JP2008022784A - Biodegradable lure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable lure made from a natural raw material, equipped with tearing strength and heat resistance of enduring practical uses and solving a problem of the decrease of the tearing strength caused by swelling with water absorption. <P>SOLUTION: This biodegradable lure consists mainly of gelatin gel having ≥4.0 mPa s viscosity measured in accordance with the JIS K6503. Or, it is formed as a gelled material of a gelatin composition containing at least one kind of a cross-linking component in epoxy cross-linking agents and aldehyde cross-linking agents and the gelatin, or it consists mainly of the gelatin-gelled material cross-link-treated with the above cross-linking agent, and some non-melted substance remains in molten gelatin in the measurement of the viscosity in accordance with the JIS K6503. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a biodegradable pseudo bait that has little impact on the environment, and more specifically, a biodegradable pseudo bait that has improved durability against water absorption swelling or breakage during use and ensures a satisfactory usable time. About.

  In recent years, the popularity of fishing as a hobby has increased, and the fishing population has increased. With this increase, fishing gear such as artificial baits and fishing lines are left in the environment in large quantities, affecting the living environment and the natural environment. The impact is noticeable. For this reason, from the viewpoint of environmental protection, there is a need for fishing gear that can be decomposed even if left in the environment.

In order to meet the above needs, production of a pseudo bait using a biodegradable substance has been studied. For example, in Patent Document 1 below, a pseudo bait using a biodegradable synthetic polymer has been proposed. In addition, utilization of natural materials such as persimmons, polysaccharides, agar, etc. has been studied. For example, the following patent document 2 is a smoked pseudo bait, and the following patent document 3 is a pseudo bait using agar. Document 4 proposes a pseudo bait using curdlan, and Patent Document 5 below proposes a pseudo bait using gelatin.
JP 2005-143413 A Japanese Patent Laid-Open No. 10-084884 JP 09-322676 A JP 2001-309737 A JP 2000-060363 A

  Synthetic materials can be modified in molecular design to bring them closer to the required material properties, but may be insufficiently degradable in the natural environment. In addition, some additives used in plastic simulated bait are suspected of acting as environmental hormones, and there is concern about unpredictable effects on the ecosystem. Is desirable.

  On the other hand, natural materials have good biodegradability, but the strength and heat resistance of the materials themselves are not high, so that the natural food pseudo bait is easily detached from the needle due to insufficient tear strength. For this reason, in the above-mentioned patent document, the material is improved by blending additives, enzyme treatment, chemical treatment, etc., but it is difficult to obtain satisfactory materials, and there are also problems such as water absorption swelling and insufficient heat resistance. Therefore, only the curdlan-made artificial bait is currently offered to the market.

  The present invention can provide a biodegradable artificial bait that solves the above-mentioned points, is composed of natural materials, has tear strength and heat resistance that can withstand practical use, and solves problems such as strength reduction due to water absorption swelling. The problem is to do.

  In addition, the present invention provides a biodegradable pseudo bait that can promote effective use of natural materials treated as a by-product and has physical properties equivalent to or higher than those of the biodegradable pseudo bait currently provided on the market. This is the issue.

  In order to solve the above-mentioned problem, the present inventors have found that, as a result of intensive research, they can provide a pseudo bait that can withstand practical use by devising a process for producing a pseudo bait using gelatin, The present invention has been completed.

  According to one aspect of the present invention, the biodegradable simulated bait is mainly composed of a gelatin gel product having a viscosity measured according to JIS K6503 of 4.0 mPa · s or more.

  According to another aspect of the present invention, the biodegradable simulated bait is mainly composed of a gelatin gel product crosslinked with at least one of an epoxy crosslinking agent and an aldehyde crosslinking agent, and has a viscosity according to JIS K6503. The gist is that infusible material remains in the measurement.

  Furthermore, according to another aspect of the present invention, the biodegradable simulated bait is formed of a gelled gelatin composition containing at least one crosslinking component of an epoxy crosslinking agent and an aldehyde crosslinking agent and gelatin. This is the gist.

  The content of the crosslinking component may be 1 to 10% by mass of the gelatin content.

  The biodegradable simulated bait can be obtained by gelling molten gelatin having a viscosity measured in accordance with JIS K6503 of 4.0 mPa · s or more and forming the gel.

  Alternatively, a cross-linking treatment for cross-linking gelatin of the pseudo bait is provided, and in the cross-linking treatment, the whole pseudo bait or the surface of the pseudo bait is cross-linked using at least one of an epoxy cross-linking agent and an aldehyde cross-linking agent. .

  The cross-linking of the pseudo bait surface can be performed by immersing the molded pseudo bait in an aqueous crosslinking agent solution, and the flexibility is improved by heating the pseudo bait to a temperature of 60 to 110 ° C. after the treatment with the cross-linking agent.

  The biodegradable simulated bait can be provided at a heat resistant temperature of 40 ° C. or higher, and the tear strength after water absorption can be maintained at 100 gf or higher. Those having a degree of swelling of 90% or less can be provided by the crosslinking treatment, and can be distinguished as infusible substances remaining in the viscosity measurement according to JIS K6503.

  INDUSTRIAL APPLICABILITY According to the present invention, a biodegradable pseudo bait that can withstand practical use can be manufactured using gelatin, can contribute to prevention of natural destruction by fishing gear left in the natural environment, and, as a raw material for gelatin, leather It is possible to use floor skin, which is a by-product in the manufacture of products, and can contribute to effective use of the by-product.

  Generally, the raw material skin used for the production of leather products has a structure composed of a nipple layer (silver surface) and a net layer, and is divided into an appropriate thickness before the wrinkle process. After division, the nipple layer is used as a raw material for leather products through a wrinkle process, but the mesh layer is not used as a raw material for leather because it is not dense, and becomes a by-product as a floor skin. For this reason, in order to make effective use of this, development of use for floor skins has been attempted, and one of the uses is as a raw material for gelatin. If a biodegradable pseudo bait that can withstand practical use can be produced using gelatin, it will be an effective use of by-products, which is very useful.

  However, gelatin easily swells due to water absorption, so that it swells and disintegrates in water in a short time, and has low heat resistance, so it easily melts due to an increase in summer temperature. In order to produce a pseudo bait using gelatin, (a) increase the tear strength, (b) suppress water absorption swelling and the accompanying strength reduction, (c) impart practical heat resistance, (d) It is necessary to improve the four points of ensuring appropriate flexibility as a material for the simulated food, and the means for realizing these must be such that the resulting simulated food does not affect the natural environment.

