Method for improving quality of plant meat by adding special chlorella and application thereof

Abstract

The application discloses a method for improving the quality of plant meat by adding special chlorella and application thereof. The method comprises the following steps: firstly, uniformly mixing special chlorella powder and soybean protein isolate to obtain a mixture; wherein the special chlorella powder is broken or unbroken protein nucleus chlorella CX41 algal powder, and the amount of the special chlorella powder accounts for 5-10% of the total mass of the mixture; and then, extruding the mixture by using a double screw extruder, removing redundant water after cooling to obtain an extruded product with a water content of 55-60%, namely plant meat. In the application, the addition of the special chlorella CX41 algal powder can realize the improvement and regulation of the texture and digestion of the plant meat, and the prepared plant meat has good chewiness, nutrition and digestibility.

Description

Technical Field

[0001] This invention belongs to the field of plant-based food processing technology, and specifically relates to a method for improving the quality of plant-based meat by adding special Chlorella and its application. Background Technology

[0002] Global economic development and rapid population growth have led to a surge in demand for food protein. The production of animal protein is prone to environmental damage and exacerbates climate change, and excessive consumption of animal protein can also cause health problems such as a range of chronic diseases. Furthermore, animal welfare considerations have spurred an increase in the consumption of plant protein. Plant proteins are often processed using extrusion technology to reshape the protein's dissociation and polymerization process, forming a structure similar to animal muscle fibers. These are then processed through flavoring and other steps to create products that mimic the texture and taste of animal meat—the currently popular plant-based meat analogues (plant-based meat). High-moisture extrusion technology has attracted widespread attention in the industry. Compared to low-moisture extrudates, high-moisture extrudates have a fiber structure closer to animal muscle fibers and have become the most commonly used production technology.

[0003] Research has shown that high-moisture extrusion of plant proteins depolymerizes their protein structure, and after solidification in a low-temperature cooling section, they rearrange to form a typical anisotropic fibrous structure, which can mimic animal muscle tissue. However, the texture, mouthfeel, and digestibility of high-moisture extruded products are directly affected by the properties of the raw materials and processing conditions (such as temperature, pressure, ingredient ratio, and water activity). Currently, the plant protein raw materials used in high-moisture extrusion research and application are mostly single-component such as soybean and peanut protein. However, single plant proteins have problems such as limiting amino acids and incomplete nutritional components. Furthermore, plant protein extruded products have defects such as dense structure, difficulty in flavor absorption, and difficulty in digestion and absorption, which greatly hinder the healthy development of the plant-based meat industry. Therefore, how to solve the bottleneck problems of texture, mouthfeel, and digestibility of plant protein extruded products is the key to the development of plant-based meat technology.

[0004] Current research primarily focuses on co-extruding various proteins with biomolecules such as polysaccharides and lipids to improve texture and fiber content. This only achieves a fiber content closer to that of animal meat at a macroscopic level, without improving palatability and digestibility. Numerous studies have reported on the preparation of plant-based meat using high-moisture extrusion with two or more biomolecules, but due to poor palatability and digestibility, as well as limited nutritional content, consumer acceptance is low and market promotion is difficult. Often, introducing other nutrients may damage the texture, while studies on simultaneously introducing multiple nutrients to improve texture, palatability, and digestibility are rare. Therefore, there is an urgent need for a high-moisture extrusion feedstock that is more cost-effective and can comprehensively improve the quality and digestibility of plant-based meat. Summary of the Invention

[0005] The primary objective of this invention is to overcome the shortcomings and deficiencies of the prior art and to provide a method for improving the quality of plant-based meat by adding special Chlorella.

[0006] Another object of the present invention is to provide the application of the method of adding special Chlorella to improve the quality of plant-based meat.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for improving the quality of plant-based meat by adding a special type of Chlorella includes the following steps:

[0009] (1) Mix the special Chlorella powder and soy protein isolate evenly to obtain a mixture; wherein, the amount of special Chlorella powder accounts for 5% to 10% of the total mass of the mixture; the special Chlorella powder is Auxenochlorella pyrenoidosa (Ap) CX41 algal powder or Auxenochlorella pyrenoidosa (Ap) CX41 algal powder after cell wall breaking treatment;

[0010] (2) The mixture obtained in step (1) is extruded using a twin-screw extruder, and after cooling, excess water is removed to obtain an extruded material (i.e., plant-based meat) with a moisture content of 55% to 60%. The extrusion conditions are as follows: the twin-screw speed is 175 rpm, the feeding speed is 6 g / min, the water feeding speed is 9 ml / min, the extrusion temperature (the highest temperature in the extrusion cooking zone) is 160℃, and the extrusion cooling temperature is 40℃.

[0011] The preferred amount of the special Chlorella powder mentioned in step (1) is 5% of the total mass of the mixture.

[0012] The soy protein isolate mentioned in step (1) is a conventional commercially available soy protein isolate with a total protein content of ≥90%; the remaining components are water and lipids; preferably, the total protein content is 90%, the water content is about 9%, and the lipid content is about 1%.

[0013] The mixing described in step (1) is preferably carried out using a horizontal U-shaped dry powder mixer or a V-shaped dry powder mixer.

[0014] The mixing time in step (1) is 20 to 40 minutes; preferably 30 minutes.

[0015] The Auxenochlorella pyrenoidosa (Ap) CX41 algal powder mentioned in step (1) was prepared by conventional methods, namely by activation culture, shake flask culture, fermenter culture, and then centrifugation, washing, freeze drying and pulverization.

[0016] The fermentation tank is preferably a 50L fermentation tank.

[0017] The average particle size of the Auxenochlorella pyrenoidosa (Ap) CX41 algal powder mentioned in step (1) is 3.2 μm.

