JP3007363B2 - Food material containing microbial cellulose complex - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a microbial cellulose composite-containing food material, and more particularly, to a microbial cellulose composite-containing food having excellent functions mainly composed of microbial cellulose and a polymer substance. About the material.

[Problems to be solved by conventional technology and invention]

Microbial cellulose is being developed for use as a mechanically high-strength material, food material, stabilizer, low-calorie additive, etc. (JP-A-62-36467, JP-A-62-29404).
No. 7, JP-A-63-188365, JP-A-64-16565, etc. In addition, the development of medical applications is also in progress (JP-A-63-188365).
No. 152601). Also, the disintegrated product of microbial cellulose is expected to be used as a dispersant, a water retention agent, and a reinforcing agent (JP-A-61-113601, JP-A-1-156600, etc.). However, since it is difficult to provide a function that sufficiently satisfies the above-mentioned uses only with microbial cellulose, a method of impregnating a gel of microbial cellulose with a stabilizer (Japanese Patent Laid-Open No. 63-188365) or chemical modification is used. Attempts have been made to enhance the functionality of the system (Japanese Patent Laid-Open No. 63-15 / 1988).
No. 2601). In addition, it is devised to have more excellent properties such as laminating a compound imparting functionality to the surface of the microbial cellulose membrane to form an asymmetric membrane or performing coating.

The above-mentioned microbial cellulose composite can be obtained by simply impregnating a gel of microbial cellulose with a target compound or modifying physically or chemically. However, compounding by impregnation requires time for impregnation, and compounding of a compound that is difficult to impregnate, for example, a polymer substance, is restricted. In addition, a complex formed by physical complexation is unstable, and chemical complexation has problems such as complicated chemical modification operations.

It is an object of the present invention to provide a food material containing a stable microbial cellulose composite of microbial cellulose and a wide range of macromolecular substances.

[Means for solving the problem]

The present inventors conclude that most of the constituent sugars of microbial cellulose are glucose, but the composition of constituent sugars depends on the fact that a small amount of mannose, galactose, arabinose and the like are also contained, and on the cellulose-producing strain and culture conditions. We focused on the fact that the microbial cellulose had a β-1,4-linkage of glucose as the main chain, but conducted extensive research on the presumption that there was a side chain other than the β-1,4-linkage. As a result, by actively utilizing the affinity for the main chain and side chain, it is possible to complex with a wide range of macromolecular substances. In culturing microorganisms,
By adding a macromolecular substance to be complexed to the medium in advance, microfibrils and the macromolecular substance interact during microfibril formation of microbial cellulose, and complexation easily proceeds, and furthermore, It has been found that a composite having excellent physical properties can be obtained by increasing the degree. Furthermore, they found that this was useful as a food material.

That is, the present invention provides at least one selected from chitin, carboxymethyl chitin, sulfated chitin, chitosan, sulfated chitosan, nitrated chitosan, carboxymethyl cellulose, sodium alginate, carrageenan, and xanthan gum in a medium for culturing microbial cellulose-producing bacteria. A food material containing a composite of microbial cellulose and a macromolecular substance obtained by culturing the microbial cellulose-producing bacterium by adding one type of macromolecular substance, and disaggregated and microfibrillated microbial cellulose and chitin Mixing at least one polymer selected from carboxymethyl chitin, sulfated chitin, chitosan, sulfated chitosan, nitrated chitosan, carboxymethylcellulose, sodium alginate, carrageenan and xanthan gum There is provided a food material containing a composite compound of microbial cellulose and a polymer material obtained by the.

The microbial cellulose used in the present invention is not particularly limited as long as it is produced by a microorganism that produces cellulose. There is no particular limitation on microbial cellulose-producing bacteria,
Microorganisms belonging to the genus Acetobacter, Gluconobacter, Pseudomonas, Agrobacterium and the like can be mentioned, but microorganisms belonging to the genus Acetobacter are preferred because of their high cellulose-producing ability. Specific examples include Acetobacter pasteurianus ATCC 10245.

As a medium for producing microbial cellulose, a general medium for culturing ordinary bacteria may be used, and a carbon source,
It contains nitrogen sources, inorganic salts, and if necessary, amino acids, vitamins, and other nutrient sources. When using a microorganism belonging to the genus Acetobacter, Hestrin-Schra
mm medium is particularly preferably used. In addition, by adding a heat-inactivated cellulase preparation to the medium in an autoclave or the like, the productivity of microbial cellulase can be increased.

Culture conditions may be ordinary conditions, and the pH may be a condition under which microbial cellulose-producing bacteria grow and produce microbial cellulose, and is usually 5 to 9. The culture temperature is 20-40 ° C
Range.

