Oyster powder and preparation method thereof

Abstract

The invention discloses oyster powder and a preparation method thereof, and belongs to the technical field of seasonings. According to the preparation method disclosed by the invention, the crushed oyster meat is subjected to enzymolysis, meanwhile, fermentation is combined with a compound bacterium preparation, blending is performed after fermentation is finished, the oyster meat is mixed with a modified starch aqueous solution, and then spray drying is performed, so that macromolecular protein in the oyster meat can be effectively decomposed into micromolecular oyster peptide which is easily absorbed by a human body, and the health-care function can be enhanced while the flavor is improved; the problems that the oyster powder becomes bitter and the yield is reduced due to the wall hanging phenomenon of the oyster juice can be solved, meanwhile, the storage performance of the oyster powder can be effectively improved through products in the fermentation process, the problem that grease is prone to deterioration in the storage process is solved, and the shelf life of the oyster powder is remarkably prolonged. Besides, the preparation method of the oyster powder provided by the invention does not need a step of jacketed kettle concentration in a traditional process, can effectively save energy, improves the production efficiency, and is beneficial to actual industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of condiments, and in particular relates to oyster powder and a preparation method thereof. Background Art

[0002] Oyster powder is rich in protein, amino acids (such as arginine, glutamic acid, etc.), vitamins (such as vitamin B, vitamin C, vitamin E, etc.) and minerals (such as calcium, iron, zinc, selenium, etc.). Oyster peptides have many functions such as improving immunity, improving liver function, promoting blood circulation, enhancing bone health, and assisting in improving anemia and sleep quality. Oyster powder has a unique seafood flavor and can be used as a seasoning in food to add a delicious taste and aroma to food. Traditional oyster powder is prepared by steaming, filtering, concentrating, and spraying. Specifically, S1. Wash the fresh oysters, take out the meat, add water to the oyster meat and heat it, extract the oyster soup, and filter it (wherein, the mass ratio of oyster meat to water is 1:0.2; the heating temperature can be 100-102°C, and after boiling for 3-5 minutes, stop heating and filter with a 120-mesh filter to remove impurities and oyster shells); S2. Concentrate the filtered oyster soup to obtain oyster juice (sandwich pot concentration method, heat the oyster soup to raise the temperature of the oyster soup to 100-102°C, and let the oyster soup concentrate to a solid concentration of 32-34% under boiling conditions); S3. Sterilize the obtained oyster juice (temperature 100-102°C, time 15-20 minutes); S4. Spray dry the oyster juice that has passed the physical and chemical test to obtain oyster powder (put the oyster juice into a storage tank, store it in a hopper). The outlet of the material tank is connected to the inlet of the pump. Before the spray drying starts, water is sprayed on the atomizing disk to reduce the temperature of the atomizing disk. The oyster juice is pumped from the material storage tank into the high-speed atomizer through a screw pump. The oyster juice is atomized into a mist group at high speed in the drying tower. The atomizer is driven by an electric motor. The speed of the atomizing disk is 18000r / min. The normal temperature air is filtered through the filter and sent to the steam heat exchanger by the blower for heat exchange. The normal temperature air is heated to 160-170℃ by 0.8MPa steam and electric compensation heating. The heated hot air enters the drying tower through a logarithmic spiral and contacts with the oyster juice mist group, so that the water content of the oyster juice evaporates rapidly to become dry oyster powder. The oyster powder is collected through the collecting valve. After the spray drying is completed, the pump, pipeline and atomizing disk are cleaned in time.

[0003] However, there are many problems in the above-mentioned traditional oyster powder preparation process. First, in step S1, a large amount of oyster meat and nutrients cannot be completely dissolved into the oyster soup, resulting in waste; second, the concentration time of the sandwich pot concentration method in step S2 is relatively long, and the temperature is too high, which wastes energy and also causes loss of the flavor of the oyster powder; third, in the traditional process step S4, the oyster juice is not pre-treated, and it is easy to stick to the wall during the powder spraying process, which can easily lead to the bitterness of the oyster powder, reduced yield, and easy agglomeration in subsequent storage; fourth, the oil in the traditional oyster powder is easy to deteriorate during storage, that is, the shelf life is short. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide an oyster powder which is simple to prepare, has a high nutrient content, a good taste and excellent storage performance, and a preparation method thereof.

[0005] To achieve the above object, in a first aspect of the present invention, the present invention provides a method for preparing oyster powder, the preparation method comprising the following steps:

[0006] (1) adding an enzyme preparation to the crushed oyster meat for enzymolysis, and then killing the enzyme to obtain an enzymolysis solution;

[0007] (2) adding the composite bacterial preparation to the enzymatic hydrolyzate for fermentation, filtering after the fermentation is completed, and collecting the filtrate;

[0008] (3) adding modified starch aqueous solution to the prepared filtrate and mixing evenly, followed by spray drying to obtain oyster powder;

[0009] The enzyme preparation includes protease and lipase;

[0010] The composite bacterial preparation comprises Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus.

