Processing method of fungal protein

Abstract

The invention relates to the technical field of food processing, in particular to a processing method of fungal protein. The technology provided by the invention is mainly applied to the treatment and modification of fungal proteins, and aims to improve the texture characteristics and digestion performance of the fungal proteins so as to produce substitute protein products with texture and mouth feel similar to those of meat. The technology is not only suitable for processing fungal protein products in the food industry, but also has wide application prospects including but not limited to fungal protein meat balls, fungal protein meat paste, fungal protein sausages and other food products without obvious fiber structures.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for processing fungal protein. Background Art

[0002] As people pay more and more attention to healthy diet and sustainable development, alternative protein products have gradually become a hot spot for research and development. Fungal protein has become an important source of alternative protein products due to its advantages such as high protein, high fiber, no cholesterol, low production cost and environmental sustainability. At present, fungal protein products have been widely used in many countries around the world, such as the United States, Canada, the United Kingdom, Germany and France.

[0003] Traditional fungal protein production methods usually include fermentation, centrifugation, ingredient mixing, steaming, freezing and other steps to imitate the fiber structure and taste of meat. However, there are still certain limitations in the quality characteristics and digestibility of fungal protein. Studies have shown that freezing treatment can affect the gel properties and digestibility of protein, thereby affecting the texture and taste of the product. For example, after the freezing process, the microenvironment of the protein molecules of fungal protein changes, and it is easy to release water, resulting in a decrease in water retention capacity, which in turn affects the texture and taste of the product. In addition, the digestibility of fungal protein needs to be improved. There are indigestible cell wall components in fungal protein, especially polysaccharides such as chitin and glucan, which are difficult to be digested by the human body, thereby limiting the digestibility and utilization of fungal protein.

[0004] As a non-thermal food processing technology, ultrasonic treatment technology can effectively change the physical and chemical properties of food by using the cavitation effect produced by high-frequency sound waves in liquid media. Ultrasonic treatment has been widely used in the processing of meat, dairy products, fruits and vegetables, and has the advantages of improving texture, increasing nutritional value and extending shelf life. For example, ultrasonic treatment can significantly improve the in vitro digestibility of buckwheat protein isolate (Jin J., Okagu OD, Yagoub AEA, et al. Effects of sonication on the in vitro digestibility and structural properties of buckwheat protein isolates[J].). However, the application research of ultrasonic treatment in fungal protein processing is still relatively limited, especially in optimizing ultrasonic treatment parameters to improve the quality and digestibility of fungal protein products, which needs further exploration. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a processing method of fungal protein in view of the shortcomings of the prior art, thereby significantly improving the texture characteristics and digestibility of fungal protein products, especially improving their water retention and digestibility, so as to meet consumers' demand for high-quality alternative protein products.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for processing fungal protein comprises the following steps: subjecting the fungal protein fermentation liquid obtained after fungal fermentation to heat treatment and centrifugation to obtain a fungal protein paste, dissolving the fungal protein paste in water to obtain a fungal protein suspension, and finally subjecting the suspension to ultrasonic treatment to obtain the product.

[0007] The ultrasonic treatment is carried out under the following conditions: power 200-600 W, time 5-45 min, frequency 20-40 kHz, temperature 5-20° C.

[0008] Among them, the fermentation medium formula used for the fungal fermentation is: 50 g / L glucose, 4 g / L potassium dihydrogen phosphate, 2 g / L magnesium sulfate heptahydrate, 1.8 g / L citric acid monohydrate, and 3 g / L ammonium sulfate; the fermentation conditions are: 25~30℃, and the pH value is maintained at 5.5~6.5 by ammonia water.

[0009] Wherein, the fungus includes but is not limited to Fusarium Fusarium venenatum Neurospora crassa Neurospora crassa Aspergillus oryzae Aspergillus oryzae and shiitake mushrooms Lentinula edodes Any one of the fungi used to prepare fungal protein products in the prior art is suitable for the present invention.

[0010] In some embodiments of the present invention, the fungus is Fusarium Fusarium venenatum , specifically Fusarium Fusarium venenatum A3 / 5.

[0011] The heat treatment is carried out under the following conditions: temperature 62-72°C and time 40-45 min.

