CN115960778A - Lactobacillus fermentum and application thereof in regulating and controlling flavor of rice product - Google Patents

Abstract

The invention discloses lactobacillus fermentum and application thereof in regulating and controlling flavor of rice products. The lactobacillus fermentum (Lactobacillus fermentum FR-21) is preserved in the China center for type culture Collection, university of Wuhan, 11 months and 02 days in 2022, and the number of the lactobacillus fermentum is CCTCC No: m20221709. When the lactobacillus acidophilus is applied to fermenting rice products, a fermentation container is pasteurized, and then lactobacillus fermentum FR-21 is inoculated, the inoculation amount is 106-108 cfu/mL, and the fermentation is carried out for 6-60 h at the temperature of 30-40 ℃. The flavor of the prepared rice product is evaluated as the fermented flavor by combining electronic nose test and sensory evaluation, and GC-MS analysis shows that the flavor is the fermented flavor with aldehydes and/or alcohols with 5 to 10 carbon atoms as main components. Use of the lactobacillus fermentum FR-21: can be administered directly or made into liquid, powder, tablet, or capsule.

Description

A strain of Lactobacillus fermentum and its application in regulating the flavor of rice products

technical field

The invention belongs to the technical field of microbial fermentation, and in particular relates to a lactobacillus fermentum and its application in regulating the flavor of rice products.

Background technique

Fermented rice products refer to foods with unique flavors prepared from rice fermented by microorganisms. Usually, the rice is soaked and fermented for a period of time, and processed into different forms of food, such as fresh wet rice noodles, rice cakes, rice steamed buns, rice dumplings, etc. However, the quality of rice naturally soaked and fermented is not stable, especially in high temperature weather in summer, and it is easy to produce peculiar smells such as rancidity and foul smell; when the dominant bacteria have not yet formed, it is difficult to obtain products with stable flavors. Studies have reported that adding Lactobacillus can improve the quality of fermented rice products. For example, Chinese invention patent CN104886459A discloses a method for making fermented rice flour. The natural fermented liquid is selected as the stock solution of the fermented liquid. Adding Lactobacillus fermentum, Lactobacillus salivarius, plant A method for preparing fermented rice flour which has a fermented flavor and can be processed into rice products such as rice noodles and rice cakes by fermenting a mixed bacterial solution including lactobacillus and yeast. However, this method adopts the mode of mixed fermentation of different bacteria, the volatile flavor substances of the obtained product are not clear, and the stability of quality is difficult to control. Chinese invention patent CN108165502A discloses a strain of Lactobacillus plantarum used to improve the flavor of fresh and wet rice noodles, which can make rice noodles (threads) form a pure rice fragrance, and solve the problem of unstable flavor quality of fresh and wet rice noodles in new rice noodles (threads) factories and high temperature seasons The problem of bad smell, bad smell and other peculiar smell caused by rice noodles. But the rice product fragrance that this method is made can't satisfy the demand of market diversification. Chinese invention patent CN103352014A discloses a strain of Lactobacillus fermentum LG1, which is used to solve the problems of traditional fermentation process such as long cycle and easy corruption, while improving the nutritional content of yellow rice. But this method does not involve the promotion of product flavor after fermentation.

With the improvement of living standards, the fermented rice product industry has higher and higher requirements for product flavor. Providing a rice product with unique flavor, relatively stable volatile flavor substances and convenient processing can better meet the needs of the market.

Contents of the invention

The purpose of the present invention is to provide a strain of Lactobacillus fermentum, which can form the unique fermented aroma of rice products through fermentation, and solve the problem of unprominent and unstable flavor of rice products.

In order to achieve the above invention, the present invention adopts the following technical scheme: screening a strain of Lactobacillus fermentum, characterized in that the Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) was typically cultivated at Wuhan University in China on November 02, 2022 It is preserved in the Food Collection Center, and its number is CCTCC No: M20221709, which can make fermented rice products produce a stable fermented aroma.

The present invention also relates to the application of the fermented Lactobacillus (Limosilactobacillus fermentum FR-21) in regulating the flavor of rice products.

Further, the raw material of the rice product is indica rice.

Further, for the application of the above-mentioned Lactobacillus fermentum in regulating the flavor of rice products, the said Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) is directly put into raw materials for fermentation to prepare fermented rice. The specific steps include:

S1. Container sterilization: pasteurize the fermentation container;

S2. Strain inoculation: put the raw material into the container and inoculate the strain;

S3. Micro-fermentation: control the raw material fermentation temperature after inoculation of the bacteria, and micro-ferment for a period of time to obtain fermented rice;

S4. Rice product preparation: the fermented rice is washed-refined/milled-aged-molded to obtain the rice product with a fermented flavor.

Further, the sterilization method is pasteurization, the inoculation amount of Lactobacillus fermentum (Limosilactobacillusfermentum FR-21) is 10 ⁶ -10 ⁸ cfu/mL, the fermentation temperature is 30-40°C, and the fermentation time is 6-40°C. 60h.