[0011] The present invention performs enzymatic hydrolysis on the crushed oyster meat, combines with composite bacterial preparation fermentation, and prepares after the fermentation is completed and spray-dried after mixing with modified starch aqueous solution, which can effectively decompose the macromolecular protein in the oyster meat into small molecular oyster peptides that are beneficial to human absorption, improve the flavor and enhance the health care function; and can reduce the problem of bitterness of oyster powder and reduced yield caused by the wall hanging phenomenon of oyster juice, and the product in the fermentation process can also effectively improve the storage performance of oyster powder, avoid the problem of easy deterioration of oil during storage, and significantly extend the shelf life of oyster powder. In addition, the preparation method of oyster powder provided by the present invention does not require the step of sandwich pot concentration in the traditional process, can effectively save energy, improve production efficiency, and is conducive to actual industrial production.

[0012] As a preferred embodiment of the preparation method of the present invention, the mass percentage of the enzyme preparation is 0.1-0.4% based on the mass of the crushed oyster meat.

[0013] For example, based on the mass of the crushed oyster meat, the mass percentage of the enzyme preparation can be any point value or any two point range values ​​between 0.1-0.4%, such as 0.1%, 0.2%, 0.3%, 0.4%, etc.

[0014] As a preferred embodiment of the preparation method of the present invention, the temperature of the enzymatic hydrolysis is 55-57° C. and the time is 2-2.5 h.

[0015] Exemplarily, the temperature of the enzymatic hydrolysis can be any point value or any two points in the range of 55-57°C, such as 55°C, 56°C, 57°C, etc.; the time can be any point value or any two points in the range of 2-2.5h, such as 2h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, etc.

[0016] The present invention has found that the amount of enzyme preparation added and the temperature and time of enzymatic hydrolysis will affect the content of amino acid nitrogen and sensory evaluation in the prepared oyster powder. When the amount of enzyme preparation added and the temperature and time of enzymatic hydrolysis are further selected within the above range, the comprehensive performance of the obtained oyster powder is better.

[0017] As a preferred embodiment of the preparation method of the present invention, the mass percentage of lipase is 10-15% based on the mass of protease.

[0018] For example, based on the mass of protease, the mass percentage of lipase can be any point value between 10-15% or any two points in the range, such as 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0019] The present invention has found that the protease and lipase in the enzyme preparation have a good synergistic effect, especially when the mass relationship between the two is selected within the above range, the amino acid nitrogen content in the obtained oyster powder is higher and the sensory score is also better.

[0020] As a preferred embodiment of the preparation method of the present invention, the protease includes at least one of papain, trypsin, acid protease, alkaline protease and composite protease.

[0021] As a preferred embodiment of the preparation method of the present invention, the temperature for inactivating the enzyme is 95-105° C., and the time for inactivating the enzyme is 25-30 minutes.

[0022] As a preferred embodiment of the preparation method of the present invention, the mass percentage of the composite bacteria preparation is 0.1-0.3% based on the mass of the enzymatic hydrolysate.

[0023] For example, based on the mass of the enzymatic hydrolysate, the mass percentage of the composite bacterial preparation can be any point value or any two point range values ​​between 0.1-0.3%, such as 0.1%, 0.2%, 0.3%, etc.

[0024] As a preferred embodiment of the preparation method of the present invention, the fermentation temperature is 38-45°C and the fermentation time is 45-55h.

[0025] Exemplarily, the fermentation temperature can be any point value or any two points in the range between 38-45°C, such as 38°C, 40°C, 42°C, 45°C, etc.; the fermentation time can be any point value or any two points in the range between 45-55h, such as 45h, 48h, 50h, 52h, 55h, etc.

[0026] As a preferred embodiment of the preparation method of the present invention, the mass ratio of Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus is (1.5-2.5):1:1.

[0027] Exemplarily, the mass ratio of Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus can be any point value or any two point range values ​​between (1.5-2.5):1:1, such as 1.5:1:1, 2:1:1, 2.5:1:1, etc.

[0028] The present invention has found that the mass ratio of bacteria in the composite bacterial preparation during the fermentation process, the addition amount, the fermentation temperature, time, etc. will affect the content of amino acid nitrogen in the oyster powder, and will also affect the storage performance of the oyster powder; when the addition amount of the composite bacterial preparation and the mass ratio of the components are further selected within the above range, and the fermentation temperature and time are within the above range, the comprehensive performance of the obtained oyster powder is better.

[0029] Exemplarily, the preservation number of the Lactobacillus casei is CICC6144, the preservation number of the Lactobacillus bulgaricus is CICC6047, and the preservation number of the Streptococcus thermophilus is CICC6038.

[0030] As a preferred embodiment of the preparation method of the present invention, the mass percentage of the modified starch in the modified starch aqueous solution is 2-4% based on the mass of the solid matter in the filtrate.