[0018] The average particle size of the Auxenochlorella pyrenoidosa (Ap) CX41 algal powder after cell wall disruption treatment in step (1) is 1.17 μm.

[0019] The cell wall breaking process described in step (1) is carried out by using a high-pressure homogenizer. The specific steps are as follows: add Auxenochlorella pyrenoidosa CX41 algal powder to water, stir to form a suspension, then add it to a high-pressure homogenizer, adjust the pressure to 850 bar, homogenize for 5 cycles, then adjust the pH to 6.5-7.0, collect the algal liquid, freeze dry, pulverize, and pass through an 80-mesh sieve to obtain Auxenochlorella pyrenoidosa CX41 cell wall broken algal powder.

[0020] The water mentioned is deionized water.

[0021] The ratio of Chlorella CX41 algal powder to water is 1:4-5 (g / mL); preferably 1:4 (g / mL).

[0022] The pH adjustment is preferably performed using NaOH solution.

[0023] The preferred stirring conditions are: stirring at 160–200 rpm for 20–30 min at room temperature.

[0024] The extruder mentioned in step (2) is preferably a parallel twin-screw extruder (HAAKE Process11 Hygienic, ThermoFisher Scientific Inc.).

[0025] The extrusion temperature mentioned in step (2) is divided into eight sections from the feeding section to the die section, and the heating temperatures are set to 35℃, 60℃, 90℃, 120℃, 160℃, 160℃, 160℃ and 140℃ respectively.

[0026] The cooling temperature mentioned in step (2) is 40°C, and the temperature is maintained at 40°C by circulating water through a long cooling mold.

[0027] The moisture content of the plant-based meat described in step (2) is preferably 55.72% to 59.25%.

[0028] The method of adding special Chlorella to improve the quality of plant-based meat is applied in the preparation of plant-based meat.

[0029] The present invention has the following advantages and effects compared with the prior art:

[0030] 1. This invention provides a method for preparing plant-based meat with a rich fibrous structure similar to animal meat and good digestibility. The prepared textured protein has a soft, elastic texture, and its tissue structure is significantly similar to animal muscle tissue, resulting in a good taste and excellent digestibility. In vitro digestion for 30 minutes yielded a digestibility rate exceeding 95%, a significant improvement compared to similar types of plant-based meat. Digestion experiments show that the plant-based meat prepared with the addition of a special type of Chlorella exhibits good digestibility, which is related to the observed porous network structure in its microstructure.

[0031] 2. This invention provides a method for preparing high-moisture extruded plant-based meat from soy protein isolate with added Chlorella, which further improves the extrusion performance of the material when the moisture content reaches 60%. The method includes sourcing a yellow, specialized Chlorella germplasm, fermentation preparation, nutritional component analysis, and finally compounding it with soy protein isolate. Using twin-screw high-moisture extrusion technology, by adjusting parameters such as the amount of specialized Chlorella added, extrusion temperature, and feeding speed, a texture-improved extrudate is obtained. This extrudate exhibits good elasticity and chewiness, and its hardness is significantly reduced. This invention employs twin-screw high-moisture extrusion technology, based on the mechanism of biomolecular interaction and the principle of protein molecule depolymerization and rearrangement, to regulate the quality of plant-based meat by controlling extrusion parameters and the amount of specialized Chlorella added.

[0032] 3. In this invention, the yellow Chlorella mutant strain CX41 is used as the algae strain. After fermentation, CX41 type yellow Chlorella powder is obtained and then added to soy protein isolate (including adding the freeze-dried algae powder directly to the soy protein isolate, or making freeze-dried powder after high-pressure homogenization and then adding it to the soy protein isolate). The added Chlorella CX41 algae powder is rich in nutrients, including protein (rich in essential amino acids), carbohydrates, dietary fiber, unsaturated fatty acids, lutein, and various vitamins. The starch, oil, and fiber contained therein, when added to high-moisture extrusion, significantly improve the texture of the extrudate. At the same time, the Chlorella CX41 has good processability and nutritional value, achieving a win-win situation in terms of texture and digestibility.

[0033] 4. This invention obtains a special Chlorella-soy protein isolate extrudate (plant meat) by adjusting extrusion parameters and the amount of special Chlorella added, using twin-screw extrusion technology. This can improve and regulate the texture and digestibility of plant meat, and further approach animal muscle tissue at the macroscopic level.

[0034] 5. This invention regulates the quality of extruded products by adjusting high-moisture process parameters, algae powder type (cell wall broken or non-cell wall broken) and addition amount, based on protein depolymerization and rearrangement, and macromolecular interactions during extrusion. Utilizing the excellent processing properties of a special Chlorella species, it yields a plant-based meat product with good color, greater elasticity and chewiness, and good digestibility. Its production process is simple and easy to promote, opening up new avenues for enhancing the quality and digestibility of plant-based meat, and providing new technologies for the application of Chlorella-based new resource foods in traditional and future plant-based meat. Attached Figure Description

[0035] Figure 1 The image shows the appearance characteristics and nutritional composition of Chlorella pyrenoidosa CX41 algal powder; where A represents Chlorella pyrenoidosa CX41 algal powder and B represents the main components of Chlorella pyrenoidosa CX4 algal powder.

[0036] Figure 2 The graph shows the effect of different addition amounts (soy protein isolate (SPI) to algae powder ratios of 100:0 (100SPI-0Ap), 95:5 (95SPI-5BAp, 95SPI-5Ap), 90:10 (90SPI-10BAp, 90SPI-10Ap), 85:15 (85SPI-15BAp, 85SPI-15Ap)) and different cooking zone temperatures (maximum extrusion cooking zone temperatures: 150, 160, 170℃) on the appearance of high-moisture extrudates (plant-based meat) of SPI and SPI-CX41 algae powder mixtures.

