JP2022127441A - Production method of fermented pickle - Google Patents

Abstract

To provide a production method of fermented pickles capable of stably producing nice-flavor fermented pickles by clarifying relations among a fermentation condition, ingredient composition, flavor, etc. of the fermented pickles.SOLUTION: A production method of fermented pickles according to the present invention includes: adding lactic acid bacteria of genus Lactobacillus to vegetable raw materials, the lactic acid bacteria, for example, Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus diolivorans, Lactobacillus parafarraginis, Lactobacillus plantarum, Lactobacillus buchneri and Lactobacillus paraphilia; fermenting them until reached pH becomes 4.5 or less; and acquiring fermented pickles containing at least any of a succinic acid content and an isothiocyanate content more than those of vegetable raw materials.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing fermented pickles.

Expectations for fermented foods to be of value as traditional foods and to promote health are increasing, and pickles are widely recognized as fermented vegetables. Unfermented light pickles account for the majority of pickled products. However, fermented pickles from each region are still well-known as traditional foods. Furthermore, in 2019, the “Fermented pickles certification system” was started by the All Japan Pickles Cooperative Association. Due to these trends in the industry, there is a growing momentum to return from light pickles to fermented pickles, and future demand is expected to grow. However, pickles have a deep-rooted negative image that they cause excessive salt intake, and it is necessary to dispel this for the sake of future demand for pickles. From these facts, I thought that there might be potential demand for unsalted (very low salt) pickles among fermented pickles.

The only non-salted fermented pickles that are commercially produced in Japan are the Kiso region's traditional 'sunki' made from red turnip leaves. Sunki is inhabited by various lactic acid bacteria. In Patent Document 1, starter lactic acid bacteria including Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus delbrueckii, and Lactobacillus parabuhneri stably produce sunki having good quality. is described as possible.

Japanese Patent No. 5276290

Japan's traditional fermented foods Kiso's traditional fermented vegetables "Sunki" and the secret of its deliciousness Foods & Food Ingredients Journal of Japan Vol. 223 No. 2 Page. 102-110 (2018.05.01) Efforts to elucidate the characteristics of sunki fermented lactic acid bacteria Journal of Japan Society for Lactic Acid Bacteria Vol. 28 No. 2 Page 128 (2017.06.27)

However, the relationship between lactic acid bacteria that live in salt-free and extremely low-salt fermented pickles, component composition, and quality such as flavor has not been known so far.

An object of the present invention is to clarify the relationship between the fermentation conditions of fermented pickles, component composition, and quality such as flavor, and to provide a method for producing fermented pickles with good flavor and capable of stable production.

The present invention provides the following.
[1] Fermentation by adding lactic acid bacteria to the vegetable raw material and fermenting until the final pH reaches 4.5 or less to obtain fermented pickles having at least one of the succinic acid content and the isothiocyanate content higher than the vegetable raw material. Method of making pickles.
[2] The method of [1], wherein the lactic acid bacteria are Lactobacillus lactic acid bacteria.
[3] Lactobacillus is Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus diolivorans, Lactobacillus parafaraginis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus parakephili, Lactobacillus The method of [1] or [2], which is at least one selected from Crispatus, Lactobacillus gasseri and Lactobacillus reuteri.
[4] The lactic acid bacteria include Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus diolivorans, Lactobacillus parafarraginis, Lactobacillus buchneri, Lactobacillus parakephili, Lactobacillus crispatus, and Lactobacillus - The method according to [1] or [2], which is a combination with at least one selected from gasseri.
[5] After adding the first lactic acid bacterium to the vegetable raw material and fermenting it, adding the second lactic acid bacterium and fermenting until the reaching pH is 4.3 or less, any of [1] to [4] or the method according to item 1.
[6] The method of [5], wherein the first lactic acid bacterium is Lactobacillus delbrueckii and the second lactic acid bacterium is Lactobacillus fermentum and Lactobacillus plantarum.
[7] The method according to any one of [1] to [6], wherein the fermentation is performed at a temperature of 30 to 45°C.
[8] The method according to any one of [1] to [7], wherein less than 2% (w/v) of sodium chloride is added to the fermentation medium during fermentation.
[9] The method according to any one of [1] to [8], wherein malic acid or a salt thereof is added during fermentation.
[10] The method according to any one of [1] to [9], wherein the vegetable raw material is at least one selected from turnip, cabbage, Chinese cabbage, and cucumber.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the fermented pickles which are good flavor and can be produced stably is provided.