[0031] For example, based on the mass of solid matter in the filtrate, the mass percentage of modified starch in the modified starch aqueous solution can be any point value between 2-4% or any two points in the range, such as 2%, 3%, 4%, etc.

[0032] The present invention has found that when the mass percentage of modified starch in the modified starch aqueous solution is within the above range, based on the mass of solids in the filtrate, the coating effect on the fermented oyster juice can be effectively enhanced, avoiding the problem of bitterness and yield reduction of oyster powder caused by wall adhesion in subsequent treatment, as well as the problem of decreased storage performance caused by agglomeration of oyster powder.

[0033] As a preferred embodiment of the preparation method of the present invention, in the modified starch aqueous solution, the mass ratio of modified starch to water is 1:(4-6).

[0034] For example, in the modified starch aqueous solution, the mass ratio of modified starch to water can be any point value or any range value between 1:(4-6), such as 1:4, 1:5, 1:6, etc.

[0035] As a preferred embodiment of the preparation method of the present invention, the modified starch includes potato carboxymethyl modified starch.

[0036] The present invention has found that the potato carboxymethyl modified starch has excellent dispersion stability and good film-forming properties, and can well improve the wall adhesion phenomenon in the subsequent spray drying and the moisture absorption phenomenon in the storage, thereby effectively improving the yield of oyster powder and the storage stability of oyster powder.

[0037] As a preferred embodiment of the preparation method of the present invention, the filtration includes firstly performing a primary filtration, then collecting the primary filtration filtrate, grinding it, and then performing a fine filtration.

[0038] Preferably, the primary filtration is performed using a 30-50 mesh filter; and the fine filtration is performed using a 100-150 mesh filter.

[0039] As a preferred embodiment of the preparation method of the present invention, the blending is performed by adding condiments such as salt, sugar, and spices.

[0040] Preferably, after testing the solid content in the filtrate, based on the mass of the solids, the mass percentage of salt is 18-22%, and the mass percentage of sugar is 4-6%.

[0041] Preferably, the solid content in the filtrate after formulation is ≤35%.

[0042] As a preferred embodiment of the preparation method of the present invention, the spray drying parameters are: inlet air temperature: 165-170°C, feed pump speed: 26-32, atomizer rate: 70%, air hammer: 5s / time.

[0043] Preferably, the spray drying process is as follows: 1) after starting up, first turn on the induced draft fan, set the inlet air temperature and preheat; 2) when the outlet air temperature reaches 95°C, turn on the feed pump and the atomizer and introduce clean water for adjustment; 3) when the outlet air temperature drops to 85°C, introduce the liquid to be spray-dried and start the air hammer (the outlet air temperature is related to the feed speed and the moisture content of the material, and the outlet air temperature of the spray oyster powder should be controlled at 85-90°C; 4) collect the material at the receiving port.

[0044] In a second aspect of the present invention, the present invention provides an oyster powder, which is prepared by the preparation method of the present invention.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] In the first aspect, the present invention can effectively decompose the macromolecular protein in the oyster meat into small molecular substances such as oyster peptides, amino acids, lactic acid, etc. that are beneficial to human absorption by improving the flavor while facilitating human absorption, and can also extend the storage period of oyster powder by enzymolysis of the crushed oyster meat and fermenting the composite bacterial preparation, and then mixing the mixture with a modified starch aqueous solution after the fermentation is completed and spray-dried.

[0047] Secondly, compared with the problem of low utilization rate of oyster meat in the traditional boiling process of oyster powder, the preparation method provided by the present invention uses specific enzymes for enzymatic hydrolysis and uses specific composite bacterial preparations for fermentation, which can effectively improve the utilization rate of oyster meat. Compared with the traditional boiling process, the utilization rate of oyster meat is increased by 20-30%, and the amino acid nitrogen content in the obtained oyster powder is increased by more than two times;

[0048] Thirdly, compared with traditional boiling and concentration, the method of combining enzymatic hydrolysis and fermentation provided by the present invention avoids long-term high-temperature boiling and concentration, can save energy and improve production efficiency;

[0049] Fourthly, the present invention can effectively avoid the problem of oyster powder easily sticking to the wall and affecting the flavor, production and storage agglomeration by evenly mixing the modified starch aqueous solution and the filtrate and then spray-drying. After adopting the method provided by the present invention, the wall sticking phenomenon during spray drying is reduced by 50-60%, and the water absorption rate of the prepared oyster powder is reduced by 70-80% compared with the oyster powder prepared by the traditional method. DETAILED DESCRIPTION

[0050] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0051] Unless otherwise specified, the reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in the art; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch of raw materials.