  As effective means for the improvement, there are two methods: (1) using specialized gelatin and (2) subjecting gelatin to a crosslinking treatment. In (1), the strength of the gelatinized and molded gelatin is improved by constructing the pseudo bait with higher molecular weight gelatin than general gelatin, so that it can withstand practical use even if the strength decreases due to water absorption. Strength is secured. In addition, the effectiveness is particularly enhanced by appropriately controlling the cooling rate during molding. In (2), water resistance and heat resistance are imparted by applying a crosslinking treatment to the gelatin molded into the shape of a pseudo bait (thus increasing the molecular weight), and a decrease in strength and hardness due to water absorption is suppressed. . The cross-linking treatment can be applied to the whole simulated bait or the surface-only gelatin. Furthermore, flexibility can be improved by performing a heat treatment after crosslinking. (1) and (2) are common in terms of high molecular weight. When (1) and (2) are combined, the effect increases synergistically and the effectiveness is significantly improved. Hereinafter, the manufacturing method of the biodegradable pseudo bait of this invention is demonstrated in detail.

  In the present invention, the material constituting the biodegradable simulated bait is gelatin that is a modified product of collagen due to heat or the like, and the gelatin used in the above (1) has a higher molecular weight than commercially available gelatin, that is, has a high viscosity. Gelatin. Specifically, the viscosity (measured at 60 ° C. within 15 minutes after melting the sample at 70 ° C.) of a commercially available gelatin according to JIS K6503 is generally about 2.0 to 3.5 mPa · s. On the other hand, what is used as (1) is gelatin (denatured collagen product) having a viscosity according to JIS K6503 of 4.0 mPa · s or more, preferably 7 to 30 mPa · s, more preferably 15 to 25 mPa · s. ). By gelling and molding such a high-viscosity (high molecular weight) gelatin melt, the tear strength and hardness of the resulting pseudo bait increase, and the strength and proper hardness that can withstand practical use even when water is absorbed are ensured. The heat-resistant temperature is also raised. Such gelatin can be obtained by adjusting processing conditions when solubilizing insoluble collagen contained in a collagen raw material.

  Gelatin is prepared by using raw tissues, tendons, bones and other tissues containing a large amount of collagen from animals such as cows, pigs and birds. You may obtain from aquatic raw materials, such as a fish skin and a fish scale, and it is not necessary to specifically limit a raw material. It is particularly preferable in terms of effective utilization of resources to use as a raw material collagen of the floor skin, which is a by-product of leather manufacture. Collagen raw materials such as cow skin and pork skin are prepared into raw material pieces of appropriate dimensions by performing treatments such as depilation by lime pickling, washing with water, chopping using a chopper or the like, if necessary.

  The collagen molecule is a rod-like molecule composed of three polypeptide chains, the main part has a helix structure (helix region), and a short telopeptide region that does not form a helix at both ends. In vivo, collagen exists as a macromolecule polymerized by intermolecular crosslinking formed between the telopeptide region and the helix region, so it is usually insoluble in water, dilute acid, dilute alkali, organic solvent, etc. Yes, even if the collagen raw material piece is heated, it does not dissolve. However, by subjecting the collagen raw material pieces to a solubilization treatment, the collagen in the state in which the bonds in the collagen are broken and the molecular weight is lowered and heat melting is possible. When this is denatured by heat melting or the like, it becomes gelatin.

  Collagen solubilization is performed by a method using a proteolytic enzyme (see, for example, Japanese Patent Publication No. 44-1175, hereinafter referred to as an enzyme treatment method), and a small amount of amines in an aqueous solution in which caustic alkali and sodium sulfate coexist. Alternatively, it can be roughly classified into a method of treating with an addition of an analog thereof (for example, see Japanese Examined Patent Publication No. 46-15033, hereinafter referred to as an alkali treatment method). In the present invention, the solubilization treatment is performed according to the alkali treatment method, but the solubilization treatment is performed under specific conditions in order to obtain collagen having a polymerization degree as high as possible within a range in which heat dissolution is possible. Specifically, the immersion treatment is performed using an aqueous solution containing only caustic alkali and sodium sulfate without using amines or the like that promote solubilization. This is a characteristic processing method capable of preparing gelatin having a suitable viscosity for use in the present invention, and only the telopeptide region between collagen molecules is selectively decomposed to crosslink between the telopeptide region and the helix region. Since the polymer is cleaved, the degree of polymerization is reduced, but it is difficult to cleave within the collagen molecule, and excessively low molecular weight can be avoided. The treatment time is set to about 1 to 3 days, preferably about 1 to 2 days, more preferably about 1 day. During this time, the cleavage of the collagen intermolecular crosslinks proceeds, and the molecular weight decreases as the treatment time increases. However, when the time exceeds about 4 days, the viscosity decreases excessively. Further, when the treatment temperature exceeds 30 ° C., the helix region is cut and the molecular weight of the resulting gelatin becomes small. Therefore, the temperature is kept below this temperature, preferably 20 to 28 ° C. In the alkali treatment method, the asparagine residue and glutamine residue are changed to aspartic acid residue and glutamic acid residue, respectively, by deamination reaction, and the isoionic point of collagen is generally about 4.8 to 5.0. By adjusting the pH of the aqueous solution after the solubilization treatment to an isoionic point and removing the water by dehydration or the like, the heat-dissolvable collagen maintaining the shape of the raw material pieces is recovered. Further, if necessary, impurities such as metal salts are removed by washing and dehydrating. Since this collagen is adjusted to an isoionic point, even if the metal salt is removed by washing with water, it does not dissolve in water. Collagen obtained through the solubilization treatment, pH adjustment, and water washing step is a solid collagen having a solid content of about 30% by mass and retaining the shape of the raw material pieces.

  Collagen loses its helix structure by heat treatment at about 30 ° C. and is denatured into gelatin. Therefore, when the above-described solid collagen is heated and melted, it denatures into gelatin, and the viscosity measured according to JIS K6503 is 4.0 mPa · s or more. A molten gelatin of about 7 to 30 mPa · s can be obtained under more appropriate solubilization conditions. The pH ranges from weakly acidic to neutral. In a general production method of gelatin commercially available for use as a food material, solubilized collagen is subjected to neutralization and washing with water at 60 to 100 ° C. by heat extraction at the collagen molecule in the solubilization treatment. Since it is obtained, the molecular weight is reduced during the heat extraction, so that the viscosity of commercially available gelatin according to JIS K6503 is generally about 2.0 to 3.5 mPa · s.

