JP2730313B2 - Coating agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating agent, and more particularly, to a coating agent for food containing plant-derived hemicellulose as a main component.

[0002]

2. Description of the Related Art In order to shine on processed marine products, confectionery, and other foods, mirin and sugars are generally added, but these substances are only shining and have poor gas barrier properties. Although pullulan is known as a coating agent having gas barrier properties, its production method is not only complicated but also expensive, and cannot be said to be versatile. Japanese Patent Application Laid-Open No. 49-110861 discloses pullulan as a coating agent, but pullulan is rarely used because it is expensive.

Further, glaze treatment is performed to prevent burning of frozen fish, and CMC or gelatin is used as an additive to delay evaporation of the glaze film. However, they are not widely used because they are synthetic or expensive.

Although various polysaccharides can be used as a coating agent, those having a high viscosity cannot obtain a high-concentration solution, and the coating solution is applied to an object to be coated in such an amount that the effect is expected. Therefore, there is a demand for a polysaccharide capable of forming a solution having the above effects and having a relatively low viscosity.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coating agent which overcomes the above-mentioned drawbacks, is effective in glossing food, preventing oxidation and extending shell life, and is inexpensive and easy to manufacture. Aim.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, a water-soluble hemicellulose obtained from oil seeds such as okara by a specific method has been used as a conventional coating agent. It has high stability, biodegradability, film strength, gas barrier properties, appropriate aqueous solution viscosity as a coating agent, etc., and can be produced at relatively low cost.

That is, the present invention is a coating agent containing water-soluble plant-derived hemicellulose as a main component, which is obtained by hydrolyzing water-insoluble plant fibers.

[0008] Coating agents comprising water-soluble hemicellulose extracted from plants are not only good in image because of their natural origin, but also have high industrial advantage in terms of their non-polluting properties due to their biodegradability. It can be called an agent.

By hydrolyzing the water-insoluble plant fiber, the water-insoluble plant fiber is decomposed to obtain a water-soluble plant fiber. When the hydrolyzed plant fiber is coated, the water-soluble plant fiber becomes Acts as a binder,
Give sufficient strength.

A water-soluble fraction in a hydrolyzate obtained by hydrolyzing a water-insoluble plant fiber as described above,
That is, when a portion containing a large amount of water-soluble plant fiber is separated and coated, a transparent biodegradable coating having a higher strength of the thin film, less impurities, and a thin film can be obtained.

Further, when the polymer fraction in the water-soluble fraction is separated and coated with this polymer fraction, a transparent biodegradable coating that does not discolor for a long time is obtained. can get.

As the water-insoluble plant fiber, water-insoluble components such as oil seeds such as soybean, palm and palm and water-insoluble components such as cereals such as rice, wheat and corn can be used. Okara is preferred, but is particularly preferred in that it can be obtained stably. In addition, okara is preferable because it contains a large amount of polysaccharides suitable for extracting water-soluble hemicellulose, and because the content of proteins and lipids other than polysaccharides is small, the extraction of water-soluble hemicellulose is easy. .

In the hydrolysis, when the water-insoluble vegetable fiber is soybean protein containing soybean protein, the isoelectric point of the soybean protein is p
Since it is near H 4.5, pH 2 to 7, preferably p
It is preferable to carry out at a temperature within the range of H3 to 6 and 130 ° C. or lower.

As described above, hydrolysis at the vicinity of the isoelectric point of a protein is carried out under an acidity considerably lower than the isoelectric point of a protein.
For example, okara containing soy protein as described above may be adjusted to pH 2
When hydrolysis is performed under the following strong acidity, plant fibers are excessively decomposed, the function as plant fibers is reduced, and proteins are also decomposed and eluted together with plant fibers, neutralizing this In this case, the solution becomes cloudy or the pH is low, so that the neutralization must be sufficiently performed, and the amount of the neutralized salt increases, so that a desalting step is required.

On the other hand, a water-insoluble plant fiber containing a protein is neutralized or alkalinized at a temperature much higher than the isoelectric point of the protein.
When hydrolysis is performed at higher alkalinity, proteins are solubilized and eluted together with plant fibers,
This is because the liquid becomes cloudy or the sugar generated by the decomposition reacts with the amino acid to brown to black brown.

When the water-insoluble vegetable fiber containing protein is hydrolyzed at a temperature of 130 ° C. or less, when the temperature is higher than 130 ° C., the sugar (reducing sugar) and amino acid generated by the decomposition are converted into amino acids. This is because it browns upon reaction and the odor becomes intense.

The temperature at which the water-insoluble protein fibers containing proteins are hydrolyzed may be 130 ° C. or lower as described above. However, in order to perform the decomposition efficiently, the temperature is higher than normal temperature, preferably 80 ° C. or higher. More preferably, it is performed at a temperature of 100 ° C. or higher.

As described above, by hydrolyzing the raw material plant near the isoelectric point of the protein contained therein, the protein is aggregated, and the elution of the protein into the water-soluble fraction is suppressed. This eliminates the need for deproteinization in the subsequent steps,
Highly pure water-soluble hemicellulose can be obtained at relatively low cost.

The water-soluble hemicellulose of the present invention is 10-300 cp (centipoise), preferably 30-200 cp, more preferably 40 cp at 30 ° C. in a 10% aqueous solution.
Gives a viscosity of ~ 150 cp.

