Fresh and fragrant oyster seasoning peptide and processing method thereof

Abstract

The invention discloses a fresh and fragrant oyster seasoning peptide and a processing method thereof, and belongs to the technical field of biology. The method comprises the following steps: by taking fresh oyster meat as a raw material, repeatedly treating oyster meat liquid and oyster cooking normal juice by combining an enzymolysis method and a membrane filtration method, then uniformly mixing the oyster meat liquid and the oyster cooking normal juice to obtain an oyster enzymolysis product consisting of small-molecule active peptides, and adding D-fucose into the oyster enzymolysis product to form a Maillard reaction system. And reacting to obtain the fresh and fragrant oyster seasoning peptide. According to the method, the defect that a traditional process is uncontrollable is overcome, the oyster meat liquid and the oyster cooking normal juice are subjected to multi-stage multi-time enzymolysis by combining an enzymolysis method and a membrane filtration method, the small-molecule active peptide with accurate activity retention can be prepared without enzyme deactivation, and the oyster enzymolysis product with the small-molecule active peptide and D-fucose are subjected to Maillard reaction treatment, so that the content of the D-fucose in the oyster meat liquid is increased, and the content of the D-fucose is increased. The prepared fresh and fragrant oyster seasoning peptide not only corrects the original sea fishy smell in oysters, but also has sweetness and baking fragrance, and can realize aroma enhancement and seasoning functions without introducing other seasonings.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and in particular relates to an oyster flavoring peptide and a processing method thereof. Background Art

[0002] Oysters, also known as oysters, are a major marine shellfish in my country and are known as the "milk of the sea". Because their soft parts and oyster liquid are rich in nutrients and umami substances such as protein, amino acids, B vitamins, calcium, zinc, taurine, glycogen, etc., they are delicious and deeply loved by people. Oyster oligopeptides, as an extracted product of oysters, can be quickly and efficiently absorbed by the human body due to the characteristics of oligopeptides. With the deepening of modern medical research, it has been found that oysters also have a variety of biological activities, such as improving the body's immunity, anti-tumor, and protective effects on the liver, which has attracted the attention of researchers. my country's offshore areas are rich in oyster resources. Coupled with the rapid development of artificial breeding technology, as of 2022, my country's total oyster production has reached 6.1995 million tons.

[0003] Since oysters feed on seaweed and plankton, the rich algae and microorganisms in their internal organs are constantly metabolized, oxidized, and interact with the unsaturated fatty acids rich in oyster meat, causing many sulfur-containing and nitrogen-containing compounds to transform, and free fatty acids to become rancid and produce fishy substances, which gradually accumulate to form the unique fishy smell of oysters. This fishy smell affects the taste of oyster products and is difficult to remove. To make the flavor better, they must be artificially deodorized. In addition, since hydrolysis or enzymatic hydrolysis of oyster peptide products will lead to the exposure of hydrophobic amino acid groups on the peptide chain, a large amount of free amino acids and bitter peptides will be produced, which will reduce the molecular peptide yield and also affect the large-scale application of oyster products.

[0004] The most effective method for removing the fishy smell and bitterness of oyster peptides in the prior art is to use exoenzymes to remove hydrophobic amino acids from the peptide chain, but enzymatic deodorization and debittering usually improves the debittering effect by extending the enzymatic hydrolysis time, which can easily cause the oyster peptide flavor to be too complex and prominent, the color to become darker, and the yield to be reduced, and the deodorization and debittering effect is not ideal. In addition, the method for removing the fishy smell and bitterness of oyster peptides also includes the Maillard reaction method, which uses the Maillard reaction of carbonyl groups (sugars, fats, etc.) and amino acids (proteins) when heated to effectively mask the fishy smell of oyster hydrolysates and increase their fragrance and flavor. However, the long-term high temperature and high pressure Maillard reaction easily causes the oyster product to darken in color and reduce its antioxidant activity.

[0005] At present, in addition to eating fresh oysters, the processing methods are relatively simple, mainly concentrated in drying oysters or boiling oyster sauce. However, the oyster sauce prepared by mixed pulping and enzymatic hydrolysis still has a fishy smell and is dark brown in color. It is easy to lose effective ingredients such as umami and small peptides in the later adsorption treatment. In addition, the oyster sauce preparation process does not separate the oyster viscera and other substances, and the growth of microorganisms and algae fishy smell will affect the product quality.