[0052] Example 1

[0053] The embodiment of the present invention provides an oyster powder, and the preparation method of the oyster powder comprises the following steps:

[0054] (1) taking 10 kg of frozen oyster meat and naturally slowing it down at room temperature, and then crushing it with a wall-breaking machine until there are no large pieces of oyster meat visible to the naked eye, thereby obtaining crushed oyster meat;

[0055] (2) Put the prepared oyster meat into an iron bucket of suitable size, add 34g of enzyme preparation (18g of papain, 12g of alkaline protease, and 4g of lipase), stir evenly, put it into a water bath and stir it with an electric stirrer (the water bath temperature is set to 57°C, the speed of the electric stirrer is set to 500r / min, and the timing starts when the water bath temperature reaches 56°C for 2h. During the enzymatic hydrolysis process, cover the bucket mouth with plastic wrap to prevent excessive evaporation of water);

[0056] (3) Inactivation of enzymes and sterilization: the enzymatic solution after enzymatic hydrolysis is placed in a water bath, stirred and heated to inactivate enzymes and sterilize (the water bath temperature is set to 100°C, and the timing starts when the displayed temperature reaches 95°C for 28 minutes);

[0057] (4) Fermentation: adding a composite bacterial preparation (Lactobacillus casei, Lactobacillus bulgaricus, and Streptococcus thermophilus in a mass ratio of 2:1:1) to the sterilized enzymatic hydrolysate in an amount of 0.2% of the mass of the sterilized enzymatic hydrolysate, and fermenting at 40° C. for 2 days;

[0058] (5) Filtering through a colloid mill: First, the fermented enzymatic hydrolysate is filtered through a 40-mesh sieve to remove the oyster shells and sediment remaining in the oyster meat, and then filtered through a 100-mesh sieve again after passing through a colloid mill to obtain a fermented enzymatic hydrolysate in a better state;

[0059] (6) Preparation: measuring the water content of the fermented enzymatic hydrolysate, and adding salt and sugar according to the solid content of the fermented enzymatic hydrolysate (solid content is 20%) for preparation, wherein the amount of salt added is 20% of the solid content, and the amount of sugar added is 5% of the solid content (the total solid content of the oyster juice after compounding is controlled to be less than 35%), to obtain compounded oyster juice;

[0060] (7) Modified starch embedding: adding a potato carboxymethyl modified starch aqueous solution to the oyster juice and mixing evenly (wherein, based on the solid content in the enzymatic hydrolyzate after fermentation, the mass percentage of the potato carboxymethyl modified starch is 3%, and the mass ratio of the potato carboxymethyl modified starch aqueous solution to water in the aqueous solution is 1:5), and then embedding is performed by spray drying;

[0061] (8) Powder spraying and collection: An experimental high-speed centrifugal atomizing spray dryer was used, and the parameters were set to be: inlet air temperature: 165-170°C, feed pump speed: 26-32, atomizer rate: 70%, and air hammer: 5s / time; specifically, S1, after starting the machine, first turn on the induced draft fan, set the inlet air temperature and preheat it; S2, when the outlet air temperature reaches 95°C, turn on the feed pump and atomizer and introduce clean water for adjustment; S3, when the outlet air temperature drops to 85°C, introduce the enzymatic hydrolyzate and start the air hammer (the outlet air temperature is related to the feed speed and the moisture content of the material. The outlet air temperature of the oyster powder spray should be controlled at 85-90°C; S4, collect the material at the receiving port; and obtain the oyster powder.

[0062] Example 2

[0063] The embodiment of the present invention provides an oyster powder, wherein the preparation method of the oyster powder is different from that of embodiment 1 in that the mass percentage of the enzyme preparation is 0.12% based on the mass of the crushed oyster meat;

[0064] Calculated by the mass of the enzymatic hydrolysate, the mass percentage of the composite bacterial preparation is 0.1%.

[0065] Comparative Example 1

[0066] The comparative example of the present invention provides an oyster powder, and the preparation method of the oyster powder is a traditional preparation method of the oyster powder, comprising the following steps:

[0067] (1) Oyster meat pretreatment: 10 kg of frozen oyster meat was naturally slowed down at room temperature, and then broken into pieces with a wall breaking machine until no large pieces of oyster meat were visible to the naked eye, and set aside for later use;

[0068] (2) High-pressure cooking: oyster meat and water were mixed in a mass ratio of 1:1.5 and added into a pressure cooker and kept at 120°C for 30 min;

[0069] (3) Filtration and concentration: The oyster juice after high pressure is filtered and concentrated to a refractive index of 20 using a rotary evaporator;

[0070] (4) Preparation: The water content of the oyster juice after high-pressure concentration is measured, and salt and sugar are added according to the solid content of the oyster juice after high-pressure concentration (solid content is 22%) for preparation, wherein the amount of salt added is 20% of the solid content, and the amount of sugar added is 5% of the solid content (the proportion can be adjusted or other auxiliary materials can be added according to production needs, and the total solid content of the oyster juice after compounding is controlled to be less than 35%);

[0071] (5) Powder spray collection: An experimental high-speed centrifugal atomization spray dryer was used, and the parameters were set to inlet air temperature: 165-170°C, feed pump speed: 26-32, atomizer rate: 70%, and air hammer: 5s / time; specifically: S1. After starting the machine, first turn on the induced draft fan, set the inlet air temperature and preheat it; S2. When the outlet air temperature reaches 95°C, turn on the feed pump and atomizer and introduce clean water for adjustment; S3. When the outlet air temperature drops to 85°C, introduce the enzymatic solution and start the air hammer (the outlet air temperature is related to the feed speed and the moisture content of the material. The outlet air temperature of the oyster powder spray should be controlled at 85-90°C; S4. Collect the material at the receiving port.