[0037] Figure 3 The figure shows the effect of different addition amounts (the ratio of soy protein isolate (SPI) to algae powder is 100:0 (100SPI-0Ap), 95:5 (95SPI-5BAp, 95SPI-5Ap), 90:10 (90SPI-10BAp, 90SPI-10Ap)) on the appearance of high-moisture extrudates of soy protein isolate and soy protein isolate-CX41 algae powder mixtures at a cooking zone temperature of 160℃.

[0038] Figure 4 The graph shows the effect of different addition amounts of broken or unbroken CX41 algae powder on the digestibility of high-moisture extrudates of soy protein isolate and soy protein isolate-CX41 algae powder mixtures.

[0039] Figure 5The effect of different addition amounts of broken or unbroken CX41 algae powder on the moisture distribution in high-moisture extrudates of soy protein isolate and soy protein isolate-CX41 algae powder mixture (in the figure, A21a represents bound water, A21b represents partially bound water, A22 represents bound water, and A23 represents free water).

[0040] Figure 6 The figure shows the effect of different addition amounts of broken or unbroken CX41 algae powder on the flavor of soy protein isolate and high-moisture extrudates of soy protein isolate-CX41 algae powder mixture; where A is the PCA principal component analysis and discrimination diagram of extruded textured protein; and B is the LDA linear discriminant analysis and contribution rate diagram of extruded textured protein.

[0041] Figure 7 The image shows the effect of different addition amounts of broken or unbroken CX41 algae powder on the flavor of high-moisture extrudates of soy protein isolate and soy protein isolate-CX41 algae powder mixture; where A is electronic tongue data and B is a radar chart of flavor composition based on RefSol reference solution. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field. Test methods in the following embodiments that do not specify specific experimental conditions are generally performed under conventional experimental conditions. Unless otherwise specified, the reagents and raw materials used in the present invention are all commercially available.

[0043] The special Chlorella strain used in this invention is the chlorophyll synthesis-deficient mutant strain CX41 of *Auxenochlorella pyrenoidosa* (Ap), which has been disclosed in Chinese patent (patent number: ZL 2023 105723078, titled: A Chlorophyll Synthesis-Deficient Mutant Strain of *Auxenochlorella pyrenoidosa* and its Application), with accession number GDMCC No:63357. This strain contains little or no chlorophyll and is rich in xanthophyll, exhibiting high growth and protein synthesis rates, and has no fishy odor. Its preparation method employs heterotrophic fermentation, including the following steps: germplasm activation, shake-flask transfer, fermenter culture, centrifugation, washing, freeze-drying, and pulverization to obtain the CX41 algal powder used in this invention (the specific culture method is the same as in Example 1 of the patent application for Chlorella culture). Figure 1A). The main components of CX41 algae powder were analyzed according to national standard methods (specific test methods: moisture content (GB / T 5009.3-2003 (Method 1); protein content (GB 5009.5-2010 (Method 1); crude fat (GB / T5009.6-2003 (Method 2); crude fiber (GB / T 5009.10-2003); dietary fiber (GB 28050-2011); ash content (GB 5009.4-2016 (Method 1))). The results showed that the main components of CX41 algae powder were as follows: Figure 1 As shown in B.

[0044] The CX41 algal powder involved in the embodiments and comparative examples of this invention was prepared by high-pressure homogenization, specifically through the following method: The special Chlorella (CX41) cultured in the above-mentioned fermenter was centrifuged to obtain algal slurry, which was mixed with deionized water at a ratio of 20g:80mL. The mixture was stirred at 160rpm for 20 minutes at room temperature to form a thorough suspension. This suspension was then added to a high-pressure homogenizer, and the cell wall was broken down using the breakage rate as an indicator. The pressure regulating valve of the homogenizer was slowly increased to 850bar, and the homogenization cycle was 5 times. The particle size distribution was detected using a laser particle size analyzer, showing that the average particle size of the CX41 algal cells decreased from the initial 3.2μm to 1.17μm, with 86.8% of the particles having a diameter below 1μm. Good suspension stability was observed when the mixture was allowed to stand in centrifuge tubes. The homogenized algal solution was pre-frozen at -20℃ and then freeze-dried. The freeze-dried algal powder was then pulverized in a grinder, and the algal powder passing through an 80-mesh sieve was reserved for later use.

[0045] The soy protein isolate used in the embodiments and comparative examples of this invention was purchased from Linyi Shansong Biological Products Co., Ltd.

[0046] Example 1

[0047] A nutritious and easily digestible plant-based meat product is simply made from the following raw materials: CX41 algae powder (average particle size approximately 1.17 μm) and soy protein isolate; the soy protein isolate contains 90% total protein, with the remainder being water and some lipids (approximately 9% water and 1% lipid). The CX41 algae powder and soy protein isolate are mixed at a mass ratio of 5:95 and thoroughly mixed for 30 minutes using a horizontal U-shaped dry powder mixer. The mixture is then fed into a feeder equipped with a twin-screw conveyor on a parallel twin-screw extruder (HAAKE Process11 Hygienic, ThermoFisher Scientific Inc.). The twin-screw extrusion conditions are: a fixed twin-screw speed of 175 rpm; the feed rate is determined to be 6 g / min under different material conditions, and the corresponding water feed rate is set to 9 mL / min (the water feed rate is calculated based on the material's moisture content). The extrusion process is divided into eight sections from the feeding section to the die section, with heating temperatures set at 35℃, 60℃, 90℃, 120℃, 160℃, 160℃, 160℃, and 140℃ respectively. The long cooling die is maintained at 40℃ by circulating water. During extrusion, a spatula is used to continuously feed material into the feeder to maintain a consistent material height in the feed hopper, preventing changes in the feeding rate due to gravity variations. The extrudate is collected, cooled to room temperature, and after removing surface condensation, it is placed in a vacuum bag to obtain plant-based meat. The moisture content of the extrudate was determined using the national standard method GB / T5497-85, and the measured value was 59.25%.