FIG. 1 shows a comparison of succinate and isothiocyanate signal intensities in an in vitro fermentation test (Example 1).

[Method for producing fermented pickles]
In the present invention, fermented pickles are produced by adding lactic acid bacteria to vegetable raw materials and fermenting them.

－Vegetable ingredients－
In the present specification, the vegetable raw material is a raw material containing at least one kind of vegetable. Examples of vegetables include turnips (e.g., white turnips, red turnips (e.g., Otaki turnips, Kaida turnips), cabbages, Chinese cabbages, and cucumbers. Vegetable raw materials may be added as necessary (e.g., prevention of overfermentation, seasoning, etc.). purposes), seasonings, preservatives, and other additives.

-Lactic acid bacteria-
In the present invention, the vegetable raw material is fermented by adding (inoculating) lactic acid bacteria as a starter to the vegetable raw material. Examples of lactic acid bacteria include lactic acid bacteria of the genus Lactobacillus, Lactococcus, Leuconostoc, and Pediococcus, with lactic acid bacteria of the genus Lactobacillus being preferred. Lactobacillus lactic acid bacteria include, for example, L. delbrueckii, L. fermentum, L. diolivorans, L. parafarraginis, L. plantarum, L. brevis, L. vilidescens, L. alimentarius, L. sakei, L. curvatus, L. casei, L. buchneri, L. parkefiri, L. reuteri, L. crispatus, L. gasseri, L. vaginalis, L. rossiae, L. otakiensis, L. kisonensis, L. crispatus, and L. delbrueckii, L. fermentum, L. diolivorans, L. parafarraginis, L. plantarum, L. buchneri, L. parkefiri, L. crispatus, L. gasseri, L. reuteri is preferred. Examples of Pediococcus lactic acid bacteria include, for example, P. acidilactici.

Lactic acid bacteria may be used singly or in combination of two or more. In the case of 1 type alone, L. delbrueckii, L. fermentum, L. diolivorans, and L. parafarraginis, L. reuteri is preferred, L. delbrueckii, L. fermentum, L. diolivorans are more preferred. In the case of two or more, L. Combinations containing at least L. delbrueckii are preferred. delbrueckii and L. fermentum, L. diolivorans, L. parafarraginis, L. buchneri, L. parkefiri, L. crispatus, L. A combination with at least one selected from L. gasseri is more preferred. delbrueckii and L. fermentum and L. A combination with at least one selected from parafarraginis is more preferred.

-Attained pH-
The pH at the end of fermentation (ultimate pH) may be lower than the initial pH (usually weakly acidic, ie, 5.0 to 6.0), preferably 4.5 or less, more preferably 4.4. 4.3 or less, more preferably 4.3 or less. The final pH may be adjusted according to fermentation conditions such as the type and amount of lactic acid bacteria used, temperature, and salt concentration. The lower limit of the reached pH is usually 3.3 or more, preferably 3.4 or more, but is not particularly limited.

-Fermentation temperature-
The fermentation temperature is preferably 30-45°C, more preferably 30-40°C. Thereby, the attained pH can be lowered to a preferable value.

-Multi-stage fermentation-
When two or more kinds of lactic acid bacteria are used, each lactic acid bacterium may be added at the same time for fermentation, or so-called multistage fermentation may be performed for sequential addition and fermentation. For example, after adding the first lactic acid bacterium to the vegetable raw material and fermenting it, the operation of adding other lactic acid bacteria and fermenting is repeated, and the final lactic acid bacterium is added and fermented to reach a pH of 4.3 or less. It can be fermented until The multi-stage fermentation is preferably two-stage fermentation, and L. After the first fermentation with L. delbrueckii, as the second lactic acid bacterium, L. fermentum and L. More preferably, a second fermentation using plantarum is performed. Conditions for fermentation using each lactic acid bacterium in multistage fermentation can be determined independently.

－Salinity concentration－
In fermentation, sodium chloride may be added, and the amount added is preferably less than 2% (w/v), more preferably 1.5% (w/v) or less, relative to the medium. As a result, the negative image that excessive salt intake is a cause can be dispelled, and extremely low-salt fermented pickles with improved flavor while taking health into consideration can be obtained. The timing of adding sodium chloride may be during the fermentation, but is preferably at the start of fermentation (in the case of multistage fermentation, at the start of the first fermentation).

