Functional microcapsule ingredient and soy sauce complex fermentation process

Abstract

The present application belongs to the technical field of soy sauce brewing, and particularly relates to a functional microcapsule component and soy sauce compound fermentation process. The present application carries out enzymatic pretreatment on the functional core material before microencapsulation, abandons the traditional single wall material idea, adopts a three-dimensional composite network wall material system, and strictly sets the microcapsule adding node at the ripening period of soy sauce original juice fermentation, avoiding the strongest fermentation early stage of aspergillus enzyme activity, thereby completely avoiding the risk of wall material being enzymatically destroyed, adopting ultra-low speed stirring and sterile nitrogen micro-positive pressure protection for ripening fermentation, and being a brand new functional soy sauce production process. The present application successfully solves the technical contradiction between the stability of functional factors and the basic quality of soy sauce, so that the functional soy sauce realizes the dual goals of long-acting function stability and excellent sensory quality without affecting the fermentation quality.

Description

Technical Field

[0001] This invention belongs to the field of soy sauce brewing technology, and particularly relates to a compound fermentation process of functional microencapsulated components and soy sauce. Background Technology

[0002] Traditional soy sauce production relies primarily on long-term fermentation by microorganisms such as Aspergillus oryzae at specific temperatures and salinities. As the modern food industry moves towards functionalization, incorporating medicinal and edible components and natural antioxidants into the soy sauce system has become a core strategy for product differentiation. Currently, the mainstream process for introducing functional factors into the soy sauce system involves blending them into the finished product after fermentation. After the mash has fully fermented, various functional extracts are directly added to the finished soy sauce base liquid, simply stirred, sterilized, and bottled, without participating in the fermentation process. Many leading soy sauce brands on the market use this method for their functional soy sauces. While this method is simple and has a short production cycle, soy sauce itself is a complex, multiphase system with high salt (15%–18% NaCl), weak acid (pH 4.5–5.5), and rich in free amino acids and inorganic ions. Directly adding unprotected functional ingredients can easily lead to oxidation, discoloration, hydrolysis, precipitation, or severe off-flavors. Some manufacturers are currently attempting to add functional ingredients during in-situ co-fermentation in the koji-making stage, directly introducing them into the process. However, this method suffers from the drawback of large-scale degradation and inactivation of functional factors, leading to various problems such as flavor imbalance, prominent off-flavors, uncontrolled color, and premature browning. Furthermore, the active substances without protective wall materials exhibit extremely poor long-term storage stability. Ordinary emulsifiers alone cannot withstand high-salt and weakly acidic environments, and within a few months of storage at room temperature, separation, oil floating, and sedimentation are likely to occur, making it difficult for the product to reach a shelf life of 12 months. Therefore, a new functional soy sauce preparation process needs to be developed.

[0003] To address the issue of active ingredient inactivation, existing technologies employ microencapsulation to protect functional core materials. However, traditional microencapsulation systems are ill-suited to the complex, high-salt system of soy sauce, exhibiting several technical limitations. Firstly, traditional microcapsules often use gum arabic or monocyclodextrin as wall materials. These colloids are ionic polymers; the abundant sodium and chloride ions in soy sauce compress the colloidal double layer, reducing the particle zeta potential, leading to microcapsule aggregation, shell rupture, and premature release and inactivation of the core material. Secondly, traditional microcapsules do not pre-treat the fat-soluble and poorly soluble core material, resulting in poor oil-water compatibility, easy stratification during emulsification, severe wall adhesion during spray drying, generally lower encapsulation rates below 75%, uneven powder particle size, and rapid sedimentation after addition to soy sauce. Thirdly, existing microcapsules can only be added during the blending stage of finished soy sauce and cannot be integrated into the soy sauce fermentation system, thus failing to... Using salt-tolerant yeast to generate complex fermented aromas can dilute the original soy sauce aroma, resulting in a thin product flavor. If microcapsules are added during the Daqu fermentation or early brine fermentation stages, the highly active proteases and amylases in the fermentation system will directly degrade the starch and protein wall materials, completely rendering the microcapsule protective structure ineffective. Fourth, traditional microcapsule sterilization processes often employ prolonged pasteurization, and the continuous high temperatures can damage the microcapsule shell, causing significant oxidation and loss of the core material. Furthermore, existing processes lack a comprehensive online quality control system, relying solely on finished product sampling. This results in significant differences in encapsulation rates, suspension stability, and active substance content between different batches, leading to poor product quality consistency. In addition, existing microcapsule processes often add chemically synthesized emulsifiers and antioxidants to aid in molding. Some of these raw materials are controversial new food ingredients, posing food safety compliance risks and hindering the development and marketing of clean label products.

