Thin-shell polypeptide-basil natural flavoring base material as well as preparation method and application thereof

Abstract

The invention discloses a thin-shell polypeptide-basil natural flavoring base material as well as a preparation method and application thereof, and belongs to the technical field of seasonings, the thin-shell peptide-enriched flavoring base material is prepared through a composite enzymolysis process, efficient utilization of protein is realized, and the taste is rich. And by combining a Maillard process, a fermentation process and a compounding process with spice basil, the effective fishy smell removing and freshness increasing effects are realized, and the problem that the seafood enzymatic hydrolysate is large in fishy smell is solved. The preparation process of the flavoring base material is simple and efficient, the production speed is high, the flavoring base material has the characteristics of rich taste, obvious delicate flavor and small fishy smell, the prepared flavoring base material is applied to traditional fermented condiments such as soy sauce and fish sauce, the flavor and nutritional value of the condiments can be remarkably improved, meanwhile, the flavoring base material conforms to the concept of natural health, and the flavoring base material is worthy of popularization and application. Wide market application prospects are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of seasoning additives, and in particular relates to a thin-shell polypeptide-basil natural flavor base material and a preparation method and application thereof. Background Art

[0002] Thin shell, scientifically known as Musculus senhousei, is a common low-value shellfish in the coastal areas of southern my country. It has the characteristics of strong reproduction, fast growth and high yield. Thin shell is not only delicious and nutritious, but also has biological activities such as antioxidant and blood sugar regulation. It is a high-protein, low-fat high-quality seafood with the potential for development as a natural seafood flavor base. However, the thin shell currently sold on the market is mainly eaten fresh, and the research and application of its deep processing are relatively scarce, and its economic value has not been fully explored.

[0003] As consumers become increasingly aware of nutrition and health, the market demand for natural, healthy, and high-nutritional condiments continues to rise. The peptide-rich flavor base obtained from food protein through enzymatic hydrolysis not only has a rich and full flavor and taste, but also has good absorbability and nutritional value, which has obvious advantages over traditional flavor enhancers such as MSG. However, the enzymatic hydrolysis of seafood such as clams will produce a series of substances with fishy odors, such as aldehydes, alcohols, and amines, which seriously affect the flavor and taste of the product. Therefore, achieving an effective deodorization and flavor enhancement process is not only to improve the flavor quality, but also the key to ensure its successful application in seasonings.

[0004] Basil (Ocimum basilicum), also known as basil, is widely used as a spice due to its unique aroma. Basil is rich in volatile substances such as terpenes, flavonoids, and phenylpropanoids, as well as plant polysaccharides, and has antibacterial, anti-corrosion, anti-diabetic and antioxidant effects. In addition, basil is also often used as an auxiliary ingredient in the cooking process of shellfish and seafood, and has a significant effect of removing fishy smell and enhancing freshness. It has high application value and potential in the preparation of seafood seasonings. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a thin-shell polypeptide-basil natural flavor base material with strong taste, obvious fresh taste and small fishy smell, and a preparation method and application thereof.

[0006] The technical solution of the present invention to solve the above technical problems is: A method for preparing a thin-shell polypeptide-basil natural flavor base comprises the following steps: S1: pretreatment of the thin shell, pretreatment of the thin shell and draining of the thin shell to obtain a thin shell preform for standby use; S2: preparing a homogenate, adding an appropriate amount of water to the thin shell preform and putting it into a homogenizer for homogenization to obtain a homogenate; S3 enzymatic hydrolysis, adding alkaline protease and trypsin to the homogenate simultaneously for enzymatic hydrolysis to obtain an enzymatic hydrolyzate; S4: enzymatic inactivation treatment, wherein the enzymatic hydrolysate is inactivated by a boiling water bath, and then the treated liquid is centrifuged to obtain an enzymatic hydrolysate supernatant; S5 Maillard reaction, adding glucose to the enzymatic supernatant, mixing evenly and then putting into a pressure cooker for Maillard reaction to obtain a Maillard reaction solution; S6 fermentation, adding yeast to the Maillard reaction solution cooled to room temperature, fermenting under constant temperature conditions, then sterilizing in a boiling water bath, cooling to room temperature, and obtaining a fermentation solution; S7 flavor treatment, add fresh basil leaves to the fermentation liquid and put it into a homogenizer for homogenization. After the homogenization is completed, filter to obtain a filtrate, boil the filtrate and place it in cold water for rapid cooling to obtain a thin-shell polypeptide-basil natural flavor base.

[0007] Specifically, in step S1, the thin shell preform obtained by pre-treating the thin shell includes: Desalination preformed products, soak fresh thin shells in 40~45℃ warm water until the shells slightly open, change warm water to wash 2~3 times to desalinate, then pick up and drain to obtain; To prepare the shelled product, pour the fresh thin shell into boiling water and boil it for 3 to 5 minutes. Then use a stick to rotate and stir the boiling water to separate the meat and shell. While stirring, use a mesh sieve to scoop up the thin shell meat floating on the upper layer. After collecting, drain it.

[0008] Specifically, the conditions for homogenizing the desalted preform or the shelled preform in step S2 are: The desalted preform is used for homogenization, the weight ratio of the desalted preform to water is 3-3.5:1, the homogenization is carried out for 10 minutes, and then the mixture is allowed to stand and settle, and the upper layer of liquid is taken as the homogenate; The shelled preform is used for homogenization, the weight ratio of the shelled preform to water is 0.5-0.7:1, the homogenization is carried out for 10 minutes, and the obtained solution is a homogenized liquid.

