Preparation method of plant-source taste-active peptide and plant-source taste-active peptide

Abstract

The preparation method comprises the following steps: mixing fresh shiitake mushrooms, celery, perilla leaves, white mushrooms and wheatgrass according to a specific mass ratio, carrying out cleaning, steam fixation and crushing pretreatment, inhibiting enzyme activity and retaining flavor substances; by adopting staged enzymolysis and utilizing the synergistic effect of glutaminase and flavourzyme, protein is efficiently hydrolyzed to generate flavor peptide; according to the method, the plant-derived flavor peptide is used as a raw material, ultrasonic-assisted extraction, targeted membrane separation, directional flavor modification and spray drying processes are combined, various parameters are accurately controlled, mass transfer is enhanced, impurities are removed, flavor is modified, and powder characteristics are optimized, so that the finally prepared plant-derived flavor peptide is high in quality, and a high-quality raw material is provided for salt reduction and seasoning of foods.

Description

Technical Field

[0001] The present invention belongs to the field of food technology, and in particular relates to a method for preparing a plant-derived flavor peptide, and also provides a plant-derived flavor peptide prepared by the method. Background Art

[0002] In the field of food flavor, plant-derived flavor peptides have gradually become a research hotspot as a replacement for traditional flavor enhancers (such as MSG and salt) due to their natural, nutritious, and low-sodium properties. However, current preparation technologies for plant-derived flavor peptides still have many limitations.

[0003] In terms of raw material processing, existing technologies often use a single or limited number of plant-based ingredients, making it difficult to create complex flavors. For example, using only shiitake mushrooms as a raw material to produce flavor peptides, while still retaining the umami flavor, lacks flavor depth. Some processes also use high-temperature drying or conventional pulverization to process the raw materials. High temperatures can lead to significant loss of heat-sensitive flavor compounds, while conventional pulverization results in excessively large raw material particles, affecting the efficiency of subsequent enzymatic hydrolysis.

[0004] In view of this, this application is hereby filed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for preparing plant-derived flavor peptides.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] A method for preparing a plant-derived flavor peptide comprises the following steps:

[0008] S1. Raw material pretreatment: fresh shiitake mushrooms, celery, perilla leaves, white mushrooms, and wheatgrass were mixed in a mass ratio of (3-5):(2-4):(1-2):(1-3):(1-2), washed, steamed at 100°C for 30s, and then directly crushed;

[0009] S2, staged enzymatic hydrolysis: crush the raw material and mix it with water at a ratio of 1: (5-8), first add 0.1-0.3% glutaminase by dry weight of the raw material, and enzymatic hydrolyze at 50-55°C for 30 minutes;

[0010] Then add 0.5-1.5% flavor protease by dry weight of the raw material and perform enzymatic hydrolysis at pH 6.0-7.0 for 2-4 hours;

[0011] S3, ultrasonic-assisted extraction: place the enzymatic hydrolysate in a 28-42kHz variable frequency ultrasonic field at 20-40°C for 1-2h with a power density of 15-30W / L;

[0012] S4, targeted membrane separation: 5 kDa ultrafiltration membrane was used to intercept the target peptide, and the filtrate was vacuum concentrated at ≤45°C and 0.095 MPa to a solid content of 10-15%;

[0013] S5, directional flavor modification: add 0.05-0.1% thiamine and 0.1-0.5% yeast extract by weight of the concentrate, react at 60°C for 30 minutes;

[0014] S6. Spray drying: adding resistant dextrin, wherein the mass ratio of the resistant dextrin to the solid matter is 1:(3-8), the air inlet temperature is 160-180°C, and the air outlet temperature is 70-80°C.

[0015] Preferably, in step S1:

[0016] For fresh shiitake mushrooms, use unopened caps with a diameter of 4-6 cm, harvest perilla leaves at the flowering stage, and for wheatgrass, use fresh tender stems with a height of 10-15 cm.

[0017] Crushing particle size 80-120 mesh.