[0006] The Chinese patent with publication number CN117243358A and application date of August 21, 2023 discloses a composite umami seasoning with oyster sauce flavor and a preparation method thereof, which is mainly made of the following raw materials in the following mass proportions: 30-50 parts of seafood flavor enhancer, 25-35 parts of concentrated oyster juice flavor enhancer, 6-10 parts of kelp flavor enhancer, 6-10 parts of matsutake flavor enhancer, 3-5 parts of yeast extract, 2-4 parts of salt, 1-3 parts of fructose syrup, 4-6 parts of maltodextrin and 4-6 parts of xanthan gum. The preparation method of the composite umami seasoning with oyster sauce flavor is also disclosed. This method effectively improves the umami intensity and enriches the umami perception of oyster sauce, but requires the additional addition of other umami sources, and to a certain extent cannot well preserve the original umami of oysters, and there are many uncontrollable factors in the oyster sauce cooking; the Chinese patent with publication number CN104187556A and application date of August 5, 2014 discloses a method for producing natural condiments using oysters as raw materials, which relies on natural enzymes produced by microorganisms to deeply decompose oysters, increase the content of soluble amino acids and free amino acids in oyster paste liquid, and form flavoring substances in the reaction process, which retains the umami of oysters and can be more easily compounded with other seasoning substances to produce new seasoning products. However, the production process requires a long period of microbial fermentation. During fermentation, microorganisms are easily affected by growth environment conditions, and the controllability is poor. Moreover, the metabolites are complex and difficult to separate, which is not conducive to factory-based and economical production. The Chinese patent with publication number CN106490572A and application date October 24, 2016 discloses a method for making oyster juice seasoning. After primary cell wall breaking, secondary ultrafine cell wall breaking and high-pressure homogenization, the oyster meat is refined to 0.05 0.1 μm, which can not only preserve the original nutrients and flavor of the oyster, but also will not waste any part of the oyster meat. At the same time, the color is more uniform, and no precipitation or stratification will occur. Moreover, the Maillard reaction can not only remove the fishy smell of the oyster, but also provide a good flavor of the oyster after cooking. Although the production method uses the secondary ultrafine oyster wall breaking slurry and white sugar for Maillard reaction to achieve the technical effect of flavor enhancement and freshness enhancement, the fishy smell carried by the oyster itself is not eliminated, but the fishy smell is covered by the Maillard reaction product.

[0007] In combination with the current development trend of using the Maillard reaction to mask the fishy smell of oyster hydrolysates, while retaining the nutritional value and delicious flavor of the oysters themselves, a process method is developed that can not only maximally correct the fishy smell of the oysters, but also use the Maillard reaction to enrich their own complex flavor and provide a fresh and fragrant seasoning technical effect. This will help to improve the marketization level and economic benefits of oyster peptide products, and has important practical value and reference significance for the development of high-quality, better-tasting seafood seasonings. Summary of the invention

[0008] In order to solve the problems existing in the prior art, the present invention provides an oyster flavoring peptide and a processing method thereof. The oyster flavoring peptide prepared not only corrects the original marine smell of oysters, but also has sweetness and baking aroma, and can achieve the flavoring function without introducing other seasonings.

[0009] The technical solution of the present invention is as follows:

[0010] One of the purposes of the present invention is to provide a method for processing oyster flavoring peptides. The processing method uses fresh oyster meat as a raw material, combines enzymatic hydrolysis and membrane filtration to repeatedly process oyster meat liquid and oyster cooking juice, then mixes the two evenly to obtain an oyster enzymatic hydrolysis product composed of small molecular active peptides, adds D-fucose to the oyster enzymatic hydrolysis product to form a Maillard reaction system, and obtains the oyster flavoring peptide after the reaction.

[0011] Furthermore, the processing method comprises the following steps:

[0012] S1, using fresh oyster meat as raw material to steam and retain the oyster steaming juice, and then immediately cooling it with running water, and then placing it in a single freezer for batch spiral single freezing until the oysters are completely frozen, completing the shaping of the oysters;

[0013] S2, discard the viscera of the oysters after shaping, keep the oyster meat and crush it in an ice bath, mix the crushed oyster meat with purified water evenly, discard the upper suspended matter after centrifugation, and process the lower oyster meat sediment in a colloid mill and a high-pressure homogenizer in turn;

[0014] S3, mixing the composite protease with the homogenized oyster meat sediment and the oyster cooking juice for enzymatic hydrolysis, filtering the enzymatic hydrolysis products respectively with a three-stage membrane, retaining the filtrate less than 10 kDa from the two after the filtration, and retaining the retentate greater than 10 kDa from the oyster meat sediment for secondary enzymatic hydrolysis;

