JPH08289770A - Preservative for food - Google Patents

Abstract

PURPOSE: To obtain a safe preservative for foods, having wide antimicrobial activity, remarkably increased in keeping quality of food and not affecting on quality of food by blending reuterin which Lactobacillus reuteri produces with a natural antimicrobial substance. CONSTITUTION: This preservative for foods is obtained by blending reuterin produced by culturing bacterial strains [e.g. Lactobacillus reuteri DSM20016 (ATCC53609), etc.] of Lactobacillus reuteri in a culture medium with a peptide or a protein such as protamine and its decomposed material, lysozyme or polylysin, saccharide such as pectin (decomposed material), (oligo)galacturonic acid or chitosan (decomposed material) and antimicrobial spices such as cinnamon and rosemary as natural antimicrobial substances (excluding a peptide and protein derived from lactobacillus. The preservative for foods has wide antimicrobial spectrum and is effective in prolonging quality retaining period of foods polluted by yeasts and fungus and safe and does not affect on quality of foods.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a preservative for foods.

[0002]

2. Description of the Related Art Many conventional preservatives for foods have an antibacterial effect against bacteria, and the deterioration of foods due to the growth of yeasts and molds poses a problem. Especially in the field of food industry such as prepared foods, it tends to be low salt and low sugar due to health-consciousness, so that the storage stability is poor, and microorganisms derived from raw materials of foods,
Alternatively, there is a large problem of alteration of foods due to propagation of fungi mixed during the manufacturing process. Therefore, there is a need for a food preservative that suppresses the growth of these microorganisms.

Under such circumstances, Lactobacillus reuter, which is a type of intestinal bacterium,
Reuterin, which is an antibacterial substance i) produced in a medium under anaerobic conditions, has an antimicrobial effect on some bacteria, yeasts and molds, and therefore, uses reuterin as a food preservative. Was proposed (Tokuheihei 2-503
385 publication).

[0004]

However, since reuterin alone has a narrow antibacterial spectrum and needs to be used in a large amount in order to improve the storability of foods, reuterin alone is used as a food preservative. It was practically difficult to use.

Therefore, the present invention increases the antimicrobial action of reuterin in foods, thereby reducing the amount of reuterin added to foods as much as possible, covering a broad antibacterial spectrum, and providing safe and highly preservable foods. It is an object to provide a food preservative for manufacturing.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and as a result, by incorporating a natural antibacterial substance into a food together with reuterin, the antibacterial activity of reuterin in the food has been improved. It was found that the antibacterial spectrum can be increased, the antibacterial spectrum can be broadened, and the preservability of the added food can be dramatically improved, and the present invention has been accomplished.

That is, the present invention provides a food preservative containing reuterin produced by the lactic acid bacterium Lactobacillus reuteri and a natural antibacterial substance.

Lactobacillus Lactobacillus reuteri
acillus reuteri) is a type of animal intestinal bacterium, is a heterolactic acid bacterium that grows in a medium in the intestine or under anaerobic conditions, and its strain has been deposited with the ATCC in two strains (Accession No. 53608 and 53609).

Reuterin is an antibacterial substance produced by Lactobacillus reuteri in a medium containing glycerin under an anaerobic atmosphere. In the culture supernatant, β-hydroxypropionaldehyde, which is a fermentation product of glycerin, is detected, and this β-hydroxypropionaldehyde is a monomer, a hydrate and a dimer in an aqueous solution. It is presumed to exist in the form and is called reuterin. Reuterin exhibits antibacterial properties against Gram-positive bacteria, Gram-negative bacteria, yeasts and molds.

In the present invention, as reuterin, Lactobacillus reuteri (L. reuteri) is cultured in a medium containing glycerin, and then, for example, Japanese Patent Publication No. 2-5033.
As described in Japanese Patent Publication No. 85, a culture supernatant separated and purified by HPLC or the like is used. Further, a concentrate of the culture supernatant can also be used.

As the natural antibacterial substances, peptides or proteins having antibacterial properties, sugars having antibacterial properties, polysaccharides composed of sugar acids and amino sugars and / or partial decomposition products thereof, and spices having antibacterial properties. Alternatively, essential oils or plant components thereof are preferable and can be mentioned.

In the present invention, the peptides or proteins having antibacterial properties exclude peptides and proteins derived from lactic acid bacteria, and examples thereof include protamine and its degradation products, lysozyme and polylysine. Protamine binds to the cell membrane of bacterial cells and leaks out cell contents, lysozyme is a degrading enzyme of the cell wall component of Gram-positive bacteria, acts on Gram-positive bacteria to lyse cells, and polylysine binds to bacterial cell wall structures. In both cases, it is presumed to enhance the invasion of reuterin into the bacterial cell.