-malic acid-
In fermentation, malic acid or its salt may be added. As a result, fermented pickles containing a larger amount of succinic acid can be obtained. The amount of malic acid to be added is usually 50 mM or more, preferably 70 mM or more, more preferably 90 mM or more, relative to the medium. Malic acid or a salt thereof may be added during fermentation, but is preferably added at the start of fermentation (at the start of the first fermentation in the case of multistage fermentation).

-Other fermentation conditions-
Fermentation conditions other than the above are not particularly limited, but an example is as follows. The amount of lactic acid bacteria to be inoculated is usually 1.0×10 ⁵ to 1.0×10 ¹⁰ cfu/mL, preferably 5.0×10 ⁵ to 5.0×10 ⁹ cfu/mL, more preferably 1.0×10 5 to 5.0×10 9 cfu/mL. 0×10 ⁶ to 1.0×10 ⁹ cfu/mL. The inoculum amount can be adjusted according to a conventional method such as preculture. Fermentation time is usually 12 hours or more, preferably 20 hours or more, more preferably 24 hours or more. Although the upper limit is not particularly limited, it is sufficient if it is about 5 days, and usually within 3 days. In addition, as lactic acid bacteria, L. delbrueckii, L. fermentum, L. When oxygen-sensitive lactic acid bacteria such as reuteri are used, fermentation is preferably performed under anaerobic conditions. Fermentation may be carried out while the medium is still, or may be stirred as necessary.

[Fermented pickles]
A fermented pickle can be obtained by the above production method. As used herein, “fermented pickles” means pickles produced by a method including a step of fermenting (eg, lactic acid fermentation) a food material (eg, vegetable raw material). Examples include sunki, suguki, fermented kimchi, fermented shibazuke, nozawana pickles, sauerkraut, and pickles.

At least one of the succinic acid content and the isothiocyanate content of the fermented pickles is preferably higher than that of the vegetable raw material, usually 4 times or more, preferably 5 times or more. The succinic acid content and isothiocyanate content of the fermented pickles vary depending on the vegetable raw material, so it is difficult to uniformly specify them, but they are usually 0.5 mM or more, preferably 5 mM or more, and more preferably 6 mM or more. Isothiocyanates are degradation products of glucosinolates, which are components unique to cruciferous vegetables, and are contained in cruciferous vegetables (eg, white turnip, red turnip, cabbage, Chinese cabbage). As used herein, the isothiocyanate content refers to the total amount of isothiocyanates (e.g., 4-pentenyl ITC, 3-butenyl ITC, 2-phenethyl ITC, allyl ITC), usually 8 as a relative amount to unfermented vegetables. 10 or more, preferably 10 or more. The succinic acid content and isothiocyanate content can be adjusted according to the type of vegetable raw material, the type and amount of lactic acid bacteria, and fermentation conditions.

It is preferable that the fermented pickles contain more acids other than succinic acid than the vegetable raw material. Examples of acids other than succinic acid include acetic acid and lactic acid. These acid contents of fermented pickles also vary depending on the vegetable raw material, so it is difficult to uniformly specify them. For example, the acetic acid content is usually 5 mM or higher, preferably 6 mM or higher. The lactic acid content is usually 10 mM or more, preferably 12 mM or more.

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

Reference example 1
We compared the component composition of 49 samples that were exhibited at a competition for ``Sunki'', the only salt-free fermented pickle produced in Japan, and clarified the characteristics of the best product (Table 1).
・The pH value was 4.1, indicating good lactic acid fermentation even when compared with the average value (4.0). ・The content of succinic acid was remarkably high among the 49 samples (a component that contributes to umami).
・High content of lactic acid, acetic acid, glutamic acid, and isothiocyanate (ITC) (components that contribute to the flavor and aroma of pickles)
・Low content of ethanol, ethyl acetate, acetoin, and diacetyl (components that cause fermentation odor and morning sickness odor)

From the results of this reference example, it became clear that the contents of succinic acid and isothiocyanate are important for high-quality salt-free fermented pickles. In addition, since all of the other characteristic components have taste and aroma, they are considered to contribute to the good flavor in multiple ways.