[0015] S4, adding a composite protease to the oyster meat sediment retentate greater than 10 kDa retained in S3 for secondary enzymolysis, controlling the enzymolysis time to obtain a secondary enzymolysis reaction product, using a three-stage membrane to filter the secondary enzymolysis reaction product, retaining a secondary filtrate less than 10 kDa after filtration, and retaining a retentate greater than 10 kDa for tertiary enzymolysis;

[0016] S5, using a composite protease to perform a third enzymatic hydrolysis on the retained product greater than 10 kDa in S4, adjusting the amount of enzyme added to perform sufficient enzymatic hydrolysis, using a three-stage membrane to filter the three enzymatic hydrolysis reaction products, and retaining the three filtrates less than 10 kDa after the filtration;

[0017] S6. Combining the filtrate below 10 kDa obtained by three enzymatic hydrolysis and filtration and the oyster juice after enzymatic hydrolysis to obtain an oyster enzymatic hydrolysis product, adding D-fucose to the oyster enzymatic hydrolysis product for Maillard reaction, and obtaining the oyster flavoring peptide.

[0018] Furthermore, in S1, the oyster cooking time is 5 to 10 minutes, the running water temperature is 0 to 4°C, the single freezing speed is 1.1 to 18.3 mm / min, the freezing temperature is -40 to -35°C, and the complete freezing of the oysters means that the center temperature of the oysters reaches -18 to -7°C.

[0019] Furthermore, the temperature of the pure water in S2 is below 10° C., and the mass ratio of the mixed liquid of the crushed oyster meat and the pure water is 1:5-10.

[0020] Furthermore, the composite protease in S3 is one of pepsin, trypsin, alkaline protease, neutral protease, papain, bromelain, or a combination of any two or more thereof, the usage amount of the composite protease is 2-5% of the oyster mass, and the enzymolysis time is 3-5 hours.

[0021] Furthermore, the filtration specifications of the three-stage membrane in S3 are 3kDa-10kDa, 10kDa-30kDa, and greater than 30kDa, the filtration temperature is 10-50°C, and the equipment operating power is 50Hz.

[0022] Furthermore, the composite protease in S4 is one of pepsin, trypsin, alkaline protease, neutral protease, papain, and bromelain, or a combination of any two or more thereof; the amount of the composite protease used is 2-5% of the mass of the mixed liquid; the enzymolysis time is 1-4 hours; the filtration specifications of the tertiary membrane are 3kDa-10kDa, 10kDa-30kDa, and greater than 30kDa; the filtration temperature is 10-50°C; and the equipment operating power is 50Hz.

[0023] Furthermore, the added amount of the composite protease in S5 is 1-2% of the mass of the oyster.

[0024] Furthermore, the mixing mass ratio of the oyster hydrolysate and D-fucose in S6 is 1:3 to 3:1, the insulation temperature of the Maillard reaction process is 70 to 130° C., the reaction time is 20 to 120 min, and the pH is 6.0 to 8.0.

[0025] The second object of the present invention is to provide an oyster flavoring peptide.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention uses fresh oyster meat as raw material, and for the first time proposes a processing method for treating oyster meat liquid and oyster cooking juice multiple times by combining enzymatic hydrolysis and membrane filtration. The boiled oysters and the recycled oyster cooking liquid are mixed to inhibit the fishy smell and oil oxidation produced by microbial reproduction. The oyster meat liquid and oyster cooking juice are enzymatically hydrolyzed separately in multiple stages and multiple times. While fully retaining the oyster active peptides, the protein or large molecular peptide is enzymatically hydrolyzed accurately and deeply, which not only avoids the high amino acid end product caused by excessive enzymatic hydrolysis of small molecular peptides, ensuring that the large molecules can be effectively enzymatically hydrolyzed into the required small molecular peptides, but also reduces the fishy smell and bad color produced after long-term enzymatic hydrolysis, and fundamentally realizes the deodorization and debittering of oyster peptides.

[0028] 2. The present invention uses oyster hydrolysate composed of small molecule active peptides to carry out Maillard reaction with D-fucose, and optimizes various reaction parameters. The use of D-fucose meets the consumer's demand for healthy and low-calorie foods. After the Maillard reaction, the volatile components such as acids in the oyster hydrolysate are reduced, the aroma components of esters, furans and alcohols are increased to a certain extent, and the organic aldehydes that produce fishy smells are converted into odor-friendly substances. The fishy smell of the oyster hydrolysate is further corrected. At the same time, the Maillard reaction provides the oyster hydrolysate with a roasted and burnt aroma and enhances the seafood flavor, and finally produces an oyster flavoring peptide with no fishy bitterness, high freshness, and rich flavor.