[0009] Specifically, in step S3, the enzymatic hydrolysis conditions are: the weight ratio of alkaline protease to trypsin is 0.5-2:1, the total amount of enzyme added is 0.24%-0.36% of the weight of the desalted preform or 0.72%-1.1% of the weight of the shelled preform, the enzymatic hydrolysis pH is 8-9, the enzymatic hydrolysis temperature is 45-55°C, and the enzymatic hydrolysis time is 4-7h.

[0010] Specifically, in step S4, the purification step is as follows: the enzymatic solution is boiled in boiling water for 10 minutes to inactivate the enzyme, and then cooled to room temperature in cold water; the centrifugation condition is: centrifugation at 10000-12000g for 15 minutes at 4°C.

[0011] Specifically, in step S5, the amount of glucose added is 1% to 6% of the weight of the enzymatic supernatant, the temperature of the Maillard reaction is 115 to 125° C., and the reaction time is 0.5 to 2 h.

[0012] Specifically, the yeast in step S6 is L-Au brewer's yeast of the Eufranc brand, the addition amount is 1% to 2% of the weight of the Maillard reaction solution, the fermentation temperature is 25 to 30° C., the fermentation time is 1 to 4 hours, and the boiling water bath sterilization time is 10 minutes.

[0013] Specifically, in step S7, the amount of basil leaves added is 5% to 20% of the weight of the fermentation liquid, and the broth is filtered using a 200-mesh filter. The boiling process is to boil over high heat and then turn to low heat for boiling for 3 to 9 minutes.

[0014] A thin-shell polypeptide-basil natural flavor base material is prepared by the preparation method of the thin-shell polypeptide-basil natural flavor base material.

[0015] An application of the above-mentioned thin-shell polypeptide-basil natural flavor base is to add the thin-shell polypeptide-basil natural flavor base as a seasoning additive to a seasoning in an amount of 10% to 15% of the quality of the seasoning.

[0016] The present invention has the following beneficial effects: (1) The present invention optimizes the enzymatic hydrolysis preparation process of thin shells by response surface methodology, thereby improving the hydrolysis degree, solid content and protein utilization rate of the enzymatic hydrolyzate, and then combines the Maillard reaction and yeast fermentation process to improve the taste and flavor of the thin shell enzymatic hydrolyzate. Finally, by compounding with the spice basil, effective fishy smell removal and freshness enhancement are achieved, thereby preparing a thin shell polypeptide-basil natural flavor base with a rich taste, obvious umami and low fishy smell.

[0017] (2) The present invention makes full use of the thin, brittle and easy-to-crush texture of the thin shells. It uses warm water to remove salt, then directly homogenizes the shells, and finally removes shell debris by static sedimentation; or directly boils the thin shells in boiling water and separates the shell and meat by rapid stirring. This method overcomes the problem of small thin shells and difficulty in extracting the meat, significantly improves processing convenience, and saves labor and time costs.

[0018] (3) The present invention adopts the composite enzymatic hydrolysis technology of alkaline protease and trypsin, and by optimizing the enzymatic hydrolysis process, fully improves the utilization rate of the thin shell protein and releases the flavor peptides in the thin shell to the maximum extent. Combining the Maillard reaction and yeast fermentation technology, the taste and flavor of the enzymatic hydrolyzate are significantly improved through the precise selection and control of the process conditions; (4) The present invention achieves the purpose of effectively removing fishy smell and enhancing freshness by compounding with the spice basil leaves. Basil is rich in aromatic substances such as terpenes, flavonoids and phenylpropanoids, as well as plant polysaccharides. It not only has antibacterial, antiseptic, anti-diabetic and antioxidant effects, but also can significantly inhibit the unpleasant flavor produced during seafood processing, thereby effectively solving the limitation of fishy smell on the application of thin-shell polypeptides in food and significantly improving the quality of the product; (5) The preparation method disclosed in the present invention is simple, has a short preparation time and high production efficiency. The prepared product is applied to traditional fermented condiments such as soy sauce and fish sauce, which can significantly improve the flavor and nutritional value of traditional condiments, making them rich in taste, with obvious umami and less fishy smell. In addition, this method conforms to the concept of natural health and has broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram showing the molecular weight distribution of polypeptides of the products of step S4 of examples 1 to 3 of the present invention and step S4 of comparative examples 1 to 2.

[0020] Figure 2 The graph is a distribution diagram of the absorbance values ​​of the products of step S5 of examples 4 to 6 of the present invention and step S5 of comparative examples 3 to 10 at 294 nm (a) and 420 nm (b).

[0021] Figure 3 This is a principal component analysis diagram of the electronic tongue detection results of the products of step S4, step S5, step S6, and step S7 of Example 1 of the present invention and step S4 of the example and step S5 of comparative example 13.

[0022] Figure 4 This is a cross-substance comparison diagram of different flavor substances in the products of step S4, step S5, step S6, and step S7 of Example 1 of the present invention and step S4 of Example 1 and step S5 of comparative example 13.

[0023] Figure 5 This is a percentage chart of the content of different flavor substances in the products of step S4, step S5, step S6, step S7 of Example 1 of the present invention and step S4 of Example 1 and step S5 of comparative example 13.

