Plant-based fermented milk powder and preparation process thereof

Abstract

The invention discloses plant-based fermented milk powder and a preparation technology thereof, and belongs to the technical field of food processing. The preparation process comprises the steps of cleaning and baking, wet crushing, high-pressure jet milling, curing, liquefying, saccharifying, homogenizing, vacuum concentrating, sterilizing, fermenting, spray drying and the like. The plant-based fermented milk powder taking plants as main raw materials can be obtained through the method, and a high-stability fermentation base material is obtained by adopting novel pulping equipment in combination with an enzymolysis process; meanwhile, the smoothness and the thickness of the fermented slurry are increased by selecting a lactic acid bacteria strain with high exopolysaccharide yield; the product not only can be directly brewed for drinking, but also can be used as an auxiliary material to be applied to healthy leisure foods such as beverages, candies, biscuits, functional foods and the like, so that more food enterprises are assisted to open a new plant-based track.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and in particular, relates to a plant-based fermented milk powder and a preparation process thereof. Background Art

[0002] Based on health and sustainable development, people are paying more and more attention to plant-based products. As a dairy substitute, plant-based fermented milk is popular among people with lactose intolerance, milk protein allergy or vegetarians due to its nutritional and functional properties. In order to improve the defects of plant-based fermented milk in texture and reduce the addition of additives such as stabilizers, people will improve and optimize the existing production formula and process of plant-based fermented milk, and improve product quality starting from the starter and process conditions.

[0003] Patent 201610096894.8 discloses a method for preparing oat fermented milk, and the method is as follows: put oats into a cleaning machine for cleaning, and then put them into an infrared oven for baking; soak oats in softened water at room temperature according to a certain material-water ratio, grind, filter to remove pulp residue, obtain oat pulp for standby use; activate and culture lactic acid bacteria; add a certain amount of skim milk powder, sucrose, citric acid, and thickener to the oat pulp according to the weight of the oat pulp, stir evenly, transfer to a fermentation tank, add a certain amount of bacteria to ferment at a constant temperature; homogenize the prepared oat fermented milk using a secondary homogenization process; sterilize using UHT sterilization, and cool and fill after sterilization. In the process of refining, the invention removes the residue by filtering, which will cause a large amount of nutrients such as starch and dietary fiber to be lost, reducing the nutritional value of the product.

[0004] Patent 202011111963.0 discloses a preparation method of probiotic fermented rice milk, which includes the following steps: raw material pretreatment: selecting selenium-rich broken rice produced during the processing of selenium-rich rice; crushing: ultrafine grinding the selenium-rich broken rice to obtain selenium-rich broken rice powder; drying: drying the selenium-rich broken rice powder; soaking; grinding; enzymolysis: adding neutral protease, alkaline protease and flavor protease to the slurry for enzymolysis, then inactivating the enzyme, drying to obtain rice flour; adding auxiliary materials: adding milk powder and sugar to the rice flour, adding water to dissolve, and obtaining a mixed material; homogenization: homogenizing the mixed material through a homogenizing device, then sterilizing, and cooling; fermentation: thermophilic streptococci and bulgaricus lactobacillus are connected to the cooled mixed material and mixed and fermented through a fermentation device, and probiotic fermented rice milk is obtained after fermentation. The invention obtains a mixed material by adding sugar and milk powder to rice flour for fermentation. The mixed material is not liquefied by α-amylase, which will cause starch aging and regeneration, affecting the sensory quality of the product.

[0005] Existing plant-based fermented milk products have a certain gap in texture compared to yogurt, and cannot be as mellow and smooth as yogurt. In addition, when processing plant raw materials to prepare the fermentation base, the existing production process filters the large particles (starch, dietary fiber) in the slurry, which leads to a large loss of nutrients. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a plant-based fermented milk powder and a preparation process thereof. The present invention can obtain a plant-based fermented milk powder with plants themselves as the main raw materials. The product adopts a new type of pulping equipment combined with an enzymatic hydrolysis process to obtain a highly stable fermentation base material; at the same time, lactic acid bacteria strains with high production of extracellular polysaccharides are selected to increase the smoothness and thickness of the fermentation slurry; in addition to being able to be directly prepared and drunk, the product can also be used as an auxiliary material in healthy and leisure foods such as beverages, candies, biscuits, functional foods, etc., helping more food companies to open up a new plant-based track.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A plant-based fermented milk powder is prepared from the following raw materials: cereal raw materials, alpha-amylase and bacterial strains.