[0004] In summary, the industry currently lacks a functional microencapsulation composite fermentation process that is suitable for high-salt fermentation systems of soy sauce and combines stable microencapsulation with synergistic fermentation flavor. Therefore, this invention proposes a composite fermentation process of functional microencapsulated components and soy sauce to solve the above-mentioned technical problems. Summary of the Invention

[0005] The problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a process for the compound fermentation of functional microencapsulated components and soy sauce.

[0006] This invention is achieved through the following technical solution: a compound fermentation process of functional microencapsulated components and soy sauce, comprising the following steps: Step 1: Mix the functional core material with deionized water at a mass ratio of 1:(4-6), add food-grade neutral protease or compound cellulase, and the mass ratio of food-grade neutral protease or compound cellulase to functional core material is (0.003-0.007):1. Stir and enzymatically hydrolyze for 180 minutes at 48℃±1℃ and pH 6.8±0.2, controlling the degree of hydrolysis to 8.5%-11.0%. Then, heat to 90-95℃ and hold for 8-12 minutes to inactivate the enzyme, obtaining the core material enzymatic hydrolysis pretreatment solution. Step 2: Dissolve the main wall material, sodium octenyl succinate starch, auxiliary wall material A, and auxiliary wall material B in deionized water to prepare a composite wall material solution; based on the total weight of the composite wall material solution, the mass fraction of sodium octenyl succinate starch is 20%–30%, the mass fraction of auxiliary wall material A is 6%–15%, the mass fraction of auxiliary wall material B is 3%–8%, and the mass fraction of deionized water is 50%–70%. Step 3: Cool the core material enzymatic hydrolysis pretreatment solution to 55℃ and mix it with the composite wall material solution, controlling the total solids mass fraction to be 30.5%~33.5%, and obtain a homogeneous emulsion through one-stage coarse emulsification and two-stage ultra-high pressure homogenization; Step 4: Spray dry the homogenized emulsion with an inlet air temperature of 175℃~185℃ and an outlet air temperature of 80℃~85℃, and collect the microcapsule dry powder. Step 5: On the 120th to 150th day of the post-fermentation maturation period of the original soy sauce, add microcapsule dry powder to the fermentation tank at a rate of 2.2% to 2.8% of the total mass of soy sauce. Under sterile nitrogen protection, stir at low speed to carry out post-fermentation and obtain fermentation liquid. Step 6: After the fermentation broth undergoes multi-stage fine filtration and ultra-high temperature instantaneous sterilization, it is cooled and bottled.

[0007] As a preferred option: In step one, the functional core material is any one of rosemary extract, tea polyphenols, ginger oleoresin, garlic essential oil, Sichuan pepper essential oil, cinnamon essential oil, curcumin, hawthorn flavonoids, and refined fish oil.

[0008] In step two, the wall-wall material A is whey protein isolate or soy protein isolate, and the wall-wall material B is maltodextrin or resistant dextrin.

[0009] In step three, the primary coarse emulsification conditions are: rotation speed 2800-3200 rpm, shearing time 20-30 minutes; the two-stage ultra-high pressure homogenization conditions are: primary valve pressure 45MPa±2MPa, secondary valve pressure 8MPa; the particle size D90 of the homogenized emulsion is ≤3.5μm, and the absolute value of the Zeta potential is below -30mV.

[0010] In step four, the spray drying uses a centrifugal atomizing disc with a rotation speed of ≥18000 rpm.

[0011] In step two, the temperature of the deionized water is 50–60°C.

[0012] In step five, the low-speed stirring speed is 18-25 rpm; the sterile nitrogen gas has a purity of ≥99.99% and is maintained at a slight positive pressure of 0.015-0.025 MPa.

[0013] In step six, the multi-stage fine filtration includes a primary filtration with a pore size of 5 μm and a secondary filtration with diatomaceous earth cross-flow, and the turbidity of the filtrate is ≤1.0 NTU.

[0014] In step one, the stirring speed is 80-100 rpm.

[0015] In step six, the ultra-high temperature instantaneous sterilization conditions are: temperature 117℃~119℃, residence time 4~6 seconds; after sterilization, cool to 22℃~26℃ for aseptic filling.

[0016] Compared with the prior art, the functional microencapsulated components and soy sauce compound fermentation process of the present invention have the following beneficial effects: 1. The functional retention rate is greatly improved. The microcapsules completely isolate high salt, acid, metal ions, oxygen and fermentation enzymes, resulting in a significant improvement in the retention rate of active ingredients in the finished product. There is no significant attenuation during the 360-day shelf life simulated using an extreme accelerated temperature of 45℃.