[0048] The macrostructure of the extruded material was observed, and the results are as follows: Figure 2 As shown, after adding 5% of broken CX41 algae powder, the extrudate (No.: 95SPI-5BAP 160℃ group) has a uniform texture, good fiberization and tearing properties, no damage, and is similar to real muscle fibers.

[0049] The microstructure of the extrudate was observed using scanning electron microscopy, and the results are as follows: Figure 3 As shown, adding a small amount of cell-wall broken CX41 algae powder resulted in a dense three-dimensional network structure in the extrudate, indicating that the extrudate in this embodiment has a good internal structure and can better absorb flavor during cooking.

[0050] Texture characteristics of the extrudates were characterized using a texture analyzer. Tear resistance was assessed by hand-tear test results, categorized as excellent, good, average, poor, and very poor. Texture testing (hardness, chewiness, and elasticity) was performed using a Brookfield CT3 texture analyzer (USA). The test mode was set to TPA mode. The extrudates were cut into 25mm square structures, with a P / 36R probe, a test speed of 1.0mm / s, and a deformation rate of 50%. The experiment was repeated three times. The results are shown in Table 1. The addition of CX41 algae powder significantly affected the extrudate texture, reducing its hardness. Adding 5% of broken CX41 algae powder significantly improved the extrudate's elasticity and chewiness.

[0051] Simulated digestion of the extruded product (plant-based meat) was performed, following the method described by Wu Kaiyun (Effects of Heat Treatment and Hot-Melt Extrusion on In Vitro Digestibility of Soy Protein [D]. South China University of Technology, 2022. DOI:10.27151 / d.cnki.ghnlu.2022.004382). The differences in digestibility of the extruded products were compared by calculating their in vitro digestibility. Three replicates were set up for the experiment. The results are as follows: Figure 4 As shown, the extrudate with 5% (mass fraction) of broken CX41 algae powder exhibits the best digestibility, achieving an in vitro digestibility of approximately 97% after 60 minutes. The final in vitro digestibility is about 33.6% higher than the control. This is positively correlated with the extrudate's excellent three-dimensional network structure, which increases the specific surface area in contact with digestive enzymes, thereby enhancing digestibility. Based on this, the extrudate prepared by this process can simulate animal meat tissue with a distinct fibrous structure, such as beef shank and pork tenderloin.

[0052] The distribution of water (bound water, partially bound water, restricted water, and free water) in extruded materials was determined using a nuclear magnetic resonance imaging (NMR) system (MNI20-040H-I type). Specifically, the samples were wrapped in transparent polytetrafluoroethylene (PTFE) plastic wrap and placed in a 40 mm probe for transverse relaxation time (T2). The T2 relaxation time test used a CPMG pulse sequence, with the waiting time (TW), echo time (TE), echo count (NECH), and scan count (NS) set to 12000 ms, 0.15 ms, 6000, and 8, respectively. The CPMG decay signal was inverted to a spin-spin T2 relaxation time distribution using T-invfit software and a multi-exponential fitting analysis program. All samples were tested three times. The results are as follows: Figure 5 As shown, the proportion of bound water in the extrudate increased and the proportion of bound water decreased when 5% of cell wall-broken CX41 algae powder was added, indicating that the extrudate has a higher bound water content, which in turn gives the extrudate better moisture stability.

[0053] Flavor and taste of the extruded material were determined. First, an electronic nose (electronic nose system, PEN3, AIRSENSE, Germany) was used to measure flavor changes. Specifically, after the sample was naturally thawed and brought to room temperature, it was cut into uniformly sized small pieces. 5g of sample was weighed into a clean 100mL beaker, sealed with double-layered plastic wrap, and allowed to stand at room temperature for 1 hour before testing. Three parallel samples were prepared for each sample. The direct headspace aspiration method was used, with the injection needle directly inserted into the sealed beaker containing the sample, and the sample was drawn into the electronic nose for measurement. The measurement conditions were set as follows: sampling time 1 second / group; sensor self-cleaning time 80 seconds; sensor zeroing time 5 seconds; sample preparation time 5 seconds; injection flow rate 400mL / min; analysis sampling time 80 seconds. All samples were tested in triplicate. The results are as follows: Figure 6 As shown, all extruded protein products exhibit a distinct odor, which is well-received by the electronic nose. The flavor of extrudates with added CX41 algae powder differs significantly from those without, while the difference between extrudates with and without CX41 algae powder is minimal. The main components causing this difference are (W1W) inorganic sulfides, (W5S) nitrogen oxides, and (W1S) short-chain alkanes. Therefore, the effect of adding CX41 algae powder on the flavor of extrudates is primarily contributed by algal proteins and algal oils, without the generation of any unpleasant odors.