[0009] More preferably, the cereal raw material is any one of rice, millet, oats and highland barley.

[0010] More preferably, the bacterial species is a combination of two or more of Lactobacillus plantarum, Streptococcus thermophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus acidophilus, and Lactobacillus paracasei.

[0011] The present invention also provides a process for preparing a plant-based fermented milk powder, comprising the following steps:

[0012] (1) Cleaning and baking: The cleaned and shade-dried grain raw materials are baked in an oven at 140-170° C. for 10-30 min and set aside;

[0013] (2) Wet grinding: The roasted grains are mixed with drinking water in a mass ratio of 5:95-10:90, and pre-grinded in a wet grinder to prepare a grain slurry;

[0014] (3) High-pressure jet milling: Pour the grain slurry into the feed barrel of the high-pressure jet mill, set the pressure to 60-120 MPa, and prepare the refined grain slurry;

[0015] (4) Cooking: The grain slurry obtained in step (3) is placed in a pulp cooker and cooked at 95-100° C. for 20-30 min to fully cook it;

[0016] (5) liquefaction: the grain slurry obtained in step (4) is placed in an enzymatic hydrolysis tank, 0.03-0.1% of the mass of the grain slurry is added with α-amylase, and liquefied at 70-90° C. for 1-2 h;

[0017] (6) Saccharification: Add saccharifying enzyme to the enzymatically hydrolyzed grain slurry for treatment, add saccharifying enzyme at a rate of 0.02-0.5% of the mass of the enzymatically hydrolyzed grain slurry, saccharify at 50-70° C. for 1-2 h, and then place at 90° C. to inactivate the enzyme for 25-30 min;

[0018] (7) Homogenization: Add the grain slurry obtained in step (6) into a high-pressure homogenizer and homogenize at 20-50 MPa for 15-20 min;

[0019] (8) Vacuum concentration: The grain slurry obtained in step (7) is subjected to vacuum concentration treatment at a vacuum degree of 0.04-0.08 MPa and a temperature of 60-80° C., and is concentrated until the soluble solid content reaches 25-30%;

[0020] (9) Sterilization: sterilize the concentrate at 90-100°C for 25-30 min;

[0021] (10) Fermentation: Cool down to 42°C or 37°C (suitable fermentation temperature), add 0.02-0.05% of the bacterial strain based on the weight of the grain slurry, stir gently and ferment for 8-12 hours, and stop fermentation when the pH value reaches 3.4-3.8;

[0022] (11) The fermented grain slurry is fed into a spray drying tower for drying, with an inlet temperature of 170-190° C. and an outlet temperature of 70-90° C., and the dried plant-based fermented milk powder particles are collected.

[0023] Beneficial effects of the present invention:

[0024] (1) A new type of pulping equipment combined with an enzymatic hydrolysis process is used to obtain a highly stable fermentation base material, which does not need to be filtered, effectively avoiding the loss of nutrients;

[0025] (2) Selecting lactic acid bacteria with high extracellular polysaccharide production to increase the smoothness and thickness of the fermentation slurry;

[0026] (3) The obtained plant-based fermented milk powder can be directly prepared for drinking and can also be used as an ingredient in food industry production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings.

[0028] Figure 1 The present invention is a flow chart of the preparation process. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] A preparation process of plant-based fermented milk powder, such as Figure 1 As shown, the following steps are included:

[0032] (1) Cleaning and baking: The cleaned and shade-dried rice is baked in an oven at 140° C. for 30 min and set aside;

[0033] (2) Wet grinding: The roasted grains were mixed with drinking water in a mass ratio of 5:95 and pre-grinded in a wet grinder to prepare grain slurry;

[0034] (3) High-pressure jet milling: Pour the grain slurry into the feed barrel of the high-pressure jet mill, set the pressure to 60 MPa, and prepare the refined grain slurry;