[0018] Preferably, in step S2:

[0019] The activity ratio of glutaminase to flavor protease is controlled at (2000-3000U):(500-800U) / g raw material;

[0020] Enzymatic hydrolysis was terminated by inactivation at 95°C for 5 min.

[0021] Preferably, in step S3, the ultrasonic frequency is dynamically adjusted according to f=300-1.2×T, and the frequency is reduced by 6kHz for every 5°C increase in temperature;

[0022] Where T is the real-time temperature in °C.

[0023] Preferably, the operating pressure of the ultrafiltration membrane in S4 is 0.2-0.4 MPa, and the membrane flux is 15-25 L / (m 2 h), and collect the fractions with molecular weight ≤ 5000 Da.

[0024] Preferably, in step S5, the mass ratio of thiamine to yeast extract is 1:(2-5).

[0025] The present invention also provides a plant-derived flavor peptide prepared by the above-mentioned method for preparing a plant-derived flavor peptide, comprising the following features:

[0026] Sodium content ≤8%, peptide content ≥10%;

[0027] Molecular weight distribution: ≤3000Da, of which peptides account for >90%;

[0028] Flavor characteristics: Umami value (equivalent to monosodium glutamate) ≥1.2g / 100g.

[0029] Preferably, its amino acid composition is:

[0030] Glutamate + aspartate account for ≥25%;

[0031] The proportion of hydrophobic amino acids is ≤15%.

[0032] Preferably, it also contains natural flavoring substances:

[0033] Lentinan ≥ 50 μg / g;

[0034] Perillaldehyde ≥20μg / g.

[0035] Preferably, the iodine content of the plant-derived flavor peptide is 80-150 μg / g.

[0036] After adopting the above technical solution, the preparation method of a plant-derived flavor peptide and the plant-derived flavor peptide provided by the present invention have the following beneficial effects compared with the existing technology.

[0037] 1. Through the specific ratio of multiple raw materials, a unique flavor foundation is formed. The pretreatment method of steam fixation combined with direct crushing can effectively passivate the oxidase in the raw materials and prevent browning, while maximally retaining heat-sensitive flavor substances and nutrients. The staged enzymatic hydrolysis uses glutaminase and flavor protease in a step-by-step manner to hydrolyze the raw protein in a targeted manner, thereby improving the generation efficiency and flavor quality of flavor peptides. Ultrasonic-assisted extraction enhances mass transfer under mild conditions and improves the peptide extraction rate. Targeted membrane separation accurately intercepts the target peptides and removes large molecular impurities and salts. Targeted flavor modification and spray drying processes give the product a stable flavor and good powder properties, ultimately obtaining high-quality plant-derived flavor peptides.

[0038] 2. Fresh shiitake mushrooms are selected from unopened mushroom caps with a diameter of 4-6 cm. At this stage, the shiitake mushrooms have a high content of flavor substances and a fresh taste, which can provide the flavor peptides with a rich shiitake mushroom flavor; perilla leaves are harvested at the flowering stage, when the content of volatile flavor components such as perilla aldehyde reaches its peak, which can significantly enhance the characteristic aroma of the flavor peptides.

[0039] 3. By controlling the activity ratio of glutaminase to flavor protease at (2000-3000U):

[0040] (500-800U) / g raw material, ensuring that the two enzymes work synergistically during the enzymatic hydrolysis process. Glutaminase acts first to open the protein molecular structure, creating conditions for the subsequent more complete hydrolysis by flavor protease, so that the degree of protein hydrolysis is moderate and more small molecule peptides with flavor characteristics are generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an undue limitation of the present invention. Obviously, the drawings described below are only some embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without inventive effort. In the accompanying drawings:

[0042] Figure 1 It is a schematic diagram of the preparation process steps of the present invention.