[0012] Wherein, the centrifugation condition is: 5000-6000 rpm for 10-20 min.

[0013] Wherein, the mass volume ratio of the fungal protein paste to water is 1:10.

[0014] The ultrasonic treatment is carried out under the following conditions: power 400-600 W, time 30-45 min, frequency 25-30 kHz, temperature 8-10°C.

[0015] Preferably, the ultrasonic treatment is carried out under the following conditions: power 400W or 600W, time 30-45 min, frequency 25-30kHz, temperature 8-10°C.

[0016] More preferably, the ultrasonic treatment is carried out under the following conditions: power 400 W or 600 W, time 30 or 45 min, frequency 25-30 kHz, temperature 8-10°C.

[0017] Most preferably, the ultrasonic treatment is carried out under the following conditions: power 400W or 600W, time 30 min, frequency 25-30kHz, temperature 8-10°C.

[0018] The fungal protein paste obtained by centrifuging the ultrasonically treated fungal protein suspension at 5500 rpm for 10 min was evenly mixed with other ingredients, and then heated and frozen to prepare the corresponding fungal protein product.

[0019] The other ingredients include but are not limited to any one or a combination of water, protein powder, wheat gluten, calcium salt, sodium salt, spices, carrageenan, wheat fiber and pea fiber.

[0020] The heating conditions are as follows: heating in a water bath at 80-90°C for 30 min; the cooling conditions are as follows: cooling at 4°C for 3 hours, and finally freezing at -20°C for two weeks.

[0021] Among them, the fungal protein products include but are not limited to fungal protein meatballs, fungal protein meat paste, and fungal protein sausages. Fungal protein foods without obvious fiber structure in the prior art are all within the scope of protection of the present invention.

[0022] Beneficial effects: (1) Improving water retention: The ultrasonic treatment of the present invention significantly improves the water retention capacity of the fungal protein product and improves its texture and taste.

[0023] (2) Enhanced digestibility: The ultrasonic treatment of the present invention improves the in vitro digestibility of fungal protein by destroying the cell wall structure of fungal protein, thereby increasing the nutritional utilization of fungal protein.

[0024] (3) Simple process: The process flow of the present invention is simple and easy to industrialize, and is suitable for large-scale production of high-quality fungal protein products.

[0025] (4) Wide application: The present invention provides a process for significantly improving the quality and digestibility of fungal protein products by ultrasonic treatment. The process is applicable to a variety of fungal proteins, including but not limited to Fusarium venenatum , Neurospora crassa , Aspergillus oryzae , Lentinula edodesIn addition, the present invention can be applied to a variety of fungal protein products, including but not limited to: fungal protein meatballs, fungal protein meat paste, fungal protein sausages and other foods without obvious fiber structure, so it has broad application prospects and significant industrial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described in detail below with reference to the accompanying drawings, and the above and / or other advantages of the present invention will become more clear.

[0027] Figure 1 The microstructure of fungal protein changes after different ultrasonic powers (200, 400, 600 W) and times (15, 30, 45 min).

[0028] Figure 2 The particle size (D43) of fungal protein changes after different ultrasonic powers (200, 400, 600W) and times (15, 30, 45min).

[0029] Figure 3 Viscosity curves of fungal protein after different ultrasonic powers (200, 400, 600 W) and times (15, 30, 45 min).

[0030] Figure 4 The secondary structure of fungal protein was transformed after different ultrasonic powers (200, 400, 600 W) and times (15, 30, 45 min).

[0031] Figure 5 The digestibility of fungal protein changes with different ultrasonic powers (200, 400, 600 W) and times (15, 30, 45 min).

[0032] Figure 6 Changes in the texture properties of fungal protein products prepared with different ultrasonic powers (200, 400, 600 W) and times (15, 30, 45 min), including (a) elasticity; (b) hardness; (c) chewiness. DETAILED DESCRIPTION

[0033] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0034] In the following embodiments, the Fusarium Fusarium venenatum A3 / 5 comes from the American Type Culture Collection (AATCC), and the strain number is: ATCC20334.