[0054] The taste of the extruded material was determined using a taste analysis system (model: TS-5000Z) from INSENT Corporation, Japan. This device is equipped with an artificial lipid membrane sensor that simulates the taste perception mechanism of living organisms. It evaluates five basic tastes (sour, sweet, bitter, salty, and umami) and astringency by detecting changes in membrane potential generated by electrostatic or hydrophobic interactions between various taste substances and the artificial lipid membrane. Specifically, after thawing, the sample was cut into small pieces with scissors. 15g of the sample was weighed and placed in a beaker, and 150g of purified water (boiling water) was added. The water bath was preheated to 95℃. The beaker containing the sample was sealed with plastic wrap and placed in the water bath for 2 hours, then removed and allowed to stand at room temperature for 2 hours. The sample and water were then blended in a household food processor for 30 seconds, poured into centrifuge tubes, and centrifuged at 4000 rpm for 10 minutes. The supernatant was used for testing. A nearly tasteless solution (30mM potassium chloride + 0.3mM tartaric acid) was selected as the reference electrolyte. All samples were tested in triplicate. The results are as follows: Figure 7 As shown, the acidity, astringency, bitterness, and astringency aftertaste of the extrudate are all below the tastelessness point. The differences in taste are mainly reflected in the astringency, richness, and saltiness indicators. Compared with the group without added algae powder (Comparative Example 1), adding 5% cell-wall broken CX41 algae powder can reduce the richness of the extrudate's taste. The astringency, bitterness, and astringency aftertaste are all below the aftertaste point, indicating that the extrudate produced by this process is more suitable for subsequent seasoning and cooking of plant-based foods.

[0055] Example 2

[0056] A nutritious and easily digestible plant-based meat product is simply made from the following raw materials: uncrushed CX41 algae powder (average particle size of approximately 3.2 μm) and soy protein isolate, wherein the soy protein isolate contains 90% total protein, and the remaining components are water and some lipids (water content approximately 9%, lipid content approximately 1%). The uncrushed CX41 algae powder and soy protein isolate are mixed at a mass ratio of 5:95 and thoroughly mixed using a horizontal U-shaped dry powder mixer for 30 minutes. The mixture is then fed into a feeder equipped with a twin-screw conveyor on a parallel twin-screw extruder (HAAKE Process11 Hygienic, ThermoFisher Scientific Inc.). The twin-screw extrusion conditions are: a fixed twin-screw speed of 175 rpm; the flow rate of the feeder under different material conditions is tested, and the feed rate is determined to be 6 g / min, with a corresponding water feed rate set at 9 mL / min. The extrusion process is divided into eight sections from the feeding section to the die section, with heating temperatures set at 35℃, 60℃, 90℃, 120℃, 160℃, 160℃, 160℃, and 140℃ respectively. The long cooling die is maintained at 40℃ by circulating water. During extrusion, a spatula is used to continuously feed material into the feeder to maintain a consistent material height in the feed hopper, preventing changes in the feeding rate due to gravity variations. The extrudate is collected, cooled to room temperature, and after removing surface condensation, placed in a vacuum bag to obtain the extrudate. The moisture content of the extrudate was determined using the national standard method GB / T 5497-85, and the measured value was 58.49%.

[0057] The properties of the extrudate prepared in this embodiment were characterized by macroscopic structural observation, scanning electron microscopy, textural characterization, nuclear magnetic resonance, electronic nose, electronic tongue (i.e., taste analysis system), and simulated digestion (methods are the same as in Example 1). The results are as follows: Figures 2-7 As shown in Table 1. The results indicate that the extrudate prepared with 5% (mass fraction) of unbroken CX41 algae powder (group number: 95SPI-5AP 160℃) exhibits significantly different fiber characteristics compared to the group with 5% broken CX41 algae powder. It presents a similar sheet-like structure, and the surface morphology, observed by microstructure, shows a three-dimensional network structure, but is less uniform than the group with 5% broken CX41 algae powder. Regarding moisture distribution, the proportion of bound water is significantly increased, while the proportion of restricted water is not significantly different from the control group (Comparative Example 1). In terms of flavor, whether or not the CX41 algae powder is broken has little effect on the flavor. However, the addition of unbroken CX41 algae powder can reduce the astringency of the plant-based meat and further reduce its richness and saltiness. The digestibility is slightly lower than the extrudate with broken CX41, but not significantly. Extrudates prepared using this process can simulate poultry meat with a relatively tender fibrous structure, such as duck and chicken breast.

[0058] Example 3

[0059] A nutritious and easily digestible plant-based meat product is simply made from the following ingredients (with the addition of broken CX41 algae powder): broken CX41 algae powder (average particle size approximately 1.17 μm) and soy protein isolate; the soy protein isolate contains 90% total protein, with the remainder being water and some lipids (approximately 9% water and 1% lipids). The broken CX41 algae powder and soy protein isolate are mixed at a mass ratio of 10:90 and thoroughly mixed using a horizontal U-shaped dry powder mixer for 30 minutes. The mixture is then fed into a feeder equipped with a twin-screw conveyor on a parallel twin-screw extruder (HAAKE Process11 Hygienic, ThermoFisher Scientific Inc.). The twin-screw extrusion conditions are: a fixed twin-screw speed of 175 rpm; the feed rate was tested under different material conditions, and a feed rate of 6 g / min was determined, with a corresponding water feed rate of 9 ml / min. The extrusion process is divided into eight sections from the feeding section to the die section, with heating temperatures set at 35℃, 60℃, 90℃, 120℃, 160℃, 160℃, 160℃, and 140℃ respectively. The long cooling die is maintained at 40℃ by circulating water. During extrusion, a spatula is used to continuously feed material into the feeder to maintain a consistent material height in the feed hopper, preventing changes in the feeding rate due to gravity variations. The extrudate is collected, cooled to room temperature, and after removing surface condensation, placed in a vacuum bag to obtain the extrudate. The moisture content of the extrudate was determined using the national standard method GB / T5497-85, and the measured value was 56.75%.

[0060] The characteristics of the plant-based meat prepared in this example were characterized by macroscopic structural observation, scanning electron microscopy, textural characterization, nuclear magnetic resonance, and simulated in vitro digestion (methods were the same as in Example 1). The results are as follows: Figures 2-5 As shown in Table 1, the extrudate (No. 90SPI-10BAP, 160℃ group) prepared with more than 10% (mass fraction) of broken CX41 algae powder exhibited reduced fiber specificity. Compared with Example 1 with 5% broken CX41 algae powder, its hardness increased significantly, but its elasticity and chewiness decreased extremely significantly. The agglomerated microstructure resulted in lower digestibility of the plant-based meat in this example. This may be due to the excessive addition of CX41 algae powder inhibiting protein rearrangement in the cold zone mold, leading to agglomeration and reducing enzyme-substrate binding sites.