[0024] Figure 6 This is a cluster analysis heat map of the contents of different flavor substances in the products of step S4, step S5, step S6, step S7 of Example 1 of the present invention and step S4 of Example 1 and step S5 of comparative example 13. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0026] The experimental methods of the test indicators involved in the experimental examples of the present invention are as follows: Protein recovery rate: The total nitrogen content of the homogenate, enzymatic supernatant and high-pressure cooking liquid was determined by Kjeldahl method. The protein recovery rate was calculated as follows: Protein recovery rate (%) = total nitrogen content of enzymatic supernatant (or high-pressure cooking liquid) / total nitrogen content of homogenate × 100%.

[0027] Determination of hydrolysis degree: The amino acid nitrogen content in the enzymatic supernatant and high-pressure cooking liquid was determined by formaldehyde potentiometric titration, and the total nitrogen content in the homogenate was determined by Kjeldahl nitrogen determination. The calculation formula of hydrolysis degree is as follows: Degree of hydrolysis (%) = amino acid nitrogen content in the enzymatic hydrolysis supernatant (or high-pressure cooking liquid) / total nitrogen content in the homogenate × 100%.

[0028] Determination of solid content: Weigh a certain amount of enzymatic supernatant or high-pressure cooking liquid into a weighing bottle and dry it in an oven at 110°C to constant weight. The solid content is calculated as follows: Solid content (g / 100g) = weight of enzymatic hydrolysis supernatant (or high-pressure cooking liquid) after drying / weight of enzymatic hydrolysis supernatant (or high-pressure cooking liquid) before drying.

[0029] Molecular weight distribution: Liquid chromatography was used to determine the molecular weight distribution of peptides, with 0.05M hydrochloric acid solution as the mobile phase. The enzymatic supernatant and high-pressure cooking liquid were diluted to a 1 mg / mL solution and filtered through a 0.22 μm syringe filter. The peptides were separated using a Superdex30 Increase 10 / 300 GL (Cytiva) column, with an ultraviolet detection wavelength of 214 nm. Molecular weight standard curves were drawn using cytochrome C, aprotinin, bacitracin, triglycine, and glycine as standards.

[0030] Determination of absorbance at 294 nm and 420 nm: The Maillard reaction solution was diluted to an appropriate multiple and the absorbance at 294 nm and 420 nm was determined using an ELISA reader.

[0031] Sensory evaluation: The sensory evaluation panel consisted of 8 trained tasters (4 men and 4 women, aged between 25 and 35 years old). The samples were diluted to 1 mg / mL, and the tasters performed sensory evaluation on each sample. The evaluation indicators included umami, fishy, ​​aromatic odor and overall score. The umami, fishy and overall scores of the enzymatic supernatant in Example 1 were set to 5 points, and the aromatic odor of the thin-shelled polypeptide-basil natural flavor base in Comparative Example 11 was positioned at 10 points. The sensory samples were scored using a 10-point linear coordinate from 0 (very weak) to 10 (very strong), and the average score of the tasters was taken as the final score.

[0032] Electronic tongue test: The sample was diluted to 1 mg / mL and analyzed using Shanghai Baosheng cTongue electronic tongue. Pure water and 0.35% MSG solution were used as references. The principal component analysis method was used to reduce the dimensionality of the original data and analyze it.

[0033] Analysis of flavor composition: The sample was diluted 3 times, 1.5 mL was weighed into a 20 ml sealed headspace bottle, and the sample was pre-equilibrated at 80 °C for 10 min. The extraction head was inserted into the sample bottle for headspace extraction for 30 min, and then immediately inserted into the injection port of the gas chromatography-mass spectrometry instrument and thermally analyzed at 250 °C.

[0034] GC-MS conditions: TG-5SILMS capillary column (30m×0.25mm×0.25um); injection port temperature of 250°C; temperature program: initial temperature of 50°C for 3 min, then increased to 200°C at 5°C / min; then increased to 250°C at 20°C / min and maintained for 5 min; in splitless injection mode, helium was used as the carrier gas with a constant flow rate of 3 ml / min; solvent delay was 3.0 min.

[0035] MS conditions: EI source, 230°C ion source, 280°C mass spectrometer interface temperature; electron energy 70 eV, full scan data acquisition mode, mass scan range 29-500 m / z. Quantitative analysis was performed using 2-octanol as an internal standard. Example 1

[0036] A method for preparing a thin-shell polypeptide-basil natural flavor base material according to Example 1 of the present invention comprises the following steps: S1 Thin shell pretreatment, soak the fresh thin shell in 40℃ warm water until the shell opens slightly, change the warm water to wash 3 times to desalinate, then pick up and drain to obtain the desalted preform.

[0037] S2: Prepare a homogenate. Take 410 g of the desalted preform, add 125 g of pure water and homogenize for 10 min. Then let it stand for 1 min to precipitate shell debris. Take the upper layer of liquid as the homogenate.

[0038] S3 Enzymatic hydrolysis: adjust the pH of the homogenate to 8.7 with sodium hydroxide, add 0.65 g alkaline protease and 0.65 g trypsin, and perform enzymatic hydrolysis at 51° C. for 6.2 h in a water bath shaker to obtain an enzymatic hydrolyzate.