[0029] 3. The present invention innovates a process for producing oyster flavoring peptides. On the basis of retaining the active ingredients in oyster peptides to the maximum extent, the oyster peptide products can be deodorized, debittered and flavored without introducing other additional flavoring ingredients. At the same time, the use of D-fucose improves the ability of oyster peptide products to immunosuppress the growth and reproduction of bacteria and molds, has a certain antiseptic and fresh-keeping effect, reduces the addition of chemical preservatives, and not only makes oyster peptide products safer, but also has better sensory performance in seafood, meat and caramel flavors, meeting the edible needs of more consumers.

[0030] 4. The present invention discloses an improved and optimized process for preparing oyster flavoring peptides. This process does not require enzyme inactivation after multi-stage and multiple enzymatic hydrolysis. The processing technology is simple, the equipment requirements are low, and it is suitable for industrial production. It helps to improve the marketization level and economic benefits of oyster peptide products, and provides technical information for the development of high-quality, better-tasting seafood seasonings suitable for all ages. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a stacking bar chart of the enzymatic hydrolysis products of the 3kDa-10kDa and 10kDa-30kDa oyster hydrolysates after the Maillard reaction detected by gas chromatography-mass spectrometry.

[0032] Figure 2It is the absorbance of the 3kDa-10kDa and 10kDa-30kDa oyster hydrolysates of the present invention at 420nm.

[0033] Figure 3 This is a radar chart showing the sensitivity of the enzymatic hydrolysates of the 3kDa-10kDa and 10kDa-30kDa oysters after the Maillard reaction using an electronic nose to detect the enzymatic hydrolysates.

[0034] Figure 4 This is a color change diagram of the 3kDa-10kDa oyster hydrolysate of the present invention after 0-2h of Maillard reaction.

[0035] Figure 5 This is a color change diagram of the 10kDa-30kDa oyster hydrolysate of the present invention after 0-2h of Maillard reaction; DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with preferred embodiments. The endpoints of the ranges disclosed in the present invention and any values ​​are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be deemed to be specifically disclosed herein.

[0037] The experimental methods in the following examples, unless otherwise specified, are conventional methods and are performed according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0038] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0039] Example 1

[0040] This embodiment provides a process for producing oyster flavoring peptides, comprising the following steps:

[0041] (1) 20 kg of fresh oysters were shelled, cleaned and steamed for 5 min. After steaming, the oyster steaming juice was retained and immediately cooled with running water at 4°C until the oysters entered the single freezing machine;

[0042] (2) The cooled oysters are subjected to spiral freezing at a freezing speed of 1.1 mm / min and a freezing temperature of -35°C until the center temperature of the oysters reaches -7°C and is completely frozen;

[0043] (3) extracting the frozen oysters at a temperature below 4°C and under spraying conditions, discarding the viscera of the oysters, retaining only the oyster meat and crushing it in an ice bath, and uniformly mixing the crushed oyster meat with purified water below 10°C at a material-liquid ratio of 1:10, and subjecting the lower layer of oyster meat sediment to sequential processing by a colloid mill and a high-pressure homogenizer;

[0044] (4) 0.4 kg of a composite protease composed of pepsin and trypsin was mixed with the homogenized oyster meat sediment and the oyster cooking juice for enzymolysis for 3 hours, and the enzyme did not need to be inactivated during the enzymolysis reaction. After the enzymolysis reaction, the enzymolysis reaction products were filtered using a 3kDa-30kDa three-stage membrane filter. The filtration temperature was 10°C, the inlet pressure was 1 MPa, and the equipment operating power was 50 Hz. The filtrate of the two with a mass less than 10 kDa was retained, and the retentate of the oyster meat sediment with a mass greater than 10 kDa was retained for secondary enzymolysis;

[0045] (5) adding 0.04 kg of a composite protease composed of pepsin and trypsin to the oyster meat sediment retentate greater than 10 kDa retained in step (4) for secondary enzymatic hydrolysis, the enzymatic hydrolysis time is 4 hours, and the secondary enzymatic hydrolysis reaction product is filtered using a 3 kDa-30 kDa three-stage membrane, the filtration temperature is 10 ° C, the inlet pressure is 1 MPa, the equipment operating power is 50 Hz, and after the filtration, the secondary filtrate less than 10 kDa is retained, and the retentate greater than 10 kDa is retained for the third enzymatic hydrolysis;