[0061] Example 4

[0062] A nutritious and easily digestible plant-based meat product is simply made from the following ingredients (with the addition of unbroken CX41 algae powder): unbroken CX41 algae powder (average particle size approximately 3.2 μm) and soy protein isolate; the soy protein isolate contains 90% total protein, with the remainder being water and some lipids (approximately 9% water and 1% lipid). The unbroken CX41 algae powder and soy protein isolate are mixed at a mass ratio of 10:90 and thoroughly mixed using a V-type dry powder mixer for 30 minutes. The mixture is then added to a feeder equipped with a twin-screw conveyor on a parallel twin-screw extruder (HAAKE Process 11 Hygienic, Thermo Fisher Scientific Inc.). The twin-screw extrusion conditions are: a fixed twin-screw speed of 175 rpm; the feed rate is determined to be 6 g / min under different material conditions, and the corresponding water feed rate is set to 9 mL / min. The extrusion process is divided into eight sections from the feeding section to the die section, with heating temperatures set at 35℃, 60℃, 90℃, 120℃, 160℃, 160℃, 160℃, and 140℃ respectively. The long cooling die is maintained at 40℃ by circulating water. During extrusion, a spatula is used to continuously feed material into the feeder to maintain a consistent material height in the feed hopper, preventing changes in the feeding rate due to gravity variations. The extrudate is collected, cooled to room temperature, and after removing surface condensation, it is placed in a vacuum bag to obtain the extrudate. The moisture content of the extrudate is measured and found to be 55.72%.

[0063] The properties of the extrudate prepared in this example were characterized by macroscopic structural observation, scanning electron microscopy, textural characterization, nuclear magnetic resonance, and simulated in vitro digestion (methods are the same as in Example 1). The results are as follows: Figures 2-5 As shown in Table 1, the fiber specificity of the extrudate prepared by adding more than 10% (mass fraction) of unbroken CX41 algal powder (No.: 90SPI-10AP, 160℃ group) was further reduced. Compared with Example 2 with 5% broken CX41 powder, there was no significant difference in hardness, but the elasticity and chewiness were significantly reduced. Its microstructure exhibited an aggregated state, resulting in a lower in vitro digestibility of the extrudate in this example. Under scanning electron microscopy, intact Chlorella could be seen. Under these conditions, the macroscopic fiberity of the sample increased, but the microstructure became more compact, resembling "dough," leading to slower and lower digestibility.

[0064] Comparative Example 1

[0065] The raw material composition of this comparative example consisted only of soy protein isolate, with a total protein content of 90%, and the remainder being water and some lipids (approximately 9% water and 1% lipids). The twin-screw extrusion conditions were as follows: a fixed twin-screw speed of 175 rpm; the feed rate was tested under different material conditions, and a feed rate of 6 g / min was determined, with a corresponding water feed rate of 9 ml / min. The extrusion process was divided into eight sections from the feed section to the die section, with heating temperatures set at 35℃, 60℃, 90℃, 120℃, 160℃, 160℃, 160℃, and 140℃, respectively. The long cooling die was maintained at 40℃ using circulating water. The extrudate was collected, cooled to room temperature, and after removing excess moisture, placed in a vacuum bag to obtain the extrudate. The moisture content of the extrudate was measured and found to be 57.83%.

[0066] The properties of the extrudate prepared in this comparative example were characterized by macroscopic structural observation, scanning electron microscopy, textural characterization, nuclear magnetic resonance, electronic nose, electronic tongue (i.e., taste analysis system), and simulated in vitro digestion (methods are the same as in Example 1). The results are as follows: Figures 2-7 As shown in Table 1, the extrudate without added Chlorella powder (No.: 100SPI-0AP, 160℃ group) exhibits an aggregated clump structure. Figure 3 ).

[0067] Comparative Examples 2-3

[0068] The method is the same as in Example 4, except that the amount of algae powder (broken CX41 algae powder and unbroken CX41 algae powder) added is increased from 10% to 15%, and the amount of soy protein isolate added is reduced from 90% to 85% (both are mass fractions). Other processing conditions are the same as in Example 4, and an extruded product of (broken) CX41 algae powder-soy protein isolate with an added amount of 15% is prepared. Among them, Comparative Example 2 added 15% broken CX41 algae powder, and Comparative Example 3 added 15% unbroken CX41 algae powder.

[0069] The properties of the extrudates prepared in Comparative Examples 2-3 were characterized by macroscopic structural observation and a texture analyzer (methods were the same as in Example 1), and the results are as follows. Figure 2 As shown in Table 1, Comparative Examples 2-3 revealed that, under the same conditions as Examples 1-4, increasing the CX41 algae powder content to 15% inhibited fiber formation in the extruded material, gradually forming a dough-like structure with poor tearability, resulting in breakage during tearing. This indicates that high levels of CX41 algae powder and broken-cell algae powder have a significant negative impact on the macroscopic texture structure of high-moisture extruded materials.

[0070] Comparative Examples 4-10

[0071] (1) Comparative Example 4, the method is the same as in Example 1, except that: the amount of broken CX41 algae powder added is 0% (no algae powder added), and the heating temperature is set to 35℃, 60℃, 90℃, 120℃, 150℃, 150℃, 150℃, 120℃ respectively, and the long cooling mold is kept at 40℃ by circulating water temperature control.