  In the production of the pseudo bait of the present invention, the solid collagen obtained above or gelatin obtained by heat denaturation thereof is used as a raw material, and a melt obtained by heating and melting collagen or gelatin is formed into the shape of the pseudo bait. That is, liquid molten gelatin is cooled and gelled in a mold in the shape of a pseudo bait, thereby forming a pseudo bait. The molten gelatin may be obtained by heating solid collagen or gelatin in a mold, or may be melted outside the mold and poured into the mold. Alternatively, the gelatinized gelatin mass can be formed into a pseudo food by cutting or the like. Collagen and gelatin are reduced in molecular weight by heating and melting and the viscosity is lowered. Therefore, it is desirable to avoid repeated gelatinization / melting and long-time heating of raw material gelatin. It is optimal to use collagen as a raw material. When using collagen whose water content is extremely reduced by drying, it is preferable to add water to adjust the water content to about 50 to 80% by mass. From the viewpoint of mold releasability, it is desirable to use a silicone rubber mold. The heating temperature for melting collagen or gelatin is preferably 70 to 95 ° C, more preferably about 90 ° C. When the heating temperature is less than 70 ° C., there is a possibility that a uniform melt cannot be obtained due to incomplete melting. When the heating temperature exceeds 95 ° C., the decomposition of gelatin is promoted and the molecular weight is remarkably reduced. Excessive heating causes the decomposition of gelatin molecules, so melting with heating for as short a time as possible is preferable and within 10 minutes is desirable. In this respect, steam heating is effective, heat conduction is promoted, and transparent molten gelatin can be obtained by heating within about 5 minutes.

  When the molten gelatin is cooled, the gelatin gels and is formed into a pseudo food. The cooling rate at this time influences the strength of the pseudo food to be obtained, and when it is slowly cooled, the strength of the gelatin gel product increases. This is presumably because spiral unwinding easily occurs between gelatin molecules during gelation. Therefore, air cooling is more suitable than ice cooling, water cooling, etc. from the viewpoint of improving the strength of the pseudo food. It is preferable to adjust the cooling rate to 1 ° C./min or less (particularly the average from the gelation temperature to room temperature).

  When cross-linking treatment is applied to gelatin that constitutes a pseudo bait, a pseudo bait having improved water resistance and heat resistance can be obtained, which makes it possible to produce a practical bait even when commercially available low-viscosity gelatin is used. Become. Usable crosslinking agents are water-soluble crosslinking agents, and examples thereof include hydrophilic epoxy crosslinking agents and aldehyde crosslinking agents. However, since the aldehyde crosslinking agent may cause coloring, it is necessary to consider the product color tone. By crosslinking treatment, the amino group of gelatin reacts with the epoxy group or aldehyde group of the crosslinking agent to form a crosslinking. In order to impart water resistance and heat resistance to the gelatin molded product, the crosslinking agent may act as an anchor that suppresses dissociation of the helix of gelatin. A cross-linking agent having a molecular structure having three or more reactive groups (epoxy groups or the like), particularly four or more, has a high effect of suppressing helix dissociation. However, if the molecular structure of the cross-linking agent is rigid, the flexibility of gelatin is lowered. Therefore, when emphasizing the flexibility of the pseudo bait, it is desirable that the cross-linking agent has a flexible molecular structure. For this purpose, it is preferable to use, as a crosslinking agent, a compound having a molecular structure in which reactive groups are bonded with a flexible chain group mainly composed of a single bond. The chain group includes, for example, a linear or branched hydrocarbon chain, and may contain an oxygen atom, a sulfur atom, or the like as a constituent atom. A chain hydrocarbon having a certain length or more can impart water resistance to gelatin due to its lipophilicity (hydrophobicity). In addition, when the cross-linking agent has a hydroxyl group, the affinity between molecules increases due to hydrogen bonding with the polar group of gelatin, so intermolecular interaction and cross-linking reactivity are enhanced, and the cross-linking is formed close to the surface of the molded product. Easy to do. For this reason, preferable epoxy-based crosslinking agents include aliphatic compounds having one or more hydroxyl groups and a plurality (preferably three or more) terminal epoxy groups, such as polyglycerol polyglycidyl ether. Preferably used. Examples of the commercially available products include Denacol EX-512 (trade name) manufactured by Nagase Chemtech, which is a compound having four terminal epoxy groups and two hydroxyl groups.

  The cross-linking treatment may be a method of cross-linking gelatin on the whole pseudo bait or a method of cross-linking gelatin on the surface of the pseudo bait. The surface cross-linking is particularly excellent in imparting water resistance, and the entire cross-linking is useful for obtaining a pseudo bait excellent in flexibility depending on conditions.

  When cross-linking the gelatin of the whole pseudo bait, the cross-linking agent is uniformly mixed with the melted gelatin before gelation / molding to form the pseudo bait, and the cross-linking reaction proceeds during or after gelation / molding. . At this time, since the aldehyde-based crosslinking agent has a high reaction rate, an epoxy-based crosslinking agent may be used when the molding operation becomes difficult. Further, it is preferable that a cross-linking agent is blended with molten gelatin having a temperature of about 50 ° C., and is put into the mold within about 30 minutes after blending. In order to facilitate uniform blending of the crosslinking agent, fluidity may be imparted to the molten gelatin by adding water as necessary to reduce the solid content. In this case, in order to ensure the strength of the molded product, it is preferable to adjust the amount of water so that the solid content is about 10% by mass or more, preferably about 15% by mass or more. However, if the solid content exceeds 40% by mass, the fluidity is lowered and it becomes difficult to pour into the mold, so care must be taken. The amount of the crosslinking agent is preferably about 1 to 10% by mass of gelatin (dry mass), more preferably about 2 to 8% by mass. If the crosslinking agent is excessive, the gelled product becomes brittle. By allowing the gelled product to stand at about 20 to 30 ° C. for about 1 day or longer, the crosslinking reaction sufficiently proceeds and stabilizes. Alternatively, the gelled product is heated to about 60 to 70 ° C. for about 30 minutes to complete the crosslinking reaction.

  When cross-linking the gelatin on the surface of the pseudo bait, the pseudo bait obtained by gelling / molding the melted gelatin is brought into contact with the aqueous crosslinking agent solution. That is, the molded pseudo bait is immersed in an aqueous crosslinking agent solution, and gelatin is cross-linked from the surface of the pseudo bait that comes into contact with the cross-linking agent. In this case, an aldehyde-based cross-linking agent having a high reaction rate can be suitably used. The concentration of the crosslinking agent in the aqueous crosslinking agent solution is preferably about 0.05 to 0.4% by mass, and the crosslinking reaction is preferably performed at a temperature of about 23 to 28 ° C. for about 2 to 7 days. As a result, the cross-linking agent mainly reacts on the pseudo bait surface, and part of the cross-linking agent penetrates from the pseudo bait surface depending on the situation, and the reaction proceeds inward. As a result, the gelatin on the surface portion of the pseudo bait is strongly cross-linked and increases in strength and hardness from the inside, acts like a film, imparts water resistance near the surface and improves heat resistance. The pseudo bait after the crosslinking treatment is washed with water or the like as necessary after removing the crosslinking agent aqueous solution.