Example 1 Search for Lactic Acid Bacteria Strains Related to Component Composition of High-Quality Sunki Among the lactic acid bacteria that inhabit sunki, those involved in the production of high succinic acid were searched. 250 lactobacillus colonies belonging to 18 different lactobacillus species were collected from commercially available or self-produced sunki. An extract prepared by hot water extraction from freeze-dried red turnip (Kaida turnip) leaves was inoculated with lactic acid bacteria cultured for 24 hours at 30°C in Lactobacillus MRS medium (manufactured by Difco), and fermented at 30°C for 3 days. let me The concentrations of water soluble and volatile components produced after fermentation were analyzed by nuclear magnetic resonance (NMR) and solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) methods.

As a result of the analysis, it was found that L. delbrueckii (Table 2, Fig. 1). Furthermore, L. The juice of turnip greens fermented with A. delbrueckii came closest to the characteristics of the winner shown in Reference Example 1. That is, it exhibited characteristics such as good pH reduction, excellent lactic acid/acetic acid content, small production amounts of ethanol/acetoin/ethyl acetate, and high signal intensity of isothiocyanates.
As a lactic acid bacterium that showed a moderate amount of succinic acid production, L. fermentum, L. parafarraginis, L. reuteri, L. diolivorans was also selected. These lactic acid bacteria are also excellent in the production of acetic acid. However, L. Due to the higher final pH of the fermentate compared to C. delbrueckii, it may not be used alone to reach an adequate quality pH. In addition, in the fermentation of these strains, the characteristics of the component composition became different from the best product, Sunki.

Example 2 Analysis of applicability to various pickled vegetables Using white turnip, Kiso red turnip (Kaida turnip, Otaki turnip), cabbage, Chinese cabbage, and cucumber, extract from the leaves of each plant in the same manner as in Example 1 The obtained extract was inoculated with the lactic acid bacteria shown in Tables 3 to 5 cultured at 30°C for 24 hours in Lactobacillus MRS medium (manufactured by Difco) and fermented at 30°C for 3 days. The composition of the water-soluble metabolites of the resulting fermented product is analyzed by the NMR method, and the reached pH is analyzed with a pH meter, and the suitability for raw materials is judged in three stages (◎: particularly good, 〇: generally good, △: usable). (Tables 3-5).

As a result, lactic acid bacteria showed succinic acid-producing ability in each vegetable. delbrueckii showed the highest succinic acid-producing ability among sunki lactic acid bacteria in any vegetable. Regarding the pH of the fermented product, white turnip, red turnip (Kaida turnip), Chinese cabbage, and cucumber were particularly favorable, red turnip (Otaki turnip) was generally favorable, and cabbage showed a limited decrease in pH. For this reason, L. It was found that even if C. delbrueckii is used for other vegetables that are widely used for pickles, salt-free fermented pickles with good flavor characterized by succinic acid can be produced.

However, L. delbrueckii is inferior to other strains in suitability for cabbage fermentation, and although the production of succinic acid is at the highest level, the pH reached remains at around 4.5. In contrast, L. spp., which showed moderate succinic acid production in other vegetables. fermentum in the fermentation of cabbage, L. succinic acid production comparable to that of C. delbrueckii. Also, L.I. fermentum, L. diolivorans, L. Parafarraginis and the like were also confirmed to have the same metabolite production tendency as Kaida turnip.

Example 3 Co-fermentation test using multiple lactic acid bacteria Using white turnip, Kiso red turnip (Kaida turnip, Otaki turnip), cabbage, Chinese cabbage, and cucumber, extraction was performed from the leaves of each plant in the same manner as in Example 1. The extract was inoculated with the lactic acid bacteria shown in Tables 6 and 7 (single or a combination of two types) cultured at 30°C for 24 hours in Lactobacillus MRS medium (manufactured by Difco) and fermented at 30°C for 3 days. The resulting fermented product was analyzed for the composition of water-soluble metabolites and the reached pH in the same manner as in Example 2, and the suitability for raw materials was determined in the same manner as in Examples 1 and 2 (Tables 6 and 7).

As a result of the test, using cabbage, L. delbrueckii and L. Co-fermentation of fermentum increased the accumulation of succinic acid (Tables 6 and 7). Furthermore, the production of lactic acid and acetic acid was also greatly improved, respectively, and the pH drop was greatly improved. Since the improvement was better than when both lactic acid bacteria were used alone, a synergistic fermentation promotion effect could be obtained by the combined use of these lactic acid bacteria. Although this synergistic effect has not been scientifically verified and the mechanism is not clear, L. delbrueckii subsp. It is presumed that some kind of symbiotic relationship is established in which bulgaricus and Streptococcus thermophilus supplement each other's lacking nutrients.

