CA1103984A - Process for preparing squid products - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

This invention relates to a process for preparing semi-processed squid products comprising a washing step wherein raw squids previously dressed by removing legs and intestinal parts therefrom and opening the body to spread out are washing in water while stirring to remove any sticky dirt from the inner and outer surfaces thereof; a skin softening step wherein the skin of the washed squids, particularly the collagen layer, is softened while hot, followed by cooling to an ambient temperature;
a seasoning step wherein a mixture of the above treated squids and seasoning agents of a desired composition are mixed by stirring in a mixer, and the mixture of squids and the seasoning agents is then transferred to an appropriate container followed by allowing the mixture to stand for about 2 hours; and a drying step wherein the seasoned squids are dried at about 35°C for about 4 hours to a water content of 35 - 50% by weight.

Description

1 This invention relates to a process for preparing squid products, more particularly semi-processed squid products and press-heated squid products.
Known products made of raw squids include press-heated squid products, particularly whole squid products obtained by removing the intestinal parts" opening the body and press-heating and torn-up squid products prepared by tearing the press-heated squids into long strips.
These squid products have been produced by a step-wise process comprising dressing, i.e., removing the intestinal parts and opening the body, washing, first seasoning, press-heating, tearing if desired, and second seasoning. It depends upon availability of raw squids, particularly geographical conditions such as places of landing and processing, and other various factors whether these processing steps are carried out in the same factory or some former steps and some latter steps are carried out in different factories.
Among various kinds of squids, those having a relatively thick collagen layer, in the skin such as short-finned squid [Illex illecebrosus ~Lesueur)] and flying squid ~ ..
lOmmastrephes bartrami (Lesueur)] have particularly hard skin ; because of this collagen layer. Therefore, it has been difficult by the conventional processes to obtain edible products.
`~ Further, the conventionally known processes for producing squid products generally involve a step of skinning raw squids in warm water and a step of boiling. In this skinning `: :
treatment with warm water, raw squids are placed in an appro-priate skin-removing machine and at the same time warm water at 55 to 65C is poured thereinto followed by stirring. How-ever, this skinning treatment with warm water is disadvantageous ~.

1 in that an extra,ct of squids is drained off and the tissue protein of squids is heat-coagulated so that various enzymes contained in the flesh are destroyed, resulting in preventing any further increase in tasty substances, and thus greatly reducing the flavour inherent in squids. Further, the growth of mold and rancidity cannot be sufficiently prevented because of the water generated throughout the subsequent treating steps and, therefore, storage of products for a long period of time cannot always be safe. In addition, the warm water used for skinning becomes contaminated water having a biochemical oxygen demand of 10,000 to 30,000 ppm due to the dissolution of the skin itself and the escape of pigments present in the skin. This contaminated water gives rise to environmental problems if discharged as such.
Furthermore, in case of processing those squids having a relatively thick collagen layer as above enumerated, the skinning treatment with warm water as described above only removes the outermost layer of the skin with the collagen layer remaining hard.
On the other hand, Japanese Patent Publication No.
15727/1967 dlscloses a process for producing softened and seasoned squid products wherein a part of the body of raw squid is opened and the intestinal parts are removed therefrom. The thus dressed raw squids are immediately subjected to a seasoning step followed by a drying step, without a roasting step, thereby to obtain semi-processed squid products which need roasting before eating. Since this process does not employ the skinning treatment before seasoning~ it seems that the above described disadvantages associated with the skinning, particularly in warm water, are eliminated. However, the purpose of the present invention, i.e., to obtain products rich in flavour and -1 the amino acid type tasty substances and durable in storage for a long period of time without using preservatives or packing in vacuo, cannot be accomplishea simply by omitting the skinning treatment before the seasoning step or by omitting an aging or press-heating step after the seasonin~ step. Further, since the above process does not involve the skinning step as described above, in case of processing those squids the skin of which is composed of a relatively thick collagen layer, the skin remains so hard that it is very difficult to eat.
The first object of this invention is to provide a process for easily producing semi-processed squid products free from the above described disadvantages.
- The second object of this invention is to provide a process for producing press-heated squid products from the thus obtained semi-processed squid products, wherein palatable products rich in flavour and durable in storage for a long time can be obtained without using any particular preservatives or packing in vacuum.
The third object of this invention is to provide a process for producing more palatable torn-up squid products from the thus obtained press-heated squid products.
In the present invention, raw squids are dressed by removing the legs and the intestinal parts from the body and opening the body. Immediately after washing, the squids are subjected to a skin softenin~ treatment with hot water at 80 to 90C for 1 to 2 minutes, without the skinning treatment in warm water and the subsequent boiling treatment, whereby the collagen layer is gelatinized, the rate of absorption of seasoning agents is increased and autodigestive enzymes inherent to squid protein can be retained without being destroyed. The .