[0020]

EXAMPLES Preparation of Coating Agent To the raw soybean curd obtained in the step of producing separated soybean protein was added twice the amount of water, the pH was adjusted to 4.5 with hydrochloric acid, and the mixture was hydrolyzed at 120 ° C. for 1.5 hours. . Then centrifuge (10,000G
× 30 minutes), and separated into a supernatant and a precipitate. The supernatant thus separated was treated with an activated carbon column and deodorized. The liquid thus obtained was dried to obtain water-soluble hemicellulose.

Table 1 shows the food analysis value and the constituent sugar composition of the water-soluble hemicellulose. Its molecular weight was 178,000. The molecular weight was determined from the intrinsic viscosity [η] using pullulan as a standard substance. [Η] = KM ^a (η = 0.495, K = 2.87 × 10 ⁻⁴ , a = 0.64) Measurement conditions: 25 ° C., 0.1 M solution of NaNO ₃ .

[Table 1] The following experiment was performed using this water-soluble hemicellulose as a coating agent.

Effect on sardine mirin dried Sardine mirin dried with the seasoning liquid shown in Table 2 (30 ° C, RH50)
%. For 10 hours), the sample was stored at 40 ° C., and after 10 days, the lipid of the sample was extracted with hexane, and its POV was measured. Table 3 shows the results.

[0023]

[Table 2]

[0024]

[Table 3]

From these results, it is apparent that mixing the water-soluble hemicellulose in the seasoning liquid of mirin dried has a more effective oxygen blocking effect and suppresses the increase in POV. In addition, the mirin-boshi made with the composition of B and C was glossy, and the gloss was the same as that made with A.

Glaze effect After freezing sardine at -30 ° C as a whole, 2% water-soluble soybean hemicellulose is prepared, glazed with water as a control, stored at -20 ° C, and frozen fish surface The burnt (oxidized) state of was observed over time. Table 4 shows the results.

[0027]

[Table 4]

From these results, it can be said that the glazing treated with a 2% solution of water-soluble soybean hemicellulose not only has a high effect of preventing the frozen preserved fish from burning, but also has an effect of preventing the glaze from drying.

Egg Preservation Effect Eggs were immersed in a shell in a water-soluble soybean hemicellulose aqueous solution (5%), dried, and subjected to a storage test at 5 ° C. using the untreated egg as a control. Then, the albumen height and the yolk height were measured over time, and used as indices of freshness. Table 5 shows the results.

[0030]

[Table 5]

Coating Film Strength In order to measure the coating film strength, a film was prepared using water-soluble soybean hemicellulose. The strength of the film was measured to determine the strength. Table 6 shows these measured values.

[0032]

[Table 6]

Effect on Yakiniku Yakitori was prepared using the sauce shown in Table 7. First, the chicken on the skewers is roasted in seven parts and allowed to cool for 30 minutes. Then, it was soaked in the sauce and left for 3 minutes, and the weight increase of the chicken was measured. After that, the baked product was subjected to a sensory test.

[Table 7] Table 8 shows the measurement results and the sensory evaluation results. The riding on the sauce after the seven-part grilling was clearly better in the test section, and the surface condition and taste after the final grilling were also good. These results indicate that when water-soluble soybean hemicellulose is added to the sauce, a certain coating effect is exhibited due to its film properties, and good shine and good riding on the sauce are brought out.

[Table 8] (Evaluation method) Amount of attachment The amount of sauce attached to chicken baked 7 parts was evaluated by the calculation on the right. Attached amount (%) = (amount of sauce (g) / 7-part roasted chicken (g)) × 100 Effect on rice cracker (cracked rice) Using the seasoning liquid shown in Table 9, a cracked rice cracker was prepared. That is,
Apply each seasoning liquid to the cracked rice cracker with a brush and dry,
The condition of the surface was evaluated. As a result, it adheres evenly to the surface of the rice cracker, and after drying, not only is the surface shining good, but the penetration of the seasoning liquid is small, and the surface condition is good for the small amount of applied seasoning liquid. I got it. Furthermore, in the case of a rice cracker to which glue is adhered, the adhesiveness of glue after drying was improved.

[Table 9] Polishing effect of cooked rice When cooking rice (standard rice), 3% of water-soluble soybean hemicellulose was added to the water used for cooking, lightly stirred, and cooked as usual. After cooking, the pot was left open for 10 minutes without opening. The cooked rice thus obtained was subjected to a sensory evaluation using water-soluble soybeans to which no cellulose was added as a control (Table 10).

[Table 10] From these results, it was not possible to improve the texture of cooked rice by adding water-soluble soybean hemicellulose, but the luster was not only cooked but also tens of minutes better than the control group. This is presumably because when water was added to and cooked with water-soluble soybean hemicellulose, the water-soluble soybean hemicellulose formed a film on the surface of the cooked rice to give gloss. As is clear from these results, the strength of the water-soluble soybean hemicellulose film is generally higher than that of the pullulan film having higher strength, and the strength at the time of coating is expected to be higher than that of pullulan.

[0034]

Industrial Applicability According to the present invention, it has high stability, biodegradability, film strength, gas barrier properties, appropriate aqueous solution viscosity as a coating agent, etc., which are not found in conventional coating agents, and is relatively inexpensive to manufacture. A possible coating agent is obtained.

Claims (1)

(57) [Claims] 1. A coating agent comprising water-soluble plant-derived hemicellulose as a main component, obtained by hydrolyzing water-insoluble plant fibers.