[0039] S4 Inactivation of enzyme treatment: using boiling water bath method, boil the enzymatic hydrolysate in boiling water for 10 minutes for inactivation of enzyme treatment, then cool it to room temperature in cold water, and then centrifuge the treated liquid at 4°C and 11897g for 15 minutes to obtain the enzymatic hydrolysate supernatant.

[0040] S5 Maillard reaction: 200 g of the enzymatic supernatant was added with 6 g of glucose, mixed evenly, and placed in a pressure cooker for reaction at 120° C. for 1.5 h to obtain a Maillard reaction solution.

[0041] S6 fermentation, 3 g of yeast was added to 200 g of Maillard reaction solution cooled to room temperature, and fermented at a constant temperature of 30° C. for 2 h, then sterilized in a boiling water bath for 10 min, and cooled to room temperature to obtain a fermentation liquid.

[0042] S7 flavor treatment, add 20g of fresh basil leaves to 200g of fermentation liquid and put it into a homogenizer for homogenization. After the homogenization is completed, filter it with a 200-mesh filter to obtain a filtrate. Boil the filtrate over high heat, then turn to low heat and boil for 5 minutes, then place it in cold water for rapid cooling to obtain a thin-shell polypeptide-basil natural flavor base. Example 2

[0043] A method for preparing a thin-shell polypeptide-basil natural flavor base material according to Example 1 of the present invention comprises the following steps: S1 Thin shell pretreatment, pour fresh thin shell into boiling water and boil for 3 minutes, then use a stick to rotate and stir the boiling water to separate the meat and shell, and use a mesh sieve to scoop up the thin shell meat floating on the upper layer while stirring. After collection, drain and obtain the shelled preform for use.

[0044] S2: Prepare a homogenate solution. Take 138 g of the shelled preform and add 237 g of pure water. Homogenize for 10 minutes. The resulting solution is a homogenate solution.

[0045] S3 Enzymatic hydrolysis: adjust the pH of the homogenate to 8.7 with sodium hydroxide, add 0.65 g alkaline protease and 0.65 g trypsin, and perform enzymatic hydrolysis at 51° C. for 6.2 h in a water bath shaker to obtain an enzymatic hydrolyzate.

[0046] S4 Inactivation of enzyme treatment: using boiling water bath method, boil the enzymatic hydrolysate in boiling water for 10 minutes for inactivation of enzyme treatment, then cool it to room temperature in cold water, and then centrifuge the treated liquid at 4°C and 11897g for 15 minutes to obtain the enzymatic hydrolysate supernatant.

[0047] S5 Maillard reaction: 200 g of the enzymatic supernatant was added with 6 g of glucose, mixed evenly, and placed in a pressure cooker for reaction at 120° C. for 1.5 h to obtain a Maillard reaction solution.

[0048] S6 fermentation, 3 g of yeast was added to 200 g of Maillard reaction solution cooled to room temperature, and fermented at a constant temperature of 30° C. for 2 h, then sterilized in a boiling water bath for 10 min, and cooled to room temperature to obtain a fermentation liquid.

[0049] S7 flavor treatment, add 20g of fresh basil leaves to 200g of fermentation liquid and put it into a homogenizer for homogenization. After the homogenization is completed, filter it with a 200-mesh filter to obtain a filtrate. Boil the filtrate over high heat, then turn to low heat and boil for 5 minutes, then place it in cold water for rapid cooling to obtain a thin-shell polypeptide-basil natural flavor base. Example 3

[0050] This Example 3 is basically the same as Example 1, except that in step S3, the pH value of the homogenate is adjusted to 8, the amount of alkaline protease and trypsin added is 0.5 g, the enzymolysis temperature is 50° C., and the enzymolysis time is 4 h. Example 4

[0051] This Example 4 is basically the same as Example 1, except that in step S5, the reaction time of the Maillard reaction is 0.5 h. Example 5

[0052] This embodiment 5 is basically the same as embodiment 1, except that in step S5, the reaction time of the Maillard reaction is 1 hour. Example 6

[0053] This Example 6 is basically the same as Example 1, except that in step S5, the reaction time of the Maillard reaction is 2 hours. Example 7

[0054] This embodiment 7 is basically the same as embodiment 1, except that in step S6, the fermentation time is 1 hour. Example 8

[0055] This Example 8 is basically the same as Example 1, except that in step S6, the fermentation time is 3 hours. Example 9

[0056] This embodiment 9 is basically the same as embodiment 1, except that in step S6, the fermentation time is 4 hours. Example 10

[0057] The present embodiment 10 is basically the same as the embodiment 1, except that in step S7, the boiling time over low heat is 3 minutes. Embodiment 11

[0058] The present embodiment 10 is substantially the same as the embodiment 1, except that in step S7, the boiling time over low heat is 7 minutes. Example 12

[0059] The present embodiment 10 is substantially the same as the embodiment 1, except that in step S7, the boiling time over low heat is 9 minutes. Comparative Example 1

[0060] The preparation of thin shell high pressure cooking liquid comprises the following steps: S1 Thin shell desalination: Soak the fresh thin shell in 40℃ warm water until the shell opens slightly, wash it 2-3 times with warm water to desalinate, pick it up and drain it.

[0061] S2 Preparation of homogenate: 410 g of desalted thin shells were homogenized by adding 125 g of water. The mixture was allowed to stand for 1 min to allow the shell debris to settle. The upper homogenate was then poured out for later use.