  The above-mentioned pseudo bait can be used for fishing as it is. However, when heat treatment is performed for a short time, the hydrogen bond between the peptide chains of gelatin molecules is dissociated inside the pseudo bait, resulting in decomposition and improved flexibility. To do. Thereby, it becomes easy to show a behavior preferable as a pseudo bait in water. The temperature at which the heat treatment is performed is about 60 to 110 ° C., preferably about 90 to 105 ° C., and the processing time is about 1 to 60 minutes, preferably about 5 to 30 minutes. If the treatment temperature is too high and the treatment time is too long, the strength of the pseudo food is reduced due to the degradation of gelatin.

By preparing according to the above, a pseudo bait having improved strength and heat-resistant temperature due to high molecular weight of gelatin can be obtained. For this reason, the intensity | strength which can be endured use is hold | maintained even if the intensity | strength fall by water absorption is passed. When forming a pseudo bait with gelatin not subjected to cross-linking treatment, if gelatin having a viscosity of JIS K6503 of 4.0 mPa · s or more, preferably 7.0 mPa · s or more is used, the tear strength is about 500 gf or more, and the heat resistance temperature. Is obtained, a pseudo bait of 40 ° C. or higher is obtained, and the breaking strength per area is improved to about 2000 gf / cm ² or more. Such a pseudo bait does not collapse even after water absorption, and exhibits a tear strength of about 100 gf or more and a breaking strength per area of about 500 gf / cm ² or more. In the case of a pseudo bait made from cross-linked gelatin, even if the viscosity of the raw material gelatin JIS K6503 is 4.0 mPa · s or less, a pseudo bait having a tear strength of 300 gf or more and a heat resistant temperature of 40 ° C. or more can be obtained. At the same time, since the degree of swelling is 90% or less and the strength reduction due to water absorption swelling is suppressed, it is possible to achieve a tear strength after water absorption of about 100 gf or more and a breaking strength per area of about 500 gf / cm ² or more. By using gelatin with higher viscosity (15 mPa · s or higher) or combined with a crosslinking treatment, it is possible to obtain a gelatin biodegradable pseudo bait having a tear strength of 700 gf or higher and a heat-resistant temperature of about 70 ° C. A value of 200 gf or more is secured for the subsequent tear strength. Since gelatin is decomposed by heating, the viscosity according to JIS K6503 of the pseudo bait is close to the value of the raw gelatin but is close to the value. Since infusible material remains, it is used as a criterion. Water resistance and heat resistance can be imparted by cross-linking, and strength can be increased without impairing flexibility, so that a pseudo bait that exhibits favorable behavior in water is provided.

  Furthermore, by preserving the pseudo bait, the period during which the pseudo bait can be stored becomes longer. Preservation treatment is possible by bringing a preservative into contact with the gelatin molded product, for example, using ethylene glycol, propylene glycol, hexylene glycol, pentylene glycol, sodium sulfate aqueous solution or the like as the preservative, and soaking for about 12 to 24 hours. do it. The pseudo food after the antiseptic treatment can be stored at about 20 to 25 ° C. for 4 months or more.

  As described above, the gelatin-made pseudo bait is preferably made of a gelatin gel product or a cross-linked gelatin gel product, but does not exclude the addition of additives in a range that does not substantially impair the properties thereof. . In other words, an additive that does not affect the function of the main component, such as a colorant, preservative, attractant, fluorescent agent, etc., can be blended with the gelatin gel product or the gelatin gel product subjected to crosslinking treatment as the main component. . The mixing ratio is limited to 20% by mass as the total amount of additives, and is introduced so that uniform mixing can be performed when gelatin is melted. Moreover, it is also possible to apply the pseudo bait so as to be composed of a main body mainly composed of gelatin gelled material or a cross-linked gelatin gelled material and a sub-body that assists the main body. For example, a string-like sub-body is prepared with a biodegradable material insoluble in water such as natural fibers, and the sub-body is embedded or pivoted in the main body during gel forming, or the sub-body is wound around the main body. The main body can be reinforced by wearing it.

  The pseudo bait is configured for fishing, but it can also be used as a fish culture and growth bait, and various commonly used additives can be blended as necessary. May be.

  Hereinafter, the method for producing simulated bait according to the present invention will be specifically described with reference to examples. In the present application, the isoionic point of the sample is measured according to the following operation.

  First, a cation exchange resin (Amberlite IPR-120B, manufactured by Organo Corp.) and an anion exchange resin (Amberlite IPA-400, manufactured by Organo Corp.) that have been activated and washed in advance are 2: 5. To prepare a mixed bed ion exchanger. Next, after 100 mL of the mixed bed ion exchanger is equilibrated with deionized water, 50 mL of a sample solution in which the sample is dissolved in water so that the protein concentration is 5% is added and kept in a 40 ° C. water bath. Gently mix for 30 minutes, separate the supernatant from the mixture, measure the pH of the supernatant, and use that value as the isoionic point (JW Janus, AW Kenchington and AGWard, Research, 4247 (1951 ) Is used as a reference).

(Sample A1)
<Preparation of gelatin>
According to the standard method, the skin obtained through the steps of washing and immersing from beef salted hide, fleshing (removing the meat surface), trimming, depilatory lime pickling, the silver surface layer with the silver surface and the meat surface layer (floor skin) The resulting skin was cut into strips. The following operations were performed using this as a raw material.

  As a solubilizing solution, 1600 g of an aqueous solution containing 5.0% by mass of sodium hydroxide and 12.0% by mass of sodium sulfate was prepared, and the temperature of the solution was kept at 25 ° C. 28.3 mass%) was immersed, mixed with stirring for about 30 minutes to be well blended with the solubilized solution, and then allowed to stand for 24 hours. Thereafter, while maintaining the liquid temperature at 23 to 25 ° C., a 37.5 mass% aqueous sulfuric acid solution was gradually added to neutralize, and the pH was adjusted to 4.8 to bring the collagen to an isoelectric precipitation state. A skin piece retaining the raw material shape was obtained. The neutralized solubilized solution was removed from the skin pieces, and further squeezed lightly to extrude moisture contained therein. Furthermore, after the skin pieces are washed with running water and desalted, they are lightly squeezed again to extrude and remove moisture contained therein, and 401 g of alkali-treated skin pieces (solid content 26.9% by mass, recovery rate 95%) Got. In the alkali-treated skin pieces, denaturation (gelatinization) of collagen does not occur, but cross-linking between collagens proceeds. The viscosity (measured at 60 ° C. after melting gelatin at a temperature of 70 ° C.) of this alkali-treated skin piece measured according to JIS K6503 was 24.7 mPa · s.

  The protein content of this dried alkali-treated skin product was calculated from the result of total nitrogen measurement by the Kjeldahl method, and found to be 91.3% by mass. The crude fat detected by the hydrochloric acid-decomposed hexane extraction method according to JIS K6503 was 2.40% by mass. Moreover, the ash content (refer to the ash measurement method of JIS K6503: 2001) of the dried alkali-treated skin piece was 0.5% by mass.