[0017] 2. The process of this invention uses microcapsules to block off-odors and prevent oxidation and blackening, resulting in soy sauce that remains clear and bright for a long time, without layering, sedimentation, or fishy or astringent odors, and with a richer soy sauce aroma.

[0018] 3. This invention abandons the traditional single wall material approach and adopts a three-dimensional composite network wall material system. Sodium octenyl succinate starch introduces both hydrophilic carboxylic acid groups and hydrophobic octenyl long chains into the molecular chain. Its non-ionic / weakly anionic surface structure endows the microcapsules with extremely high electrolyte tolerance, and no salting out occurs in a high concentration of NaCl environment. The protein wall material undergoes thermal denaturation and cross-linking during spray drying, and together with the modified starch, it constructs a dense semi-permeable membrane network shell, which significantly improves the structural stability of the microcapsules in the soy sauce system.

[0019] 4. This invention is the first to pretreat the functional core material with neutral protease or complex cellulase before microencapsulation, which moderately degrades the matrix protein or polysaccharide into small molecule short peptides or oligosaccharides. These degradation products are excellent natural surfactants that can spontaneously coat the surface of the active factor crystal nucleus, significantly improving the efficiency and encapsulation rate of subsequent emulsification and homogenization.

[0020] 5. This invention strictly sets the microcapsule addition point during the post-fermentation stage of soy sauce (days 120-150), avoiding the early fermentation stage when Aspergillus enzyme activity is strongest, thus completely avoiding the risk of enzymatic degradation of the wall material. Simultaneously, ultra-low speed stirring (18-25 rpm) and sterile nitrogen micro-positive pressure protection during this stage ensure stable three-dimensional redistribution of the microcapsules and completely remove oxygen from the top of the high-salt fermentation liquid. This creates an ideal environment for the natural fermentation-promoting factors in the microcapsules to be absorbed and transformed in trace amounts by salt-tolerant yeast, producing a unique post-fermentation aroma.

[0021] 6. This invention constructs a complete industrial chain solution of "bio-enzymatic hydrolysis-assisted modification → high-pressure fluid shear emulsification → thermodynamic spray drying into capsules → multi-dimensional integration in the later stage of fermentation", which is a brand-new functional soy sauce production process.

[0022] 7. In terms of raw material selection, this invention strictly adopts traditional medicinal and edible ingredients, common food raw materials and natural extracts (functional core materials such as rosemary extract, tea polyphenols, ginger oleoresin, and garlic essential oil) supported by my country's current food safety laws and regulations. It avoids any new food raw materials with ambiguous legal boundaries and chemically synthesized food additives, and has both functionality and clean label compliance. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Example

[0024] Step 1: Enzymatic pretreatment of functional core materials Tea polyphenols and deionized water were added to a fermentation-grade reactor equipped with jacketed heating and high-speed shear stirring, with a tea polyphenol to deionized water mass ratio of 1:5. The jacketed heating was started and the temperature was raised to 48°C. The pH was adjusted to 6.8 using food-grade citric acid. Food-grade neutral protease (activity unit: 200,000 U / g) was added, with a food-grade neutral protease to tea polyphenol mass ratio of 0.006:1. Low-speed stirring was started at 90 rpm, and the reaction was carried out for 180 minutes.

[0025] Formaldehyde was tested by titration at regular intervals to control the overall degree of hydrolysis (DH) at 9.5%.

[0026] After the reaction is complete, high-pressure steam is immediately introduced into the reactor to rapidly raise the material temperature to 92°C within 3 minutes. This temperature is maintained for 10 minutes to inactivate the enzyme, yielding the core material enzymatic hydrolysis pretreatment solution. This not only completely denatures and inactivates the protease and locks in its molecular weight distribution, but also provides primary sterilization by thoroughly killing heat-resistant Bacillus spp.

[0027] Step 2: Preparation of Composite Wall Material The soy sauce system contains a large amount of sodium ions (Na) + ) and chloride ions (Cl -This will compress the electric double layer of ordinary colloids, leading to a decrease in potential, thereby causing colloid aggregation and microcapsule rupture. Therefore, this invention avoids using single gum arabic or cyclodextrin and adopts a three-dimensional composite network wall material design: the main wall material is sodium octenyl succinate starch (HI-CAP / SSSA, a modified starch with common food raw material properties), which introduces hydrophilic carboxylic acid groups and hydrophobic octenyl long chains onto the starch molecular chain. Its hydrophobic ends spontaneously anchor the lipophilic core material inward, while the hydrophilic ends extend outward, forming a strong steric hindrance effect in the aqueous phase. Most importantly, its nonionic or weakly anionic surface structure gives it extremely high electrolyte tolerance to high concentrations of NaCl, completely preventing salting out; the auxiliary wall material A is... Whey protein isolate (WPI) or soy protein isolate (SPI) provides abundant free amino and carboxyl groups. During the high-temperature instantaneous spray drying, the protein molecules undergo thermal denaturation and cross-linking, forming a dense, semi-permeable, and robust network shell together with modified starch. The wall-mounting material B uses maltodextrin (DE value 10-15) and resistant dextrin (soluble dietary fiber) as solid fillers. The DE value is controlled between 10 and 15 to ensure good water solubility without causing severe non-enzymatic browning (Maillard reaction) due to excessive reducing sugar, thus preventing sticking to the wall during spray drying.