[0062] S3 High-pressure cooking: The homogenate is placed in a pressure cooker and cooked at 120°C for 2 h.

[0063] S4 Centrifugation: The homogenate after high pressure cooking was cooled to room temperature in cold water, and then centrifuged at 11897g for 15min at 4°C to remove the precipitate and obtain the high pressure cooking liquid. Comparative Example 2

[0064] The preparation of thin shell high pressure cooking liquid comprises the following steps: S1 Remove the meat from the lamina: Pour fresh lamina into boiling water and cook for 3 minutes. Use a stick to rotate and stir the boiling water to separate the meat from the lamina. While stirring, use a mesh sieve to scoop up the lamina meat floating on the top and drain it.

[0065] S2 Preparation of homogenate: Take 138 g of thin shell meat, add 237 g of water and homogenize for 10 minutes to prepare a homogenate.

[0066] S3 High-pressure cooking: The homogenate is placed in a pressure cooker and cooked at 120°C for 2 h.

[0067] S4 Centrifugation: The homogenate after high pressure cooking was cooled to room temperature in cold water, and then centrifuged at 11897g for 15min at 4°C to remove the precipitate and obtain the high pressure cooking liquid. Comparative Examples 3~6

[0068] Comparative Examples 3 to 6 are substantially the same as Example 1, except that the glucose in step S5 is replaced by galactose, and the reaction times are 0.5 h, 1 h, 1.5 h and 2 h, respectively. Comparative Examples 7-10

[0069] Comparative Examples 7 to 10 are substantially the same as Example 1, except that the glucose in step S5 is replaced by xylose, and the reaction times are 0.5 h, 1 h, 1.5 h and 2 h, respectively. Comparative Examples 11-12

[0070] Comparative Examples 11 to 12 are substantially the same as Example 1, except that the boiling time in step S7 is 0 min and 15 min, respectively. Comparative Example 13

[0071] Comparative Example 13 includes steps S1 to S4 in the embodiment. After obtaining the enzymatic supernatant, the flavor treatment of step S7 is directly performed without steps S5 and S6. Specifically, 20 g of fresh basil leaves are added to 200 g of the enzymatic supernatant for homogenization, and the residue is filtered with a 200-mesh sieve; the filtrate is poured into a pot, quickly boiled over high heat, then reduced to low heat and continued to boil for 5 minutes, and then the pot is transferred to cold water for rapid cooling to prepare a flavor base.

[0072] The above-mentioned Examples 1 to 12 are compared with Comparative Examples 1 to 13 as follows.

[0073] 1. The enzymatic hydrolysis supernatant of step S4 of Examples 1 to 3 and the high pressure cooking liquid in step (4) of Comparative Examples 1 to 2 were compared in terms of hydrolysis degree, protein recovery rate, solid content and molecular weight distribution.

[0074] Table 1 Protein recovery, degree of hydrolysis and solid content of enzymatic supernatant / high pressure cooking liquid sample Protein recovery rate (%) Degree of hydrolysis (%) Solid content g / 100g Example 1 90.61±1.95 37.51±0.74 6.21±0.18 Example 2 87.84±1.85 30.34±1.15 6.5±0.2 Example 3 87.94±2.26 28.14±0.52 5.92±0.2 Comparative Example 1 45.35±2.08 15.5±0.65 3.77±0.35 Comparative Example 2 32.67±3.65 10.12±0.75 2.57±0.18 Table 1 shows the results of protein recovery rate, hydrolysis degree and solid content of the enzymatic supernatant and high-pressure cooking liquid. As can be seen from Table 1, the protein recovery rate, hydrolysis degree and solid content of the enzymatic supernatant in Examples 1 to 3 are higher than those of the high-pressure cooking liquid in Comparative Examples 1 to 2, indicating that the enzymatic hydrolysis process has a higher utilization efficiency for nutrients such as protein in the thin shell, and can more effectively release small molecule flavoring substances such as polypeptides and amino acids. Compared with Example 3, the protein recovery rate and solid content of Example 1 increased slightly, while the increase in hydrolysis degree was more obvious, from 28.14% to 37.51%. The enzymatic hydrolysis conditions of Example 1 are the best conditions after process optimization, under which more small molecule polypeptides can be obtained. Both Example 1 and Example 2 were enzymatically hydrolyzed under the same conditions, but the hydrolysis degree of Example 1 was significantly higher than that of Example 2. This is because the raw material of Example 2 is thin shell meat after boiling water, and the high temperature will cause the protein fiber to deform and shrink, reducing the contact area between the enzyme and the protein, thereby reducing the enzymatic hydrolysis efficiency.

[0075] Depend on Figure 1It can be seen that the enzymatic supernatants of Examples 1 to 3 are mainly small molecule peptides, and the proportion of polypeptides with a molecular weight of less than 3 kDa reaches 80.68%, 80.23% and 72.67% respectively. In addition, the proportion of polypeptides with a molecular weight of less than 0.5 kDa in Example 1 is higher than that in Example 2 and Example 3, indicating that the enzymatic hydrolysis efficiency of Example 1 is higher. On the contrary, in Comparative Examples 1 to 2, the proportion of polypeptides with a molecular weight of more than 10 kDa in the high-pressure cooking liquid reached 49.54% and 53.29%, while the proportion of polypeptides with a molecular weight of less than 3 kDa was only 40.69% and 34.60%. Studies have shown that flavor peptides are mainly small molecule peptides with a molecular weight of less than 3 kDa, so the use of enzymatic hydrolysis can obtain more flavor peptides, thereby enriching the taste of the flavor base.