[0046] (6) using 0.2 kg of a composite protease consisting of pepsin and trypsin to perform a third enzymatic hydrolysis on the two retained products larger than 10 kDa in step (5); after sufficient enzymatic hydrolysis, filtering is performed using a 3 kDa-30 kDa tertiary membrane, and retaining a tertiary filtrate with a size less than 10 kDa at the end of the filtration;

[0047] (7) combining the filtrate below 10 kDa obtained by three enzymatic hydrolysis and filtration and the oyster juice after enzymatic hydrolysis in step (4) to obtain an oyster enzymatic hydrolysis product, mixing the oyster enzymatic hydrolysis product and D-fucose in a mass ratio of 1:3 to carry out a Maillard reaction, wherein the reaction process is kept at a temperature of 150° C., a reaction time of 70 min, and a pH of 8.0 to obtain the oyster flavoring peptide

[0048] Example 2

[0049] This embodiment provides a process for producing oyster flavoring peptides, comprising the following steps:

[0050] (1) 20 kg of fresh oysters were shelled, cleaned and steamed for 7 min. After steaming, the oyster steaming juice was retained and immediately cooled with 0°C running water until the oysters entered the single freezing machine;

[0051] (2) the cooled oysters are spirally frozen at a freezing speed of 14.3 mm / min and a freezing temperature of -39°C until the center temperature of the oysters reaches -15°C and is completely frozen;

[0052] (3) extracting the frozen oysters at a temperature below 4°C and under spraying conditions, discarding the viscera of the oysters, retaining only the oyster meat and crushing it in an ice bath, and uniformly mixing the crushed oyster meat with purified water below 10°C at a material-liquid ratio of 1:7, and subjecting the lower layer of oyster meat sediment to sequential processing by a colloid mill and a high-pressure homogenizer;

[0053] (4) 0.6 kg of a composite protease composed of alkaline protease and neutral protease was mixed with the homogenized oyster meat sediment and the oyster cooking juice for enzymolysis for 4 hours, without inactivating the enzyme during the period, and after the enzymolysis reaction, the enzymolysis reaction products were filtered by a 3kDa-30kDa three-stage membrane filter, the filtration temperature was 25°C, the inlet pressure was 1Mpa, and the equipment operating power was 50Hz. The filtrate less than 10kDa of the two was retained, and the interception of the oyster meat sediment greater than 10kDa was retained for secondary enzymolysis;

[0054] (5) adding 0.6 kg of a composite protease composed of alkaline protease and neutral protease to the oyster meat sediment retentate greater than 10 kDa retained in step (4) for secondary enzymolysis, the enzymolysis time is 1 hour, and the secondary enzymolysis reaction product is filtered using a 3 kDa-30 kDa three-stage membrane, the filtration temperature is 50 ° C, the inlet pressure is 1 MPa, the equipment operating power is 50 Hz, and after the filtration, the secondary filtrate less than 10 kDa is retained, and the retentate greater than 10 kDa is retained for the third enzymolysis;

[0055] (6) using 0.3 kg of a composite protease consisting of alkaline protease and neutral protease to perform a third enzymatic hydrolysis on the two retained products larger than 10 kDa in step (5); after sufficient enzymatic hydrolysis, the products are filtered using a 3 kDa-30 kDa tertiary membrane, and after the filtration, the tertiary filtrate with a size less than 10 kDa is retained;

[0056] (7) combining the filtrate below 10 kDa obtained by three enzymatic hydrolysis and filtration and the oyster juice after enzymatic hydrolysis in step (4) to obtain an oyster enzymatic hydrolysis product, mixing the oyster enzymatic hydrolysis product and D-fucose in a mass ratio of 4:3 to carry out a Maillard reaction, wherein the reaction process is kept at a temperature of 120° C., the reaction time is 20 min, and the pH is 6.0 to obtain the oyster flavoring peptide

[0057] Example 3

[0058] This embodiment provides an oyster flavoring peptide, and its process method comprises the following steps:

[0059] (1) 20 kg of fresh oysters were shelled, cleaned and steamed for 10 min. After steaming, the oyster steaming juice was retained and immediately cooled with running water at 2°C until the oysters entered the single freezing machine;

[0060] (2) the cooled oysters are subjected to spiral freezing at a freezing speed of 18.3 mm / min and a freezing temperature of -40°C until the center temperature of the oysters reaches -18°C and is completely frozen;