[0028] In this embodiment, sodium octenyl succinate starch, whey protein isolate, and maltodextrin (DE value 12) were dissolved in deionized water. The mass fraction of sodium octenyl succinate starch was 23.4%, the mass fraction of whey protein isolate was 11.2%, the mass fraction of maltodextrin was 4.7%, the mass fraction of deionized water was 60.7%, and the temperature of the deionized water was 58°C. The solution was stirred until completely dissolved to obtain a composite wall material solution.

[0029] Step 3: High-pressure emulsification and homogenization The enzymatic hydrolysis pretreatment solution of the core material in step one is cooled to 55°C and then mixed with the pre-dissolved composite wall material solution in a mixing tank. The total solids mass fraction in the mixing tank is 32%.

[0030] Primary coarse emulsification: Start a high-speed, high-shear emulsifier (such as a high-shear dispersion emulsifier head) at 3000 rpm and continuously shear for 25 minutes to obtain a crude emulsion. At this time, the droplet size (D50) of the crude emulsion is about 20-30 μm.

[0031] Two-stage ultra-high pressure homogenization: The crude emulsion is pumped into an ultra-high pressure homogenizer (equipped with a ceramic or diamond homogenizing valve).

[0032] The pressure of the primary valve (core shear and cavitation effect valve) is set at 45 MPa. Under high pressure, the fluid passes through the slit, generating ultra-high-speed fluid shear of up to 200 m / s and a strong cavitation explosion effect, which pulverizes grease and active crystal nuclei.

[0033] The pressure of the secondary valve (anti-agglomeration and dispersion valve) is set at 8 MPa. Its core function is to eliminate the secondary aggregation phenomenon that spontaneously occurs after the primary homogenization due to the sudden increase in the surface energy of the particles, so that the material presents a uniform Newtonian fluid state.

[0034] The homogenized emulsion particle size D90 was less than 3.5 μm, and the absolute value of the Zeta potential remained below -30 mV, indicating that the system has extremely high steric repulsion.

[0035] Step 4: Spray drying The homogenized emulsion must be converted into solid dry powder within a very short time to lock in the volatile components and heat-sensitive functional activity of the core material. An industrial-grade spray drying tower equipped with a variable frequency continuously variable centrifugal atomizing disc (20,000 rpm) is used. The inlet air temperature is 178℃, which provides sufficient heat flux to instantly dehydrate and form a film on the droplet surface, preventing the outward migration of the internal core material. The outlet air temperature is 82℃, regulated by a closed-loop PID control based on the pump flow rate of the feed pump. Excessively high outlet air temperatures will deactivate heat-sensitive components, while excessively low temperatures will result in excessive residual moisture in the powder, causing subsequent agglomeration and adhesion to the wall.

[0036] The homogenized emulsion is spray-dried to form microcapsule dry powder, which is then collected. The exhaust gas from the drying tower is equipped with a high-efficiency cyclone separator and a two-stage bag filter. The collected microcapsule dry powder enters a vibrating fluidized bed with a cold air jacket for rapid cooling, causing the powder temperature to drop below 30°C within 1 minute.

[0037] Physical properties of microencapsulated dry powder: The obtained microcapsule powder passed through a 100-mesh sieve, with a moisture content of 3.2% and a loose packing density of 0.60 g / cm³. The encapsulation efficiency was determined to be 93.2% by petroleum ether surface oil extraction method.

[0038] Step 5: Secondary fermentation of soy sauce This invention integrates microencapsulated finished products into the core process of seasoning, breaking the traditional concept of "direct mixing".

[0039] It is strictly forbidden to add the microcapsules during the early stage of Aspergillus fermentation (Daqu stage) or the early stage of brine fermentation, because at this time there is extremely strong protease and amylase activity (secreted by Aspergillus) in the system, which will rapidly degrade the protein and starch wall material of the microcapsules, leading to complete failure of the encapsulation. This invention selects the post-fermentation stage (late maturation stage) of the soy sauce original juice, that is, day 120 to 150 of fermentation. At this time, the Aspergillus enzyme activity has basically decayed, the acidity, aroma and amino acid nitrogen of the system have been established, and the microbial community (mainly salt-tolerant Zygosaccharomyces rouxii and halophilic Pediococcus) has entered the stable or declining stage.