[0072] Comparative Example 2

[0073] The comparative example of the present invention provides an oyster powder, the preparation method of which is different from that of Example 1 in that the enzyme preparation contains only protease (20.4 g papain and 13.6 g alkaline protease); the preparation method specifically comprises the following steps:

[0074] (1) taking 10 kg of frozen oyster meat and naturally slowing it down at room temperature, and then crushing it with a wall-breaking machine until there are no large pieces of oyster meat visible to the naked eye, thereby obtaining crushed oyster meat;

[0075] (2) Put the prepared oyster meat into an iron bucket of suitable size, add 34 g of enzyme preparation (24 g of papain and 13.6 g of alkaline protease), stir evenly, put into a water bath and stir with an electric stirrer (the water bath temperature is set to 57° C., the electric stirrer speed is set to 500 r / min, and the timing starts when the water bath temperature reaches 56° C. for 2 h. During the enzymolysis process, cover the bucket mouth with plastic wrap to prevent excessive evaporation of water);

[0076] (3) Inactivation of enzymes and sterilization: the enzymatic solution after enzymatic hydrolysis is placed in a water bath, stirred and heated to inactivate enzymes and sterilize (the water bath temperature is set to 100°C, and the timing starts when the displayed temperature reaches 95°C for 28 minutes);

[0077] (4) Fermentation: adding a composite bacterial preparation (Lactobacillus casei, Lactobacillus bulgaricus, and Streptococcus thermophilus in a mass ratio of 2:1:1) to the sterilized enzymatic hydrolysate in an amount of 0.2% of the mass of the sterilized enzymatic hydrolysate, and fermenting at 40° C. for 2 days;

[0078] (5) Filtering through a colloid mill: First, the fermented enzymatic hydrolysate is filtered through a 40-mesh sieve to remove the oyster shells and sediment remaining in the oyster meat, and then filtered through a 100-mesh sieve again after passing through a colloid mill to obtain a fermented enzymatic hydrolysate in a better state;

[0079] (6) Preparation: measuring the water content of the fermented enzymatic hydrolysate, and adding salt and sugar according to the solid content of the fermented enzymatic hydrolysate (solid content is 20%) for preparation, wherein the amount of salt added is 20% of the solid content, and the amount of sugar added is 5% of the solid content (the total solid content of the oyster juice after compounding is controlled to be less than 35%), to obtain compounded oyster juice;

[0080] (7) Modified starch embedding: adding a potato carboxymethyl modified starch aqueous solution to the oyster juice and mixing evenly (wherein, based on the solid content in the enzymatic hydrolyzate after fermentation, the mass percentage of the potato carboxymethyl modified starch is 3%, and the mass ratio of the potato carboxymethyl modified starch aqueous solution to water in the aqueous solution is 1:5), and then embedding is performed by spray drying;

[0081] (8) Powder spraying and collection: An experimental high-speed centrifugal atomizing spray dryer was used, and the parameters were set to be: inlet air temperature: 165-170°C, feed pump speed: 26-32, atomizer rate: 70%, and air hammer: 5s / time; specifically, S1, after starting the machine, first turn on the induced draft fan, set the inlet air temperature and preheat it; S2, when the outlet air temperature reaches 95°C, turn on the feed pump and atomizer and introduce clean water for adjustment; S3, when the outlet air temperature drops to 85°C, introduce the enzymatic hydrolyzate and start the air hammer (the outlet air temperature is related to the feed speed and the moisture content of the material. The outlet air temperature of the oyster powder spray should be controlled at 85-90°C; S4, collect the material at the receiving port; and obtain the oyster powder.

[0082] Comparative Example 3

[0083] The comparative example of the present invention provides an oyster powder, and the preparation method of the oyster powder is different from that of Example 1 only in that the composite bacterial preparation is yeast, and fermented at 32° C. for 2 days; specifically comprising the following steps:

[0084] (1) taking 10 kg of frozen oyster meat and naturally slowing it down at room temperature, and then crushing it with a wall-breaking machine until there are no large pieces of oyster meat visible to the naked eye, thereby obtaining crushed oyster meat;

[0085] (2) Put the prepared oyster meat into an iron bucket of suitable size, add 34g of enzyme preparation (18g of papain, 12g of alkaline protease, and 4g of lipase), stir evenly, put it into a water bath and stir it with an electric stirrer (the water bath temperature is set to 57°C, the speed of the electric stirrer is set to 500r / min, and the timing starts when the water bath temperature reaches 56°C for 2h. During the enzymatic hydrolysis process, cover the bucket mouth with plastic wrap to prevent excessive evaporation of water);