[0035] Example 1: A processing method for changing the quality and digestibility of fungal protein products using ultrasonic treatment 1. Fermentation: Ferment the fungus Fusarium Fusarium venenatum After A3 / 5 was activated in a PDA plate, it was inoculated into the following culture medium: 50 g / L glucose, 4 g / L potassium dihydrogen phosphate, 2 g / L magnesium sulfate heptahydrate, 1.8 g / L citric acid monohydrate, and 3 g / L ammonium sulfate; shake flask culture was performed, and then inoculated into a fermenter at an inoculum of 5% v / v for continuous fermentation. The fermentation conditions were 25-30°C, the pH value was maintained between 5.5 and 6.5, and the fermentation was performed for 24 hours to obtain the fermentation liquid.

[0036] 2. Heat treatment: After fermentation, the fermentation liquid is heat treated to activate the RNase in the fungus, reduce the RNA content in the fungal protein, and inactivate the fungus. The heat treatment temperature is 62~72℃ and lasts for 45 minutes.

[0037] 3. Centrifugation: Centrifuge the heat-treated fermentation broth at 5000-6000 rpm for 10-20 min to obtain a fungal protein paste.

[0038] 4. Preparation of fungal protein solution: dissolve the fungal protein paste obtained by centrifugation in water at a solution ratio of 1:10 (mass / volume ratio) to fully disperse the fungal protein in water to obtain a fungal protein suspension.

[0039] 5. Ultrasonic treatment: Place the fungal protein suspension in an ice bath for ultrasonic treatment, maintain the treatment temperature at 5~20℃ to prevent the thermal effect on the fungal protein, and treat it at different ultrasonic treatment powers (200, 400, 600 W) and different treatment times (15, 30, 45 min) at an ultrasonic frequency of 20~40 kHz.

[0040] The protein suspension after ultrasonic treatment was centrifuged at 5500 rpm for 10 min to obtain fungal protein paste, and the fungal protein sample was characterized from the following aspects. The fungal protein paste without ultrasonic treatment was used as the control.

[0041] (1) Microstructure observation The fungal protein pastes under different ultrasonic treatment conditions were placed on a glass slide and observed in the bright field using an upright microscope (BX51, Olympus Corporation, Japan) at a magnification of 20 times, and photographed and recorded using the microscope camera.

[0042] The results are as follows Figure 1 As shown in the figure, it can be seen that the mycelial structure of the control group (CK) is complete and clear. Under the conditions of 200 W and 15 min of ultrasonic treatment, the mycelial structure remains intact; but when the ultrasonic power exceeds 400 W, the mycelium begins to be destroyed. Under the treatment conditions of 600 W and 400 W and 45 min, the mycelial structure is severely damaged and granular.

[0043] (2) Particle size analysis The particle size of the fungal protein paste was analyzed using a laser particle size analyzer (Mastersizer 3000, Malvern Instruments, UK). Deionized water was used as the dispersion medium, and the refractive index of the dispersed phase was set to 1.33. The laser shielding level ranged from 8% to 20%. The refractive index and absorbance of the sample were standardized to 1.7 and 0.001, respectively.

[0044] The results are as follows Figure 2 As shown in the figure, it can be seen that with the increase of ultrasonic time and power, the size of mycelium particles gradually decreased, especially when treated at 600W for 30 min, 400W and 600W for 45 min, the mycelium was almost completely broken into fine particles.

[0045] (3) Rheological curve of ultrasonically treated fungal protein paste The rheological properties of mycoprotein paste were evaluated using a dynamic rheometer (MCR301, Anton Paar Ltd., Austria). The geometry of the parallel plates was 50 mm in diameter and 1 mm in gap. The mycoprotein paste was evenly coated on the parallel plates and the gap was adjusted to 1 mm. Then, the plates were equilibrated at 25 °C for 30 s to reach the test temperature. The apparent viscosity was tested within the shear rate range of 0.01 to 100 s⁻¹ at 25 ± 1 °C.

[0046] The results are as follows Figure 3 As shown in the figure, compared with the control group (CK), the flow resistance and viscosity of the fungal protein paste after ultrasonic treatment were lower. With the increase of ultrasonic power and time, the viscosity gradually decreased.