[0040] In this embodiment, on the 135th day of soy sauce fermentation, 2.5% of the total mass of soy sauce was added to a sterile post-fermentation tank using the microcapsule powder obtained in step four. Post-fermentation was carried out under sterile nitrogen protection with low-speed stirring to obtain a fermentation liquid. A large-blade frameless paddle mixer was used at a speed of 22 rpm. This ultra-low-speed shearing ensured stable three-dimensional spatial redistribution of the microcapsules in the fermentation liquid, while preventing mechanical damage to the outer walls of the microcapsules. Sterile pure nitrogen (99.99% purity) was introduced into the top of the tank to maintain a slight positive pressure of 0.02 MPa, completely removing oxygen from the top of the high-salt soy sauce fermentation liquid. During this stage, the natural fermentation-promoting factors in the microcapsule powder were absorbed and transformed in trace amounts by salt-tolerant yeast, producing a unique complex "post-fermentation aroma."

[0041] Step Six: Fine Filtration and Filling After post-ripening, the fermentation broth is pumped into an automatic plate and frame filter press for primary filtration using a composite polypropylene filter cloth with a pore size of 5μm. It then undergoes secondary fine filtration using a diatomaceous earth cross-flow filter press to control the turbidity of the filtrate to ≤1.0 NTU. The microcapsules used here, with a particle size controlled between 1 and 5μm and possessing excellent hydraulic flexibility, can perfectly pass through the filter pores without being trapped.

[0042] Traditional long-term pasteurization can damage the physical structure of microcapsules. This embodiment uses a plate-type ultra-high temperature instantaneous sterilizer (UHT) at a sterilization temperature of 118°C and a residence time of 5 seconds. Utilizing extremely high heat flux density, all pathogenic bacteria and fungal spores are instantly killed within seconds. Simultaneously, due to the extremely short thermal hysteresis period in the nanometer-thickness of the microcapsule wall material, the core material inside the microcapsule remains intact thanks to the instantaneous thermal insulation protection of the wall material.

[0043] After sterilization, the soy sauce temperature is immediately reduced to 24°C within 15 seconds by a three-stage plate heat exchanger, and then it enters the Class 100 aseptic filling workshop for airtight sealing using polyester bottles (PET) or dark glass bottles. Example

[0044] The difference from Example 1 is that in step five, microcapsule dry powder is added to the fermentation tank on the 120th day after the fermentation of the soy sauce. Example

[0045] The difference from Example 1 is that in step five, microcapsule dry powder is added to the fermentation tank on the 150th day after the fermentation of the soy sauce. Example

[0046] The difference from Example 1 is that in step five, on the 125th day after the fermentation of the soy sauce, microcapsule dry powder is added to the fermentation tank, and the amount added is 2.2% of the total mass of the soy sauce. Example

[0047] The difference from Example 1 is that in step five, on the 145th day after the fermentation of the soy sauce, microcapsule dry powder is added to the fermentation tank, and the amount added is 2.8% of the total mass of the soy sauce. Example

[0048] The difference from Example 1 is as follows: In step one, the functional core material is garlic oil, the mass ratio of garlic oil to deionized water is 1:4, the mass ratio of added food-grade neutral protease to garlic oil is 0.007:1, the pH value is 7, and the degree of hydrolysis is controlled at 9.5%; In step two, wall aid A is soy protein isolate, wall aid B is resistant dextrin, the mass fraction of sodium octenyl succinate starch is 30%, the mass fraction of soy protein isolate is 6%, the mass fraction of resistant dextrin is 8%, and the mass fraction of deionized water is 56%; In step three, the total solids mass fraction is 30.5%; In step four, the inlet air temperature is 175℃ and the outlet air temperature is 80℃; In step five, on the 120th day of the post-fermentation maturation period of the soy sauce original juice, microcapsule dry powder is added to the fermentation tank. Example

[0049] The difference from Example 1 is that in step one, the functional core material is rosemary extract, the mass ratio of rosemary extract to deionized water is 1:6, a compound cellulase is added, the mass ratio of the added compound cellulase to rosemary extract is 0.003:1, the pH value is 6.6, and the degree of hydrolysis is controlled at 8.5%. Example

[0050] The difference from Example 1 is as follows: In step two, wall aid A is made of soy protein isolate, wall aid B is made of resistant dextrin, the mass fraction of sodium octenyl succinate starch is 20%, the mass fraction of soy protein isolate is 15%, the mass fraction of resistant dextrin is 3%, and the mass fraction of deionized water is 62%; in step three, the total solids mass fraction is 33.5%; in step four, the inlet air temperature is 185°C and the outlet air temperature is 85°C. Example

[0051] The difference from Example 7 is that the functional core material is hawthorn flavonoids, the mass ratio of hawthorn flavonoids to deionized water is 1:5, a compound cellulase is added, the mass ratio of compound cellulase to hawthorn flavonoids is 0.005:1, the pH value is 6.8, and the degree of hydrolysis is controlled at 11%.