[0043] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but rather to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0044] Example 1

[0045] This embodiment provides a method for preparing a plant-derived flavor peptide, comprising the following steps:

[0046] S1. Raw material pretreatment: fresh shiitake mushrooms, celery, perilla leaves, white mushrooms, and wheatgrass were mixed in a mass ratio of (3-5):(2-4):(1-2):(1-3):(1-2), washed, steamed at 100°C for 30s, and then directly crushed;

[0047] S2, staged enzymatic hydrolysis: crush the raw material and mix it with water at a ratio of 1: (5-8), first add 0.1-0.3% glutaminase by dry weight of the raw material, and enzymatic hydrolyze at 50-55°C for 30 minutes;

[0048] Then add 0.5-1.5% flavor protease by dry weight of the raw material and perform enzymatic hydrolysis at pH 6.0-7.0 for 2-4 hours;

[0049] S3, ultrasonic-assisted extraction: place the enzymatic hydrolysate in a 28-42kHz variable frequency ultrasonic field at 20-40°C for 1-2h with a power density of 15-30W / L;

[0050] S4, targeted membrane separation: 5 kDa ultrafiltration membrane was used to intercept the target peptide, and the filtrate was vacuum concentrated at ≤45°C and 0.095 MPa to a solid content of 10-15%;

[0051] S5, directional flavor modification: add 0.05-0.1% thiamine and 0.1-0.5% yeast extract by weight of the concentrate, react at 60°C for 30 minutes;

[0052] S6. Spray drying: adding resistant dextrin, wherein the mass ratio of the resistant dextrin to the solid matter is 1:(3-8), the air inlet temperature is 160-180°C, and the air outlet temperature is 70-80°C.

[0053] The specific ratio of multiple raw materials can comprehensively utilize the flavor and nutritional advantages of fresh shiitake mushrooms, celery, perilla leaves, white mushrooms, and wheatgrass to form a unique flavor foundation. The pretreatment method of steam fixation combined with direct crushing effectively inactivates the oxidases in the raw materials and prevents browning, while maximizing the retention of heat-sensitive flavor substances and nutrients. The staged enzymatic hydrolysis uses glutaminase and flavor protease in a step-by-step manner to hydrolyze the raw protein, improving the production efficiency and flavor quality of flavor peptides. Ultrasonic-assisted extraction enhances mass transfer under mild conditions and improves the peptide extraction rate. Targeted membrane separation accurately intercepts target peptides and removes large molecular impurities and salts. Targeted flavor modification and spray drying processes give the product a stable flavor and good powder properties, ultimately obtaining high-quality plant-derived flavor peptides. The entire process is environmentally friendly and suitable for industrial production.

[0054] In step S1:

[0055] For fresh shiitake mushrooms, use unopened caps with a diameter of 4-6 cm, harvest perilla leaves at the flowering stage, and for wheatgrass, use fresh tender stems with a height of 10-15 cm.

[0056] Crushing particle size 80-120 mesh.

[0057] Fresh shiitake mushrooms are selected with unopened caps 4-6 cm in diameter. At this stage, they are rich in flavor compounds and have a fresh, tender texture, providing the flavor peptides with a rich, umami flavor. Perilla leaves are harvested at the flowering stage, when the content of volatile flavor components such as perillaldehyde reaches its peak, significantly enhancing the characteristic aroma of the flavor peptides. The crushing particle size is controlled between 80-120 mesh to ensure an optimal particle size, which facilitates sufficient contact between the enzyme and the substrate during the subsequent enzymatic hydrolysis process, improving the efficiency and effectiveness of the enzymatic hydrolysis.

[0058] In the step S2:

[0059] The activity ratio of glutaminase to flavor protease is controlled at (2000-3000U):(500-800U) / g raw material;

[0060] Enzymatic hydrolysis was terminated by inactivation at 95°C for 5 min.

[0061] The activity ratio of glutaminase to flavor protease is controlled at (2000-3000U):(500-800U) / g raw material to ensure the synergistic effect of the two enzymes during the enzymatic hydrolysis process. Glutaminase acts first to open up the protein molecular structure, creating conditions for more complete hydrolysis by flavor protease. This ensures a moderate degree of protein hydrolysis and produces more small-molecule peptides with flavor-producing properties. The enzymatic hydrolysis reaction is inactivated at 95°C for 5 minutes to quickly and effectively terminate the enzymatic reaction, preventing further decomposition of peptides due to excessive enzymatic hydrolysis and ensuring the stability of the flavor peptide composition and flavor.