[0086] (3) Inactivation of enzymes and sterilization: the enzymatic solution after enzymatic hydrolysis is placed in a water bath, stirred and heated to inactivate enzymes and sterilize (the water bath temperature is set to 100°C, and the timing starts when the displayed temperature reaches 95°C for 28 minutes);

[0087] (4) Fermentation: adding yeast to the sterilized enzymatic hydrolysate in an amount of 0.2% of the mass of the sterilized enzymatic hydrolysate, and fermenting at 32° C. for 2 days;

[0088] (5) Filtering through a colloid mill: First, the fermented enzymatic hydrolysate is filtered through a 40-mesh sieve to remove the oyster shells and sediment remaining in the oyster meat, and then filtered through a 100-mesh sieve again after passing through a colloid mill to obtain a fermented enzymatic hydrolysate in a better state;

[0089] (6) Preparation: measuring the water content of the fermented enzymatic hydrolysate, and adding salt and sugar according to the solid content of the fermented enzymatic hydrolysate (solid content is 20%) for preparation, wherein the amount of salt added is 20% of the solid content, and the amount of sugar added is 5% of the solid content (the total solid content of the oyster juice after compounding is controlled to be less than 35%), to obtain compounded oyster juice;

[0090] (7) Modified starch embedding: adding a potato carboxymethyl modified starch aqueous solution to the oyster juice and mixing evenly (wherein, based on the solid content in the enzymatic hydrolyzate after fermentation, the mass percentage of the potato carboxymethyl modified starch is 3%, and the mass ratio of the potato carboxymethyl modified starch aqueous solution to water in the aqueous solution is 1:5), and then embedding is performed by spray drying;

[0091] (8) Powder spraying and collection: An experimental high-speed centrifugal atomizing spray dryer was used, and the parameters were set to be: inlet air temperature: 165-170°C, feed pump speed: 26-32, atomizer rate: 70%, and air hammer: 5s / time; specifically, S1, after starting the machine, first turn on the induced draft fan, set the inlet air temperature and preheat it; S2, when the outlet air temperature reaches 95°C, turn on the feed pump and atomizer and introduce clean water for adjustment; S3, when the outlet air temperature drops to 85°C, introduce the enzymatic hydrolyzate and start the air hammer (the outlet air temperature is related to the feed speed and the moisture content of the material. The outlet air temperature of the oyster powder spray should be controlled at 85-90°C; S4, collect the material at the receiving port; and obtain the oyster powder.

[0092] Comparative Example 4

[0093] The comparative example of the present invention provides an oyster powder, and the preparation method of the oyster powder is different from that of Example 1 only in that the composite bacterial preparation is Lactobacillus casei; the method specifically comprises the following steps:

[0094] (1) taking 10 kg of frozen oyster meat and naturally slowing it down at room temperature, and then crushing it with a wall-breaking machine until there are no large pieces of oyster meat visible to the naked eye, thereby obtaining crushed oyster meat;

[0095] (2) Put the prepared oyster meat into an iron bucket of suitable size, add 34g of enzyme preparation (18g of papain, 12g of alkaline protease, and 4g of lipase), stir evenly, put it into a water bath and stir it with an electric stirrer (the water bath temperature is set to 57°C, the speed of the electric stirrer is set to 500r / min, and the timing starts when the water bath temperature reaches 56°C for 2h. During the enzymatic hydrolysis process, cover the bucket mouth with plastic wrap to prevent excessive evaporation of water);

[0096] (3) Inactivation of enzymes and sterilization: the enzymatic solution after enzymatic hydrolysis is placed in a water bath, stirred and heated to inactivate enzymes and sterilize (the water bath temperature is set to 100°C, and the timing starts when the displayed temperature reaches 95°C for 28 minutes);

[0097] (4) fermentation: adding Lactobacillus casei to the sterilized enzymolyzate in an amount of 0.2% by mass of the sterilized enzymolyzate, and fermenting at 40° C. for 2 days;

[0098] (5) Filtering through a colloid mill: First, the fermented enzymatic hydrolysate is filtered through a 40-mesh sieve to remove the oyster shells and sediment remaining in the oyster meat, and then filtered through a 100-mesh sieve again after passing through a colloid mill to obtain a fermented enzymatic hydrolysate in a better state;

[0099] (6) Preparation: measuring the water content of the fermented enzymatic hydrolysate, and adding salt and sugar according to the solid content of the fermented enzymatic hydrolysate (solid content is 20%) for preparation, wherein the amount of salt added is 20% of the solid content, and the amount of sugar added is 5% of the solid content (the total solid content of the oyster juice after compounding is controlled to be less than 35%), to obtain compounded oyster juice;