[0047] (4) Determination of moisture distribution of fungal protein 2.50 g of fungal protein paste was placed in a specific sample tube, and then the signal was collected at the center of the RF coil of the magnet box. The instrument parameters were set as follows: temperature 32 °C, resonance frequency 40 MHz. The spin relaxation time (T2) was measured by the CPMG pulse sequence. The parameters were set as follows: SW=100 kHz, RFD=0.080 s, Tw=2000 ms, RG1=20.0 db, TD=89990, DRG1=3, NS=4, DR=1, TE=0.3 ms, NECH=3000. The CPMG exponential decay curve was inverted by Multi Exp-Inv Analysis software.

[0048] The results are shown in Table 1. As can be seen from the table, there is no obvious change trend in the bound water (p2b) of each group, which indicates that ultrasonic treatment does not change the bound water in fungal protein. In the ultrasonic treatment group, the peak area ratio of immobile water (i.e. p21 in the table) increased, and the peak area ratio of free water (i.e. p22 in the table) decreased. (1) When the ultrasonic power was 200 W for 15-45 min or 200-600 W for 15 min, the peak area ratio of immobile water decreased and the peak area ratio of free water increased with the passage of time, indicating that 200 W ultrasonic power and 15 min did not enhance the water holding capacity of fungal protein; (2) When the ultrasonic power was 400 W for 15-45 min, the peak area ratio of immobile water began to increase, and the effects of treatment for 30 min and 45 min were similar; when the ultrasonic power was 200-600 W for 30 min, with the increase of ultrasonic power, the transformation of free water into immobile water was obvious, and the effect of 600 W ultrasonic treatment for 30 min was better than that of 400 W ultrasonic treatment for 45 min. The above results indicate that when the ultrasonic time starts from 30 min, free water begins to transform into immobile water, and ultrasonic power has a greater influence on the transformation of the two than time; (3) When the ultrasonic power was 600 W for 15-45 When the ultrasonic power was 200-600 W for 45 min, the conversion of free water to non-flowing water first increased and then decreased. When the ultrasonic power was 200-600 W for 45 min, the treatment effects of 400 W and 600 W were equivalent. This shows that it is not possible to continuously enhance the water holding capacity of fungal protein by simply increasing the ultrasonic power and time. It is necessary to be within a specific ultrasonic power and time range. After 600 W ultrasonic treatment for 30 min, the non-flowing water ratio reached the highest value, accounting for 95.3%; the free water ratio dropped to the lowest point. This shows that ultrasonic treatment affects the water distribution in fungal protein paste and promotes the conversion of free water to non-flowing water. This shows that ultrasonic treatment conditions under a specific range can enhance the water holding capacity of fungal protein.

[0049] Table 1 Effects of different ultrasonic treatments on moisture distribution of fungal protein

[0050] (5) Determination of secondary structure of fungal proteins The fungal protein paste was diluted to 0.1 mg / mL with ultrapure water and then transferred to a quartz sample cell with an optical path of 0.1 cm and measured in the range of 260–195 nm at a scanning speed of 100 nm / min at 25 °C.

[0051] The results are as follows Figure 4As shown in the figure, compared with the control group (CK), the proportion of α-helix decreased and the proportion of random coil structure increased in all ultrasonic treatment groups. With the increase of ultrasonic intensity and duration, the α-helix content first decreased and then increased when treated with 400 W for 15-45 min, and first increased and then decreased when treated with 600 W for 15-45 min, but the overall trend of α-helix content was significantly decreased; while the random coil structure was in a trend of first increasing and then decreasing, but it was still increased compared with the control. The above results show the transition of fungal protein structure to a disordered state. This trend is consistent under different ultrasonic powers and durations, especially at 600 W for 45 min, the β-fold content increased significantly, indicating that strong ultrasonic conditions may promote the formation of this structure. The reduction of α-helix and the increase of β-fold and random coil indicate that ultrasound has a significant effect on protein structure. The random coil structure is more accessible and vulnerable to enzyme attack, indicating that the digestion properties of fungal protein may be enhanced.