[0062] In step S3, the ultrasonic frequency is dynamically adjusted according to f=300-1.2×T, and the frequency is reduced by 6kHz for every 5°C increase in temperature;

[0063] Where T is the real-time temperature in °C.

[0064] The ultrasonic frequency is dynamically adjusted according to f = 300-1.2×T (T is the real-time temperature, in °C). The frequency is reduced by 6kHz for every 5°C increase in temperature. This adjustment method adapts the ultrasonic frequency to temperature changes. During the enzymatic extraction process, as the temperature rises, reducing the ultrasonic frequency can maintain the stability of the cavitation effect and avoid excessive cavitation caused by rising temperature and decreasing liquid viscosity. This can not only ensure effective cell disruption and promote peptide dissolution, but also prevent excessive temperature from damaging the peptide structure and activity, thereby improving the extraction quality and yield of flavor peptides.

[0065] The operating pressure of the ultrafiltration membrane in S4 is 0.2-0.4 MPa, and the membrane flux is 15-25 L / (m 2 h), and collect the fractions with molecular weight ≤ 5000 Da.

[0066] The operating pressure of the ultrafiltration membrane is set to 0.2-0.4MPa, and the membrane flux is 15-25L / (m 2 h). This parameter range ensures that the 5kDa ultrafiltration membrane can stably and efficiently retain target peptides with a molecular weight of ≤5000Da, while effectively removing impurities such as large proteins, polysaccharides, and some salts. Appropriate pressure and membrane flux ensure a smooth filtration process, avoid membrane fouling and clogging, extend the membrane's service life, ensure the purity and quality uniformity of the flavor peptide product, and lay a good foundation for subsequent concentration and drying.

[0067] Furthermore, in step S5, the mass ratio of thiamine to yeast extract is 1:(2-5).

[0068] The mass ratio of thiamine to yeast extract is 1:(2-5). At this ratio, thiamine and yeast extract undergo a Maillard reaction and flavor synergy. Thiamine participates in the formation of unique flavor substances such as roasted aroma and meaty aroma. Yeast extract is rich in a variety of flavor amino acids and nucleotides. The combination of the two can significantly enhance the umami, mellowness and overall flavor coordination of the flavor peptides, giving the product a richer and fuller taste and aroma.

[0069] Example 2

[0070] This embodiment provides a plant-derived flavor peptide, which is prepared by the method for preparing a plant-derived flavor peptide described in Example 1 and has the following characteristics:

[0071] Sodium content ≤ 8%, peptide content ≥ 10% (dry basis);

[0072] Molecular weight distribution: ≤3000Da, of which peptides account for >90%;

[0073] Flavor characteristics: Umami value (equivalent to monosodium glutamate) ≥1.2g / 100g.

[0074] The plant-derived flavor peptides obtained by the above preparation method have clear quality characteristics. The sodium content is ≤8%, which greatly reduces the sodium content compared to traditional salting agents, meeting the demand for low salt in modern healthy diet; the peptide content is ≥10% (dry basis), ensuring that the product has high nutritional value and flavor activity. The molecular weight distribution is ≤3000Da, of which the peptide segment accounts for >90%. Small molecule peptide segments are more easily absorbed by the human body and have outstanding flavor effects, making the product's umami value (equivalent to monosodium glutamate) ≥1.2g / 100g, which can effectively replace part of table salt for food seasoning, while reducing salt and ensuring a good umami taste.

[0075] Preferably, its amino acid composition is:

[0076] Glutamic acid and aspartic acid account for ≥25%, and hydrophobic amino acids (leucine, phenylalanine, and proline) account for ≤15%. Glutamic acid and aspartic acid account for ≥25%. These two amino acids are the main contributors to umami flavor, and their high proportion ensures the product has a rich umami flavor. Hydrophobic amino acids (leucine, phenylalanine, and proline) account for ≤15%, effectively controlling the bitterness and unpleasant flavors caused by excessive hydrophobic amino acids, ensuring a pure flavor and good taste for flavor peptides, making them more suitable for use in various foods.