[0035] (4) Cooking: The grain slurry obtained in step (3) is placed in a pulp cooker and cooked at 95° C. for 20 min to fully cook the grain slurry;

[0036] (5) liquefaction: the grain slurry obtained in step (4) was placed in an enzymatic hydrolysis tank, 0.03% of α-amylase was added to the grain slurry by weight, and liquefied at 70° C. for 1 h;

[0037] (6) Saccharification: Add saccharifying enzyme to the enzymatically hydrolyzed grain slurry for treatment, add saccharifying enzyme at a rate of 0.02% by weight of the enzymatically hydrolyzed grain slurry, saccharify at 50° C. for 1 h, and then place at 90° C. for 25 min to inactivate the enzyme;

[0038] (7) Homogenization: Add the grain slurry obtained in step (6) into a high-pressure homogenizer and homogenize at 20 MPa for 15 min;

[0039] (8) Vacuum concentration: The grain slurry obtained in step (7) is subjected to vacuum concentration treatment at a vacuum degree of 0.04 MPa and a temperature of 60° C., and is concentrated until the soluble solid content reaches 25-30%;

[0040] (9) Sterilization: sterilize the concentrate at 90°C for 25 min;

[0041] (10) Fermentation: Cool down to 42° C. or 37° C. (suitable fermentation temperature), add 0.02% Lactobacillus plantarum based on the weight of the cereal slurry, stir gently and ferment for 8-12 hours, and stop fermentation when the pH value reaches 3.4-3.8;

[0042] (11) The fermented grain slurry was input into a spray drying tower for drying, with an inlet temperature of 170°C and an outlet temperature of 70°C, and the dried plant-based fermented milk powder particles were collected.

[0043] Example 2

[0044] A preparation process of plant-based fermented milk powder, such as Figure 1 As shown, the following steps are included:

[0045] (1) Cleaning and baking: The cleaned and shade-dried millet is baked in an oven at 150° C. for 25 min and set aside;

[0046] (2) Wet grinding: The roasted grains were mixed with drinking water in a mass ratio of 6:94 and pre-grinded in a wet grinder to prepare grain slurry;

[0047] (3) High-pressure jet milling: Pour the grain slurry into the feed barrel of the high-pressure jet mill, set the pressure to 80 MPa, and prepare the refined grain slurry;

[0048] (4) Cooking: The grain slurry obtained in step (3) is placed in a pulp cooker and cooked at 97° C. for 23 min to fully cook the grain slurry;

[0049] (5) liquefaction: the grain slurry obtained in step (4) was placed in an enzymatic hydrolysis tank, 0.05% of the mass of the grain slurry was added with α-amylase, and liquefied at 74° C. for 1.3 h;

[0050] (6) Saccharification: Add saccharifying enzyme to the enzymatically hydrolyzed grain slurry for treatment, add saccharifying enzyme according to 0.1% of the mass of the enzymatically hydrolyzed grain slurry, saccharify at 55° C. for 1.2 h, and then place at 90° C. for 26 min to inactivate the enzyme;

[0051] (7) Homogenization: Add the grain slurry obtained in step (6) into a high-pressure homogenizer and homogenize at 30 MPa for 17 min;

[0052] (8) Vacuum concentration: The grain slurry obtained in step (7) is subjected to vacuum concentration treatment at a vacuum degree of 0.05 MPa and a temperature of 65° C., and is concentrated until the soluble solid content reaches 25-30%;

[0053] (9) Sterilization: The concentrate was sterilized at 92°C for 26 min;

[0054] (10) Fermentation: Cool down to 37° C. (optimal fermentation temperature), add 0.03% thermophilic Streptococcus based on the weight of the grain slurry, stir gently and ferment for 9 hours. Stop fermentation when the pH value reaches 3.4-3.8;

[0055] (11) The fermented grain slurry was input into a spray drying tower for drying, with an inlet temperature of 175°C and an outlet temperature of 75°C, and the dried plant-based fermented milk powder particles were collected.