[0072] (2) Comparative Example 5, the method is the same as in Example 1, except that the heating temperature is set to 35℃, 60℃, 90℃, 120℃, 150℃, 150℃, 150℃, and 120℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of broken CX41 algae powder added is 5%).

[0073] (3) Comparative Example 6, the method is the same as in Example 2, except that the heating temperature is set to 35℃, 60℃, 90℃, 120℃, 150℃, 150℃, 150℃, and 120℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of unbroken CX41 algae powder added is 5%).

[0074] (4) Comparative Example 7, the method is the same as in Example 3, except that the heating temperature is set to 35℃, 60℃, 90℃, 120℃, 150℃, 150℃, 150℃, 120℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of broken CX41 algae powder added is 10%).

[0075] (5) Comparative Example 8, the method is the same as in Example 4, except that the heating temperature is set to 35℃, 60℃, 90℃, 120℃, 150℃, 150℃, 150℃, and 120℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of unbroken CX41 algae powder added is 10%).

[0076] (6) Comparative Example 9, the method is the same as in Example 1, except that: the amount of broken CX41 algae powder added is 15%, and the heating temperature is set to 35℃, 60℃, 90℃, 120℃, 150℃, 150℃, 150℃, 120℃ respectively, and the long cooling mold is kept at 40℃ by circulating water temperature control.

[0077] (7) Comparative Example 10, the method is the same as in Example 2, except that: the amount of unbroken CX41 algae powder added is 15%, and the heating temperature is set to 35℃, 60℃, 90℃, 120℃, 150℃, 150℃, 150℃, 120℃ respectively, and the long cooling mold is kept at 40℃ by circulating water temperature control.

[0078] The properties of the extrudates prepared in Comparative Examples 4-10 were characterized by macroscopic structural observation and a texture analyzer (methods were the same as in Example 1), and the results are as follows. Figure 2As shown in Table 1, Comparative Examples 4-10 reduced the extrusion temperature from 160°C in Examples 1-4 to 150°C. It was found that the temperature requirements of the extrusion process were further increased after adding either broken or unbroken CX41 algae powder. With the increase in algae powder content, the hardness decreased, while elasticity and chewiness also decreased simultaneously, resulting in a dough-like consistency with poor tearability and palatability. Comparative Example 10 exhibited extremely poor tearability in the tear test, almost impossible to tear.

[0079] Comparative Examples 11-17

[0080] (1) Comparative Example 11, the method is the same as in Example 1, except that: the amount of broken CX41 algae powder added is 0%, and the heating temperature is set to 50℃, 70℃, 90℃, 130℃, 170℃, 170℃, 170℃, and 150℃ respectively, and the long cooling mold is kept at 40℃ by circulating water temperature control.

[0081] (2) Comparative Example 12, the method is the same as in Example 1, except that the heating temperature is set to 50℃, 70℃, 90℃, 130℃, 170℃, 170℃, 170℃, and 150℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of broken CX41 algae powder added is 5%).

[0082] (3) Comparative Example 13, the method is the same as in Example 2, except that the heating temperature is set to 50℃, 70℃, 90℃, 130℃, 170℃, 170℃, 170℃, and 150℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of unbroken CX41 algae powder added is 5%).

[0083] (4) Comparative Example 14, the method is the same as in Example 3, except that the heating temperature is set to 50℃, 70℃, 90℃, 130℃, 170℃, 170℃, 170℃, and 150℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of broken CX41 algae powder added is 10%).

[0084] (5) Comparative Example 15, the method is the same as in Example 4, except that the heating temperature is set to 50℃, 70℃, 90℃, 130℃, 170℃, 170℃, 170℃, and 150℃ respectively, and the long cooling mold is kept at 40℃ by circulating water (the amount of unbroken CX41 algae powder added is 10%).

[0085] (6) Comparative Example 16, the method is the same as in Example 1, except that: the amount of broken CX41 algae powder added is 15%, and the heating temperature is set to 50℃, 70℃, 90℃, 130℃, 170℃, 170℃, 170℃, and 150℃ respectively, and the long cooling mold is kept at 40℃ by circulating water temperature control.

[0086] (7) Comparative Example 17, the method is the same as in Example 2, except that: the amount of unbroken CX41 algae powder added is 15%, and the heating temperature is set to 50℃, 70℃, 90℃, 130℃, 170℃, 170℃, 170℃, and 150℃ respectively, and the long cooling mold is kept at 40℃ by circulating water temperature control.

[0087] The properties of the extrudates prepared in Comparative Examples 11-17 were characterized by macroscopic structural observation and a texture analyzer (methods were the same as in Example 1), and the results are as follows: Figure 2 As shown in Table 1. Comparative Examples 11-17 further increased the extrusion temperature from 160°C in Examples 1-4 to 170°C. The results showed that the extruded material without CX41 algae powder exhibited large protein gel-like structures, with its fibrous structure completely lost. However, the addition of 5% cell-wall-broken CX41 algae powder could inhibit the formation of large protein gel-like structures and exhibit a certain degree of fibrous structure, but its degree of fibrosis was significantly worse than that of the examples with the same amount of added CX41 algae powder.