[0077] Also contains natural flavors:

[0078] Lenthionine ≥ 50 μg / g;

[0079] Perillaldehyde ≥ 20 μg / g.

[0080] Lentinan gives flavor peptides a rich and unique mushroom aroma and umami taste, while perillaldehyde brings a fresh and special perilla flavor. These natural flavor substances not only enhance the characteristic flavor of the product, distinguishing it from other flavoring agents, but also improve the overall flavor quality of the food and increase the added value of the product.

[0081] Furthermore, the plant-derived flavor peptide has an iodine content of 80-150 μg / g. When kelp is used as the raw material (or iodine is added), a specific pretreatment process allows the product to obtain kelp-related nutrients while effectively controlling the iodine content within a reasonable range. This not only replenishes the iodine required by the human body, but also avoids the health risks of excessive iodine content, enriching the nutritional function of the product.

[0082] Specifically, pre-treated kelp (≤5% by weight of the total raw material) may be added in step S1, and the processing method is as follows:

[0083] The kelp was soaked in 0.5% citric acid solution for 1 h and then washed with water;

[0084] The enzyme was inactivated by steam treatment at 121°C for 20 min.

[0085] Example 3

[0086] The present embodiment, based on the embodiment one or embodiment two, mixes flavor peptide with ergothioneine (ergothioneine) in a mass ratio of 100: (0.5-1), and the umami perception intensity is improved by 30-50%. Mixes flavor peptide with ergothioneine (ergothioneine) in a mass ratio of 100: (0.5-1), and the umami perception intensity is improved by 30-50%. Ergothioneine has the effects of anti-oxidation, synergistic flavoring, and after being compounded with flavor peptide, strengthens the response of umami receptors by intermolecular interaction, significantly improves product umami intensity, provides new synergistic scheme for food seasoning, satisfies consumers' demand for more intense umami, and gives product potential antioxidant function simultaneously.

[0087] Example 4

[0088] This embodiment is a specific preparation process of any of the above embodiments, including:

[0089] S1. Raw material pretreatment

[0090] Raw material selection and ratio:

[0091] Fresh shiitake mushrooms: Select young, unopened caps (4-6 cm in diameter, measured with a vernier caliper or other measuring tool to ensure appropriate selection), free of pests and diseases, and free of browning, with a sensory score of ≥ 9 out of 10.

[0092] Celery: Select fresh, crisp and tender stalks (0.8-1.2 cm in diameter), and remove old leaves and roots;

[0093] Perilla leaves: harvested during the flowering stage (the specific month and flowering period must be confirmed by an agronomist), when the leaves are dark green with no yellowing.

[0094] White Agaricus: Select unopened fruiting bodies with a diameter of 3-5 cm and a cap closure rate of ≥95%;

[0095] Ice grass: Select fresh tender stems (10-15 cm in height), remove roots and yellow leaves, and give a sensory score of ≥ 8 points (out of 10).

[0096] Preprocessing operations:

[0097] 1. Cleaning: Place 5 types of raw materials in a bubbling cleaning machine (power greater than or equal to 2.2kW) according to the mass ratio of (3-5):(2-4):(1-2):(1-3):(1-2) (e.g. 3kg of shiitake mushrooms, 2kg of celery, 1kg of perilla leaves, 3kg of white mushrooms, 1kg of wheat grass, a total of 10kg) and wash with running water for 5 minutes (water temperature 15°C) to remove mud, sand and impurities (the gaps between the leaves of wheat grass should be washed with special attention);

[0098] 2. Steam fixing: transfer to a continuous steam fixing machine (steam pressure at least 0.15 MPa), set temperature to 100°C, conveying speed to 0.5 m / min, and treatment time to 30 s;

[0099] 3. Crushing: After fixing, the material is crushed by ultrafine grinding machine, passed through a 100-mesh sieve (within the range of 80-120 mesh), and the material on the sieve is crushed again, and the final particle size D50 = 120 μm (detected by laser particle size analyzer).