[0052] Example 10: The difference from Example 1 is that the functional core material in step one is refined fish oil; and the amount of microcapsule dry powder added in step five is 2.8% of the total mass of soy sauce.

[0053] Example 11: The difference from Example 1 is that the functional core material in step one is refined fish oil; and the amount of microcapsule dry powder added in step five is 2.2% of the total mass of soy sauce.

[0054] For the above embodiments, the microcapsule encapsulation rate was detected using petroleum ether surface oil extraction, and the encapsulation rate was calculated based on the surface free oil content; the retention rate (%) of functional factors after sterilization was detected using high-performance liquid chromatography (HPLC), with the functional core materials of each embodiment as the detection targets, such as rosmarinic acid, which was detected at a wavelength of 280 nm; curcumin was extracted using methanol shaking; the sedimentation rate after 180 days on a shelf was detected using centrifugation sedimentation (4000 rpm, 15 min), and the percentage of precipitate volume to total volume was determined; high-performance liquid chromatography was used... The retention rate of functional factors after 360 days of shelf life was determined by HPLC at a temperature of 45°C. Accelerated shelf life testing was performed, with 90 days of accelerated testing at 45°C directly simulating 360 days at room temperature (25°C). Therefore, the data from 90 days of accelerated testing at 45°C is equivalent to the data from 360 days of shelf life testing. A blind sensory evaluation was conducted by 10 professionals, providing a comprehensive sensory score based on the following criteria: color (20 points), aroma (25 points), flavor harmony (30 points), and absence of off-odors (25 points), for a maximum score of 100. Turbidity (NTU) was measured using a turbidimeter, and the turbidity of the filtrate was determined after fine filtration. Example 1 used EGCG (epigallocatechin gallate) in tea polyphenols as a marker for HPLC detection; Example 6 used allicin as a marker; Examples 7 and 9 used rosmarinic acid as a marker; and Examples 10 and 11 used DHA as a marker. The detection data for the above examples are shown in Table 1. Table 1 Key performance test data for Examples 1-11

[0055] To verify the advancements of the present invention's technical solution compared to existing mainstream industry processes, the following comparative examples were designed: Comparative Example 1: This comparative example adopts the most commonly used functional soy sauce production process among leading brands in the soy sauce industry. Functional materials are added to the finished product after fermentation. The soy sauce base is prepared using Aspergillus oryzae koji and fermented in brine. After 180 days of fermentation (when the mash is fully fermented), it is pressed, sterilized, and finely filtered to obtain the finished soy sauce base liquid. Tea polyphenol powder (food grade, purity ≥98%) is weighed directly at 2.5% of the total mass of the finished soy sauce and added to the base liquid. A high-shear emulsifier is used to shear and stir at 3000 rpm for 30 minutes to ensure even dispersion. Subsequently, it undergoes plate-type ultra-high temperature instantaneous sterilization (118℃, 5 seconds), cooling, and then bottling.

[0056] Comparative Example 2: This comparative study simulates the "pre-addition of functional ingredients" process attempted by some soy sauce manufacturers. In the soy sauce koji-making process, tea polyphenol powder is mixed evenly with flour and bran at 2.5% of the total raw material mass, and then inoculated with Aspergillus oryzae for koji-making. The tea polyphenols and koji are co-cultured at 30–35℃ and 90%–95% humidity for 48 hours, followed by brine fermentation. Subsequent fermentation, pressing, sterilization, and bottling operations are the same as conventional soy sauce processes.

[0057] Comparative Examples 1 and 2 were tested for their performance using the same testing methods described above. Since the tea polyphenol powders of Comparative Examples 1 and 2 were not microencapsulated, the encapsulation rate was not tested. The test data are shown in Table 2 below: Table 2 Key performance test data for Comparative Examples 1-2

[0058] It is evident that while the blending process represented by Comparative Example 1 is simple and inexpensive, over 70% of the functional components are lost during the sterilization stage, and the product rapidly degrades during its shelf life, producing a bitter odor and significant sedimentation. This makes it difficult to meet consumers' dual demands for functional soy sauce that is both functional and delicious. Comparative Example 2, representing the co-fermentation process, essentially loses its functional components, rendering the product completely commercially worthless.

