JP2006055717A - Method for regenerating residue of fisheries processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems of known methods for treating the residue of fisheries processing with a low-pH acid solution to make heavy metals leached out into the acid solution so as to remove heavy metals contained in the residue, e.g. internal organs of scallops and squids, for utilization of the residue, where the problems includes one that the treatment with the low-pH acid solution solubilizes proteins in the residue to leached out and/or decreases the enzymatic activity of the proteins, respectively resulting in poor recovery of the residue and/or difficulty of utilization of the residue as a raw material for fermentation, and provide a method for regenerating the residue of fisheries processing permitting utilization of the residue by removing heavy metals effectively without denaturation of proteins in the residue. <P>SOLUTION: The method twice or more repeats a process of bringing the residue of fisheries processing into contact with an acidic treating solution to leach out heavy metals in the residue into the treating solution at pH=3.7-5.0 so as to remove heavy metals in the residue. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for reclaiming fishery processing residue that can remove heavy metals contained in the fishery processing residue and make the fishery processing residue usable as an edible resource.

  A large amount of heavy metals may be contained in fishery processing residues such as scallops and squid, and such aquatic processing residues have not been used before and have been disposed of by incineration or landfill. It had been. However, seafood processing residue is also a valuable protein resource, and in recent years, it has become necessary to effectively use the seafood processing residue by removing heavy metals from the viewpoint of effective use of resources and environmental conservation.

  As a method for removing heavy metals from the seafood processing residue, Patent Document 1 discloses a weak pH of 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. Produce acid, further decompose protein bound to heavy metal by the action of proteolytic enzyme, dissociate heavy metal from protein and elute heavy metal in acid treatment solution, separate heavy metal in eluted aqueous solution with chelating agent etc. A method is described. Patent Document 2 describes a method of eluting heavy metals by contacting an aqueous solution of phosphoric acid, an organic acid, hydrochloric acid, nitric acid, boric acid or sulfuric acid.

JP 2001-137810 A JP-A-12-296389

  In the method of Patent Document 1 in which heavy metals in a fishery processing residue are eluted in an acid treatment solution, it is necessary to perform treatment at a low pH of 3 to 3.5 in order to increase the removal efficiency of heavy metals. When treated at a low pH, the protein in the fishery processing residue is solubilized and eluted, and the residue recovery rate decreases. In addition, since the enzyme activity also decreases in the protein that remains without elution, it cannot be used as a raw material for fermented foods even though it can be used as a fishery extract, and the effective use range of fishery processed residue is narrowed. is there. In particular, when the treatment is performed in combination with a low pH acid treatment solution and a proteolytic enzyme as in the method described in Patent Document 1, the above-described problem is further increased. The processing method for using as a food processing raw material such as fermented food, because it is limited to a pretreatment method for safely disposing of fishery processing residue or a processing method when using fishery processing residue as feed or fertilizer Could not be applied. Moreover, although the removal rate of cadmium is good when the acid concentration to be used is high in the method described in Patent Document 2, there is a possibility that the residue recovery rate is lowered and the enzyme activity may be lost. When it is low, there are disadvantages such as a low removal rate of cadmium.

  The present invention has been made in view of the above-described conventional problems, and can effectively remove the heavy metals in the fishery processing residue and effectively use the components such as proteins contained in the fishery processing residue as food. An object of the present invention is to provide a reproduction processing method.

That is, the present invention
(1) Repeating the process of bringing aquatic processing residue into contact with an acidic treatment liquid and eluting heavy metal in the residue into the acidic treatment liquid at pH = 3.7 to 5.0, and removing heavy metals in the aquatic processing residue. A method for reclaiming processed fishery residue,
(2) The method for reclaiming fishery processing residue according to (1) above, wherein the step of eluting heavy metals in the fishery processing residue into the acidic treatment liquid is repeated 2 to 5 times,
(3) The method for reclaiming fishery processing residue according to (1) or (2) above, wherein the acidic treatment liquid is an organic acid solution,
Is the gist.