Further, the fermentation temperature is 37° C., and the fermentation time is 48 hours.

Further, the above-mentioned fermented strains are used in direct injection or in the form of liquid, powder, tablet or capsule.

Further, the use of the above-mentioned Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) is applied to the product produced when fermenting indica rice, and its flavor is judged as fermented flavor by electronic nose test combined with sensory evaluation; GC-MS analysis shows that the The fermented flavor comes from aldehydes and/or alcohols with 5-10 carbon atoms.

The invention has the advantages that: the flavor of the rice product prepared by fermenting the lactobacillus fermentum is pure and unique, and the volatile flavor substances are stable.

Detailed ways

The invention provides Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) and its application in regulating the flavor of rice products. Those skilled in the art can refer to the content of this patent and appropriately improve the process parameters to realize it. In particular, it should be pointed out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously make changes or appropriate changes and combinations to the method and application herein without departing from the content, spirit and scope of the present invention to realize and apply the present invention Invent technology.

Example 1

The present embodiment provides the method for preparing fresh and wet rice noodles with Lactobacillus fermentum (Limosilactobacillus fermentum FR-21), and the specific steps include:

(1) Preparation of raw materials:

The fermenter was carefully cleaned and pasteurized at 70°C;

Take by weighing 3kg of indica rice Zhefu 802 raw material, put into the fermenter after sterilization;

Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) is ready for use.

(2) Preparation of fermented rice:

Add 1.2 times (mass) distilled water to the indica rice Zhefu 802 raw material weighed in step (1), and inoculate the prepared Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) at 10 ⁸ cfu/mL;

The inoculated indica rice was fermented at 37° C. for 48 hours to obtain fermented rice.

(3) Preparation of fresh wet rice noodles:

The product obtained in step (2) is cleaned, pulped, steamed, shredded, boiled, re-steamed, and washed to obtain fresh wet rice noodles.

(4) Flavor evaluation and data characterization:

The evaluation of aroma is judged by the combination of sensory evaluation and flavor component analysis.

Sensory evaluation methods include the combination of electronic nose and manual evaluation.

The flavor of the fresh wet rice noodles prepared in this example was judged as yeast flavor by electronic nose and sensory evaluation.

The fresh wet rice noodles prepared in this example were analyzed for volatile substances by GC-MS, and the results are shown in Table 1.

In Table 1, the organic volatile substances are mainly aldehydes with 5 to 10 carbon atoms, 1-nonanol and acetic acid, and these substances are the source of the fermentation aroma of this embodiment.

Specifically, in this embodiment, aldehydes account for 54%, and alcohols account for 33%.

Table 1 The content of volatile compounds in fresh wet rice noodles (fermented by Limosilactobacillus fermentum FR-21)

Example 2

The present embodiment provides the method for preparing rice dumpling wrapper with Lactobacillus fermentum (Limosilactobacillus fermentum FR-21), and the specific steps include:

(1) Preparation of raw materials:

The fermenter was carefully cleaned and pasteurized at 70°C;

Take by weighing 3kg of indica rice Zhefu 802 raw material, put into the fermenter after sterilization;

Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) is ready for use.

(2) Preparation of fermented rice:

Add 1.1 (mass) times distilled water to the indica rice Zhefu 802 raw material weighed in step (1), and inoculate the prepared Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) at 10 ⁷ cfu/mL;

The inoculated indica rice was fermented at 30° C. for 24 hours to obtain fermented rice.

(3) Preparation of rice dumpling wrappers:

The product obtained in the step (2) is cleaned, pulped, steamed, rolled, pressed, and shaped to obtain the rice dumpling wrapper.

(4) Flavor evaluation and data characterization:

The evaluation of aroma is judged by the combination of sensory evaluation and flavor component analysis.

Sensory evaluation methods include the combination of electronic nose and manual evaluation.

The flavor of the rice dumpling wrappers prepared in this example was judged as yeast flavor by electronic nose and sensory evaluation.

The rice dumpling wrappers prepared in this example were analyzed for volatile substances by GC-MS, and the results are shown in Table 2.

In Table 2, the organic volatile substances are mainly aldehydes with 5 to 10 carbon atoms and 1-nonanol, and these substances are the source of the fermentation aroma of this embodiment.

Specifically, in this embodiment, aldehydes account for 52%, and alcohols account for 39%.

Table 2 The volatile compound content table of rice dumpling skin (Limosilactobacillus fermentum FR-21 fermentation)

Example 3

The present embodiment provides the method for preparing rice cake with Lactobacillus fermentum (Limosilactobacillus fermentum FR-21), and the specific steps include:

(1) Preparation of raw materials:

The fermenter was carefully cleaned and pasteurized at 70°C;

Take by weighing 3kg of indica rice Zhefu 802 raw material, put into the fermenter after sterilization;

Lactobacillus fermentum (Limosilactobacillus fermentum FR-21) is ready for use.