1 thus treated squids are then seasoned, followed by drying at about 35c for about ~ hours to obtain semi-processed products having a water content of 35 to 50~.
The semi~processed products as above prepared, even those obtained from short-finned squid, flyin~ squid and the like having a hard skin, have palatable softness and exhibit high penetrability of seasoning agents and also are free from various disadvantages associated with the skinning treatment with warm water and the boiling treatment.
Further, since the skin softening step, the seasoning treatment and the drying treatment are carried out with the skin being on the squids unlike the conventional process wherein the skin is peeled off in the initial stage, various components contained in the skin are penetrated into the flesh and can be retained therein as nutrients and tasty substances after removing the skin in the subsequent step.
In addition, the conventional process requires 1,500 liters of warm water or hot water and 17 liters of A heavy oil fuel per 1,000 Kg of raw squids, thus resulting in increase of the preparation cost. Further, in the conventional process about 5,000 liters of contaminated water including water for cooling has been discharged thus giving rise to a serious environmental problem. Whereas, the present invention does not - involve the skinning treatment with warm water and the boiling treatment so that loss of water-soluble proteins can be avoided, the yield can be increased, the preparation cost can be reduced, and the cause of environmental pollution, i.e., discharge of contaminated water, does not occur.
~he semi-processed product as obtained above are then subjected to an aging treatment by allowing them to stand in an _4_ ., . . -:' :

~l~g~4 1 appropriate container at about 20 to 25C for at least about 24 hours in such a manner that drying does not proceed further.
By this aging treatment, the above described autodigestive enzymes are activated, and autodigestion and absorption of the decompositiOnproducts of the skin into the tissue protein result in a synergestic lncrease of nucleic acid and amino acid type tasty substances, thus making it possible to retain the flavour inherent in squids in the products. Further, the above aging treatment allows the water content (35 to 50~ by weight) and the seasoning agents to spread uniformly throughout the flesh and provides conditions which enhance enzymatic decomposition of collagen fibers in the fourth layer constituting the epidermis, and also conditions which impart moderate softness of the final products. Additionally, the above aging treatment decreases the activity of water content in the products, and the enzymatic decomposition makes it easy to separate the skin layer from the flesh.
The squids after the aging treatment has been finished are then spread between an upper and lower heat plates and heated at 1~0 to 200C for about 3 minutes under a pressure of about 30 Kg/cm to effect a press-heating and also sterilization, thereby to obtain heat-pressed products having a water content of 27 to 35%. The resulting products have palatable softness and are durable in storage for an extended period of time without the need of using preservatives or of packing the products in a vacuum.
The press-heated products obtained as above are eatable as they are, and therefore, marketable as final product. If desired, however, the press-heated products are then placed on rollers to destroy fibrous tissue and to peel the skin therefrom.

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1 The resulting squids are torn into pieces and finally seasoned with seasoning agents to obtain torn-up products.
A process according to the present invention will now be illustrated in greater detail by reference to the following example. This example is not to be construed as limiting the scope of the present invention.

E X A M P L E
(1) Washing Step Legs and intestinal parts of raw short-finned squids - (including defrozen squids) were removed, and the body was opened and spread out~ The body was then washed with water wnile stirring to remove any dirt attached to the inner and outer surfaces of the body. In this washing step, the use of salt water enhances the removing effect.