<Manufacture of simulated bait>
Place 4g of alkali-treated skin in a worm-shaped mold hole (width: about 0.8cm, length: about 8cm) in a silicone mold, place the mold in a stainless steel container containing water for steam generation, And the alkali-treated skin melted by heating with steam for about 5 minutes. Thereafter, the mold was taken out and allowed to cool at room temperature to obtain a gelatin molded product.

  An aqueous crosslinking agent solution (pH 8.5) containing 0.1% by mass of an epoxy crosslinking agent (trade name: Denacol EX-512, manufactured by Nagase ChemteX Corporation), 12% by mass of sodium sulfate and 3% by mass of sodium acetate, The gelatin molded product taken out from the mold was immersed in this and allowed to stand at 25 ° C. for 3 days. Here, if sodium sulfate is not used, the gelatin molded product will swell during processing. Thereafter, the gelatin molded product was taken out from the aqueous solution of the crosslinking agent, put into water and washed with running water for 12 hours to obtain a pseudo food. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

(Sample A1 ′)
In the production of the pseudo bait of sample A1, before performing the antiseptic treatment, the pseudo bait of sample A1 ′ was obtained by performing the same operation as sample A1, except that the pseudo bait was subjected to a heat treatment at 105 ° C. for 10 minutes. .

(Sample a1)
In the production of the pseudo bait of the sample A1, a pseudo bait of the sample a1 was obtained by performing the same operation as the sample A1 except that the crosslinking treatment with the epoxy crosslinking agent was not performed.

(Sample A2)
Except that the solubilization time was changed from 24 hours to 3 days in the preparation of gelatin, the same operation as in sample A1 was performed to obtain 559 g of alkali-treated skin pieces (solid content 14.9% by mass, recovery rate 74%). Obtained. The viscosity (measured at 60 ° C. by dissolving gelatin at a temperature of 70 ° C.) of the alkali-treated skin piece measured according to JIS K6503 was 7.9 mPa · s. The protein content of this dried alkali-treated skin product was calculated from the result of total nitrogen measurement by the Kieldahl method. As a result, it was 89.4% by mass, and the crude fat detected by the hydrochloric acid-decomposed hexane extraction method according to JIS K6503 was It was 0.24 mass%. Moreover, the ash content (refer to the ash measurement method of JIS K6503: 2001) of the dried alkali-treated skin piece was 0.5% by mass.

  A simulated bait of Sample A2 was produced by the same operation as Sample A1, except that the gelatin was used.

(Sample A3)
Except for changing the solubilization time from 24 hours to 5 days in the preparation of gelatin, the same operation as Sample A1 was performed to obtain 512 g of alkali-treated skin pieces (solid content: 16.3% by mass, recovery rate: 74%). It was. The viscosity (measured at 60 ° C. by dissolving gelatin at a temperature of 70 ° C.) of the alkali-treated skin piece measured in accordance with JIS K6503 was 5.8 mPa · s. The protein content of this dried alkali-treated skin piece was calculated from the result of total nitrogen measurement by the Kjeldahl method. As a result, it was 88.5% by mass, and the crude fat detected by the hydrochloric acid-decomposed hexane extraction method according to JIS K6503 was It was 0.13 mass%. The ash content of the dried gelatin product (see ash content measurement method of JIS K6503: 2001) was 0.5% by mass.

  A simulated bait of Sample A3 was produced in the same manner as Sample A1, except that the gelatin was used.

(Samples B1 to B3)
When three types of commercially available dried gelatin were measured for viscosity according to JIS K6503, Sample B1 (trade name: PG-80, manufactured by Gelita) was 2.3 mPa · s, Sample B2 (trade name: PG-120 , Manufactured by Gelita) was 3.1 mPa · s, and sample B3 (trade name: PG-240, manufactured by Gelita) was 3.4 mPa · s.

  The simulated baits of Samples B1 to B3 were produced by the same operation as Sample A1 except that the above-mentioned commercially available dried gelatin was used.

(Physical property evaluation of simulated food)
About the pseudo bait of sample A1-A3, A1 ', a1, B1-B3, tear strength, elongation, breaking strength, and hardness (flexibility) were measured according to the following. As a reference sample, commercially available curdlan pseudo food (sample C1, trade name: EDUM, manufactured by Jackall Bros.), plastic simulated food (sample C2, trade name: Paramax 5 inch, manufactured by Marquee) and silicone The same measurement was performed on a simulated bait (sample C3, trade name: Crazy Shaker 315-Orange Neon Craw, manufactured by Angler Technologies).

  In addition, the same measurement was performed on a pseudo bait after being immersed in water at 18 ° C. for 24 hours to evaluate the influence of water absorption swelling on physical properties.

<Tear strength and elongation>
Cut the pseudo bait to a length of 3cm, hang 2 fishhooks (product name: WIDE GAPE WRM951 Size 1, FINA) at 5mm intervals, and a rheometer (product name: FUDOH NRM-2010J-CW, Rheotech). ), And by plotting the relationship between elongation and load until the pseudo bait breaks by applying a tensile load by increasing the distance between the fishing hooks at a rate of 6 cm / min. Maximum load [gf]). The results are shown in Table 1. In the description of Table 1, the pseudo bait of the sample C2 before water absorption means that it did not break in the predetermined measurement range, and the blank is omitted from the measurement.

  According to Table 1, the pseudo bait (samples A1 and A1 ′) manufactured using gelatin with a high viscosity has a much higher tear strength than that when gelatin with a low viscosity is used (samples B1 to B3). Is clear. Even when there is no cross-linking treatment (sample a1), a tear strength of a practical level is ensured even if the strength decreases due to water absorption. The curdlan artificial bait (sample C1) has a remarkable decrease in tear strength due to water absorption swelling.

(Table 1)
Elongation and tear strength of simulated food
Sample Tear time [sec] Elongation [%] Tear strength [gf]
Before water absorption After water absorption Before water absorption After water absorption Before water absorption Before water absorption
A1 18 19 360 380 780 420
A1 '27 13 540 260 560 250
a1 29 11 580 220 720 280
A2 19 25 380 500 720 220
A3 16 11 320 220 550 120
B1 14 0 280 0 100 0
B2 20 0 400 0 220 0
B3 13 8 260 160 330 100
C1 19 20 380 400 580 100
C2>39>39>780>780>740> 880
(No tearing before and after water absorption)
C3 12 19 240 380 160 250

<Break strength>
The maximum when a pseudo bait breaks when a tooth mold is attached to a rheometer (trade name: FUDOH NRM-2010J-CW, manufactured by Rheotech Co., Ltd.) and the pseudo bait is pushed to the tooth mold at a rate of 6 cm / min. The load [gf] was examined and determined as the breaking strength. Moreover, the cross-sectional area of the pseudo bait was measured to calculate the breaking strength [gf / cm ² ] per unit area. The results are shown in Table 2.