Protamine is a strongly basic protein existing as nucleoprotamine bound to deoxyribonucleic acid in sperm nuclei of fish such as salmon, herring, trout, etc. When it is used in food, it may be separated from the nucleic acid. Good luck
Also in the present invention, it is preferable to use such a state. Polylysine is isolated from a culture obtained by culturing a polylysine-producing bacterium belonging to the genus Streptomyces. As lysozyme, those commercially available for foods can be used.

These peptides or proteins having antibacterial properties are 0.003 to 10 relative to reuterin.
00, more preferably 0.01 to 0.2 (weight ratio) so that it is added to be used. When the food is in the state of a seasoning liquid or a solution, or when it is stored in an aqueous solution, it may be used within this range.

Further, as the polysaccharide consisting of sugar having antibacterial properties, sugar acid and amino sugar and / or its partially decomposed product,
Examples thereof include those known as pectin, pectin degradation products, oligogalacturonic acid, galacturonic acid, chitosan, chitosan degradation products, and alginic acid degradation products. There are many unclear points about the mechanism of growth inhibition of microorganisms by using these substances in combination, but in actual foods, there are many cases where apparently synergistic effects appear, and therefore, it is necessary to use them in a useful combination. You can

Regarding the pectin degradation product, the pectin separated from fruits such as grapefruit of the citrus family and apples of the rose family proposed by the applicant of the present invention by enzymatic degradation (Japanese Patent Publication No. 62-53140). Good to use. As chitosan, chitin obtained from the shells of crustaceans such as crab and shrimp is deacetylated by heating with concentrated alkaline solution, and the one obtained by further concentrating this with concentrated hydrochloric acid or enzymatically is preferably used.

It is preferable that the polysaccharide comprising an antibacterial sugar, a sugar acid and an amino sugar and / or a partially decomposed product thereof is contained in an amount of 0.1 to 1000 (weight ratio) with respect to reuterin.

Further, as spices having antibacterial properties,
For example, cinnamon, rosemary, and mace can be mentioned. Extracts and essential oils thereof can also be used. Further, as the plant component having antibacterial properties, organic solvent extracts such as these alcohols, for example, pepper extract, licorice extract, wasabi extract, hop extract and Moso bamboo extract; polyphenols such as tea tannin, Mention may be made of tea catechins, cinnamic acid, ferulic acid, caffeic acid and hinokitiol. The antibacterial action of these plant components is considered to be due to the fact that the phenolic substance in these components damages the cell membrane of the microorganism, and is presumed to help the invasion of reuterin into the microbial cells.

Among these, as the pepper extract, it is preferable to use the water-soluble fraction extracted from pepper fruits with an aqueous solvent, which was previously proposed by the present applicant in JP-A-4-1650263. As the horseradish extract, the same was proposed in JP-A-6-153882 and extracted with water or a mixed solvent of water and an organic solvent in a state in which the enzyme contained in horseradish was inactivated, It is preferable to use an antibacterial substance produced by heating the extract.

As the licorice extract, a substance extracted from licorice with aromatic hydrocarbons, acetone, ethanol or the like, which is also proposed in Japanese Patent Application No. 60-17298, can be used. Although the substance of this licorice extract is unknown at present, it is considered to be a substance completely different from glycyrrhizin used as a so-called sweetener.

These spices having an antibacterial property and their essential oils or plant components are contained in an amount of 0.05 to 0.05 with respect to reuterin.
It is preferable to contain it at 1000 (weight ratio).

When two or more kinds of these antibacterial natural products are used in combination, the effect is further enhanced.

The preservative for food of the present invention is added so that reuterin is contained in the food in an amount of preferably 0.003 to 0.5% by weight, more preferably 0.01 to 0.2% by weight. To use. If the food is a seasoning liquid or solution,
It is recommended to use within this range even when storing in an aqueous solution.

The case where the reuterin and the natural antibacterial substance are separately added to the food or its material is also included in the range of the food preservative of the present invention.

[0025]

The reuterin in the food preservative of the present invention is DN depending on the ribonucleotide reductase activity of the microorganism.
It is known to exhibit antibacterial properties by inhibiting the synthesis of A. The mechanism of action by which the above-mentioned natural antibacterial substance is allowed to coexist to enhance the antibacterial action of reuterin against bacteria, yeasts and molds (fungi) is not clear, but these natural antibacterial substances damage the cell membrane of microorganisms. Thus, it is presumed that it assists the invasion of reuterin into microbial cells and exerts the DNA synthesis inhibitory action of reuterin.