[0100] (7) Modified starch embedding: adding a potato carboxymethyl modified starch aqueous solution to the oyster juice and mixing evenly (wherein, based on the solid content in the enzymatic hydrolyzate after fermentation, the mass percentage of the potato carboxymethyl modified starch is 3%, and the mass ratio of the potato carboxymethyl modified starch aqueous solution to water in the aqueous solution is 1:5), and then embedding is performed by spray drying;

[0101] (8) Powder spraying and collection: An experimental high-speed centrifugal atomizing spray dryer was used, and the parameters were set to be: inlet air temperature: 165-170°C, feed pump speed: 26-32, atomizer rate: 70%, and air hammer: 5s / time; specifically, S1, after starting the machine, first turn on the induced draft fan, set the inlet air temperature and preheat it; S2, when the outlet air temperature reaches 95°C, turn on the feed pump and atomizer and introduce clean water for adjustment; S3, when the outlet air temperature drops to 85°C, introduce the enzymatic hydrolyzate and start the air hammer (the outlet air temperature is related to the feed speed and the moisture content of the material. The outlet air temperature of the oyster powder spray should be controlled at 85-90°C; S4, collect the material at the receiving port; and obtain the oyster powder.

[0102] Comparative Example 5

[0103] The comparative example of the present invention provides an oyster powder. The only difference between the preparation method of the oyster powder and that of Example 1 is that step (7) is not included. Specifically, the preparation method comprises the following steps:

[0104] (1) taking 10 kg of frozen oyster meat and naturally slowing it down at room temperature, and then crushing it with a wall-breaking machine until there are no large pieces of oyster meat visible to the naked eye, thereby obtaining crushed oyster meat;

[0105] (2) Put the prepared oyster meat into an iron bucket of suitable size, add 34g of enzyme preparation (18g of papain, 12g of alkaline protease, and 4g of lipase), stir evenly, put it into a water bath and stir it with an electric stirrer (the water bath temperature is set to 57°C, the speed of the electric stirrer is set to 500r / min, and the timing starts when the water bath temperature reaches 56°C for 2h. During the enzymatic hydrolysis process, cover the bucket mouth with plastic wrap to prevent excessive evaporation of water);

[0106] (3) Inactivation of enzymes and sterilization: the enzymatic solution after enzymatic hydrolysis is placed in a water bath, stirred and heated to inactivate enzymes and sterilize (the water bath temperature is set to 100°C, and the timing starts when the displayed temperature reaches 95°C for 28 minutes);

[0107] (4) Fermentation: adding a composite bacterial preparation (Lactobacillus casei, Lactobacillus bulgaricus, and Streptococcus thermophilus in a mass ratio of 2:1:1) to the sterilized enzymatic hydrolysate in an amount of 0.2% of the mass of the sterilized enzymatic hydrolysate, and fermenting at 40° C. for 2 days;

[0108] (5) Filtering through a colloid mill: First, the fermented enzymatic hydrolysate is filtered through a 40-mesh sieve to remove the oyster shells and sediment remaining in the oyster meat, and then filtered through a 100-mesh sieve again after passing through a colloid mill to obtain a fermented enzymatic hydrolysate in a better state;

[0109] (6) Preparation: measuring the water content of the fermented enzymatic hydrolysate, and adding salt and sugar according to the solid content of the fermented enzymatic hydrolysate (solid content is 20%) for preparation, wherein the amount of salt added is 20% of the solid content, and the amount of sugar added is 5% of the solid content (the total solid content of the oyster juice after compounding is controlled to be less than 35%), to obtain compounded oyster juice;

[0110] (7) Powder spraying and collection: An experimental high-speed centrifugal atomizing spray dryer was used, and the parameters were set to be: inlet air temperature: 165-170°C, feed pump speed: 26-32, atomizer rate: 70%, and air hammer: 5s / time; specifically, S1, after starting the machine, first turn on the induced draft fan, set the inlet air temperature and preheat it; S2, when the outlet air temperature reaches 95°C, turn on the feed pump and atomizer and introduce clean water for adjustment; S3, when the outlet air temperature drops to 85°C, introduce the enzymatic hydrolyzate and start the air hammer (the outlet air temperature is related to the feed speed and the moisture content of the material. The outlet air temperature of the oyster powder spray should be controlled at 85-90°C; S4, collect the material at the receiving port; and obtain the oyster powder.