  According to Table 2, the pseudo bait (samples A1 and A1 ′) manufactured using gelatin with a high viscosity has a significantly higher breaking strength than that when gelatin with a low viscosity (samples B1 to B3) is used. Further, it is clear that the decrease in breaking strength due to water absorption swelling is also suppressed. From comparison between A1 and a1, it is understood that not only the strength is increased by the crosslinking treatment, but also a decrease in strength due to water absorption can be suppressed and water resistance is imparted. Even when there is no cross-linking treatment, a practically sufficient post-water absorption breaking strength can be obtained.

(Table 2)
Fracture strength of simulated bait
Sample Cross-sectional area [cm ² ] Breaking strength [gf] Breaking strength per area [gf / cm ² ]
Before water absorption After water absorption Before water absorption After water absorption Before water absorption Before water absorption
A1 0.63 0.71 2700 2200 4279 3099
A1 '0.63 0.76 2800 2700 4438 3541
a1 0.74 0.84 1600 550 2173 654
A2 0.55 0.97 2000 1550 3622 1593
A3 0.45 0.76 1100 550 2461 721
B1 0.71 1.26 400 220 563 182
B2 0.58 1.10 400 800 692 721
B3 0.63 0.87 800 1250 1268 1441
C1 0.50 0.82 800 80 1602 98
C2 0.71 0.60 1200 1200 1690 1984
C3 0.21 0.42 1100 1400 5230 3328

<Hardness (flexibility)>
Using a hardness meter for rubber and plastic (trade name: Durometer GS-754G, manufactured by Teclock Corporation), the hardness of the pseudo bait was measured in the elastic mode. The results are shown in Table 3.

  The fluctuation of the hardness due to the water absorption swelling of the gelatinous pseudo bait is suppressed by the cross-linking treatment, but according to Table 3, when the gelatin is manufactured using a high viscosity gelatin, the pseudo bait has a high hardness and lacks flexibility. However, it is clear from the sample A1 'that this point can be improved by performing a heat treatment after the crosslinking treatment.

(Table 3)
Simulated bait hardness
Sample Hardness Difference in hardness
Before water absorption After water absorption
A1 70 68 -2
A1 '43 41 -2
a1 53 40 -13
A2 57 52-5
A3 45 56 11
B1 1 9 8
B2 16 10 -6
B3 45 45 0
C1 38 25 -13
C2 22 19 -3
C3 30 15 -15

<Effect of heat treatment>
In order to evaluate the effect of heat treatment after crosslinking, a pseudo bait was produced from gelatin having a viscosity of 25 mPa · s in the same manner as sample A1, and the hardness was measured while heating this to 105 ° C. I investigated. In addition, the length of the sample was measured, and the shrinkage rate due to heating was calculated. The results are shown in Table 4.

  According to Table 4, it is clear that the hardness of the pseudo bait is reduced by heating and the flexibility is improved. However, as shown in Table 1, since the tear strength also decreases, it is necessary to set the heating time in consideration of this point.

(Table 4)
Hardness change due to heating
Heating time [min] Hardness Hardness change Sample length [mm] Shrinkage [%]
0 57 0 78 0
5 43 -14 75 4
10 41 -16 73 6
20 30 -27 71 9
30 20 -37 70 10

<Swelling degree>
The simulated bait was immersed in water at 18 ° C. for 24 hours, and the change in mass before and after immersion was examined to calculate the degree of swelling (the ratio (%) of the change in mass with respect to the mass before immersion). The results are shown in Table 5.

<Heat resistance>
The pseudo bait was enclosed in a polypropylene bag, placed in a heat dryer, the temperature was raised from room temperature to 105 ° C., and the temperature at which the pseudo bait melted (heat resistant temperature) was measured. The results are shown in Table 5.

  According to Table 5, the results of A1 and a1 indicate that the water absorption swelling is suppressed by the crosslinking treatment, and the heat resistant temperature is improved. It can also be seen that the use of gelatin with high viscosity improves the heat resistance of the pseudo bait and suppresses water absorption swelling.

(Table 5)
Swelling degree and heat-resistant temperature of simulated food
Sample Swelling degree [%] Heat-resistant temperature [° C]
A1 10-70
A1'44-70
a1 147 60
A2 85-70
A3 84 40
B1 111 30
B2 97 30
B3 53 40
C1 45 does not melt C2 2 does not melt
C3-5 not melted

<Preparation of gelatin molding>
In a stainless steel container containing water for generating steam, a container containing a dried gelatin product of sample B3 in Example 1 (240 bloom, viscosity according to JIS K6503: 3.4 mPa · s) and water was placed, By heating to 70 ° C. and steam heating for about 10 minutes, 18 g of an aqueous gelatin solution having a solid content of 30% by mass was prepared. This was poured into a worm-shaped mold hole (width: about 0.8 cm, length: about 8 cm) of a silicone mold, and the mold was allowed to cool at room temperature to obtain a gelatin molded product.

<Crosslinking of gelatin by immersion treatment>
A crosslinking agent aqueous solution having a crosslinking agent concentration of 0.1% by mass, a sodium sulfate concentration of 12% by mass and a sodium acetate concentration of 3% by mass was prepared using one of the following crosslinking agents, sodium sulfate and sodium acetate. . When the raw material crosslinking agent was an aqueous solution, it was blended so that the concentration after preparation was 0.1% by mass in terms of the concentration. The gelatin molded product taken out from the above mold was immersed in this solution and allowed to stand at 25 ° C. for 3 days. Thereafter, the gelatin molded product was taken out from the aqueous solution of the crosslinking agent, put into water and washed with running water for 12 hours to obtain a pseudo food. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

  About the obtained pseudo bait, it carried out similarly to Example 1, and measured the tear strength after water absorption, and heat-resistant temperature. Further, the appearance and properties were observed to evaluate the tactile sensation such as coloring, flexibility and stickiness. The results are shown in Table 6. The measured value is an average value of two measurements.

  According to Table 6, the tendency of the effectiveness of the crosslinking treatment varies depending on the type of the crosslinking agent. In the metal-based crosslinking agents M1 and M2, water resistance and strength are imparted, but flexibility is impaired and heat resistance is difficult to obtain. In the aldehyde-based crosslinking agents L1 to L3, flexibility and heat resistance may not be obtained or coloring may occur, but it is generally understood from the tear strength after water absorption that water resistance and strength are imparted. Epoxy crosslinking agents E1 to E6 have different effects depending on the compound, but coloration does not occur, and the crosslinking agent E4 is good in all of water resistance, strength, heat resistance and touch. Crosslinker E4 has a large number of reactive groups (epoxy groups), the reactive groups are bonded with flexible molecular chains, and has a hydroxyl group that expresses hydrophilicity and affinity for gelatin. In addition, it is considered that flexibility and reactivity are expressed. The crosslinking agent E3 is considered to be less water-soluble and therefore less reactive to gelatin than the crosslinking agent E4.