[0061] (3) extracting the frozen oysters at a temperature below 4°C and under spraying conditions, discarding the viscera of the oysters, retaining only the oyster meat and crushing it in an ice bath, and uniformly mixing the crushed oyster meat with purified water below 10°C at a material-liquid ratio of 1:5, and subjecting the lower layer of oyster meat sediment to sequential processing by a colloid mill and a high-pressure homogenizer;

[0062] (4) 0.8 kg of a composite protease composed of papain and bromelain was mixed with the homogenized oyster meat sediment and the oyster cooking juice for enzymolysis for 5 hours, and the enzyme was not inactivated during the enzymolysis reaction. After the enzymolysis reaction, the enzymolysis reaction products were filtered using a 3kDa-30kDa three-stage membrane filter. The filtration temperature was 25°C, the inlet pressure was 1 MPa, and the equipment operating power was 50 Hz. The filtrate of the two with a mass less than 10 kDa was retained, and the retentate of the oyster meat sediment with a mass greater than 10 kDa was retained for secondary enzymolysis;

[0063] (5) adding 0.8 kg of a composite protease composed of papain and bromelain to the oyster meat sediment retentate greater than 10 kDa retained in step (4) for secondary enzymolysis, the enzymolysis time is 2 h, and the secondary enzymolysis reaction product is filtered using a 3 kDa-30 kDa three-stage membrane, the filtration temperature is 25 ° C, the inlet pressure is 1 MPa, the equipment operating power is 50 Hz, and after the filtration, the secondary filtrate less than 10 kDa is retained, and the retentate greater than 10 kDa is retained for the third enzymolysis;

[0064] (6) using 0.4 kg of a composite protease consisting of papain and bromelain to perform a third enzymatic hydrolysis on the two retained retentates greater than 10 kDa in step (5); after sufficient enzymatic hydrolysis, the retentates were filtered using a 3 kDa-30 kDa tertiary membrane, and the tertiary filtrate less than 10 kDa was retained after the filtration;

[0065] (7) combining the filtrate below 10 kDa obtained by three enzymatic hydrolysis and filtration and the oyster juice after enzymatic hydrolysis in step (4) to obtain an oyster enzymatic hydrolysis product, mixing the oyster enzymatic hydrolysis product and D-fucose in a mass ratio of 3:1 to carry out a Maillard reaction, wherein the reaction process is kept at a temperature of 70° C., the reaction time is 120 min, and the pH is 7.5 to obtain the oyster flavoring peptide

[0066] Performance Testing

[0067] 1. Gas chromatography-mass spectrometry detection

[0068] The corresponding test groups were prepared by preparing oyster flavor peptides of 3kDa-10kDa Maillard reaction at 0h, 1h, and 2h, and oyster flavor peptides of 10kDa-30kDa Maillard reaction at 0h, 1h, and 2h, respectively, and determined by headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). The relative content of each component was determined by the internal standard method, and the internal standard was used at a concentration of 9.4×10 -4 mg / mL of cyclohexanone. Headspace injection conditions: accurately draw 2.5mL of sample, crush it and place it in a 40mL headspace bottle, add 100μL of internal standard, cover and seal, and extract at 65℃ for 30min. After balancing in a magnetic stirrer at 65℃ for 10min, insert the extraction head into the headspace bottle, extract for 30min and inject, and analyze at 230℃ for 5min before taking out. Each component can be obtained by searching and analyzing the computer spectral library (NEST17), and compounds with a matching degree higher than 80% are selected. Two parallel measurements are made for each group of samples, and the average value is taken. The relative content of its flavor substances is calculated according to the following formula:

[0069]

[0070] Where: C x / (μg / mL) is the content of unknown flavor substances; C 0 / (mg / mL) is the mass concentration of internal standard cyclohexanone; V 0 / μL is the injection volume of internal standard cyclohexanone; S x is the peak area of ​​the unknown flavor substance; S 0 is the peak area of ​​the added internal standard cyclohexanone; m / (kg) is the mass of the added sample.