[0111] Effect example

[0112] The effects of the present invention are as follows: The performance of oyster powder prepared by Examples 1-2, Comparative Examples 1-5 and the traditional method (the specific operation method is as described in the background technology) is explored, including the following aspects:

[0113] 1. Sensory scoring

[0114] The oyster powder prepared in the embodiment and the comparative example was brewed with hot water, and sensory evaluation personnel were organized to evaluate and analyze the product, and the aroma, color, flavor, taste and preference of the oyster powder were scored. The evaluation was given in turn according to the acceptance degree of the sensory evaluation personnel. The scoring evaluation table is shown in Table 1;

[0115] Table 1

[0116] Evaluation Description Difference Poor medium Better good Strength score 1 2 3 4 5

[0117] 2. Output: According to the theoretical amount of 10kg, calculate the theoretical powder output Z = solid content of the prepared liquid * mass of the prepared liquid, and record the actual powder output X, and then calculate the output = X / Z * 100%;

[0118] 3. Amino acid nitrogen: Amino acid nitrogen is the content of nitrogen in the form of amino acids. The higher the content, the stronger the umami taste and the better the quality. The determination of amino acid nitrogen is to determine the content of amino acid nitrogen in the sample through the acidity of the amino acid carboxyl group. The detection method refers to GB 5009.235-2016 National Food Safety Standard Amino Acid Nitrogen in Food;

[0119] 4. Water absorption rate: After drying the oyster powder, weigh m grams and expose it to an environment with a temperature of 23.0℃±1℃ and a relative humidity of 50%±5% for 12 hours and weigh it again to obtain M grams. Water absorption rate = (Mm) / m*100%;

[0120] The results obtained are shown in Table 2;

[0121] Table 2

[0122]

[0123]

[0124] It can be seen from Table 2 that when the technical solution provided by the present invention is adopted, the obtained product has a good sensory score, a high yield and amino acid nitrogen content, and excellent storage performance, and a low water absorption rate after exposure to air; specifically, in the sensory score of the obtained product, the aroma score is above 4.2 points, the color score is above 4.2 points, the flavor score is above 4.2 points, the taste score is above 4.4 points, and the preference score is above 4.3 points; the yield is above 79.02%, the amino acid nitrogen content in the oyster powder is above 1.63g / 100g, and the water absorption rate in the storage test is below 1.90%;

[0125] Compared with the conventional method in Example 1 and the conventional method in Comparative Example 1, the technical solution provided by the present invention can significantly enhance the sensory score of oyster powder, and can effectively increase the amino acid nitrogen content in the oyster powder, and can also improve the storage performance of the oyster powder;

[0126] It can be seen from Example 1 and Comparative Example 2 that the type of enzyme preparation in the preparation process of oyster powder will also affect the comprehensive performance of the product. When the type of enzyme preparation in Comparative Example 2 is not within the range given in the present invention, the yield of the obtained product is significantly reduced;

[0127] It can be seen from Example 1 and Comparative Examples 3-4 that the selection of the composite bacterial preparation in the fermentation process will also affect the performance of the product. When only yeast is used in Comparative Example 3, the sensory scores of the obtained product are significantly reduced, especially the scores of aroma and color; when only Lactobacillus casei is used in Comparative Example 4, the yield of the obtained product shows a certain downward trend;

[0128] It can be seen from Example 1 and Comparative Example 5 that whether or not to use modified starch aqueous solution for coating will affect the comprehensive performance of oyster powder. When modified starch aqueous solution is not used for coating in Comparative Example 5, the obtained product not only has a significantly reduced yield, but also significantly deteriorates in storage performance.

[0129] Finally, it should be noted that the above embodiments are intended to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing oyster powder, characterized in that: The preparation method comprises the following steps: (1) adding an enzyme preparation to the crushed oyster meat for enzymolysis, and then killing the enzyme to obtain an enzymolysis solution; (2) adding the composite bacterial preparation to the enzymatic hydrolyzate for fermentation, filtering after the fermentation is completed, and collecting the filtrate; (3) adding modified starch aqueous solution to the prepared filtrate and mixing evenly, followed by spray drying to obtain oyster powder; The enzyme preparation includes protease and lipase; The composite bacterial preparation comprises Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus.

2. The preparation method according to claim 1, characterized in that: The mass percentage of the enzyme preparation is 0.1-0.4% based on the mass of the crushed oyster meat; And / or, the temperature of the enzymatic hydrolysis is 55-57° C., and the time is 2-2.5 h.

3. The preparation method according to claim 1, characterized in that: The mass percentage of lipase is 10-15% based on the mass of protease; And / or, the protease includes at least one of papain, trypsin, acid protease, alkaline protease, and composite protease.

4. The preparation method according to claim 1, characterized in that: The mass percentage of the composite bacterial preparation is 0.1-0.3% based on the mass of the enzymatic hydrolysate; And / or, the fermentation temperature is 38-45°C and the fermentation time is 45-55h.

5. The preparation method according to claim 1, characterized in that: The mass ratio of Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus is (1.5-2.5):1:

1.

6. The preparation method according to claim 1, characterized in that: Calculated based on the mass of solid matter in the filtrate, the mass percentage of modified starch in the modified starch aqueous solution is 2-4%.

7. The preparation method according to claim 1, characterized in that: In the modified starch aqueous solution, the mass ratio of modified starch to water is 1:(4-6).

8. The preparation method according to claim 1, characterized in that: The filtration comprises firstly performing a primary filtration, then collecting the primary filtration filtrate, grinding it, and then performing a fine filtration.

9. An oyster powder, characterized in that: The oyster powder is prepared by the preparation method described in any one of claims 1 to 8.

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