  In addition, when the pseudo bait using the crosslinking agents E1 to E6 and L1 to L3 was immersed in lake water and left at 25 ° C., it was confirmed that it decayed and dissolved in 30 to 40 days.

(Crosslinking agent)
Cross-linking agent E1: glycidol (manufactured by Aldrich), number of epoxy groups: 1
Crosslinking agent E2: Glycerol polyglycidyl ether (trade name: Denacol EX-313, manufactured by Nagase ChemteX Corporation), number of epoxy groups: 2-3
Crosslinking agent E3: Pentaerythritol polyglycidyl ether (trade name: Denacol EX-414, manufactured by Nagase ChemteX Corporation), number of epoxy groups: 4
Crosslinking agent E4: Polyglycerol polyglycidyl ether (trade name: Denacol EX-512, manufactured by Nagase ChemteX Corporation), number of epoxy groups: 3
Crosslinking agent E5: Sorbitol polyglycidyl ether (trade name: Denacol EX-614B, manufactured by Nagase ChemteX Corporation), number of epoxy groups: 4 or more Crosslinking agent E6: Polyethylene glycol glycidyl ether (trade name: Denacol EX-830, Nagase ChemteX Corporation) Product), epoxy group number: 2
Crosslinking agent M1: Chromium sulfate (trade name: Bare Chromium, manufactured by Nippon Electric Works)
Crosslinking agent M2: Aluminum sulfate (trade name: sulfate band, manufactured by Nippon Light Metal Co., Ltd.)
Crosslinking agent L1: 40% by weight glyoxal aqueous solution (Nacalai)
Cross-linking agent L2: 36% by weight aqueous formaldehyde solution (manufactured by Koso Chemical Co., Ltd.)
Crosslinking agent L3: 40% by weight glutaraldehyde aqueous solution (manufactured by Nacalai)
(Table 6)
Effect of crosslinking agent (immersion method)
Cross-linking agent Tear strength [gf] Heat-resistant temperature [° C] Coloring Touch
E1 12 30 None Defective (sticky)
E2 30 30 None Good E3 70 40 None Good E4 330 70 None Good E5 10 30 None Defective (sticky)
E6 0 30 None Defective (sticky)
M1 320 30 Green Defect (hard)
M2 610 30 None Defective (hard)
L1 220 60 Light brown Good L2 260 30 None Defective (hard)
L3 210 30 Light brown Poor (hard)

<Crosslinking agent in gelatin>
(Gelatin molded product using cross-linking agent E4)
In a stainless steel container containing water for generating steam, a container containing the dried gelatin (240 bloom, viscosity according to JIS K6503) of sample B3 in Example 1 and water was placed. 48 g of an aqueous gelatin solution having a solid content of 30% by mass was prepared by heating to 70 ° C. and steam heating for about 10 minutes. To this, 1.5 g of sodium acetate and 0.48 g of the cross-linking agent E4 are uniformly mixed and poured into a worm-shaped mold hole (width: about 0.8 cm, length: about 8 cm) of a silicone mold. Was allowed to cool at room temperature to obtain a gelatin molded product.

  The obtained gelatin molded product was allowed to stand at 25 ° C. for 4 days, and then the gelatin molded product was taken out of the mold, poured into water and washed with running water for 12 hours to obtain a pseudo food. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

  About the obtained pseudo bait, it carried out similarly to Example 1, and measured the tear strength after water absorption, and heat-resistant temperature. The appearance and properties were observed to evaluate coloring and touch. The results are shown in Table 7 (measured values are average values of two measurements).

(Gelatin molded product using cross-linking agent L1)
In a stainless steel container containing water for generating steam, a container containing the dried gelatin (240 bloom, viscosity according to JIS K6503) of sample B3 in Example 1 and water was placed. 30 g of an aqueous gelatin solution with a solid content of 30% by mass was prepared by heating to 90 ° C. and steam heating for about 5 minutes. 27 g of glycerin and 3 g of the cross-linking agent L1 are uniformly mixed into this, and poured into a worm-shaped mold hole (width: about 0.8 cm, length: about 8 cm) of a silicone mold, and the mold is left at room temperature. This was gradually cooled to obtain a gelatin molded product.

  The obtained gelatin molded product was heated at 70 ° C. for 30 minutes and then allowed to cool, and the gelatin molded product was taken out of the mold to obtain a pseudo bait. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

  About the obtained pseudo bait, it carried out similarly to Example 1, and measured the tear strength after water absorption, and heat-resistant temperature. The appearance and properties were observed to evaluate coloring and flexibility. The results are shown in Table 7.

(Gelatin molded product using D-glucose as a crosslinking agent)
In a stainless steel container containing water for generating steam, a container containing the dried gelatin (240 bloom, viscosity according to JIS K6503) of sample B3 in Example 1 and water was placed. By heating to 70 ° C. and steaming for about 10 minutes, 9 g of a gelatin aqueous solution having a solid content of 30% by mass was prepared. 0.9 g of D-glucose (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed with this to confirm that it was uniform, and the worm-shaped mold hole (width: about 0.8 cm, length: about 8 cm) of the silicone mold And the mold was allowed to cool at room temperature to obtain a gelatin molded product.

  The obtained gelatin molded product was heated at 90 ° C. for 1 hour and then allowed to cool, and the gelatin molded product was taken out of the mold to obtain a pseudo bait. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

  About the obtained pseudo bait, it carried out similarly to Example 1, and measured the tear strength after water absorption, and heat-resistant temperature. The appearance and properties were observed to evaluate coloring and touch. The results are shown in Table 7.

(Table 7)
Effect of crosslinking agent (mixing method)
Cross-linking agent Tear strength [gf] Heat-resistant temperature [° C.] Colored feel E4 180 40 None Good L1 160> 90 Brown Good
D-glucose 50 30 Light brown Good

<Preparation of gelatin molding>
In a stainless steel container containing water for generating steam, a container containing the dried gelatin (240 bloom, viscosity according to JIS K6503) of sample B3 in Example 1 and water was placed. By heating to 70 ° C. and steam heating for about 10 minutes, 18 g of an aqueous gelatin solution having a solid content of 30% by mass was prepared. This was poured into a worm-shaped mold hole (width: about 0.8 cm, length: about 8 cm) of a silicone mold, and the mold was allowed to cool at room temperature to obtain a gelatin molded product.

<Crosslinking agent concentration in immersion treatment>
Using sodium sulfate, sodium acetate, and the above-mentioned epoxy-based crosslinking agent E4 as a crosslinking agent, a crosslinking agent concentration: 0 to 1.0% by mass, sodium sulfate concentration: 12% by mass, and sodium acetate concentration: 3% by mass An aqueous crosslinking agent solution was prepared.