[0026]

The present invention will be described in more detail with reference to the following examples. In the examples,% is% by weight unless otherwise specified. The production method of reuterin used in the examples is as follows.

Lactobacillus Lactobacillus reuteri strain DS
M20016 (ATCC53609) in medium (1% peptone, 1% meat extract, 1% yeast extract, 1% glucose)
%, Ammonium citrate 0.2%, sodium acetate 0.5%, magnesium sulfate 0.01%, manganese sulfate 0.005%, dipotassium phosphate 0.2%, pH 7.
0) 50 ml of a platinum loop was inoculated, and then 50 ml of the culture solution which had been statically cultured overnight at 37 ° C. was inoculated into 1 liter of a medium (production medium) in which 4.6% of glycerin was added to the medium, and the mixture was incubated at 37 ° C.
The cells were cultivated overnight at This culture solution is 4,000 rpm,
After centrifugation for 10 minutes, the resulting supernatant was filtered with a membrane filter having a pore size of 0.45 μm to remove bacteria. About 1 liter of the sterilized culture solution was concentrated under reduced pressure at 40 ° C. to 100 g using a rotary evaporator. This concentrate contained about 1% of reuterin, and this concentrate was used as reuterin in the examples.

Further, protamine, pectin degradation product, pepper extract, hop extract, wasabi extract and licorice extract are manufactured by Asama Kasei Co., Ltd., and polylysine is Chisso Co., Ltd.
As the chitosan, a product manufactured by Yaegaki Fermentation Giken Co., Ltd. was used.

Example 1 Alaska pollack frozen surimi 2.5 kg, salt 75 g, mirin 50 g, sodium glutamate 25 g, sugar 25 g,
To the basic composition of 175 g of potato starch and 1 kg of ice water, the preservatives shown in Table 1 were added in the proportions shown in Table 1, and after crushing for 30 minutes, the resulting meat paste was mixed with vinylidene chloride film (folded). About 100 g was packed in a diameter of 48 mm), both ends were ligated, heated in hot water of 90 ° C. for 30 minutes, and then cooled in running water for 30 minutes to obtain a kamaboko. The obtained kamaboko was used as a sample for a storage test together with the kamaboko obtained in the same manner without adding a preservative. In the preservation test, 10 kamaboko were stored in a thermostat at 25 ° C. per test section, and the appearance was visually observed to determine the antiseptic effect. That is,

0 point: No change. 0.5 point: An extremely small spot appears. 1 point: 1 colony-like spot or 1 partial expansion, syneresis and slightly cloudy. 2 points: 2 or more colony-like spots or 2 partial expansions
Individually, the water is a little cloudy. 3 points: Many colony-like spots or many small partial expansions. 4 points: Partially expanded many or partially softened. 5 points: The whole is softened and expanded.

The number of days until the evaluation reached 1 point was obtained for each of the 10 test specimens, and the average was taken as the number of effective storage days. Table 2 shows the results. In addition, as a result of the sensory test, the test section to which the preservative of the present invention was added showed no difference in taste, color, odor, etc., compared with the control section to which the control product was added, and the adverse effect on the quality due to addition was observed. Was not recognized.

[0032]

[Table 1]

[0033]

[Table 2]

It can be seen from Table 2 that the products to which the preservative of the present invention has been added have a far longer effective storage period than those of the product containing reuterin alone and the natural antibacterial substance alone.

Example 2 A preservative having the composition shown in Table 1 was added to a basic composition containing 500 g of strong flour, 60 g of water and 5 g of flour and mixed well, and then noodle strings were made with a small noodle making machine and boiled. 4 in the water
Boiled and cooled in water for a minute. After draining, 25 g of this is put in a polyethylene bag and sealed, and 10 bags per test zone are put in 25 bags.
Store in a thermostat at ℃, observe the change in appearance, evaluate as follows, determine the number of days until the evaluation becomes 1 point for each of 10 test specimens, and save the average effectively. The number of days. The results are shown in Table 3.

0 point: No change. 1 point: Discoloration, softening, net and mold occur in one place. 2 points: discoloration, softening, netting, mold occurred in 2 places or 1
The deterioration of the place spreads. 3 points: Discoloration, softening, neto, and mold spread to half of the whole. 4 points: Discoloration, softening, net and mold spread to 3/4 of the whole. 5 points: Discoloration, softening, neto, and mold spread throughout.

[0037]

[Table 3]

It is apparent from Table 3 that the noodles to which the preservative of the present invention is added have a longer effective storage period than the noodles to which the control product is added.