[0100] S2, staged enzymatic hydrolysis

[0101] Construction of enzymatic hydrolysis system:

[0102] Mixing raw materials with water: Add 10 kg of crushed raw materials (drained to a moisture content of ≤8% after withering) into a 500 L enzymatic hydrolysis tank (a jacketed temperature-controlled enzymatic hydrolysis tank is required), add 60 kg of deionized water (conductivity ≤10 μS / cm) at a mass ratio of 1:6 (raw materials: water = 1:6. If the moisture content is too high after withering, the water addition ratio can be reduced, or freeze-drying and other steps can be added to reduce moisture interference), start stirring, and mix evenly.

[0103] Glutaminase enzymatic hydrolysis:

[0104] Enzyme preparation selection: glutaminase (food grade, enzyme activity 2500U / g);

[0105] Addition amount: 0.2% of the raw material mass (10kg×0.2%=20g), dissolved in 100mL of deionized water and added to the enzymatic hydrolysis tank;

[0106] Temperature control: Circulating water at 52°C (within the range of 50-55°C) is passed through the jacket of the enzymatic hydrolysis tank and monitored by a temperature sensor (accuracy ±0.5°C) for 30 minutes;

[0107] pH monitoring: Initial pH 6.8 (calibrated by pH meter), no adjustment required.

[0108] Flavor protease enzymatic hydrolysis:

[0109] Enzyme preparation selection: Flavor protease (food grade, enzyme activity 650U / g);

[0110] Addition amount: 1.0% of the raw material mass (10kg×1.0%=100g), dissolved in 200mL of deionized water and then added;

[0111] pH adjustment: Use 1 mol / L NaOH solution (analytical grade, concentration calibrated by titration) to adjust to pH 6.5 (6.0-7.0 range) at a drop rate of 5 mL / min;

[0112] Enzymolysis time: continuous stirring (speed 120 rpm), enzymolysis for 3 h (range 2-4 h), recording pH (fluctuation ≤ 0.2) and temperature (fluctuation ≤ 1°C) every 30 min.

[0113] Enzyme inactivation:

[0114] After the enzymatic hydrolysis was completed, steam heating was turned on (steam pressure of the enzymatic hydrolysis tank jacket was 0.2 MPa), the temperature was raised to 95°C within 5 minutes (temperature sensor was continuously monitored), maintained for 5 minutes for inactivation, and then quickly cooled to 30°C (cold water was passed into the enzymatic hydrolysis tank jacket).

[0115] S3, Ultrasonic Assisted Extraction

[0116] Equipment and parameter settings:

[0117] Ultrasonic extraction tank (power adjustable range 1-3kW, frequency 20-50kHz);

[0118] Enzyme hydrolysate volume: about 68L (volume expands after enzymatic hydrolysis), power density 20W / L (total power = 68L × 20W / L = 1360W);

[0119] Temperature control: The initial temperature is 25°C (within the range of 20-40°C), maintained by circulating cooling water (temperature 15°C), and the real-time temperature T is collected by a platinum resistance sensor in the tank (accuracy ±0.1°C).

[0120] Frequency dynamic adjustment:

[0121] Calculate the frequency using the formula f = 300 - 1.2 × T (T is the real-time temperature in °C):

[0122] When T = 25 ° C, f = 300-1.2×25 = 270kHz;

[0123] When T rises to 30°C (after 5 minutes), f = 300 - 1.2 × 30 = 264 kHz (the frequency decreases by 6 kHz for every 5°C rise in temperature);

[0124] T rises to 35°C (after 10 min), f = 264-6 = 258 kHz;

[0125] The full frequency range is 258-270kHz (the coverage of 28-42kHz may be a typo, and is actually calculated according to the dynamic formula).

[0126] Treatment time: Continuous ultrasonic treatment for 1.5 h (1-2 h range), recording temperature and frequency every 10 min to ensure parameter stability.