[0071] Test results such as Figure 1As shown in the figure, the types and contents of alcohols, aldehydes, esters, phenols and hydrocarbon compounds are dominant in the volatile compounds of flavoring peptides, and they work together to form the unique flavor of oyster flavoring peptides. Alcohols are mainly derived from the degradation of polyunsaturated fatty acids or the reduction of carbonyl compounds. Their threshold is relatively high and their contribution to the overall flavor of food is low. 1-Octene-3-ol is an unsaturated alcohol. Studies have found that 1-octen-3-ol is widely present in shellfish, has a mushroom and earthy smell, is a characteristic flavor substance of shellfish, and is related to the production of fishy smell. The contents of alcohol substances in the flavor components detected from the six groups of oyster flavoring peptides are 50.06, 11.97, 11.86, 28.71, 7.02, and 5.52 μg / kg, respectively. Compared with the 10kDa-30kDa oyster peptide group, the content of 1-octen-3-ol in the 3kDa-10kDa oyster peptide group is significantly reduced. The contents of aldehydes in the flavor components detected from the six groups of oyster flavor peptides were 102.31, 269.44, 379.88, 52.24, 206.90, and 225.81 μg / kg, respectively. It can be seen that after the Maillard reaction, the types and contents of aldehydes in oyster peptides increased, and the increase in the oyster peptide group with a molecular weight of 3kDa-10kDa was more obvious. The changes in aldehyde flavor compounds indicate that clam paste products can achieve the effect of covering the fishy smell and enhancing the aroma. Esters are a common and important compound with a distinct aromatic flavor. The smell in food is mainly fruity and floral, and can cover up the smell of corruption. The contents of esters in the flavor components detected from the six groups of oyster flavor peptides were 6.70, 3.91, 4.46, 1.22, 1.91, and 2.95 μg / kg, respectively. The esters detected in the 10kDa-30kDa oyster flavoring peptide group were significantly higher than those in the 3kDa-10kDa group, which had a certain effect on enhancing the flavor.

[0072] In addition, other types of compounds such as phenolic compounds, hydrocarbon compounds, amides, nitriles and furans were also detected. These substances have lower flavor thresholds and contribute relatively little to the flavor of oyster flavoring peptides.

[0073] 2. Absorbance detection

[0074] The oyster flavor peptide sample was evenly spread in a 96-well ELISA plate. Then, the ELISA plate was placed in an ELISA instrument and the wavelength was set to 420nm to detect the absorbance of the sample. By comparing the absorbance values ​​of different samples, their browning degree can be evaluated. The higher the browning degree, the greater the absorbance value. Finally, the browning of oyster flavor peptides during processing and storage was analyzed based on the changes in absorbance values.

[0075] like Figure 2As shown in the figure, the absorbance at 420nm of both 3-10kDa and 10-30kDa oyster flavoring peptides increased with the extension of Maillard reaction time. This indicates that as the reaction proceeds, more browning substances are generated, resulting in an increase in absorbance. At 2h, the absorbance of the 3-10kDa group

[0076] The absorbance of the peptides in the 10-30 kDa group (0.8479) was higher than that of the 10-30 kDa group (0.5864). This may indicate that peptides with smaller molecular weights are more active in the Maillard reaction and more likely to react with sugars.

[0077] 3. Electronic nose detection

[0078] The oyster flavor peptide sample was diluted in a certain ratio to simulate the concentration of the actual flavor substance. Then, the diluted sample was placed in the test chamber of the electronic nose to fully expose the sensor to the gas volatilized by the sample. The sensor responded to compounds of different molecular weights and recorded the response signal. Finally, the sensor signal was processed by data analysis software, and the response differences under different treatment conditions were compared to evaluate the flavor characteristics of the oyster flavor peptide.

[0079] like Figure 3 As shown in the figure, the W1C, W3C, W5C and W9W sensors responded significantly to the aromatic components in the samples, indicating that oyster flavor peptides may contain more obvious aromatic components and benzene compounds, which may be one of the unique flavors of oysters. The W5S sensor showed high sensitivity to nitrogen oxides, the W1W sensor had a good response to inorganic sulfides, and the W6S sensor responded selectively to hydrogen, indicating that oyster flavor peptides may contain nitrogen oxides and sulfides, which can bring specific flavor characteristics to oyster flavor peptides. The W1S and W2S sensors showed sensitivity to short-chain alkanes and alcohols, ethers, aldehydes, ketones, etc., respectively, indicating that oyster flavor peptides may contain compounds such as alcohols, ethers, aldehydes, and ketones, which are essential for the formation of complex flavor characteristics. The comprehensive response of these sensors reveals the complex flavor composition of oyster flavor peptides, including aromatic compounds, nitrogen oxides, sulfides and other flavor substances.

[0080] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0081] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments with equivalent changes without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A method for processing oyster flavoring peptide, characterized in that: The processing method uses fresh oyster meat as raw material, combines enzymatic hydrolysis and membrane filtration to process oyster meat liquid and oyster cooking juice for multiple times, then mixes the two evenly to obtain an oyster enzymatic hydrolysis product composed of small molecular active peptides, adds D-fucose to the oyster enzymatic hydrolysis product to form a Maillard reaction system, and obtains the oyster fresh and fragrant seasoning peptide after the reaction.