[0052] (6) In vitro digestibility determination The in vitro digestion model was based on the INFOGEST method (Brodkorb, A., Egger, L., Alminger, M., et al. INFOGEST static in vitro simulation of gastrointestinal food digestion [j].). 2.5 g of fungal protein paste was taken, mixed with 7.8 mL of simulated gastric fluid (the formula of simulated gastric fluid SGF is shown in Table 2) and homogenized at 6000 rpm for 30 seconds. The mixture was then acidified to pH 3.0 with 6 M HCl, and CaCl2·2H2O was added to a final concentration of 0.075 mM. Next, pepsin was added to a final concentration of 2000 U / mL. After homogenization, the mixture was incubated at 37°C for 2 hours. Finally, the pH was adjusted to 7.0 with 1 M NaOH to terminate the enzyme reaction.

[0053] The digested pepsin-treated product was mixed with 10 mL of simulated intestinal fluid (the formula of simulated intestinal fluid SIF is shown in Table 2) and the pH was neutralized to 7.0. CaCl2·2H2O, bile salts, and trypsin were added to the mixed solution so that the final concentrations of CaCl2, bile salts, and trypsin were 0.3 mmol / L, 10 mmol / L, and 200 U / mL, respectively. The reaction was allowed to proceed at 37°C for 2 hours and terminated by heating in a 95°C water bath for 5 minutes.

[0054] The simulated digestive fluid was prepared according to Table 2, wherein the pH of simulated gastric fluid (SGF) was adjusted to 3, and the pH of simulated intestinal fluid (SIF) was adjusted to 7. Finally, the volume was fixed to 400 mL with distilled water and stored at -4°C for later use.

[0055] Table 2 Configuration of simulated digestive fluid

[0056] The hydrolyzates from the stomach and intestine were mixed with anhydrous ethanol at a ratio of 1:3 and stored at 4°C for 12 h. They were then centrifuged at 10,000 rpm for 20 min at 4°C and the supernatant was discarded. The protein content in the fungal protein samples before and after digestion was determined using the Kjeldahl method. The in vitro digestibility was calculated as follows: .

[0057] Wherein, DT represents protein digestibility, m0 represents the protein content in fungal protein paste before digestion (g), and m1 represents the protein content in precipitate after digestion (g).

[0058] The results are as follows Figure 5 As shown in the figure, it can be seen that in the gastric digestion stage, different ultrasonic treatments have no significant effect on the digestibility ( P >0.05). However, in the intestinal stage, the digestibility of each group was higher than that of the control group (CK). When the ultrasonic power was 200 W, the intestinal digestibility of fungal protein increased with the increase of treatment time; but when the ultrasonic power was 400 W and 600 W, the intestinal digestibility was in a state of first increasing and then decreasing. This indicates that ultrasonic treatment destroyed the mycelium and protein structure, exposing more restriction sites, thereby improving gastrointestinal digestibility. The subsequent decrease in digestibility may be due to excessive ultrasonic treatment leading to partial deconstruction or aggregation of proteins, changing their tertiary structure and surface properties, thereby affecting the binding efficiency of proteins with digestive enzymes such as pepsin and trypsin. This structural change may make it more difficult for digestive enzymes to effectively degrade protein molecules.

[0059] Example 2: Preparation of fungal protein sausage 1. Fermentation: After Fusarium venenatum A3 / 5 was activated on a PDA plate, it was inoculated into a culture medium (glucose 50 g / L, potassium dihydrogen phosphate 4 g / L, magnesium sulfate heptahydrate 2 g / L, citric acid monohydrate 1.8 g / L, ammonium sulfate 3 g / L) for fermentation. The fermentation conditions were 28°C, pH was maintained at 6.0, and the fermentation time was 24 hours to obtain a fermentation liquid.

[0060] 2. Heat treatment: After fermentation, heat the fermentation broth to reduce the RNA content in fungal protein. Heat the fermentation broth to 70°C for 40 min.

[0061] 3. Centrifugation: Centrifuge the heat-treated fermentation broth at 5000 rpm for 15 min to obtain fungal protein paste.

[0062] 4. Preparation of fungal protein solution: The fungal protein paste obtained by centrifugation is dissolved in water at a solution ratio of 1:10 (mass / volume ratio), so that the fungal protein is dispersed in water to obtain a fungal protein suspension.