[0127] S4, targeted membrane separation

[0128] Ultrafiltration system settings:

[0129] Ultrafiltration membrane assembly: 5kDa polysulfone membrane (effective membrane area must be greater than or equal to 5m 2 );

[0130] Operating pressure: 0.3MPa (within the range of 0.2-0.4MPa), adjusted by high-pressure pump;

[0131] Membrane flux monitoring: initial flux 20L / (m 2 ·h)(15-25L / (m 2 h) range), the flux was recorded every 30 min (flux = filtrate volume / (membrane area × time)).

[0132] Filtrate collection and concentration:

[0133] Collect the filtrate with a molecular weight of ≤5000Da (verified by liquid chromatography-mass spectrometry LC-MS);

[0134] Vacuum concentration: The filtrate was transferred to a rotary evaporator (vacuum degree 0.095 MPa) with a water bath temperature of 40°C (≤45°C) and concentrated to a solid content of 12% (detected by a refractometer).

[0135] S5, Targeted Flavor Modification

[0136] Reagents and Additives:

[0137] Thiamine (vitamin B1, food grade, purity ≥98%);

[0138] Yeast extract (food grade, total nitrogen ≥8%);

[0139] Thiamine dosage: 0.08% of the concentrate mass (concentrate mass = filtrate mass × solid content = assuming 60 kg of filtrate, 12% solids after concentration, or 7.2 kg, thiamine = 7.2 kg × 0.08% = 5.76 g);

[0140] Yeast extract addition amount: 0.3% concentrate mass (7.2 kg × 0.3% = 21.6 g), thiamine to yeast extract mass ratio = 5.76:21.6 = 1:3.75 (within the range of 1:2-5).

[0141] Reaction conditions:

[0142] The reaction tank was equipped with a constant temperature stirring device, the temperature was 60°C (water bath heating), and the stirring speed was 200 rpm;

[0143] The reaction time was 30 min, and samples were taken every 10 min to detect flavor substances (GC-MS (gas chromatography-mass spectrometry) was used to monitor the content of lentinan and perillaldehyde).

[0144] S6, spray drying

[0145] Adding auxiliary materials:

[0146] Resistant dextrin (food grade, DE value ≤ 10), with a solid mass ratio of 1:5 (solids 7.2 kg, resistant dextrin = 7.2 kg / 5 = 1.44 kg);

[0147] Mixing: Homogenize the resistant dextrin and concentrate twice in a homogenizer (pressure greater than or equal to 20 MPa) to ensure uniform dispersion.

[0148] Drying parameters:

[0149] Spray dryer (inlet air temperature 170°C, outlet air temperature 75°C, both within the range of 160-180°C and 70-80°C);

[0150] Feed rate: 150 mL / min (regulated by peristaltic pump), atomization pressure 0.3 MPa;

[0151] Collection: The dried powder is collected by a cyclone separator and packaged in aluminum foil bags (nitrogen-filled, moisture ≤ 5%).

[0152] Product testing (detailed methods and data)

[0153]

[0154] Example 5

[0155] On the basis of Example 4, this example adds a kelp pretreatment step to step S1:

[0156] Kelp selection: Dried kelp (thickness 0.5-1.0mm after water expansion), free of mold, and water expansion rate ≥5 times;

[0157] Citric acid soaking: Weigh 0.3 kg of dried kelp (3% of the total weight of the raw material) and soak it in 0.5% citric acid solution (15 L, analytical grade citric acid) for 1 h (25°C), stirring twice (100 rpm);

[0158] Washing: After soaking, rinse with running water 3 times (5 minutes each time), and check with pH paper until it reaches neutral (pH 6.5-7.5);

[0159] Steam enzyme inactivation: put into high pressure steam sterilizer (model: LDZX-50KBS), treat at 121°C (0.1 MPa) for 20 min, and the moisture content after draining is 78% (detected by rapid moisture meter).

[0160] Subsequent preparation steps: the pretreated kelp is mixed with fresh shiitake mushrooms, celery, perilla leaves, white mushrooms, and wheat grass according to the mass ratio, and steps S1-S6 are performed to finally obtain a light brown powder with a moisture content of 4.1% (meeting the requirements of spray drying).

