JP2012039955A - Method for removing heavy metal in fish sauce - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a method for removing solid matters including heavy metals by adding tannin or a food additive containing tannin to a fish sauce, wherein liberated heavy metals can not be removed because the target of removal is heavy metals bound with protein only, and problems of a method for removal by eluding heavy metals in an acid treatment solution, wherein the taste is changed and therefore, the sauce can not be used in the state as a seasoning because it is necessary to treat the heavy metals in the solution at a low pH of 3-3.5 to increase the efficiency in removing the heavy metals and protein in the fish sauce is solubilized and eluded when treated in the solution at such a low pH.SOLUTION: Heavy metals are removed from the fish sauce without affecting the oxidation-reduction potential of the fish sauce and without impairing useful components such as flavor components in the fish sauce by adding a food additive filtration auxiliary agent to the fish sauce, separating the solid and liquid, and feeding the fish sauce into a column filled with a heavy metal adsorbent.

Description

  The present invention removes heavy metals contained in fish soy sauce, enhances the safety of fish soy sauce, and removes heavy metals from fish soy sauce that can be used as a food that does not impair the characteristics of fish soy sauce (useful ingredients such as umami). Regarding the method.

Fish soy sauce that uses built-in fish and shellfish such as sardines and squid may contain a large amount of heavy metals.
However, until now, as a habit of local residents in production areas, such fish soy sauce has been ingested constantly, but there have been no reports of cases of specific diseases (pollution such as Itai Thai disease). .

For these reasons, fish soy sauce has been commercialized without being subjected to heavy metal removal treatment.
However, when aiming to expand consumption, such as the use of useful ingredients in fish soy sauce, nationwide expansion as a seasoning, and overseas exports, the inclusion of heavy metals becomes a problem from the viewpoint of food safety and security, and its removal treatment is required It is expected to be.

One prior art document focusing on removing heavy metals from fishery processed products such as fish soy sauce is disclosed. Patent Document 1 is a method of adding tannin or food additives containing tannin to fish soy sauce and removing solids containing heavy metals, and useful ingredients such as umami ingredients are not impaired, and food processing applications are possible. There are advantages such as.
In addition, a method for removing heavy metals from visceral residues has been disclosed in order to effectively use visceral residues such as scallops and squids without being disposed of, although they are not processed fish products themselves. In Patent Document 2, it is weakly acidic at pH 3 to 3.5 using organic acids such as formic acid, lactic acid and acetic acid, and mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid, and further binds to heavy metals by the action of proteolytic enzymes. A method is described in which a heavy protein is dissociated from a protein by decomposing the produced protein, the heavy metal is eluted in an acid treatment solution, and the heavy metal in the eluted aqueous solution is separated by a chelating agent or the like.

JP 2009-254274 A JP 2001-137810 A

  The method of patent document 1 which adds the food additive containing a tannin or a tannin to fish soy sauce, and removes the solid substance containing a heavy metal makes only the heavy metal couple | bonded with the protein removal object, and the subject which cannot remove the free heavy metal has the subject. is there.

In the method of Patent Document 2 in which heavy metals are eluted in the acid treatment solution, it is necessary to treat at a low pH of 3 to 3.5 in order to increase the removal efficiency of heavy metals. The protein is solubilized and eluted, and the taste changes, so it cannot be used as a seasoning as it is.
In other words, since the enzyme activity decreases even in proteins that remain without elution, it can be used as a marine extract, but if used for fermented foods such as fish soy sauce, the quality of the product is reduced. There's a problem.

  In order to solve the above-mentioned problems, the redox potential of fish soy sauce can be obtained by adding a filter additive for food additives to fish soy sauce, solid-liquid separation, and passing the fish soy sauce through a column filled with heavy metal adsorbent. It removes heavy metals from fish soy without being damaged by useful components such as umami components of fish soy.

Heavy metals in fish soy sauce are bound to proteins by the redox potential of fish soy sauce.
Either the method of adding a filter aid by measuring the oxidation-reduction potential of fish soy or the method of using a heavy metal removing agent may be used intensively. By combining both methods, Heavy metals in fish sauce can be reliably removed regardless of the redox potential.