In addition, the effect of co-fermentation was also observed in vegetables other than cabbage. For example, in the fermentation of white turnip and red turnip, the effect of increasing acetic acid was obtained with almost no effect on succinic acid and lactic acid production. This effect was demonstrated by L. The same applies to other lactic acid bacteria as well as fermentum. L. succinic acid-producing ability is relatively low. buchneri, L. parkefiri, L. crispatus, L. Even if gasseri is used for co-fermentation, the effect of increasing lactic acid and acetic acid can be similarly obtained.

Example 4 Effect of additional fermentation by two-step co-fermentation Extraction from the leaves of each plant in the same manner as in Example 1 using white turnip, Kiso red turnip (Kaida turnip, Otaki turnip), cabbage, Chinese cabbage, and cucumber Lactobacillus cultured in Lactobacillus MRS medium (manufactured by Difco) at 30° C. for 24 hours was added to the extract. delbrueckii and fermented at 30° C. for 3 days. Subsequently, the lactic acid bacteria shown in Tables 8 and 9 were further inoculated and further fermented at 30°C for 3 days. The resulting fermented product was analyzed for the composition of water-soluble metabolites and the reached pH, and its suitability as a raw material was determined in the same manner as in Examples 1 and 2 (Tables 8 and 9).

The effect of co-fermentation was obtained not only when two strains were inoculated simultaneously as in Example 3, but also when the fermentation was divided into two stages (Tables 8 and 9).

Like cabbage, L. delbrueckii alone is capable of accumulating succinic acid, but in the case of raw materials with poor pH reduction, L. By performing the second stage of additional fermentation with lactic acid bacteria suitable for cabbage fermentation such as fermentum, acetic acid and lactic acid can be greatly increased without decreasing succinic acid, and the pH can be lowered to 4.0 or less. This is L. This is because S. delbrueckii utilizes the property of preferentially producing succinic acid even from raw materials with low suitability, and the majority of remaining carbon sources are additionally fermented with other lactic acid bacteria.

Like Otaki turnip, L. L. delbrueckii alone gives a slightly higher pH. Additional fermentation with a plantarum or the like can increase the accumulation of acetic acid and lactic acid while maintaining a high succinic acid concentration, and assist in lowering the pH. This is because glucose, which is generally preferentially consumed by lactic acid bacteria compared to other carbon sources, is used by L. This was realized based on the discovery in this research that it is rather likely to survive in the fermentation of vegetable juice by delbrueckii. L. In addition to its residual glucose, L. plantarum citric acid that is not assimilated by A. delbrueckii can also be converted to lactic acid and acetic acid.

Example 5 Effect of Fermentation Temperature Using Kiso red turnips (Kaida turnips, Otaki turnips), extracts extracted from the leaves of each plant in the same manner as in Example 1 were added with L. delbrueckii was inoculated and fermented from 1 day to 14 days under the temperature conditions shown in Tables 10 and 11. After starting the culture, the composition of water-soluble metabolites of the fermented product and the reached pH were analyzed by the same methods as in Example 2 (Tables 10 and 11).

When the effect of temperature on the fermentation of pickles was confirmed, the fermentation temperature at which the pH decreased the fastest and reached the lowest was 40°C (Tables 10 and 11). Fermentation was delayed slightly at 30°C and slightly at 45°C. At 50°C or 20°C or less, the worsening of pH drop was remarkable. The amount of succinic acid produced reached a maximum at 40°C or 30°C, showing the same difference as the progress of pH decrease. Therefore, it is believed that suitable fermentation progress is obtained preferably in the range of 30°C to 45°C, more preferably in the range of 30°C to 40°C.

Example 6 L.I. Salt Concentration Tolerance of L. delbrueckii Extracts extracted from the leaves of each plant in the same manner as in Example 1 using Kiso red turnips (Kaida turnips) were added with L. delbrueckii. delbrueckii was inoculated, 1/4 of saline solution was added to the concentration shown in Table 12, and fermented at 30°C for 3 days. After starting the culture, the composition of water-soluble metabolites of the fermented product and the reached pH were analyzed by the same methods as in Example 2 (Table 12).