[0076] 2. The experimental results of the Maillard reaction solutions in Example 1, Step S5 of Examples 4 to 6 and Step S5 of Comparative Examples 3 to 10 were compared, with the absorbance values ​​at 294 nm and 420 nm being used as indicators for comparison.

[0077] The absorbance at 294nm reflects the amount of Maillard intermediates produced. These intermediates will further react to produce flavor compounds (such as furans, pyrazines, aldehydes, etc.). The more intermediates there are, the greater the potential for further generating flavor compounds, which is very important for improving the flavor of food. The absorbance at 420nm is mainly related to the final product of the Maillard reaction (such as melanoidins). Too high an absorbance at 420nm indicates that the reaction is close to the end point and the generation of flavor compounds may be inhibited. Figure 2 It can be seen that the absorbance of the Maillard reaction solution obtained by glucose at 294nm is significantly higher than that of galactose and xylose, and it shows a trend of first increasing and then decreasing with the reaction time, reaching a maximum value at 90min. In addition, under this reaction condition, the absorbance of the Maillard reaction solution at 294nm is 1.8, which is much higher than the absorbance of 420nm 0.3, indicating that the Maillard reaction under this condition is more conducive to the formation of flavor compounds, thereby improving the flavor of the product.

[0078] 3. The fermentation broths of step S6 of Example 1 and Examples 7 to 9 were compared in terms of sensory evaluation (umami, fishy smell and overall score).

[0079] Table 2 Effect of fermentation time on sensory evaluation of fermentation broth sample Fermentation time (h) Umami Fishy smell Overall rating Example 7 1 6.2 4.1 5.7 Example 1 2 6.7 3.6 6.3 Example 8 3 6.4 3.9 6.1 Example 9 4 6.9 3.7 6.4 Table 2 shows the sensory evaluation results of the fermentation liquid under different fermentation time conditions. When the fermentation time is 1h, the umami and overall scores are the lowest, while the fishy smell is greater than other groups, indicating that the fermentation time of 1h cannot achieve a good effect of removing fishy smell and increasing freshness. When the fermentation time is 2h and 4h, the umami of the fermentation liquid is relatively high, the fishy smell is relatively low, and the overall scores are close. Considering the time cost, 2h fermentation can be selected as the optimal fermentation time.

[0080] 4. The experimental effects of the thin-shell polypeptide-basil natural flavor base materials of Example 1, Examples 10-12 and Comparative Examples 11-12 in step (7) were compared using sensory evaluation (umami, fishy smell, aromatic odor and overall score) as indicators for comparison.

[0081] Table 3 Effect of boiling time on sensory evaluation of thin-shell polypeptide-basil natural flavor base sample Boiling time (min) Umami Fishy smell Aromatic smell Overall rating Comparative Example 11 0 6.3 1.3 10 7.1 Example 10 3 7.6 2.1 7.1 8.2 Example 1 5 7.7 1.7 6.7 8.9 Embodiment 11 7 7.4 1.9 6.8 8.7 Example 12 9 7.7 2.4 5.1 7.8 Comparative Example 12 15 7.2 3.3 1.6 6.4 Table 3 shows the sensory evaluation results of thin-shelled polypeptide-basil natural flavor base under different boiling times. Comparative Example 10 compounded the enzymatic solution and basil, but did not perform boiling treatment. Although the fishy smell reached the lowest, the overall score was also relatively low. This is because the overly strong basil aromatic odor formed a pungent odor, which affected the flavor and mouthfeel of the flavor base. As the boiling time increased, the aromatic odor showed a downward trend, the umami taste showed a trend of first rising and then falling, and the fishy smell showed a trend of falling and then rising, indicating that the boiling time was too long and consumed the aromatic compounds of basil, reducing the deodorizing effect. When the boiling time was 5 min, the overall score of the flavor base reached the highest value, so 5 min was selected as the optimal boiling time.

[0082] 5. The enzymatic hydrolysis supernatant of step S4 in Example 1, the Maillard reaction liquid of step S5, the fermentation liquid of step S6, the thin-shelled polypeptide-basil natural flavor base of step S7, the enzymatic hydrolysis supernatant of step S4 in Example 2, and the product of step S5 in comparative example 13 were compared for experimental effects and marked as E-1, M-1, F-1, C-1, E-2, and C-13, respectively, and the results of sensory evaluation, electronic tongue analysis, and flavor substance composition analysis were used as indicators for comparison.

[0083] Table 4 Effects of different processes on sensory evaluation of finished products sample Umami Fishy smell Overall rating E-1 5 5 5 M-1 5.4 4.6 5.8 F-1 6.4 3.8 6.5 C-1 7.9 1.5 8.6 E-2 4.2 4.1 5.3 C-13 6.2 2.8 7.1 Table 4 shows the effects of different process products on sensory evaluation during the production of thin-shelled polypeptide-basil natural flavor base. Compared with the enzymatic supernatant E-1 in Example 1, the fishy smell and umami taste of the enzymatic supernatant E-2 in Example 2 are significantly reduced. This is because the process of separating the thin-shelled meat by boiling in Example 2 can reduce the production of fishy substances, but it will also cause some umami substances to be lost. At the same time, high temperature shrinks the protein, reduces the enzymatic efficiency, and thus reduces the release of umami peptides. The Maillard process, fermentation process, and compounding process with basil in Example 1 all have the effect of increasing umami and reducing fishy smell, thereby improving the overall score of sensory evaluation, among which the compounding process with basil has the most obvious effect on the sensory evaluation of the flavor base. In Comparative Example 13, the enzymatic supernatant is not subjected to the Maillard reaction and fermentation, and the 13-flavor base C-13 prepared by compounding with basil is also significantly improved in the results of sensory evaluation, which further illustrates that the compounding process with basil is a key step in improving the quality of the flavor base.