  When the processed fishery residue is processed by the method of the present invention, the heavy metals in the processed fishery residue can be efficiently reduced to a predetermined concentration or less, and the processed fishery residue after removing the heavy metals contains protein, It can be used in a wide range of processed raw materials, feeds, fertilizers, etc., and fishery processing residue that has been less useful in the past can be used effectively.

  In the method of the present invention, the treatment for eluting heavy metals in the seafood processing residue is carried out at pH = 3.7-5, preferably at pH = 3.7-4.5. When the fishery processing residue is added to the treatment liquid, the pH of the treatment liquid may change. The above pH means the pH of the acidic treatment liquid when processing the fishery processing residue, and does not mean adjusting the pH of the acidic treatment liquid to 3.7 to 5.0 in advance. . In order to adjust the pH of the acid treatment liquid at the time of the fishery processing residue to 3.7 to 5.0, when water is added to the fishery processing residue and the pH exceeds 5.0, an acid is added. The pH is adjusted to 3.7 to 5.0. As the acid for adjusting the pH, a mineral acid, an organic acid, or the like is used. Usually, in the first treatment, it is necessary to adjust the pH by adding an acid, but from the second time on, the treatment solution at the time of treatment becomes pH = 3.7 to 5.0 only by adding water. In this case, it is not necessary to adjust the pH by adding an acid, and it is sufficient to add an acid only when it is outside this range. Examples of the mineral acid include hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, and hydrochloric acid, sulfuric acid, and phosphoric acid are preferable. Examples of the organic acid include formic acid, acetic acid, malic acid, lactic acid, tartaric acid, citric acid, maleic acid, fumaric acid, pyruvic acid, succinic acid, phthalic acid, and oxalic acid. Malic acid is preferred. When using the fishery processing residue after heavy metal removal as a food, it is preferable to use an organic acid as the acid, and particularly when malic acid is used, the flavor becomes better.

  Specific methods for bringing the seafood processing residue into contact with the acidic treatment liquid include a method of immersion and treatment in the treatment liquid, a method of treatment with stirring, and the like. The time for contacting the seafood processing residue with the acidic treatment solution is about several minutes to one day, but preferably 30 minutes to 1 hour, and the treatment temperature with the acidic treatment solution should be such that the enzyme activity is not lost. Yes, any temperature may be used as long as it is within a temperature range of 5 to 65 ° C, but 20 to 30 ° C is preferable. Moreover, although it is preferable to use about 0.5-100 times amount processing liquid with respect to the mass 1 of a fishery processing residue, 3-20 times amount is more preferable when a heavy metal removal process process is considered.

  In the method of the present invention, after processing the fishery processing residue in contact with the acidic treatment liquid as described above, the fishery processing residue and the acidic treatment liquid are separated, and the treatment with the acidic treatment liquid is repeated again in the same manner as described above. . The method of the present invention is preferably processed so that the heavy metals in the fishery processing residue are 1 ppm or less, and the number of repetitions of treatment is the pH of the acid treatment solution, the amount of heavy metals in the fishery processing residue, the fishery processing residue. Depending on the amount of acid treatment solution used, etc., 2 to 5 times is preferable. Any method may be used as a method for separating the processed marine product residue and the acidic treatment liquid as long as the method can separate the treatment residue from the treatment liquid, such as centrifugation, decantation, and filtration. Absent. The processing liquid after processing the fishery processing residue can be used as a food processing raw material, feed, and fertilizer after removing heavy metals by a conventional method.

  The fishery processing residue treated as described above can be used as a raw material for food processing, fertilizer, or the like as it is or after drying by an appropriate method. When using after drying, since the enzyme activity in the residue may be lost when heated and dried, it is preferably dried by a method other than heating, such as vacuum drying or vacuum freeze drying. Examples of fishery processing residues to be treated by the method of the present invention include scallop viscera, squid viscera, built-in octopus, other built-in fish and shellfish, etc., which have been discarded because of the heavy metal content. It is desirable to treat the oil and fat content with an acid treatment solution after the degreasing treatment. Also when degreasing, it is preferable to degrease without applying heat so that enzyme activity is not lost. In order to degrease without applying heat, a method such as organic solvent extraction can be used.