  The gelatin molded product taken out from the above mold was immersed in this solution and allowed to stand at 25 ° C. for 3 days. Thereafter, the gelatin molded product was taken out from the aqueous solution of the crosslinking agent, put into water and washed with running water for 12 hours to obtain a pseudo food. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

  About the obtained pseudo bait, it carried out similarly to Example 1, and measured the tear strength after water absorption, and heat-resistant temperature. The appearance and properties were observed to evaluate coloring and touch. The results are shown in Table 8. The measured value is an average value of two measurements.

  According to Table 8, when the concentration of the cross-linking agent solution in which the gelatin molded product is immersed increases, the heat resistance, water resistance and strength of the pseudo bait are improved. Decreases and the hardness becomes excessive, so that the flexibility is lost and the brittleness is caused. From the results in Table 8, it is considered that the optimum value of the concentration of the crosslinking agent is around 0.1% by mass.

(Table 8)
Effect of crosslinker concentration
Cross-linking agent concentration Tear strength Heat-resistant temperature Coloring Touch
[%] [Gf] [° C]
0 80 30 None Defective (sticky)
0.01 50 30 None Good 0.05 110 30 None Good 0.1 330 70 None Good 0.5 180 90 None Bad (brittle)
1.0 150 90 None Defective (brittle)

(Gelatin molded product mixed with crosslinking agent)
In a stainless steel container containing water for generating steam, an alkali-treated skin piece of sample A1 in Example 1 (viscosity according to JIS K6503: 24.7 mPa · s) and a container containing water were placed, and 80 to Gelatin aqueous solution having a solid content of 13 to 28% by mass (D1: 13% by mass, D2: 18% by mass, D3: 23% by mass, D4: 28% by mass) by heating to 90 ° C. and steam heating for about 10 minutes 30 g was prepared. 0.3 g of the cross-linking agent E4 (polyglycerol polyglycidyl ether) is uniformly mixed with this to form a worm-shaped hole (width: about 0.8 cm, length: about 8 cm) of a silicone mold at 50 ° C. Poured within 30 minutes and allowed to cool slowly by allowing the mold to stand at room temperature to obtain gelatin moldings of samples D1 to D4.

  The obtained gelatin molded product was taken out from the mold and allowed to stand at 25 ° C. for 3 days, and then the gelatin molded product was poured into water and washed with running water for 12 hours to obtain a pseudo food. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

  About the obtained pseudo bait, similarly to Example 1, the elongation and tear strength before and after water absorption (Table 9), the breaking strength (Table 10), the hardness (Table 11), the degree of swelling and the heat resistant temperature (Table 12) It was measured.

  According to Tables 9 to 11, the higher the solid content concentration of the gelatin aqueous solution is, the higher the tear strength before water absorption, break strength and hardness are. Regarding the tear strength after water absorption, the difference due to the solid content concentration seems to decrease. Moreover, in Table 11, it turns out that hardness is small compared with the case of bridge | crosslinking by the immersion method of Table 3 (sample A1), and there exists a softness | flexibility. Moreover, according to Table 12, although the degree of swelling is slightly larger than in the case of the immersion method, the heat resistant temperature is high.

(Table 9)
Elongation and tear strength of simulated food
Sample Tear time [sec] Elongation [%] Tear strength [gf]
Before water absorption After water absorption Before water absorption After water absorption Before water absorption Before water absorption
D1 14 11 280 220 195 140
D2 15 12 300 240 220 180
D3 15 19 300 380 290 200
D4 9 16 180 320 420 420 130

(Table 10)
Fracture strength of simulated bait
Sample Cross-sectional area [cm ² ] Breaking strength [gf] Breaking strength per area [gf / cm ² ]
Before water absorption After water absorption Before water absorption After water absorption Before water absorption Before water absorption
D1 0.44 0.74 1800 1500 4091 2027
D2 0.59 0.67 1750 1700 2966 2537
D3 0.66 0.81 2600 1400 3939 1728
D4 0.50 0.72 3200 3100 6400 4306

(Table 11)
Simulated bait hardness
Sample Hardness Difference in hardness
Before water absorption After water absorption
D1 37 39 2
D2 42 41 -1
D3 43 40 -3
D4 50 49 -1

(Table 12)
Swelling degree and heat-resistant temperature of simulated food
Sample Swelling degree [%] Heat-resistant temperature [° C]
D1 42 80
D2 30 80
D3 36 80
D4 44 80

(Influence of crosslinker concentration)
Gelatin was prepared in the same manner except that the amount of the crosslinking agent E4 added was changed in the range of 0 to 5% by mass of the gelatin aqueous solution (0 to 21.5% of the gelatin mass) in the preparation of the gelatin molded product of the sample D3 described above. A molded product was prepared, and the obtained gelatin molded product was taken out from the mold and allowed to stand at 25 ° C. for 3 days. The gelatin molded product was poured into water and washed with running water for 12 hours to obtain a pseudo food. The simulated bait was immersed in propylene glycol for 12 hours for preservative treatment.

About the obtained pseudo bait, the appearance and properties were observed to evaluate the coloring and the tactile sensation, and the tear strength, the rupture strength per area, the heat resistant temperature, the swelling degree and the hardness were measured in the same manner as in Example 1. The results are shown in Table 13. The measured value is an average value of two measurements. According to Table 13, the optimum value of the amount of the crosslinking agent is considered to be around 1% by mass of the gelatin aqueous solution mass, and the tear strength at this time is 290 gf, the fracture strength The strength was 3939 gf / cm ² .

(Table 13)
Effect of crosslinker concentration
Amount of cross-linking agent Tear Heat-resistant temperature Color Tactile feel Swelling degree Hardness Breaking per area
[%] Strength [gf] [° C] [%] Strength [gf / cm ² ]
0 80 30 None Good 113 38 1883
0.1 220 30 None Good 52 35 4099
0.5 290 70 None Good 39 50 3663
1.0 290 80 None Good 36 43 3939
3.0 160 80 None Bad 22 43 3958
(brittle)
5.0 140 80 None Defective 13 50 3000
(brittle)

Claims (4)

  A biodegradable pseudo bait whose main component is a gelatin gelled product having a viscosity measured in accordance with JIS K6503 of 4.0 mPa · s or more.   A biodegradable pseudo bait which contains a gelatin gelled product cross-linked with at least one of an epoxy cross-linking agent and an aldehyde cross-linking agent as a main component and remains infusible in viscosity measurement according to JIS K6503.   A biodegradable pseudo bait formed from a gelled product of a gelatin composition containing at least one crosslinking component of an epoxy crosslinking agent and an aldehyde crosslinking agent and gelatin.   The biodegradable simulated bait according to claim 3, wherein the content of the cross-linking component is 1 to 10% by mass of the content of the gelatin.