Fermentation was greatly inhibited at NaCl concentrations of 2% (w/v) and above, whereas at less than 2% (w/v), metabolite composition was not significantly affected (Table 12). ). From this, it was found that salt may be added at a concentration of less than 2% (w/v).

Example 7 Enhancement of succinic acid production by addition of malic acid Using cabbage, the extract extracted from the leaves of each plant in the same manner as in Example 1 was added with 100 mM sodium malate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). and cultured at 30°C for 24 hours in Lactobacillus MRS medium (manufactured by Difco). After starting the culture, the composition of water-soluble metabolites of the fermented product and the reached pH were analyzed in the same manner as in Example 2 (Table 13).

After addition of 100 mM sodium malate, L. delbrueckii and L. When co-fermentation of S. fermentum was performed, the addition of sodium malate further enhanced the enhancing effect of succinic acid in the co-fermentation (Table 13). From this result, L. delbrueckii and L. It was found that the characterization of fermented pickles with succinic acid can be further enhanced by using malic acid as a base for co-cultivation with fermentum.

Most of the production of succinic acid by lactic acid bacteria in vegetable fermentation is considered to be by conversion to succinic acid using malic acid as a substrate. From the results of this example, L. In the case of vegetables capable of producing high levels of succinic acid even with lactic acid bacteria such as delbrueckii alone, it can be seen that simply adding malic acid can enhance the production of succinic acid by the lactic acid bacteria.

Example 8 Effect of oxygen on the progress of fermentation Using Kiso red turnips (Kaida turnips, Otaki turnips), extracts extracted from the leaves of each plant in the same manner as in Example 1 were added to culture tubes with two-position caps (Corning company), inoculated with the lactic acid bacteria shown in Table 14, and fermented at 30°C for 3 days. The anaerobic condition group was fermented under anaerobic conditions using an aneropack (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in a closed anaerobic jar, and the aerated group was in a semi-open anaerobic jar with a two-position cap. The plate was allowed to stand in an aerated state, and the medium was mixed and aerated every 24 hours. The resulting fermented product was analyzed for water-soluble metabolites and ultimate pH in the same manner as in Example 2 (Table 14).

L. delbrueckii showed a clear sensitivity to oxygen (Table 14). Moreover, not only the reached pH increased, but also the L. The amount of succinic acid produced by C. delbrueckii was also greatly reduced to about 1/3. L. fermentum also showed some sensitivity to oxygen. Therefore, L. delbrueckii, L. It was found that when oxygen-sensitive lactic acid bacteria such as fermentum are used, culturing is preferably carried out under anaerobic conditions.

Example 9 Small preparation test of salt-free fermented pickles At a pickle factory that has a track record of producing fermented pickles, L. A trial production of unsalted fermented pickles using C. delbrueckii was performed, and the fermented products were evaluated. For the fermentation starter, a food grade medium (0.5% high nut AM Nisei Oil Co., Ltd.), 3.0% edible yeast extract (Marmite: Unilever Co., Ltd.), 0.5% sodium acetate, 0.02% magnesium sulfate, adjusted to pH 6.5 with sodium hydroxide, 115 ° C. for 10 minutes Autoclave sterilization) to remove L. delbrueckii cultured at 37° C. for 24 hours. Using red turnip, Chinese cabbage, cucumber and cabbage, 9 kg each of the chopped raw materials was blanched in hot water at 70°C, put in a plastic bag placed in a container for pickles, and L. delbrueckii was inoculated at an initial dose of 1.0×10 ⁷ cfu/mL. After expelling air from the plastic bag so that the raw material was submerged on the surface of the liquid, the mouth was closed, and the container was wrapped in a mattress to keep it warm and allowed to stand at room temperature for fermentation for 3 days. As a control, unfermented, unsalted pickles were prepared by adding 0.5% lactic acid and pickling for 3 days. Metabolites, reached pH, lactic acid bacteria count, coliform group count, and mold/yeast count contained in the resulting pickle juice were analyzed (Table 15). In addition, the palatability of the pickled unsalted fermented pickles was evaluated by a panel of four people, each of which was judged in three stages (3 points: particularly good, 2 points: generally good, 1 point: poor), and the average score Values (average ratings) were calculated (Table 16).