The culture method may be usually stirring culture or static culture. However, when a microorganism belonging to the genus Acetobacter is used, a method of producing on the surface of the culture solution by static culture is preferable because of high productivity.

The produced microbial cellulose is subjected to deproteinization treatment if necessary, and is usually washed with water before use. If necessary, after washing with water, drying may be carried out by a method in which microbial cellulose is not decomposed, for example, by a general method such as air drying.

The polymer substance used in the present invention is not particularly limited as long as it has any interaction with microbial cellulose. Specifically, chitin, carboxymethyl chitin, sulfated chitin, chitosan, sulfated chitosan, nitrated chitosan,
Carboxymethylcellulose, sodium alginate,
Carrageenan, xanthan gum and the like can be mentioned, and one or more of these high molecular substances are used.

There is no limitation on chitin, which is one of the high molecular substances, and examples thereof include those prepared from crab and shrimp shells and those prepared from squid spine and krill. In addition, as a method for preparing chitin, there is no particular limitation, as well as an ordinary method in which crabs and shrimp shells are treated with dilute hydrochloric acid and a heated dilute alkali, and a method in which protease treatment is performed to remove proteins and purify. Chitin derivatives such as chitosan, carboxymethylated chitin, sulfated chitin, glycinated chitin, sulfated chitosan, and nitrated chitosan are described in, for example, "Last Biomass-Chitin, Chitosan" (Gihodo Publishing, 1988, p29). Can be easily prepared by known methods. In the present invention, besides chitosan obtained by deacetylation of the chitin by a conventional method, Absidia genus, Mucor
Chitosan obtained from fungal cells of the genus Rhizopus can also be used.

It is desirable to use the above-mentioned microbial cellulose and the high-molecular substance having as high a purity as possible. However, the microbial cellulose and the high-molecular substance may contain impurities to some extent depending on the use.

The following two methods can be used as a method for preparing the microbial cellulose composite of the present invention containing the microbial cellulose and the polymer substance as main components. In the first method, in producing microbial cellulose, a macromolecular substance is added to a culture medium for culturing microbial cellulose-producing bacteria, cultivation is performed, and a microbial cellulose composite compound of microbial cellulose and a macromolecular substance is obtained. How to The type of the high molecular substance to be added to the medium is not particularly limited as long as it does not significantly hinder the growth of the microbial cellulose-producing bacterium, but the addition concentration is usually 0.05 to 20%. Is preferred. The culture conditions and culture method are not particularly limited, and may be performed in the same manner as described above. The microorganism-cellulose complex obtained by complexing the produced polymer substance is subjected to deproteinization treatment if necessary, and then usually washed with water before use. Further, if necessary, after washing with water, the microorganism may be dried by a method that does not decompose microbial cellulose, for example, air drying, and then molded.

The second method is a method of mixing the disaggregated microbial cellulose and the polymer compound to form a composite, thereby obtaining a microbial cellulose composite. First, the microbial cellulose produced by the above-mentioned method is cut by mechanical shearing force such as a mixer or disintegrated by a pulp disintegrator, and then homogenized by a high-pressure homogenizer to microfibrillate.
The obtained suspension is centrifuged to obtain a paste-like disintegration product. The polymer substance to be complexed with this paste-like disintegration is mixed well by a usual method, for example, a mixer or a homogenizer. At this time, the polymer substance may be mixed as it is in a solid state, but since the mixing time with the microbial cellulose can be shortened, and since the concentration becomes quickly uniform in the mixed solution, the polymer substance is used as a solution or suspension. It is desirable to use. The mixing time may be about 5 to 60 minutes, and usually does not require heating or the like. The concentration and mixing ratio at the time of mixing the microbial cellulose and the polymer substance are not particularly limited as long as the two can be mixed, but usually the concentration of the polymer substance is 0.05 to 20%, and the mixing ratio of both is Microbial cellulose:
It is desirable that the high molecular substance is in the range of 1:10 to 10: 1.

In addition, the microbial cellulose composite obtained by the above method can be freeze-dried and solidified.
In the case of freeze-drying, the obtained complex is frozen after disaggregation, and then dried under reduced pressure in a frozen state. The freeze-drying method may be a normal method.However, in order to improve the resilience when water is absorbed, it is necessary to freeze in as short a time as possible, and to prevent the freezing from being melted due to the temperature rise during drying. There is. When the solidified composite obtained in this manner is reconstituted by water absorption, it does not impair the dispersibility, water retention, and the like, which are excellent characteristics of microbial cellulose.