[0056] Example 3

[0057] A preparation process of plant-based fermented milk powder, such as Figure 1 As shown, the following steps are included:

[0058] (1) Cleaning and baking: The cleaned and shade-dried oats are baked in an oven at 160° C. for 22 min and set aside;

[0059] (2) Wet grinding: The roasted grains were mixed with drinking water in a mass ratio of 8:92 and pre-grinded in a wet grinder to prepare grain slurry;

[0060] (3) High-pressure jet milling: Pour the grain slurry into the feed barrel of the high-pressure jet mill, set the pressure to 100 MPa, and prepare the refined grain slurry;

[0061] (4) Cooking: The grain slurry obtained in step (3) is placed in a pulp cooker and cooked at 98° C. for 28 min to fully cook the grain slurry;

[0062] (5) liquefaction: the grain slurry obtained in step (4) was placed in an enzymatic hydrolysis tank, 0.08% of the mass of the grain slurry was added with α-amylase, and liquefied at 84° C. for 1.7 h;

[0063] (6) Saccharification: Add saccharifying enzyme to the enzymatically hydrolyzed grain slurry for treatment, add saccharifying enzyme according to 0.3% of the mass of the enzymatically hydrolyzed grain slurry, saccharify at 67° C. for 1.8 h, and then place at 90° C. for 28 min to inactivate the enzyme;

[0064] (7) Homogenization: Add the grain slurry obtained in step (6) into a high-pressure homogenizer and homogenize at 40 MPa for 18 min;

[0065] (8) Vacuum concentration: The grain slurry obtained in step (7) is subjected to vacuum concentration treatment at a vacuum degree of 0.07 MPa and a temperature of 76° C., and is concentrated until the soluble solid content reaches 28%;

[0066] (9) Sterilization: sterilize the concentrate at 98°C for 27 min;

[0067] (10) Fermentation: Cool down to 42° C. (optimal fermentation temperature), add 0.04% Lactobacillus delbrueckii subsp. bulgaricus based on the weight of the grain slurry, stir gently and ferment for 10 h. Fermentation is stopped when the pH value reaches 3.4-3.8;

[0068] (11) The fermented grain slurry was input into a spray drying tower for drying, with an inlet temperature of 185°C and an outlet temperature of 78°C, and the dried plant-based fermented milk powder particles were collected.

[0069] Example 4

[0070] A preparation process of plant-based fermented milk powder, such as Figure 1 As shown, the following steps are included:

[0071] (1) cleaning and baking: the cleaned and shade-dried highland barley is baked in an oven at 170° C. for 10 min for standby use;

[0072] (2) Wet grinding: The roasted grains were mixed with drinking water in a mass ratio of 10:90 and pre-grinded in a wet grinder to prepare grain slurry;

[0073] (3) High-pressure jet milling: Pour the grain slurry into the feed barrel of the high-pressure jet mill, set the pressure to 120 MPa, and prepare the refined grain slurry;

[0074] (4) Cooking: The grain slurry obtained in step (3) is placed in a pulp cooker and cooked at 100° C. for 30 min to fully cook it;

[0075] (5) liquefaction: the grain slurry obtained in step (4) is placed in an enzymatic hydrolysis tank, 0.1% of the mass of the grain slurry is added with α-amylase, and liquefied at 90° C. for 2 h;

[0076] (6) Saccharification: Add saccharifying enzyme to the enzymatically hydrolyzed grain slurry for treatment, add saccharifying enzyme according to 0.5% of the mass of the enzymatically hydrolyzed grain slurry, saccharify at 70° C. for 2 h, and then place at 90° C. for 30 min to inactivate the enzyme;

[0077] (7) Homogenization: Add the grain slurry obtained in step (6) into a high-pressure homogenizer and homogenize at 50 MPa for 20 min;

[0078] (8) Vacuum concentration: The grain slurry obtained in step (7) is subjected to vacuum concentration treatment at a vacuum degree of 0.08 MPa and a temperature of 80° C., and is concentrated until the soluble solid content reaches 30%;

[0079] (9) Sterilization: sterilize the concentrate at 100°C for 30 min;

[0080] (10) Fermentation: Cool down to 37° C. (optimal fermentation temperature), add 0.05% Lactobacillus acidophilus based on the weight of the grain slurry, stir gently and ferment for 12 h. Fermentation is stopped when the pH reaches 3.8;

[0081] (11) The fermented grain slurry was input into a spray drying tower for drying, with an inlet temperature of 190°C and an outlet temperature of 90°C, and the dried plant-based fermented milk powder particles were collected.

