JP3043196B2 - Method for deodorizing chitin or chitosan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for deodorizing chitin or chitosan, comprising treating chitin or chitosan with warm water to deodorize chitin or chitosan.

[0002]

[Prior art]

[0003] Chitin and chitosan are polysaccharides widely present in crustaceans, insects and fungi, and chitin is a partially deacetylated N-acetyl-β-D-glucosamine polymer. Chitosan has advanced deacetylation of chitin and is soluble in dilute acid. Chitin and chitosan are expected to have the effect of so-called dietary fiber due to their indigestibility. Especially since chitosan has many amino groups, it absorbs bile acids in the digestive tract and inhibits cholesterol absorption and bile acid reabsorption. The effect shows an excellent serum cholesterol lowering effect, and the effect is said to be comparable to the cholesterol lowering agent cholestyramine. Currently, chitin and chitosan having the above actions are often added to various foods. However, chitin and chitosan have a unique fishy odor, and when added to foods, significantly impair the aroma of the foods.Conventionally, the amount of chitin and chitosan should be reduced or added to foods with strong aroma. The method was taken.

[0004]

Therefore, a deodorizing method for obtaining chitin and chitosan having a low fresh odor, which can be added to foods having a low odor, such as udon, in an effective amount has been desired.

[0005]

As a result of various studies, the present inventors have found that by treating chitin or chitosan with warm water, it is possible to deodorize a unique fresh odor.

The present invention has been completed based on the above findings. That is, the present invention relates to a method for deodorizing chitin or chitosan, which comprises treating chitin or chitosan with warm water to deodorize the unique odor of chitin or chitosan.

[0007] Chitin in the present invention is obtained from the shell of the crust such as crab and shrimp as a raw material, deproteinized with a dilute alkali or an enzyme, and further, ash is removed with a dilute acid. It is obtained by washing or neutralizing to remove acids and alkalis. In addition, chitosan is deacetylated by heat treatment of chitin with concentrated alkali, and after completion of the reaction,
It is obtained by washing or neutralizing several times to remove concentrated alkali. ("Development and application of chitin chitosan" published by the Industrial Technology Association, Takashi Nishida et al., Pp. 22-28) The treatment of the invention may be carried out immediately after the acid or alkali removal step in the above-mentioned chitin or chitosan production step. And
Further, for distribution, it may be performed on a dried product obtained through a drying step.

Examples of raw materials for chitin or chitosan include crab, shrimp shell, insect shell, and chitin such as cell walls of mushrooms and filamentous fungi, preferably crab and shrimp shells. The one obtained more is better.

In the treatment with hot water according to the present invention, chitin or chitosan may be brought into direct contact with hot water or hot water may be brought into contact with steam, or after chitin or chitosan is wetted with cold water or immersed in cold water. Heat treatment may be performed.

[0010] Examples of the method of treatment with hot water include: 1. boiling, stirring in warm water, autoclave, hot water treatment using a column, hot water treatment using a centrifugal dehydrator, etc. Heating (steaming) by steam may be used, but boiling and hot water treatment in an autoclave are preferred. Further, a stronger effect can be obtained by performing the processing by combining the above methods 1 and 2.

[0011] In the batch-type washing method such as boiling or hot water treatment in an autoclave in the above-mentioned method 1, when only one treatment is required, the volume of water is particularly limited as long as the whole amount of chitin or chitosan is in contact with water. However, it is preferably 10 to 200 times the weight of chitin or chitosan. The time required for one treatment is longer as the temperature is lower, but when the liquid temperature is 70 ° C. or higher, it is usually 10 minutes or longer, preferably 30 minutes or longer, more preferably 1 hour or longer, and the upper limit depends on the temperature. 3 hours or less is good. The number of treatments is not particularly limited, but the total amount of water required for the treatment is preferably 3 to 100 times, more preferably 10 to 1 times the weight of chitin or chitosan.
It is desirable to repeat the processing so as to increase the value to 00 times.

On the other hand, in a continuous process using a column, a centrifugal dehydrator, or the like, it is desirable that the amount of water required for the process be 2 to 100 times the total weight of chitin or chitosan.

In the above method 2, the steam must be in contact with the whole amount of chitin or chitosan, and the volume of water required for the treatment is generally 2 to 2 times the weight of chitin or chitosan.
It is desirable to perform the processing up to 100 times, preferably 5 to 50 times.

As is common to the above-mentioned methods, the liquid temperature has a deodorizing effect, but any temperature can be used.
More preferably 70 ° C. or higher, most preferably 90 ° C.
To 130 ° C.