Hereinafter, the present invention will be described in more detail with reference to examples.
Examples 1-3, Comparative Examples 1-3
To 100 g of squid liver defatted with hexane (corresponding to a solid content of 66 g), 400 mL of water was added, adjusted to the pH shown in the same table with the acid shown in Table 1, stirred for 1 hour at room temperature, and then centrifuged. (3500 rpm × 10 minutes) to separate the residue and the supernatant. In Comparative Example 3, only water was added, and pH adjustment with acid was not performed. Next, 400 mL of water was added to the collected residue, and the process of stirring at room temperature for 1 hour and then centrifugation (3500 rpm × 10 minutes) was repeated three times. Table 1 shows the pH of the acidic treatment liquid at each treatment step, the residue weight and residue collection rate after each treatment step, the cadmium concentration and cadmium removal rate in the collected residue. In Examples 1 to 3, it cannot be said that the cadmium concentration was sufficiently reduced by one treatment, and most of the cadmium can be removed by the fourth treatment, which is safe as a food processing raw material and fertilizer. High seafood processing residue was obtained. 85 g of water and 10 g of sodium chloride were added to 15 g (dry weight) of the dried residue obtained by freeze-drying the treated residue, and the mixture was stirred and allowed to stand at 50 ° C. for 14 days to recover the lower “Iru” layer. After heating at ° C. for 10 minutes, the cage was filtered to obtain a fish soy sauce-like seasoning. As a control, 85 g of water and 10 g of sodium chloride were added to 15 g (dry weight) of a defatted dry product obtained by freeze-drying squid liver defatted with hexane. The layer was collected, heated at 90 ° C. for 10 minutes, and the cage was filtered to obtain a control fish soy sauce-like seasoning (Ishiru). The sensory test results of the obtained fish soy sauce-like seasoning and the results of measuring the residual cadmium concentration in the fish sauce-like seasoning are shown in Table 1 together with the case of the control product prepared in the same manner using untreated residue. It was.

*: The residue collection rate indicates the weight ratio of the dry weight of the residue collected after the treatment to the dry weight of the residue before the treatment.
*: Cd concentration in the residue was measured by ICP emission spectrometry after the residue was dried and wet-decomposed with nitric acid and perchloric acid. The Cd concentration in the fish soy sauce-like seasoning was measured by ICP emission spectrometry after collecting the seasoning liquid and similarly wet-decomposing it with nitric acid and perchloric acid.
*: In the sensory test, 10 panelists tested the presence of umami and fragrance by comparing the control product.
The taste is ◎ ... More than 8 people have evaluated it as particularly delicious.
○ ... 5-7 people who evaluated it as particularly delicious.
Δ: 2 to 4 people who hardly felt umami.
× ... 8 or more people evaluated as unacceptable.
As evaluated.
The fragrance is ◎ ・ ・ ・ 8 or more people evaluated as particularly good fragrance.
○ ... 5-7 people evaluated as particularly good fragrance.
Δ: 2 to 4 people who hardly felt fragrance.
X: Eight or more people evaluated that there was no fragrance.
As evaluated.

Claims (3)

Remove the heavy metals in the aquatic processing residue by repeating the process of contacting the aquatic processing residue with the acidic treatment liquid and eluting the heavy metal in the residue into the acidic treatment liquid at pH = 3.7 to 5.0 multiple times. Recycling method of fishery processing residue characterized by. The method for reclaiming fishery processing residue according to claim 1, wherein the step of eluting heavy metals in the fishery processing residue into the acidic treatment liquid is repeated 2 to 5 times. The method for reclaiming fishery processing residue according to claim 1 or 2, wherein the acidic treatment liquid is an organic acid solution.