[0059] Comparative Example 3: This comparative example simulates the application of conventional microencapsulation technology in the food industry in the field of soy sauce. The preparation steps are as follows: (1) Core material selection: tea polyphenol powder (food grade, purity ≥98%); (2) Wall material preparation: The most common single wall material system in the existing technology is adopted. Weigh 25 kg of gum arabic and 12 kg of maltodextrin, dissolve them in 63 kg of deionized water (gum arabic mass fraction is about 25%, maltodextrin mass fraction is about 12%, water mass fraction is about 63%), stir until completely dissolved, and cool to 55°C for later use. The mass ratio of wall material to core material is about 4:1; (3) Emulsification and homogenization: Disperse 10 kg of tea polyphenols in 50 kg of deionized water (without enzymatic pretreatment), mix with the above wall material solution, the total solid mass fraction is about 28%. Use a high shear emulsifier to shear at 3000 rpm for 25 minutes, and then homogenize in a single stage using a high pressure homogenizer (pressure 30 MPa, only one stage of homogenization, no secondary anti-coagulation valve) to obtain a homogenized emulsion. Due to the poor compatibility between tea polyphenols and wall materials, the emulsion exhibited obvious oil-water separation after homogenization, and precipitates formed after standing for 30 minutes; (4) Spray drying: a conventional spray drying tower was used, with an inlet air temperature of 185℃ and an outlet air temperature of 90℃. Due to the poor stability of the emulsion, severe wall adhesion occurred during the spray drying process, and the collection rate was only about 65%. The obtained microcapsule dry powder passed through a 100-mesh sieve, and the particle size distribution of the powder was uneven (D90 was 8.5μm), with a moisture content of 4.8%; (5) Blending of finished soy sauce: after the original soy sauce juice was fully fermented and matured for 180 days, and after pressing and fine filtration to obtain the finished soy sauce base liquid, the above microcapsule dry powder was added to the soy sauce base liquid at 2.5% of the total mass of the finished soy sauce, and a conventional anchor mixer was used to stir and mix at 60 rpm for 30 minutes; (6) Sterilization and filling: water bath pasteurization was used, with a sterilization temperature of 85℃, maintained for 30 minutes, and then filled after cooling.

[0060] The products obtained from Comparative Example 3 were tested using the same method as described above, as shown in Table 3.

[0061] Comparative Example 3 used a traditional gum arabic single wall material system, with an encapsulation rate of only 58.0%, far lower than the 93.2% of Example 1. The main reasons include: gum arabic is an ionic polymer with poor electrolyte tolerance in the emulsion, with an absolute Zeta potential of only about -18mV (compared to -36mV in Example 1), resulting in poor emulsion stability; the core material was not pretreated with enzymatic hydrolysis, leading to insufficient surface activity and poor compatibility with the wall material, causing stratification of the emulsion after homogenization; single-stage homogenization lacked a secondary anti-agglomeration valve, causing a sudden increase in particle surface energy and secondary aggregation, resulting in a droplet diameter D90 of 8.5μm (compared to 2.7μm in Example 1). The spray drying collection rate was only ≤65%, with a large amount of material lost due to adhesion to the wall.

[0062] Comparative Example 3 showed a retention rate of only 46.2% after sterilization (compared to 95.8% in Example 1) and a retention rate of only 16.8% after 360 days (compared to 91.0% in Example 1). The low encapsulation rate indicates that a large amount of core material was not effectively encapsulated, remaining exposed in a free state on the microcapsule surface. In the soy sauce system, this exposed material was directly exposed to dissolved oxygen and metal ions, leading to rapid oxidative degradation. The prolonged heating during pasteurization (85°C, 30 minutes) caused the microcapsule shell to continuously expand and rupture due to heat, resulting in the leakage and loss of a large amount of core material during the sterilization stage. Furthermore, in a high-salt environment, the double electric layer of the gum arabic wall material was compressed, its potential decreased, causing particle aggregation and shell rupture, resulting in continuous leakage of the core material throughout its shelf life.

[0063] The sedimentation rate of Comparative Example 3 after 180 days was 28.5% (compared to only 1.5% in Example 1). The tea polyphenols released after rupture complexed with proteins and metal ions in the soy sauce to form insoluble substances, which then precipitated. Simultaneously, some microcapsules themselves precipitated due to aggregation. Furthermore, Comparative Example 3 received a sensory score of only 68 points; the oxidized tea polyphenols produced a noticeable oxidized taste and astringency; the tea aroma lacked fusion with the soy sauce base aroma, exhibiting a separation; and the cooked taste produced by pasteurization further reduced the product's flavor quality.