If the water used for the treatment has a pH of 4 or more, an organic acid or an inorganic acid may be added, or an alkali or the like may be added. Preferably, neutral water is used.

The form of chitin or chitosan may be a large flake having a size of 2 cm square or more when crab or shrimp is used as a raw material, or may be a finely pulverized product having a 100-mesh sieve. A shape smaller than the shape is preferred.

[0017]

The present invention will be described in more detail with reference to the following examples.

Example 1 The operation of adding 100 kg of boiled water to 20 kg of 2 cm square flaky chitin, stirring the mixture for 30 minutes and discharging the water was repeated twice, followed by drying to obtain deodorized chitin.

Example 2 100 kg of a 30 mesh pass product of chitosan was packed in a stainless steel column having a diameter of 1 m, and 1.44 t of boiling water was injected from the upper portion of the column at a flow rate of 1 l / mim, followed by treatment.
Drying under reduced pressure at ℃ gave deodorized chitosan.

Example 3 10 kg of water was added to 100 kg of a 30-mesh pass of chitosan, and the mixture was boiled for 1 hour and dried at 80 ° C. with ventilation to obtain deodorized chitosan.

Example 4 A dry substance of chitin derived from a 0.5 mm square crab was treated by adding 100 times the volume of water and boiling for 1 hour, followed by suction filtration.
Drying was carried out with a ventilation dryer at ℃ to obtain deodorized chitin.

Example 5 A 100-fold amount of water was added to the dried crab-derived chitosan that had passed through an 80-mesh sieve, the mixture was treated in an autoclave at 121 ° C. for 20 minutes, filtered by suction, and then passed through a 80 ° C. ventilation dryer. Dried and deodorized chitosan was obtained. Example 6 To 200 kg of 80 mesh chitosan was added 4 t of water, and the mixture was boiled and stirred for 30 minutes, cooled, filtered and washed with a centrifuge. The obtained hydrated chitosan was dried with a conical dryer at 80 ° C. to obtain deodorized chitosan.

The following experimental examples show the excellent deodorizing effect of chitin or chitosan obtained by the method of the present invention. Experimental Example 1 The deodorizing effect of boiling chitin was confirmed by a sensory test.
A 100-fold amount of water was added to the dried substance of chitin derived from crab of 0.5 mm square, and the mixture was boiled for 1 hour.
It dried with the ventilation dryer of ° C, and obtained the hot-water-processed product. Each of 1.00 g of the hot water-treated chitin and untreated chitin was placed in a 200 ml Erlenmeyer flask, and 100 ml of boiling water was added to prepare a sample for sensory test. The sensory test was performed using eight panelists and evaluated in five steps using the following preference scale.

Preference scale (sample odor) 1 point: no smell 2 points: hardly smell 3 points: slight smell 4 points: smell 5 points: strong smell

[0026]

Experimental Example 2 The deodorizing effect of chitosan by an autoclave was confirmed by a sensory test. The dried crab-derived chitosan that passed through all the 80-mesh sieves was added with 100 times the volume of water and added for 12
After treatment in an autoclave at 1 ° C, suction filtration was performed, and 8
The product was dried by a ventilation dryer at 0 ° C. to obtain an autoclaved product. As in Experimental Example 1, 1.00 g of each of the autoclaved chitosan and the untreated chitosan was placed in a 200-ml Erlenmeyer flask, and 100 ml of boiling water was added to obtain a sensory test sample. The sensory test was performed using eight panelists and evaluated in five steps using the following preference scale.

Preference scale (sample odor) 1 point: no odor 2 points: almost no odor 3 points: slightly odor 4 points: odor 5 points: strong odor

[0029]

[0030]

As is clear from the above results, the deodorization method of the present invention in which chitin or chitosan is treated with hot water,
The fishy odor peculiar to chitin or chitosan is remarkably eliminated, and an excellent food material can be obtained.

Continuation of the front page (56) References JP-A-1-167301 (JP, A) Keiichiro Ochiai, Ed., Separate volume Food Chemical 1 "Science of Chitin / Chitosan" (Published August 20, 1987, Food Chemistry Co., Ltd.) Newspaper) p. 33-35 (58) Field surveyed (Int. Cl. ⁷ , DB name) C08B 37/08 A23L 1/015 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. A method for deodorizing chitin or chitosan, comprising treating chitin or chitosan with neutral hot water or steam having a temperature exceeding 70 ° C. and 130 ° C. 2. The method according to claim 1, wherein the chitin or chitosan is heated at a temperature of 90.degree.
A method for deodorizing chitin or chitosan, which comprises treating with neutral hot water or steam at 30 ° C.