[0082] The plant-based fermented milk powder obtained in the above embodiment has good smoothness and thickness after being prepared; in addition to being directly prepared for drinking, it can also be used as an auxiliary material in healthy leisure foods such as beverages, candies, biscuits, functional foods, etc.

[0083] The above specific implementation method part specifically introduces the analytical method involved in the present invention. It should be noted that the above introduction is only to help those skilled in the art better understand the method and ideas of the present invention, rather than limiting the relevant content. Without departing from the principle of the present invention, those skilled in the art may also make appropriate adjustments or modifications to the present invention, and the above adjustments and modifications shall also fall within the scope of protection of the present invention.

Claims

1. A process for preparing plant-based fermented milk powder, characterized in that: The following steps are involved: (1) Cleaning and baking: The cleaned and shade-dried cereal raw materials are baked in an oven for later use; (2) Wet grinding: The roasted grains are mixed with drinking water in a certain proportion and pre-grinded in a wet grinder to prepare grain slurry; (3) High-pressure jet milling: Pour the grain slurry into the feed barrel of the high-pressure jet mill, set the pressure, and prepare the refined grain slurry; (4) Cooking: The grain slurry obtained in step (3) is placed in a pulp cooker and cooked to fully cook; (5) liquefaction: placing the grain slurry obtained in step (4) into an enzymatic hydrolysis tank, adding α-amylase, and liquefying; (6) Saccharification: adding saccharifying enzyme to the enzymatically hydrolyzed grain slurry for saccharification and enzyme inactivation; (7) homogenizing: adding the grain slurry obtained in step (6) into a high-pressure homogenizer for homogenization; (8) Vacuum concentration: vacuum concentrating the grain slurry obtained in step (7) until the soluble solid content reaches 25-30%; (9) Sterilization; (10) Fermentation: Cool down to 42°C or 37°C, add bacteria, and ferment; (11) The fermented grain slurry is input into a spray drying tower for drying, and the dried plant-based fermented milk powder particles are collected.

2. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: The cereal raw material in step (1) is any one of rice, millet, oats and highland barley; the baking parameters are: baking in an oven at 140-170° C. for 10-30 min.

3. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: In step (2), the ratio of grain to drinking water is 5:95-10:90 by mass.

4. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: In step (3), the pressure is set to 60-120 MPa; in step (4), the cooking conditions are: cooking at 95-100° C. for 20-30 min.

5. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: In step (5), the liquefaction conditions are as follows: α-amylase is added at 0.03-0.1% of the mass of the grain slurry, and liquefaction is carried out at 70-90° C. for 1-2 hours.

6. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: In step (6), the saccharification conditions are as follows: adding saccharifying enzyme at a rate of 0.02-0.5% of the mass of the enzymatically hydrolyzed grain slurry, saccharifying at 50-70° C. for 1-2 hours; and inactivating the enzyme at 90° C. for 25-30 minutes.

7. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: Homogenization parameters in step (7): 20-50 MPa homogenization for 15-20 min; vacuum concentration treatment parameters in step (8): vacuum degree 0.04-0.08 MPa, temperature 60-80°C.

8. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: Step (9) Sterilization operation: sterilize the concentrated solution at 90-100°C for 25-30 minutes.

9. The process for preparing a plant-based fermented milk powder according to claim 1, characterized in that: The bacterial strains in step (10) are a combination of two or more of Lactobacillus plantarum, Streptococcus thermophilus, Lactobacillus delbrueckii subspecies bulgaricus, Lactobacillus acidophilus, and Lactobacillus paracasei; and the fermentation process comprises adding 0.02-0.05% of the bacterial strains according to the weight of the cereal slurry, stirring slightly and evenly, fermenting for 8-12 hours, and stopping the fermentation when the pH value reaches 3.4-3.

8.

10. A plant-based fermented milk powder, characterized in that: Prepared according to the preparation process according to any one of claims 1 to 9.

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