[0064] Based on the above data and analysis, the core material enzymatic pretreatment + three-dimensional composite wall material microencapsulation + post-ripening addition scheme of this invention has overwhelming advantages over existing industry processes in key indicators such as functional factor retention rate, sedimentation rate, sensory quality, and shelf life. This invention successfully resolves the technical contradiction between functional factor stability and the basic quality of soy sauce, enabling functional soy sauce to achieve both long-term functional stability and excellent sensory quality without affecting fermentation quality, thus possessing significant industrial promotion value.

[0065] This invention achieves high encapsulation rate (90.2%–93.2%), high sterilization retention rate (91.6%–95.8%), long shelf stability (84.8%–91.0% retention rate after 360 days), extremely low sedimentation rate (1.5%–2.5%), and excellent sensory quality of functional core materials in high-salt soy sauce systems through the synergistic effects of core material enzymatic pretreatment, three-dimensional composite network wall material system, precise post-ripening addition node control (days 120–150), and ultra-low speed stirring protection (18–25 rpm).

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can still be made to the technical solutions described in the above embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A process for the compound fermentation of functional microencapsulated components and soy sauce, characterized in that: Includes the following steps: Step 1: Mix the functional core material with deionized water at a mass ratio of 1:(4-6), add food-grade neutral protease or compound cellulase, and the mass ratio of food-grade neutral protease or compound cellulase to functional core material is (0.003-0.007):

1. Stir and enzymatically hydrolyze for 180 minutes at 48℃±1℃ and pH 6.8±0.2, controlling the degree of hydrolysis to 8.5%-11.0%. Then, heat to 90-95℃ and hold for 8-12 minutes to inactivate the enzyme, obtaining the core material enzymatic hydrolysis pretreatment solution. Step 2: Dissolve the main wall material, sodium octenyl succinate starch, auxiliary wall material A, and auxiliary wall material B in deionized water to prepare a composite wall material solution; based on the total weight of the composite wall material solution, the mass fraction of sodium octenyl succinate starch is 20%–30%, the mass fraction of auxiliary wall material A is 6%–15%, the mass fraction of auxiliary wall material B is 3%–8%, and the mass fraction of deionized water is 50%–70%. Step 3: Cool the core material enzymatic hydrolysis pretreatment solution to 55℃ and mix it with the composite wall material solution, controlling the total solids mass fraction to be 30.5%~33.5%, and obtain a homogeneous emulsion through one-stage coarse emulsification and two-stage ultra-high pressure homogenization; Step 4: Spray dry the homogenized emulsion with an inlet air temperature of 175℃~185℃ and an outlet air temperature of 80℃~85℃, and collect the microcapsule dry powder. Step 5: On the 120th to 150th day of the post-fermentation maturation period of the original soy sauce, add microcapsule dry powder to the fermentation tank at a rate of 2.2% to 2.8% of the total mass of soy sauce. Under sterile nitrogen protection, stir at low speed to carry out post-fermentation and obtain fermentation liquid. Step 6: After the fermentation broth undergoes multi-stage fine filtration and ultra-high temperature instantaneous sterilization, it is cooled and bottled.

2. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step one, the functional core material is any one of rosemary extract, tea polyphenols, ginger oleoresin, garlic essential oil, Sichuan pepper essential oil, cinnamon essential oil, curcumin, hawthorn flavonoids, and refined fish oil.

3. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step two, the wall-wall material A is whey protein isolate or soy protein isolate, and the wall-wall material B is maltodextrin or resistant dextrin.

4. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step three, the primary coarse emulsification conditions are: rotation speed 2800-3200 rpm, shearing time 20-30 minutes; the two-stage ultra-high pressure homogenization conditions are: primary valve pressure 45MPa±2MPa, secondary valve pressure 8MPa; the particle size D90 of the homogenized emulsion is ≤3.5μm, and the absolute value of the Zeta potential is below -30mV.

5. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step four, the spray drying uses a centrifugal atomizing disc with a rotation speed of ≥18000 rpm.

6. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step two, the temperature of the deionized water is 50–60°C.

7. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step five, the low-speed stirring speed is 18-25 rpm; the sterile nitrogen gas has a purity of ≥99.99% and is maintained at a slight positive pressure of 0.015-0.025 MPa.

8. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step six, the multi-stage fine filtration includes a primary filtration with a pore size of 5 μm and a secondary filtration with diatomaceous earth cross-flow, and the turbidity of the filtrate is ≤1.0 NTU.

9. The functional microencapsulated components and soy sauce compound fermentation process according to claim 1, characterized in that: In step one, the stirring speed is 80-100 rpm.

10. The functional microencapsulated components and soy sauce co-fermentation process according to claim 1, characterized in that: In step six, the ultra-high temperature instantaneous sterilization conditions are: temperature 117℃~119℃, residence time 4~6 seconds; after sterilization, cool to 22℃~26℃ for aseptic filling.

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