[0088] Table 1 Comparison of plant flesh texture and tearability between Examples 1-4 of the present invention and Comparative Examples 1-17 of the present invention

[0089] sample Hardness (Kg) Elasticity (mJ) Chewable (g) tearing Example 1 8.87 15.11 935.93 excellent Example 2 9.30 10.49 601.67 good Example 3 9.49 8.95 468.67 good Example 4 8.41 6.07 316.13 good Comparative Example 1 11.01 4.76 387.23 good Comparative Example 2 8.34 5.20 269.47 Poor Comparative Example 3 7.80 2.26 146.65 generally Comparative Example 4 9.21 4.69 342.60 generally Comparative Example 5 8.21 12.62 761.03 good Comparative Example 6 7.96 8.17 533.23 generally Comparative Example 7 8.81 4.02 250.00 Poor Comparative Example 8 7.83 4.09 280.67 Range Comparative Example 9 7.89 5.33 293.63 Range Comparative Example 10 6.79 2.26 218.00 Extremely poor quality (cannot be torn) Comparative Example 11 9.80 4.43 298.53 Extremely poor (no fiber formation) Comparative Example 12 8.65 7.33 624.60 generally Comparative Example 13 7.83 6.83 548.87 Poor Comparative Example 14 8.14 3.66 230.73 generally Comparative Example 15 8.34 4.72 325.90 Poor Comparative Example 16 8.98 4.93 363.40 Poor Comparative Example 17 8.54 1.88 128.37 Poor

[0090] The data analysis of the above examples and comparative examples shows that the high-moisture extrudate obtained by this invention has abundant fibrous tissue, and the addition of different types (broken or unbroken) of special Chlorella CX41 algal powder can play different roles. Among them, the extrudate of Example 1 has a relatively dense and uniform fibrous tissue, moderate hardness, good elasticity and chewiness, and a chewy texture. The main body is a pale yellow color that promotes appetite. Its moisture distribution shows that due to the uniform three-dimensional network gel structure of the main body of the extrudate, the proportion of bound water is significantly increased, indicating that the sample of Example 1 has better moisture stability. The changes in related flavor and taste were analyzed by electronic nose and electronic tongue. It was found that the addition of 5% CX41 algal powder did not cause any deterioration in flavor and taste, and reduced the richness of the flavor of the extrudate itself. This has a certain positive effect on the extrudate in subsequent cooking and seasoning processes. In vitro digestion experiments revealed that the extrudate with 5% CX41 algal powder exhibited an in vitro digestibility of over 95% within 30 minutes, significantly superior to high-moisture extruded plant-based meats reported concurrently, making it a viable alternative to pork tenderloin, beef shank, and similar products. In contrast, the extrudate described in Example 2 exhibited a fibrous, sheet-like structure with weaker elasticity and chewiness than Example 1, and its 30-minute digestibility of 90% was slightly lower than Example 1. This may be due to some unbroken algal powder reducing the in vitro digestibility. Figure 4 From the perspective of texture and digestibility, the extrudate of the present invention is suitable as a substitute for plant-based poultry and seafood such as chicken and fish, which have relatively weak elasticity and chewiness.

[0091] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for improving the quality of plant-based meat by adding a special type of Chlorella, characterized in that, Includes the following steps: (1) Mix the special Chlorella powder and soy protein isolate evenly to obtain a mixture; wherein, the amount of special Chlorella powder accounts for 5% to 10% of the total mass of the mixture; the special Chlorella powder is Chlorella protein-core protein that has undergone cell wall breaking treatment ( Auxenochlorella pyrenoidosa CX41 algae powder; (2) The mixture obtained in step (1) is extruded using a twin-screw extruder, and after cooling, excess water is removed to obtain an extruded material with a moisture content of 55% to 60%; wherein, the extrusion conditions are: the twin-screw fixed rotation speed is 175 rpm, the feeding speed is 6 g / min, the water feeding speed is 9 ml / min, the extrusion temperature is 160℃, and the extrusion cooling temperature is 40℃. The cell wall disruption process described in step (1) is performed using a high-pressure homogenizer. The specific steps are as follows: The cell wall disruption process is carried out using a high-pressure homogenizer, specifically by mixing the protein-nucleated Chlorella (… Auxenochlorella pyrenoidosa CX41 algal powder was added to water and stirred to form a suspension. Then it was added to a high-pressure homogenizer, the pressure was adjusted to 850 bar, the homogenization cycle was 5 times, the pH was adjusted to 6.5-7.0, the algal liquid was collected, freeze-dried, pulverized, and passed through an 80-mesh sieve to obtain Chlorella pyrenoidosa CX41 cell wall broken algal powder. The protein-nucleated Chlorella vulgaris (Chlorella vulgaris) that has undergone cell wall disruption treatment as described in step (1) Auxenochlorella pyrenoidosa The average particle size of CX41 algal powder is 1.17 μm; The extrusion temperature mentioned in step (2) is divided into eight sections from the feeding section to the die section, and the heating temperatures are set to 35℃, 60℃, 90℃, 120℃, 160℃, 160℃, 160℃ and 140℃ respectively.

2. The method according to claim 1, characterized in that: The extrusion cooling temperature mentioned in step (2) is maintained at 40°C by circulating water through a long cooling mold.

3. The method according to claim 1, characterized in that: The total protein content of the soy protein isolate described in step (1) is ≥90%.

4. The method according to claim 3, characterized in that: The total protein content of the soy protein isolate described in step (1) is 90%, the moisture content is 9%, and the lipid content is 1%.

5. The method according to claim 1, characterized in that: The amount of the special Chlorella powder mentioned in step (1) accounts for 5% of the total mass of the mixture.

6. The method according to claim 1, characterized in that: The ratio of Chlorella CX41 algal powder to water is 1 g: 4-5 mL; The stirring conditions are: stirring at 160-200 rpm for 20-30 minutes at room temperature.

7. The method according to claim 1, characterized in that: The mixing described in step (1) is carried out using a horizontal U-shaped dry powder mixer or a V-shaped dry powder mixer; The mixing time described in step (1) is 20 to 40 minutes.

8. The method according to claim 1, characterized in that: The extruder mentioned in step (2) is a parallel twin-screw extruder.

9. The application of the method for improving the quality of plant-based meat by adding special Chlorella as described in any one of claims 1 to 8 in the preparation of plant-based meat.

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