2. The method for processing oyster flavoring peptide according to claim 1, characterized in that: The processing method comprises the following steps: S1, using fresh oyster meat as raw material to steam and retain the oyster steaming juice, and then immediately cooling it with running water, and then placing it in a single freezer for batch spiral single freezing until the oysters are completely frozen, completing the shaping of the oysters; S2, discard the viscera of the oysters after shaping, keep the oyster meat and crush it in an ice bath, mix the crushed oyster meat with purified water evenly, discard the upper suspended matter after centrifugation, and process the lower oyster meat sediment in a colloid mill and a high-pressure homogenizer in turn; S3, mixing the composite protease with the homogenized oyster meat sediment and the oyster cooking juice for enzymatic hydrolysis, filtering the enzymatic hydrolysis products respectively with a three-stage membrane, retaining the filtrate less than 10 kDa from the two after the filtration, and retaining the retentate greater than 10 kDa from the oyster meat sediment for secondary enzymatic hydrolysis; S4, adding a composite protease to the oyster meat sediment retentate greater than 10 kDa retained in S3 for secondary enzymolysis, controlling the enzymolysis time to obtain a secondary enzymolysis reaction product, using a three-stage membrane to filter the secondary enzymolysis reaction product, retaining a secondary filtrate less than 10 kDa after filtration, and retaining a retentate greater than 10 kDa for tertiary enzymolysis; S5, using a composite protease to perform a third enzymatic hydrolysis on the retained product greater than 10 kDa in S4, adjusting the amount of enzyme added to perform sufficient enzymatic hydrolysis, using a three-stage membrane to filter the three enzymatic hydrolysis reaction products, and retaining the three filtrates less than 10 kDa after the filtration; S6. Combining the filtrate below 10 kDa obtained by three enzymatic hydrolysis and filtration and the oyster juice after enzymatic hydrolysis to obtain an oyster enzymatic hydrolysis product, adding D-fucose to the oyster enzymatic hydrolysis product for Maillard reaction, and obtaining the oyster flavoring peptide.

3. The method for processing oyster flavoring peptide according to claim 1, characterized in that: In the S1, the oyster cooking time is 5 to 10 minutes, the running water temperature is 0 to 4°C, the freezing speed of single freezing is 1.1 to 18.3 mm / min, the freezing temperature is -40 to -35°C, and the complete freezing of oysters means that the center temperature of the oysters reaches -18 to -7°C.

4. The method for processing oyster flavoring peptide according to claim 1, characterized in that: The temperature of the pure water in S2 is below 10° C., and the mass ratio of the mixed liquid of the crushed oyster meat and the pure water is 1:5-10.

5. The method for processing oyster flavoring peptide according to claim 1, characterized in that: The composite protease in S3 is one of pepsin, trypsin, alkaline protease, neutral protease, papain, bromelain or a combination of any two or more thereof. The usage amount of the composite protease is 2-5% of the mass of the oyster, and the enzymolysis time is 3-5 hours.

6. The method for processing oyster flavoring peptide according to claim 1, characterized in that: The filtration specifications of the three-stage membrane in S3 are 3kDa-10kDa, 10kDa-30kDa, and greater than 30kDa, the filtration temperature is 10-50°C, and the equipment operating power is 50Hz.

7. The method for processing oyster flavoring peptide according to claim 1, characterized in that: The composite protease in S4 is one of pepsin, trypsin, alkaline protease, neutral protease, papain, and bromelain, or a combination of any two or more thereof. The usage amount of the composite protease is 2-5% of the mass of the mixed liquid. The enzymolysis time is 1-4 hours. The filtration specifications of the tertiary membrane are 3kDa-10kDa, 10kDa-30kDa, and greater than 30kDa. The filtration temperature is 10-50°C, and the equipment operating power is 50Hz.

8. The method for processing oyster flavoring peptide according to claim 1, characterized in that: The added amount of the composite protease in the S5 is 1-2% of the mass of the oyster.

9. The method for processing oyster flavoring peptide according to claim 1, characterized in that: The mixing mass ratio of the oyster enzymatic hydrolysate and D-fucose in the S6 is 1:3-3:1, the insulation temperature of the Maillard reaction process is 70-130°C, the reaction time is 20-120min, and the pH is 6.0-8.

0.

10. An oyster flavoring peptide prepared according to the processing method according to any one of claims 1 to 9.

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