a ~`
Eish me.at powder substantially retaining the functional characteristics ~namely, the KA~ABOKO-forming ability and the water-holding property) of ~the fish meat used as the raw material, to be obtained with great advantage. Thus, this invention may contribute greatly to the utility of fish meat in food processing.
The present invention will now be described with reference to the Examples given below. These Examples should not be considered as limitations of the present invention.
Example 1:
~' 100 kg of raw slices of pollack washed in advance with water was mixed with 2.5 kg of sucrose. The mix was : cooled to a temperature of O to 5C and then minced and kneaded into a sol in a colloid mill operated at a rate of 2,200 to 2,300 rpm and simultaneously cooled so as to keep the meat temperature from rising above 30C. The resultant sol was observed to have fine air bubbles uniformly distributed throughout.
~`~ The sol was continuously delivered, as soon as it `
was formed, to a vacuum drier, the interior of which was ` maintained under a vacuum of 5 to 6 Torr, and was spread to -- a uniform thickness on a belt disposed inside the dryer housing. The belt was kept at a-temperature below the temperature of the sol (not more than 30C). The sol spread ~ 30 on the belt foamed violently in the vacuum and assumed a spongy state. The belt was moved so that unit heaters, disposed one , ":

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53~66 above and one below the plane of tile belt at suitable points, heated the sol spread on the belt, the heaters being controlled so as to keep the temperature of sol below 30C. This t controlled heating was carried out by graduating the temperature of the unit heaters along the path of the belt; first at 180 to 220C for one minute, then at 130 to 170C for three mlnutes, at 90 to 110C for five minutes and finally at 30 to 50C for seven minutes. The fish meat powder which was consequently obtained by this drying treatment had a water - 10 content of 3.4%
Water was added to the fish meat powder thus obtained `
in the amount required for the solids content to reach the `
neighborhood of 25 percent, i.e. similar to that of the fish ; meat used as the starting material, and the mixture was kneaded -in the presence of the added water for ten minutes. Subsequently, the resultant mix was kneaded for ten minutes in the presence of 2.5 percent by weight of sodium chloride. It was then ` subjected to a final kneading with 5 percent by weight of starch for ten minutes in a vacuum grinder. The finally produced mix was immediately placed in a casing, heated at ~`
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85C for 30 minutes to undergo gelation, cooled, then held at 5C for 48 hours and thereafter tested for jelly strength.
For the purpose of comparison, raw SURIMI was subjected to t. the heat treatment described above, except for the omission - of water addition. The finally produced mix was cooled and thereafter tested for jelly strength. The results were as shown below. -- Jelly strength (g) ; Test specimen obtained by Example 1 700 Text specimen obtained from raw SURIMI 763 The measurement of the jelly strength was made by the ,.

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~)53066 use of an Okada type jelly strength meter and steel balls 5 mm in diameter.
The gelled mix obtained by the aforementioned steps of heating and cooling was molded into a sheet 3 mm in thickness, folded into Eour plies and subjected to a bending ; test. Ln the test, substantially no cracks were Eormed.
(The bending strength was rated as the highest AA grade according to the standard use in the trade.) Furthermore, each of the above gelled mixes was , 10 tested by a texturometer (General Foods Corp., U.S.A.) The results were as shown below.
HardnessElasticity Test specimen of Example 1 4.61 11.5 Test specimen from raw SURIMI 4.8 9.0 Example 2:
An unsalted frozen SURIMI (having a solids content of 25 percent) was defrosted at low temperature and sliced at ., ~- . .
a temperature held in the range of O to 5C. The slices were minced and kneaded in a colloid mill operated at a rate of 2,300 rpm and cooled so as to keep the temperature of the meat below 30C. The mix was then treated by repeating the procedure of Example 1, to afford a fish meat powder.
Water was added to the fish meat powder in the amount required for the solids content of the mixture thereof to reach the neighborhood of 25 percent, i.e. similar to that of the frozen SURIMI used as the starting material, then the mixture was subjected to preliminary kneading, then to kneading ~ -in the presence of sodium chloride and then to a final kneading.
The mix from the final kneading was heated to produce a gel.
The gel was cooled and then tested for jelly strength and subjected to a bending test. The results were as shown below.

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For the purpose o~ comp~is~n ~ th`~ frozen SURIMI used as the starting material was subjected to heat treatment by repeating the procedure described above, except for omission of the water addition. The sol consequently obtained was cooled and then tested Eor jelly strength.
Jelly Strength (g) Test specimen obtained by Example 2 680 Test specimen obtained from frozen SURIMI 712 The bending test performed by the procedure of ' 10 Example 1 rated the bending strength as AA grade.

Furthermore, the results tested by the texturometer ~-i mentioned in the Example 1 were as shown below. ;~
;~ Hardness Elasticity ; Test specimen of Example 2 4.58 12.0 Test specimen from raw SURIMI 4.8 9.0 ''' ::
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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of producing a fish meat powder substantially retaining the functional characteristics of fresh fish meat, comprising mincing and kneading fresh fish meat or frozen SURIMI at a temperature of not more than 30°C in such way as to form a fish meat sol having fine air bubbles uniformly distributed therein, then foaming the fish meat sol thus obtained under a vacuum to convert said sol into a porous mass and drying said porous mass in the form of a thin sheet at a temperature of not more than 30°C.

2. A method according to claim 1, wherein said mincing and kneading steps are carried out in the presence of a soluble polysaccharide, a soluble protein, a natural gum or a synthetic stabilizer at a temperature of not more than 30°C.

3. A method according to claim 2, wherein said temperature is in the range of from about 0°C to about 5°C.

4. A method according to claim 1, wherein said fish meat sol is foamed under a vacuum of from 4.6 Torr to 30 Torr.

5. A method according to claim 2, wherein said polysaccharide is dextrin.

6. A method according to claim 2, wherein said soluble protein is whey protein or egg white.

7. A method according to claim 2, wherein said natural gum is tragacanth gum.

8. A method according to claim 2, wherein said synthetic stabilizer is carboxymethyl cellulose.