(2) Preparation of fermented rice:

The indica rice in step (1) was inoculated with Lactobacillus fermentum (Limosilactobacillusfermentum FR-21) at 10 ⁶ cfu/mL, the ratio of solid to liquid was 6:5, fermented at 35°C for 6 hours, washed, and ground to obtain fermented rice flour.

(3) Preparation of fermented rice cake:

The fermented rice flour obtained in step (2) is injection molded, proofed, and steamed to obtain a rice cake.

(4) Flavor evaluation and data characterization:

The evaluation of aroma is judged by the combination of sensory evaluation and flavor component analysis.

Sensory evaluation methods include the combination of electronic nose and manual evaluation.

The flavor of the rice cake prepared in this example was judged as yeast flavor by electronic nose and sensory evaluation.

The rice cake powder prepared in this example was analyzed for volatile substances by GC-MS, and the results are shown in Table 3.

In Table 3, the organic volatile substances are mainly aldehydes and alcohols with 5 to 10 carbon atoms and acetic acid, and these substances are the source of the fermentation aroma of this embodiment.

Specifically, in this embodiment, aldehydes account for 32%, alcohols account for 34%, and acetic acid accounts for 18%.

Table 3 The volatile compound content table of rice cake (Limosilactobacillusfermentum FR-21 fermentation)

In summary, the steps in Examples 1, 2, and 3 are: S1. Container sterilization, S2. Strain inoculation, S3. Micro-fermentation, S4. Rice product preparation, and the final fermented rice product is analyzed by GC-MS to show the flavor Mainly aldehydes and alcohols with 5 to 10 carbon atoms, the detected aldehydes mainly include hexanal, nonanal, etc., the detected alcohols mainly include n-hexanol, 1 - Nonanol, n-pentanol, etc. These volatile organic compounds account for 60 to 90%, and they are mixed together to give off a fermented aroma.

In the present invention, the fermented rice product is prepared by inoculating Lactobacillus fermentum (Limosilactobacillus fermentum FR-21), and the product obtained has a pure and unique fermented aroma. During the preparation process, the volatile flavor substances of the obtained fermented rice products can be stabilized by controlling the inoculum amount of bacteria, fermentation time and fermentation temperature.

Claims (10)

1. Lactobacillus fermentum FR-21 with the preservation number of CCTCC No: m20221709.

2. Use of lactobacillus fermentum FR-21 according to claim 1 for modulating the flavour of rice products.

3. Use of lactobacillus fermentum FR-21 for modulating the flavour of a rice product, according to claim 2, wherein the raw material of the rice product is indica rice.

4. The use of lactobacillus fermentum FR-21 for the modification of the flavor of rice products according to claim 2, wherein said lactobacillus fermentum FR-21 is directly added to said raw material for micro-fermentation to produce fermented rice.

5. Use of lactobacillus fermentum FR-21 according to any of claims 2-4 for modulating the flavour of a rice product, characterized in that: the method for preparing the rice product fermentation specifically comprises the following steps:

s1, container sterilization: pasteurizing the fermentation vessel;

s2, inoculating strains: putting the raw materials into a container, and inoculating strains;

s3, micro-fermentation: controlling the fermentation temperature of the inoculated raw materials, and carrying out micro-fermentation for a period of time to obtain fermented rice;

s4, rice product preparation: and cleaning, pulping, curing and molding the fermented rice to obtain the rice product with the aroma of the fermentation.

6. Use of lactobacillus fermentum FR-21 according to claim 5 for modulating the flavour of a rice product, characterized in that: the sterilization method of the fermentation container is pasteurization;

and/or the inoculation amount of the lactobacillus fermentum FR-21 is 10 ⁶ ～10 ⁸ cfu/mL, the fermentation temperature is 30-40 ℃, and the fermentation time is 6-60 h.

7. Use of lactobacillus fermentum FR-21 according to any of claims 2-4 for modulating the flavour of a rice product, characterized in that: the lactobacillus fermentum FR-21 is applied in a direct-throwing mode or is prepared into liquid, powder, tablets or capsules.

8. Use of lactobacillus fermentum FR-21 according to claim 6 for modulating the flavour of a rice product, characterized in that: the fermentation temperature is 37 ℃, and the fermentation time is 48h.

9. Use of a lactobacillus fermentum FR-21 according to any one of claims 2 to 4 for modulating the flavour of a rice product, characterized in that: the rice product contains aldehydes and/or alcohols with 5-10 carbon atoms.

10. A rice product fermented with Lactobacillus fermentum FR-21 according to claim 1; the rice product comprises but is not limited to fresh wet rice flour, rice steamed sponge cake, rice steamed bread, rice dumpling wrapper and other different product forms.