Example 3 1,000 g of ground minced meat, 300 g of onion, 10 g of salt,
The preservative shown in Table 1 was added to a basic composition containing 60 g of wheat flour and 50 g of water, and the mixture was sufficiently mixed, then molded into 10 hamburgers, steamed for 25 minutes, and cooled. After that, 10 pieces per test section were stored at 25 ° C., the change in appearance was observed, and the number of effective storage days was determined according to the same criteria as in Example 2 and the results are shown in Table 4. As shown in Table 4, the effective preservative days were longer when the preservative of the present invention was added than when the control product was added. In addition, as a result of the sensory test, the test plots to which the preservative of the present invention was added were compared with the control plots in color, taste, and
No difference was found in odor and morphology, and no adverse effect on quality due to addition was observed.

[0040]

[Table 4]

Example 4 160 g of egg yolk, 1,440 g of milk, 38 g of sugar, 6.5 g of wheat flour and 6.5 g of cornstarch were used as basic compositions, to which the preservatives shown in Table 5 were heated under low heat with sufficient stirring. , 10% of the total weight was boiled down. After cooling this custard cream, it was filled in a cup and stored at 25 ° C. to observe the change in appearance. The number of days until the number of general viable bacteria reached 1 × 10 ⁶ cells / g was defined as the number of effective storage days. The results are shown in Table 6. As shown in Table 6, the addition of the preservative of the present invention
The effective storage days were much longer than those to which the control product was added. Further, as a result of the sensory test, the test group to which the preservative of the present invention was added showed no difference in taste, color, odor, morphology, etc., as compared with the control group, and adverse effects on quality due to addition were recognized. There wasn't.

[0042]

[Table 5]

[0043]

[Table 6]

Example 5 40 ml of commercially available soymilk (pH 7.0) was dispensed into a glass bottle and autoclaved. An aqueous solution of the preservative having the composition shown in Table 5 was sterilized by filtration, and then added to and mixed with sterile soymilk so that the amount shown in Table 5 was obtained, and the total amount was 50 ml. Then, a spore suspension of Bacillus subtilis was inoculated into soy milk so that the spores became about 10 ² / ml, heated in a water bath at 90 ° C for 40 minutes, and then cooled with water,
The cells were stored at 5 ° C and the number of bacteria was measured daily. Number of bacteria is 10
The number of days until reaching ⁶ cells / ml was defined as the number of effective storage days. The results are shown in Table 7.

[0045]

[Table 7]

Example 6 To 6 kg of an equal mixture of minced pork and mutton,
15% of lard, 2.5% of salt, 0.1% of polymerized phosphate, 0.5% of spice, 70 ppm of sodium nitrite and 10% of ice water were added, and cutting was performed with a silent cutter for 10 minutes. About 15 g of the obtained emulsion meat was filled into the sheep intestine using a manual stuffer. This was dried in a smoke house for 40 minutes, then smoked and steamed, and heated so that the center temperature became 75 ° C. to prepare a wiener sausage. After storing this Wiener sausage in a refrigerator overnight, it was immersed in an aqueous solution of a preservative having the composition shown in Table 5 (prepared so that the amount of each component in the aqueous solution was the amount shown in Table 5) for 2 minutes, and drained and air dried. , Sterile petri dish 1
Ten pieces of one test section each containing two pieces of wiener sausage were prepared and stored at 25 ° C. to observe changes in appearance. The number of days of effective storage was determined according to the same criteria as in Example 2. Table 8 shows the results.

[0047]

[Table 8]

[0048]

The food preservative of the present invention can remarkably improve the storability of food, and is particularly effective for extending the shelf life of food contaminated with yeast or mold. Moreover, the original taste and color tone of the food are not changed, and the quality of the food is not adversely affected by the addition, which is extremely effective for preservation of various foods.

Claims (4)

[Claims] 1. A lactic acid bacterium Lactobacillus reuteri (Lact)
reuterin produced by obacillus reuteri)
uterin) and natural antibacterial substances (excluding peptides and proteins derived from lactic acid bacteria), food preservatives. 2. The food preservative according to claim 1, wherein the natural antibacterial substance is an antibacterial peptide or protein (excluding peptides and proteins derived from lactic acid bacteria). 3. A natural antibacterial substance is a sugar having antibacterial properties,
The food preservative according to claim 1, which is a polysaccharide composed of sugar acid and amino sugar and / or a partially decomposed product thereof. 4. The food preservative according to claim 1, wherein the natural antibacterial substance is a spice having an antibacterial property, its essential oil, or a plant component.