In each fermented pickle, fermented metabolites such as succinic acid were produced and good palatability was exhibited, so fermentation proceeded well, and the produced succinic acid and ITC improved the flavor such as umami and aroma. (Tables 15 and 16).

Example 10 Effect of fermentation and co-fermentation by various lactic acid bacteria on ITC content Turnip), cabbage, Chinese cabbage) were extracted from the leaves of each plant in the same manner as in Example 1, and the lactic acid bacteria shown in Table 17 were cultured in Lactobacillus MRS medium (manufactured by Difco) at 30 ° C. for 24 hours. was inoculated and fermented at 30°C for 3 days. A fermentation test with a composite starter was also carried out. In the multiple fermentation test, co-fermentation and two-step fermentation were performed in the same manner as in Examples 3 and 4. In the co-fermentation test, L. delbrueckii and other lactic acid bacteria shown in Table 18 were inoculated and fermented at 30°C for 3 days. In the two-step fermentation test, L. delbrueckii for 3 days at 30°C, and then other lactic acid bacteria shown in Table 18 were fermented at 30°C for 3 days. Fermentations were carried out using inert glass vials with screw caps. The composition of volatile metabolites in the resulting fermentation product was analyzed using SPME-GC/MS, and the peak area values indicated by each ITC were compared as signal intensities (Tables 17 and 18).

As a result of the analysis, L. It was found that fermentation of cruciferous pickled vegetables with C. delbrueckii produced more ITC than other lactic acid bacteria (Table 17). When white turnips, red turnips (Kaida turnips/Otaki turnips), and Chinese cabbage were used, 4-pentenyl ITC and 3-butenyl ITC increased by about 1.5 to about 2.5 times compared to those not inoculated with lactic acid bacteria. . Almost only allyl ITC was detected in cabbage, whereas L. There was a slight increase in signal intensity when fermented with delbrueckii compared to non-inoculation of lactic acid bacteria. L. In the plantarum fermented samples, very strong ITC signals were detected in some vegetables. It is feared that this characteristic will bring a strong pungent taste to pickles and lead to abnormal quality. From the above, L. By using delbrueckii for fermentation of cruciferous vegetables, it is expected that the effect of moderately emphasizing the characteristics of ITC due to its aroma and pungency can be obtained.

L. In the co-fermentation between L. delbrueckii and other lactic acid bacteria, L. diolivorans, L. parafarraginis, L. Many combinations, such as parakefiri, were effective in increasing each ITC compared to non-inoculation of lactic acid bacteria (Table 18). Therefore, L. It can be seen that the high production of succinic acid and ITC by C. delbrueckii and the promotion of the production of lactic acid and acetic acid by co-fermentation shown in Example 3 can be achieved at the same time.

Claims (10)

Production of fermented pickles by adding lactic acid bacteria to vegetable raw materials and fermenting them until the final pH reaches 4.5 or less to obtain fermented pickles in which at least one of succinic acid content and isothiocyanate content is higher than that of vegetable raw materials. Method. 2. The method according to claim 1, wherein the lactic acid bacterium is Lactobacillus lactic acid bacterium. Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus diolivorans, Lactobacillus parafaraginis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus parakephili, Lactobacillus crispatus, Lacto 3. The method according to claim 1 or 2, which is at least one selected from Bacillus gasseri and Lactobacillus reuteri. Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus diolivorans, Lactobacillus parafaraginis, Lactobacillus buchneri, Lactobacillus parakephili, Lactobacillus crispatus, and Lactobacillus gasseri 3. The method of claim 1 or 2 in combination with at least one selected. 5. The method according to any one of claims 1 to 4, wherein the first lactic acid bacterium is added to the vegetable raw material and fermented, and then the second lactic acid bacterium is added and fermented until the reached pH is 4.3 or less. the method of. 6. The method according to claim 5, wherein the first lactic acid bacterium is Lactobacillus delbrueckii and the second lactic acid bacterium is Lactobacillus fermentum and Lactobacillus plantarum. The method according to any one of claims 1 to 6, wherein the fermentation is performed at a temperature of 30-45°C. A method according to any one of claims 1 to 7, wherein less than 2% (w/v) of sodium chloride is added to the fermentation medium during fermentation. The method according to any one of claims 1 to 8, wherein malic acid or a salt thereof is added during fermentation. The method according to any one of claims 1 to 9, wherein the vegetable raw material is at least one selected from turnip, cabbage, Chinese cabbage, and cucumber.

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