Further, the microbial cellulose composite obtained by the above method can be formed into a film by air drying or hot air drying as it is. Further, the melt of the microbial cellulose composite is extruded from the pores into an appropriate coagulation bath to cool and solidify, or a solution containing the microbial cellulose composite is prepared using a solvent, and extruded from the pores, and then the solvent is removed. It can be made into a fibrous form by solidifying except for. Also, by changing the shape of the pore,
The cross section of the fiber can be molded in a circular or triangular shape, and can also be made into a hollow fiber shape.

The microbial cellulose composite of the present invention has applications in the food field such as dispersants, suspension stabilizers, thickeners, water separation inhibitors, and water retention agents, and is used as a food material.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to Examples.

Preparation Example (Preparation of Microbial Cellulose) Acetobacter pasteurian ATCC 10245 Hestri
n-Schramm medium (D-glucose 2.0 g, bactopeptone (Difco) 0.5 g, yeast extract (Difco) 0.5
g, 0.115 g of citric acid, 0.27 g of disodium hydrogenphosphate, 100 ml of distilled water, pH 6.0), and cultured at 28 ° C. for 96 hours. After completion of the culture, a membrane containing the produced bacterial cellulose as a main component was taken out from the surface of the culture solution, deproteinized with a 1% aqueous NaOH solution at room temperature for 24 hours, and washed with water to obtain microbial cellulose.

Example 1 After microbial cellulose obtained in the preparation example was cut with a food cutter, a high-pressure homogenizer (homogenizer for APV goulin test, submicron disperser 15M) was used.
R) to give a suspension of microfidrillated microbial cellulose (concentration 0.3% (w / v)) by 30 passes. Next, this suspension was centrifuged (6,000 rpm, 15 minutes) to obtain a paste. 0.3% (w / v) of this paste (microbial cellulose concentration of about 1.5% (w / v)) was collected as the microbial cellulose concentration, and the final concentration was 0.3%
A polymer substance solution of carrageenan, sodium alginate, xantham gum or carboxymethylcellulose (sodium salt) was added so as to obtain (w / v), and the mixture was stirred and mixed at room temperature for 60 minutes with a mixer to form a composite. The viscosity of each solution before mixing with microbial cellulose and the viscosity after mixing (c
p) is shown in Table 1. The viscosity was measured at 20 ° C.

As is evident from Table 1, a composite was obtained by mixing the disintegrated microbial cellulose and the polymer substance, and the viscosity was significantly improved compared to the sum of the viscosity of the microbial cellulose before mixing and the viscosity of each solution.

Example 2 The paste-form microbial cellulose prepared in Example 1 was added to 0.1 ml (w / v) of a 10 ml water-oil mixture consisting of 7 ml of water and 3 ml of edible oil. This mixture is placed in a test tube, and various concentrations of xanthan gum are added thereto.
After mixing and stirring with a mixer for 3 minutes, the mixture was allowed to stand for 30 minutes to examine the mixing state of water and oil. As a control, the same operation was performed except that Avicel FD101 (derived from vegetable cellulose, manufactured by Asahi Kasei Corporation) was used instead of the paste-form microbial cellulose. The results are shown in Table 2.
In the table, ○ indicates that water and oil are maintained in a suspended state even after standing, and X indicates that water and oil are promptly separated after standing.

As is apparent from Table 2, water and oil could be kept in a stable suspension by adding a small amount of xanthan gum. In addition, even if xanthan gum and disintegrated microbial cellulose were mixed, the addition of xanthan gum was low, so that the improvement in viscosity as in Example 1 was not observed. Further, 1% addition was required to bring microbial cellulose disintegrated with xanthan gum alone into a suspended state.

Example 3 Acetobacter pasteurianus ATCC10245 was inoculated into 100 ml of a Hestrin-Schramm medium (using a 300 ml Erlenmeyer flask) used in Preparation Examples, and was cultured at 30 ° C. for 6 days. On the other hand, carboxymethyl cellulose (sodium salt), carboxymethyl chitin (degree of substitution 0.6), carboxymethyl chitin (degree of substitution 1.0) were added to 100 ml of Hestrin-Schramm medium.
Alternatively, Acetobacter pasteurianus ATCC10245 was cultured in the same manner except that a medium containing 0.5% of xanthan gum was used. After completion of the culture, the microbial cellulose produced on the surface of the culture solution or the microbial cellulose complexed with the high-molecular substance was taken out, subjected to deproteinization treatment and neutralization treatment in the same manner as in the preparation example, and washed with water. After washing with water, the sample was placed on a filter paper to sufficiently absorb adhering water, and the weight was measured. Then, after freezing each microbial cellulose at −40 ° C., a freeze-drying treatment was performed under reduced pressure overnight without melting, and the weight of the obtained solid was measured. After measurement, 100m
and suspended in water at room temperature for 2 hours. After water absorption, it was placed on a filter paper to remove adhering water, and the weight was measured. Table 3 shows the results.