[0063] 5. Ultrasonic treatment: The fungal protein suspension was subjected to ultrasonic treatment. During the treatment, the fungal protein solution was placed in an ice bath to maintain the treatment temperature at 8°C, the ultrasonic treatment power was 500 W, the treatment time was 30 min, and the ultrasonic frequency was 30 kHz. The ultrasonically treated fungal protein suspension was then centrifuged at 5500 rpm for 10 min to obtain a fungal protein paste.

[0064] 6. Ingredient mixing: evenly mix the ultrasonically treated fungal protein paste with ingredients (15% water, 5% protein powder, 5% wheat gluten, 0.3% calcium salt, 0.5% sodium salt, 0.8% spices, 1.5% carrageenan, 3% wheat fiber and 1% pea fiber) to form a mixture.

[0065] 7. Sausage shaping: Put the mixture into collagen casing with a diameter of 12 mm and use a sausage stuffer to fill it to ensure that the sausage is evenly shaped and free of air.

[0066] 8. Heating and cooling: Boil the filled fungal protein sausage in 80℃ hot water for 30 minutes to make the core temperature reach above 70℃ to ensure that the fungal protein sausage is fully cooked. Cool the cooked fungal protein sausage in a refrigerator at 4℃ for 2 hours.

[0067] 9. Freezing and storage: The cooled fungal protein sausage is placed in a freezer at -18°C for two weeks to improve the texture and taste of the fungal protein sausage.

[0068] The texture characteristics of the fungal protein sausages were evaluated using a texture analyzer (TA-XT2i, Stable Micro Systems Ltd., UK). Cylindrical fungal protein sausages with a diameter of 1.2 cm and a thickness of 1.4 cm were precisely cut using a parallel knife. The probe was selected (P 0.5), and the operating parameters were set at a test speed of 1 mm / s, and the pre-test and post-test speeds were set at 5 mm / s. There was a 3-second interval between the two cyclic compression tests.

[0069] The results are as follows Figure 6As shown in the results, the experimental results show that compared with the control group (CK), whether it is 200W, 400W or 600W, the effect on food elasticity is small, and the ultrasonic time only shows a significant effect when it increases to 45 min. When the ultrasonic power exceeds 200 W, the hardness and chewiness of the product are significantly reduced. When the ultrasonic power is set to 400 W, the hardness and chewiness of the product gradually decrease with the increase of ultrasonic time. Similarly, this trend is observed at 600 W. In particular, after the ultrasonic treatment lasts for 45 minutes, the hardness of the product is reduced by half. These changes may be attributed to the rupture of the mycelium structure caused by the ultrasonic cavitation effect, and the increase in ultrasonic time leads to more mycelium fragmentation. It is worth noting that when the ultrasonic power is 600 W and the treatment time reaches 45 minutes, the hardness and chewiness of the product are reduced to the lowest, but too low hardness and chewiness will cause the product structure to be soft and loose, which is not conducive to simulating the texture characteristics of meat products. Its taste may be too soft and glutinous, lacking chewiness, thus affecting consumer acceptance. In fact, under certain conditions, excessive ultrasonic treatment may adversely affect the textural properties of the product, indicating the need for precise control of processing parameters when applying ultrasound technology to improve food texture.

[0070] Example 3: Preparation process of ultrasonically treated fungal protein meatballs 1. Fermentation: After the Fusarium venenatum A3 / 5 strain was activated on a PDA plate, it was inoculated into a culture medium (glucose 50 g / L, potassium dihydrogen phosphate 4 g / L, magnesium sulfate heptahydrate 2 g / L, citric acid monohydrate 1.8 g / L, ammonium sulfate 3 g / L) for fermentation. The fermentation conditions were 28°C, the pH value was maintained at 6.0, and the fermentation time was 24 hours to obtain a fermentation liquid.

[0071] 2. Heat treatment: After fermentation, heat the fermentation broth to reduce the RNA content in fungal protein. Heat the fermentation broth to 68°C for 45 minutes.

[0072] 3. Centrifugation: Centrifuge the heat-treated fermentation broth at 5500 rpm for 10 min to obtain fungal protein paste.