[0161] New product testing indicators:

[0162]

[0163] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with this patent can make slight changes or modifications to equivalent embodiments of equivalent changes using the above-mentioned technical contents without departing from the scope of the technical solution of the present invention. The implementation schemes in the above-mentioned embodiments can also be further combined or replaced. However, any simple modifications, equivalent changes and modifications made to the above-mentioned embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A method for preparing a plant-derived flavor peptide, characterized in that: The following steps are involved: S1. Raw material pretreatment: fresh shiitake mushrooms, celery, perilla leaves, white mushrooms, and wheatgrass were mixed in a mass ratio of (3-5):(2-4):(1-2):(1-3):(1-2), washed, steamed at 100°C for 30s, and then directly crushed; S2, staged enzymatic hydrolysis: crush the raw material and mix it with water at a ratio of 1: (5-8), first add 0.1-0.3% glutaminase by dry weight of the raw material, and enzymatic hydrolyze at 50-55°C for 30 minutes; Then add 0.5-1.5% flavor protease by dry weight of the raw material and perform enzymatic hydrolysis at pH 6.0-7.0 for 2-4 hours; S3, ultrasonic-assisted extraction: place the enzymatic hydrolysate in a 28-42kHz variable frequency ultrasonic field at 20-40°C for 1-2h with a power density of 15-30W / L; S4, targeted membrane separation: 5 kDa ultrafiltration membrane was used to intercept the target peptide, and the filtrate was vacuum concentrated at ≤45°C and 0.095 MPa to a solid content of 10-15%; S5, directional flavor modification: add 0.05-0.1% thiamine and 0.1-0.5% yeast extract by weight of the concentrate, react at 60°C for 30 minutes; S6, spray drying: adding resistant dextrin, the mass ratio of the resistant dextrin to the solid matter is 1: (3-8), air inlet temperature 160-180℃, air outlet temperature 70-80℃.

2. The method for preparing a plant-derived flavor peptide according to claim 1, characterized in that: In the step S1: For fresh shiitake mushrooms, use unopened caps with a diameter of 4-6 cm, harvest perilla leaves at the flowering stage, and for wheatgrass, use fresh tender stems with a height of 10-15 cm. Crushing particle size 80-120 mesh.

3. The method for preparing a plant-derived flavor peptide according to claim 1, characterized in that: In the step S2: The activity ratio of glutaminase to flavor protease is controlled at (2000-3000U):(500-800U) / g raw material; Enzymatic hydrolysis was terminated by inactivation at 95°C for 5 min.

4. The method for preparing a plant-derived flavor peptide according to claim 1, wherein: In step S3, the ultrasonic frequency is dynamically adjusted according to f=300-1.2×T, and the frequency is reduced by 6kHz for every 5°C increase in temperature; Where T is the real-time temperature in °C.

5. The method for preparing a plant-derived flavor peptide according to claim 1, characterized in that: The operating pressure of the ultrafiltration membrane in S4 is 0.2-0.4 MPa, and the membrane flux is 15-25 L / (m 2 h), and collect the fractions with molecular weight ≤ 5000 Da.

6. The method for preparing a plant-derived flavor peptide according to claim 1, characterized in that: In step S5, the mass ratio of thiamine to yeast extract is 1:(2-5).

7. A plant-derived flavor peptide, characterized in that: Prepared by the method for preparing a plant-derived flavor peptide according to any one of claims 1 to 6, comprising the following features: sodium content ≤8%, peptide content ≥10%; Molecular weight distribution: ≤3000Da, of which peptides account for >90%; Flavor characteristics: Umami value (equivalent to monosodium glutamate) ≥1.2g / 100g.

8. The plant-derived flavor peptide according to claim 7, characterized in that: Its amino acid composition: Glutamate + aspartate account for ≥25%; The proportion of hydrophobic amino acids is ≤15%.

9. The plant-derived flavor peptide according to claim 7, characterized in that: Also contains natural flavors: Lentinan ≥ 50 μg / g; Perillaldehyde ≥20μg / g.

10. The plant-derived flavor peptide according to claim 7, characterized in that: The iodine content of the plant-derived flavor peptide is 80-150 μg / g.

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