  When the fish soy sauce is treated by the method of the present invention, the heavy metal physically and chemically adsorbed to the protein in the fish sauce is added with a food additive filter aid and separated from the protein by solid-liquid separation. As for heavy metals that are used, heavy metals can be removed using a heavy metal remover, and heavy metals in fish soy sauce can be efficiently reduced to a predetermined concentration or less, and heavy metals can be removed. After the fish soy sauce has been obtained, the quality of the fish soy sauce is maintained without impairing the amino acid exhibiting umami, and it has the effect that it can be commercialized as a fish soy sauce with improved safety.

Moreover, it has the effect that it can be expected to be used not only for seasoning as fish soy sauce with higher safety, but also for supplements using this as a raw material.
The method of the present invention is a simple processing method with few processing conditions such as no need to adjust the pH, and there is no problem in product safety because of the use of food additives, and the use of this method can be promoted. Has an effect.

  In the method of the present invention, after processing fish soy sauce with a filter aid, solids are separated and heavy metals bound to proteins are removed, and fish soy sauce is passed through a column filled with a heavy metal adsorbent. Alternatively, a combination of a method for removing heavy metals released by adding a heavy metal removing agent to fish soy sauce and performing solid-liquid separation, and processing is performed without being affected by the redox potential of fish soy sauce.

  Heavy metals in fish soy sauce are bound to proteins by the redox potential of fish soy sauce. In fish soy sauce in a reduced state (for example, redox potential −100 mV or less), many heavy metals are bound to proteins, and in fish soy sauce in an oxidized state (for example, −20 mV or more), heavy metals are released. There are many things that exist.

Either the method of adding a filter aid by measuring the oxidation-reduction potential of fish soy or the method of using a heavy metal removing agent may be used intensively. By combining both methods, Heavy metals in fish sauce can be reliably removed regardless of the redox potential.
Adjustment of the oxidation-reduction potential includes anaerobic fermentation at the time of production, oxidation by air bubbling after production, addition of a reducing agent or an oxidizing agent for food additives.

  In the method of the present invention, it is desirable that the filter aid and the heavy metal removing agent are permitted to be used in foods and do not impair the taste as a seasoning.

1 mL of a 5.0% tannin aqueous solution was added to 10 mL of fish soy sauce with a redox potential of −40 mV, and the mixture was stirred and then solid-liquid separated by centrifugation (8000 rpm, 15 minutes). This tannin treatment solution was passed through a glass tube filled with 1 mL of a chelating resin at a flow rate of 5 mL / h, and 5 mL was collected every hour.
Table 1 shows the total nitrogen, free amino acid content, lactic acid content, and antioxidant properties of the Cd concentrations of the stock solution, the tannin treatment solution, and the fish soy sauce that had been passed through.
The Cd removal rate was calculated from the Cd concentration before and after the treatment.

100 mL of fish soy sauce was bubbled with air for several hours and oxidized until the oxidation-reduction potential was −20 mV or higher.
Bubbled fish soy sauce was passed through a column tube filled with 1 mL of chelating resin at a flow rate of 5 mL / h.
Table 3 shows the total nitrogen, free amino acid content, lactic acid content, and antioxidant properties of the Cd concentrations of the stock solution and the fish soy sauce that had been passed through.
The Cd removal rate was calculated from the Cd concentration before and after the treatment.

Claims (2)

  Fish soy sauce is not affected by the redox potential of fish soy sauce by adding a food additive filter aid to fish soy sauce, solid-liquid separation, and passing fish soy sauce through a column filled with heavy metal adsorbent. A method of removing heavy metals in fish soy without damaging useful components such as umami components.   The method for removing heavy metals in fish soy sauce according to claim 1, wherein a heavy metal removing agent is added to fish soy sauce and solid-liquid separated instead of passing the fish soy sauce through a column filled with a heavy metal adsorbent.