(2) Skin Softening Step The above treated squids were immersed in hot water at 80 to 90C for about 1 minute. Although collagen is ~enerally unsusceptible to actions of acid, alkalis, enzymes and the like, this immersion in hot water gelatinizes the collagen layer in the skin, thereby to ensure penetration of seasoning agents, i.e., to increase the absorption rate, and to impart eatable softness to the skin. Moreover, the tissue protein is not dissolved since the treatment time is short. Instead of the immersion in hot water, the skin softening treatment may be carried out by pouring hot water at 80 to 90C onto squids for 1 to 2 minutes or by placing squids in a saturated vapor at 80 to 90C for about 1 minute.
~3) Seasoning Step The heat-treated squids as above were immersed in water to cool to an ambient temperature (18 to 25C), followed b~

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1 draining off. 50 Kg of the resulting squids were placed in a mixer together with powdery or liquid seasoning agents comprising 3000 g of sugar, 1450 g of sodium chloride, 20 g of ~lytimin (trade name, manufactured by Maruzen Kasei Kabushiki Kaisha, Japan), 50 g of glycine, 30 g of succinic acid, 300 g of sodium glutamate, 120 g of Sansugen S2 (trade name, manufactured by San-ei Kagaku Kogyo Kabushiki Kaisha, Japan), 50 g of citric acid and 1000 g of sorbit liquid (a 70% D-sorbit liquid available from Tokai Kogyo Kabushiki Kaisha, Japan). The resulting mixture was mixed for S to 10 minutes until the powdery season-ing agents were dissolved and uniformly blended. Thereafter, ~-the resulting raw material comprising the squids and the seasoning agents was transferred to an appropriate container and allowed to stand for about 2 hours to permeate the seasoning agents into the flesh of squids.

(4) Drying Step The above seasoned squids were then dried for about 4 hours using an indirect warm-air drier set at around 35C to a water content of 35 to 50%.
The first object of this invention, i.e., to obtain semi-processed products, can be achieved through the above (1) to (4) steps.

(5) Aging Step The semi-processed squids as above prepared were placed in an appropriate covered container and preserved at a low temperature ranging from 20 to 25C for 24 hours or more.

(6) Heat-Pressing Step Each of the above obtained aged squids was spread between upper and lower heat plates heated at 150 to 200C and pressed under a pressure of about 30 Xg/cm2 for 3 minutes. The ~ .

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1 flesh of the squid was thus baked flatly and uniformly to a water content of 27 to 35~. This press-heating also released the skin from the fibrous protein by instantaneous shrinkage thereof.
The second object of this invention, i.e., to obtain press-heated products, can be achieved through the above (1) to (6) steps.

(7) Skinning Step & Tearing Step The press-heated squid was then placed on metal rollers of a known type to destroy fibrous tissue as well as to peel the skin therefrom. The resulting squid was then torn into long strlps having a width of 2 to 3 mm using a conventiona~ machine to obtain eatably sized products.

(8) Seasoning Step for Finishing The above long strips of squids were seasoned with ~easoning agents of a desired composition (for example, in a powdery form of a desired taste) to obtain final products having a water content of 25 to 30% and palatable softness.
The third object of this invention, i.e., to obtain torn-up products, can be achieved through the above (1) to (8) 20 steps.

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Claims (4)

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

1. A process for preparing semi-processed squid products comprising a washing step wherein raw squids previously dressed by removing legs and intestinal parts therefrom and opening the body to spread out are washed in water while stirring to remove any sticky dirt from the inner and outer surfaces thereof;
a skin softening step wherein the skin of the washed squids, particularly the collagen layer, is softened while hot, followed by cooling to an ambient temperature;
a seasoning step wherein a mixture of the above treated squids and seasoning agents of a desired composition are mixed by stirring in a mixer, and the mixture of squids and the seasoning agents is then transferred to an appropriate container followed by allowing the mixture to stand for about 2 hours;
and a drying step wherein the seasoned squids are dried at about 35°C for about 4 hours to a water content of 35 to 50% by weight.

2. A process for preparing semi-processed squid products as claimed in Claim 1, wherein said skin softening step is carried out by immersing the washed squids in hot water.

3. A process for preparing press-heated squid products comprising an aging step wherein the semi-processed squid products as obtained in Claim 1 are allowed to stand in an appropriate covered container at 20 to 25°C for at least about 24 hours without further drying;

Claim 3 cont'd.
and a press-heating step wherein the aged squids are spread between upper and lower heat plates heated to 150 to 200°C and pressed under a pressure of about 30 Kg/cm2 for about 3 minutes to a water content of 27 to 35%.

4. A process for preparing press-heated squid products as claimed in Claim 3, which further includes a skinning step wherein the press-heated squids are placed on a grinding roller to destroy the tissue fibers of squids as well as to peel off the skin therefrom;
a tearing step wherein the squids are torn into long strips using a tearing machine;
and a final seasoning step wherein the long strips of squids are seasoned with seasoning agents of a desired composition.