[0084] like Figure 3 As shown in the figure, with pure water and MSG solution as reference, principal component 1 (PC1) explains 96.93% of the variables, while principal component 2 (PC2) only explains 2.90% of the variables. The difference between MSG solution and pure water is mainly reflected in PC1, while there is almost no difference in PC2, indicating that PC1 can better reflect the difference in umami. On PC1, different samples are located between pure water and MSG solution, and the distance between C-13 and MSG solution is the closest, indicating that C-13 has the most obvious umami characteristics. In addition, the distance between different samples and MSG solution on PC1 is very consistent with the umami value of sensory evaluation in Table 4, indicating that the results of sensory evaluation and electronic tongue analysis are consistent.

[0085] Table 5 Flavor substance content of samples like Figure 4 As shown, only 6 flavor substances are common to all samples, and there are 14, 22, 22, 35, 25 and 16 unique flavor substances in E-1, M-1, F-1, C-1, E-2 and C-13, respectively. The difference in the types of flavor substances among different samples may be an important reason for the differences in sensory results.

[0086] The fishy smell of aquatic products is the result of the combined action of a variety of volatile substances, including alcohols, aldehydes, ketones, amines and other substances. As shown in Table 5, 36 flavor substances were detected in the enzymatic hydrolysate E-1, among which 1-octen-3-ol was mainly derived from the oxidation and degradation of linoleic acid, with characteristic flavors such as earthy and fishy smells; nonanal was mainly derived from the oxidation process of fatty acids and had a strong fishy smell; trans, cis-2,6-nonadienal was the key aldehyde component of the fishy smell; nonanoic acid had an unpleasant, rancid smell; 5-aminopentylamide may have an ammonia smell or other pungent smells, which are the main causes of the fishy smell of the enzymatic hydrolysate. After the Maillard reaction, the number of flavor substances in M-1 increased to 60, among which maltol was one of the common products of the Maillard reaction and had a caramel flavor. In addition, pyrazine compounds such as isopentylpyrazine and 2-ethyl-3,6-dimethylpyrazine are also common products in the Maillard reaction, with unique nutty and roasted aromas. After fermentation, 56 flavor substances were detected in F-1, including benzyl alcohol, phenylethyl alcohol, 9-hexadecenoic acid ethyl ester and other alcohols and esters, which are common products of yeast fermentation. In addition, 2-acetylpyrrole is also a product of yeast fermentation, with the aroma of nuts, fruits and flowers. After compounding with basil, C-1 and C-13 contained 64 and 42 flavor substances, respectively, mainly adding two flavor substances, estragole and linalool. The estragole has an aroma similar to fennel or licorice, and linalool has a fresh scent of flowers and citrus. In addition, there are alcohols and olefins such as β-eudes, β-elemene and trans-caryophyllene, which have a good effect on removing the fishy smell and enhancing the freshness of the flavor base.

[0087] from Figure 5 From the above, it can be seen that the flavor substances in E-1 are mainly aldehydes, accounting for more than 50% of the content. In addition, the content of alcohols is also close to 20%. After the Maillard reaction, the percentage of aldehydes and alcohols in M-1 decreased. After fermentation, the percentage of aldehydes in F-1 further decreased. On the contrary, the percentage of alcohols increased significantly. This is because yeast fermentation will produce a variety of alcohols, which will affect the flavor and aroma of the product. After compounding with basil, the percentage of various substances such as aldehydes and alcohols in C-1 decreased significantly. On the contrary, the percentage of ethers and olefins increased significantly. The increase in the percentage of ethers is due to the introduction of a large amount of estragole, which reaches 50%. The increase in the percentage of olefins is due to the introduction of various olefins such as β-elemene and trans-caryophyllene.

[0088] from Figure 6It can be seen that acids are highly expressed in E-2, aldehydes are highly expressed in E-1, ethers and olefins are highly expressed in C-1 and C-13, alcohols are highly expressed in F-1, and phenols are highly expressed in M-1 and F-1. The clustering results show that C-1 and C-13 have high similarity, but are quite different from other samples. In addition, F-1 and M-1 also have high similarity. The above results show that processes such as Maillard, fermentation, and compounding with basil can change the flavor composition of the flavor base, thereby improving the flavor and flavoring effect of the product.

[0089] The thin-shell polypeptide-basil natural flavor base prepared by the present invention is added to soy sauce or fish sauce to form a composite seasoning, wherein the addition amount in soy sauce is 15% by weight, and the addition amount in fish sauce is 10% by weight. Chicken breasts cooked in water are dipped in the above-mentioned soy sauce composite seasoning and fish sauce composite seasoning respectively, and soy sauce and fish sauce without the addition of thin-shell polypeptide-basil natural flavor base are used as the most contrast. The results show that the composite seasoning has higher umami taste and richer taste than the control, indicating that the addition of thin-shell polypeptide-basil natural flavor base can improve the taste and mouthfeel of traditional seasonings.