[0073] 4. Preparation of fungal protein solution: The fungal protein paste obtained by centrifugation is dissolved in water at a solution ratio of 1:10 (mass / volume ratio), so that the fungal protein is dispersed in water to obtain a fungal protein suspension.

[0074] 5. Ultrasonic treatment: The fungal protein suspension was subjected to ultrasonic treatment. During the treatment, the sample was placed in an ice bath to maintain the treatment temperature at 10°C, the ultrasonic treatment power was 400 W, the treatment time was 30 min, and the ultrasonic frequency was 25 kHz. The protein suspension after ultrasonic treatment was then centrifuged at 5500 rpm for 10 min to obtain fungal protein paste.

[0075] 6. Ingredient mixing: mix the ultrasonically treated fungal protein paste and ingredients (64% fungal protein paste, 2% egg white protein powder, 3% wheat gluten, 0.2% calcium salt, 0.3% sodium salt, 0.5% spices, 1% carrageenan, 2% wheat fiber and 2% pea fiber) to form a mixture.

[0076] 7. Forming and heating: Divide the mixture into small balls of about 20 grams and roll them into meatballs manually. Heat the meatballs in a 90℃ water bath for 30 minutes until the center temperature reaches above 70℃ to ensure that the meatballs are fully cooked and form a stable structure.

[0077] 8. Cooling and freezing: Cool the heated meatballs in a refrigerator at 4°C for 3 hours. Then put the cooled meatballs in a freezer at -20°C for two weeks to improve the texture and taste of the meatballs.

[0078] The results showed that the ultrasonically treated fungal protein meatballs showed significant texture changes, specifically the reduction of product hardness and chewiness, which was attributed to the cavitation effect during ultrasonic treatment, which led to the destruction of the mycelial structure and reduced the mechanical strength of the gel fiber system in the fungal protein product. The taste and texture of the product were changed, making the fungal protein meatballs softer and closer to traditional meat products. In terms of digestion performance, ultrasonically treated fungal protein meatballs showed higher digestibility in in vitro simulated digestion experiments. This is mainly because ultrasonic treatment exposes more enzyme cleavage sites to the mycelium and changes the secondary structure of the protein. This structural change increases the contact area between the digestive enzyme and the protein, thereby promoting protein digestion. Therefore, ultrasonically treated fungal protein meatballs have potential advantages in providing higher nutrient utilization, which meets the development needs of modern healthy foods.

[0079] The present invention provides a method and idea for processing fungal protein. There are many methods and approaches to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A method for processing fungal protein, characterized in that: The fungal protein fermentation liquid obtained after fungal fermentation is subjected to heat treatment and centrifugation to obtain a fungal protein paste, and the fungal protein paste is dissolved in water to obtain a fungal protein suspension, and finally subjected to ultrasonic treatment to obtain the fungal protein suspension; Wherein, the fungus is Fusarium Fusarium venenatum A3 / 5; The ultrasonic treatment is carried out under the following conditions: power 200-600 W, time 15-45 min, frequency 20-40 kHz, temperature 5-20° C.

2. The method according to claim 1, characterized in that: The heat treatment has the following treatment conditions: temperature 62-72° C., time 40-45 min.

3. The method according to claim 1, characterized in that The centrifugation conditions are: 5000-6000 rpm for 10-20 min.

4. The method according to claim 1, characterized in that: The mass volume ratio of the fungal protein paste to water is 1:

10.

5. The method according to claim 1, characterized in that: The ultrasonic treatment is carried out under the following conditions: power 400-600 W, time 30-45 min, frequency 25-30 kHz, temperature 8-10° C.

6. The method according to claim 1, characterized in that The ultrasonic treatment is carried out under the following conditions: power 400W or 600W, time 30-45 min, frequency 25-30 kHz, temperature 8-10°C.

7. The method according to claim 1, characterized in that The ultrasonic treatment is carried out under the following conditions: power 400W or 600W, time 30 or 45 min, frequency 25-30 kHz, temperature 8-10°C.

8. The method according to claim 1, characterized in that The ultrasonic treatment is carried out under the following conditions: power 400W or 600W, time 30 min, frequency 25-30 kHz, temperature 8-10°C.

Images