As is evident from Table 3, microbial cellulose alone was able to recover only to the level of 32% before freeze-drying, whereas microbial cellulose complexed with a high molecular substance had a high recovery rate.

Example 4 A paste of microbial cellulose disintegrated prepared in the same manner as in Example 1 (microbial cellulose concentration 2% (w /
v)) 0.1g (as dry weight), carrageenan,
Add 0.1 g of xanthan gum or guar gum respectively,
The mixture was mixed by a mixer for 60 minutes to form a composite. The microbial cellulose composite compounded with the obtained polymer substance was prepared in Example 3
Lyophilization was performed in the same manner as described above to obtain a solid. After adding 30 ml of water to the obtained solid substance and allowing it to absorb water at room temperature for 2 hours,
The attached water was removed with a filter paper, and the weight was measured.
As a control, only disaggregated microbial cellulose (dry weight)
0.2 g) and the same operation was performed. Table 4 shows the results.

As is clear from Table 4, all of the microbial cellulose was heavier than the control and was solidified while maintaining water absorption.

Example 5 The composite of xanthan gum and microbial cellulose prepared in Example 1 was added to the sesame flavor sauce whose composition is shown in Table 5.

Table 5 Liquid sugar 113ml Sodium glutamate 9g Sesame paste 35g Sesame oil 7g Mirin 100ml Soy sauce 400ml Water 340ml Microbial cellulose complex 52.6g (wet weight) After raising the product temperature to 90 ° C, it was cooled and allowed to stand at room temperature. As controls, those without the microbial cellulose complex and those with only the microbial cellulose added were prepared. In each of the controls, the sesame paste floated to the upper layer after one week and solid-liquid separation was observed, but no separation was observed when the microbial cellulose composite was added.

In addition, when a sensory evaluation was conducted by a trained sensory evaluator, there was no significant difference in taste, aroma and texture when compared with the control, even when the microbial cellulose complex was added.

Example 6 400 g of minced meat, 100 g of minced onion, one egg, a little salt and pepper were added to 150 cc of milk, mixed with 2/3 of breadcrumbs, and mixed well to prepare a hamburger steak. 10 of these
0.2 g of a lyophilized product of the composite of xanthan gum and microbial cellulose prepared in the same manner as in Example 4 was added to 0 g, and mixed well. Divide this into two equal parts and wrap it in wraps.
Stored frozen at ℃ overnight. After storage, it was thawed at room temperature and the amount of drip was compared with that of a hamburger (control) without the complex of xanthan gum and microbial cellulose, which was also stored frozen at -30 ° C overnight. In addition, what was baked in a frying pan was subjected to a sensory evaluation by a well-trained sensory judge. Compared with the control, the amount of drip discharged at the time of thawing was such that the juice was slightly released to prevent water separation, and the juice was well retained. Also, the sensory evaluation showed no significant difference in texture compared to the control, and was preferred in taste.

〔The invention's effect〕

The microbial cellulose composite of the present invention is a composite of a wide range of high molecular compounds, has excellent functionality, and is useful as a food material or the like.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI A61L 17/00 C12P 19/04 C C12P 19/04 A61L 15/01 (72) Inventor Mariko Nishimura Right and left of Myojin, Kusumura-cho, Nishio-shi, Aichi 29-1 (72) Inventor Masahiro Fukaya 1-28 Morioka Hakuura-cho, Higashiura-cho, Chita-gun, Aichi Prefecture 28 (72) Inventor 1 Okumura 5-66, Iwaname-Higashi-cho, Handa-shi, Aichi 14 (72) Inventor Kawamura 132 (56) References JP-A-62-83854 (JP, A) JP-A-63-152601 (JP, A) JP-A-63-188365 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) A23L 1/05-1/09 C08B 37/00 C12P 19/04

Claims (2)

(57) [Claims] 1. A medium for culturing microbial cellulose-producing bacteria, comprising at least one selected from chitin, carboxymethyl chitin, sulfated chitin, chitosan, sulfated chitosan, nitrated chitosan, carboxymethyl cellulose, sodium alginate, carrageenan and xanthan gum. A food material containing a composite of microbial cellulose and a macromolecular substance obtained by adding one type of macromolecular substance and culturing the microbial cellulose-producing bacterium. 2. A disintegrated and microfibrillated microbial cellulose and at least one selected from chitin, carboxymethyl chitin, sulfated chitin, chitosan, sulfated chitosan, nitrated chitosan, carboxymethyl cellulose, sodium alginate, carrageenan and xanthan gum. A food material containing a composite of microbial cellulose and a polymer obtained by mixing one type of polymer.