[0090] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for preparing a thin-shell polypeptide-basil natural flavor base, characterized in that: The steps include: S1: pretreatment of the thin shell, pretreatment of the thin shell and draining of the thin shell to obtain a thin shell preform for standby use; S2: preparing a homogenate, adding an appropriate amount of water to the thin shell preform and putting it into a homogenizer for homogenization to obtain a homogenate; S3 enzymatic hydrolysis, adding alkaline protease and trypsin to the homogenate simultaneously for enzymatic hydrolysis to obtain an enzymatic hydrolyzate; S4: enzymatic inactivation treatment, wherein the enzymatic hydrolysate is inactivated by a boiling water bath, and then the treated liquid is centrifuged to obtain an enzymatic hydrolysate supernatant; S5 Maillard reaction, adding glucose to the enzymatic supernatant, mixing evenly and then putting into a pressure cooker for Maillard reaction to obtain a Maillard reaction solution; S6 fermentation, adding yeast to the Maillard reaction solution cooled to room temperature, fermenting under constant temperature conditions, then sterilizing in a boiling water bath, cooling to room temperature, and obtaining a fermentation solution; S7 flavor treatment, add fresh basil leaves to the fermentation liquid and put it into a homogenizer for homogenization. After the homogenization is completed, filter to obtain a filtrate, boil the filtrate and place it in cold water for rapid cooling to obtain a thin-shell polypeptide-basil natural flavor base.

2. The method for preparing the thin-shell polypeptide-basil natural flavor base according to claim 1, characterized in that In the step S1, the thin shell preform obtained by pre-treating the thin shell includes: Desalination preformed products, soak fresh thin shells in 40~45℃ warm water until the shells slightly open, change warm water to wash 2~3 times to desalinate, then pick up and drain to obtain; To prepare the shelled product, pour the fresh thin shell into boiling water and boil it for 3 to 5 minutes. Then use a stick to rotate and stir the boiling water to separate the meat and shell. While stirring, use a mesh sieve to scoop up the thin shell meat floating on the upper layer. After collecting, drain it.

3. The method for preparing the thin-shell polypeptide-basil natural flavor base according to claim 2, characterized in that: The conditions for homogenizing the desalted preform or the shelled preform in step S2 are: The desalted preform is used for homogenization, the weight ratio of the desalted preform to water is 3-3.5:1, the homogenization is carried out for 10 minutes, and then the mixture is allowed to stand and settle, and the upper layer of liquid is taken as the homogenate; The shelled preform is used for homogenization, the weight ratio of the shelled preform to water is 0.5-0.7:1, the homogenization is carried out for 10 minutes, and the obtained solution is a homogenized liquid.

4. The method for preparing the thin-shell polypeptide-basil natural flavor base according to claim 2, characterized in that: In step S3, the conditions for enzymatic hydrolysis are: the weight ratio of alkaline protease to trypsin is 0.5-2:1, the total amount of enzyme added is 0.24%-0.36% of the weight of the desalted preform or 0.72%-1.1% of the weight of the shelled preform, the enzymatic hydrolysis pH is 8-9, the enzymatic hydrolysis temperature is 45-55° C., and the enzymatic hydrolysis time is 4-7 hours.

5. The method for preparing the thin-shell polypeptide-basil natural flavor base according to any one of claims 1 to 4, characterized in that In step S4, the purification step is as follows: the enzymatic solution is boiled in boiling water for 10 minutes to inactivate the enzyme, and then cooled to room temperature in cold water; the centrifugation condition is as follows: centrifugation at 10000-12000g for 15 minutes at 4°C.

6. The method for preparing the thin-shell polypeptide-basil natural flavor base according to any one of claims 1 to 4, characterized in that: In step S5, the amount of glucose added is 1% to 6% of the weight of the enzymatic supernatant, the temperature of the Maillard reaction is 115 to 125° C., and the reaction time is 0.5 to 2 h.

7. The method for preparing the thin-shell polypeptide-basil natural flavor base according to any one of claims 1 to 4, characterized in that: The yeast in step S6 is L-Au cerevisiae, the addition amount is 1% to 2% of the weight of the Maillard reaction solution, the fermentation temperature is 25 to 30° C., the fermentation time is 1 to 4 hours, and the boiling water bath sterilization time is 10 minutes.

8. The method for preparing the thin-shell polypeptide-basil natural flavor base according to any one of claims 1 to 4, characterized in that: In step S7, the amount of basil leaves added is 5% to 20% of the weight of the fermentation liquid, and the broth is filtered using a 200-mesh filter. The boiling process is to boil over high heat and then turn to low heat and boil for 3 to 9 minutes.

9. A thin-shell polypeptide-basil natural flavor base, characterized in that: The invention is prepared by the preparation method of the thin-shell polypeptide-basil natural flavor base material according to any one of claims 1 to 8.

10. An application of a thin-shell polypeptide-basil natural flavor base, characterized in that: The amount of the thin-shell polypeptide-basil natural flavor base as claimed in claim 9 added to the seasoning as a seasoning additive is 10% to 15% of the quality of the seasoning.

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