Steam sterilization and clean crushing production process of spice raw materials

Abstract

The present application belongs to the technical field of food processing, and discloses a spice raw material steam sterilization and clean crushing production process. According to the differences in volatile oil content and heat resistance of different spices, differential steam pretreatment is adopted to cooperate with vacuum variable pressure pulse and intelligent temperature control for sterilization. First, the cell air is exhausted to strengthen the steam penetration, and then the pressure pulse is used to make the cell swell and shrink repeatedly to kill stubborn microorganisms such as spores and molds. After sterilization, the total number of colonies meets the standard and there is no chemical sterilization residue. Inert gas is introduced throughout the process to isolate oxygen. In the low-temperature drying stage, the volatile oil is condensed and recovered and added back in proportion. A flavor embedding system is formed with β-cyclodextrin, and a flavor retention detection module is used for dynamic parameter adjustment to minimize volatile oil loss. A closed-circuit low-temperature crushing system is used, and the crushing cavity is maintained at-10~0 DEG C with the aid of liquid nitrogen temperature control to avoid heat generation caused by high-speed friction, which can accelerate the loss of flavor substances.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically a process for steam sterilization and clean pulverization of spice raw materials. Background Technology

[0002] Spices are widely used in prepared dishes, compound seasonings, and snack foods, and their quality directly determines the flavor stability and food safety of downstream products. Currently, the spice processing industry generally suffers from crude processing techniques and insufficient quality control. Traditional production methods mainly present the following technical problems: Spices are mostly made from natural plant materials. During the planting, harvesting, drying and storage process, they are easily contaminated by microorganisms such as Salmonella, E. coli and mold. Traditional sterilization methods either use high temperature and long time treatment, which leads to a large loss of volatile essential oils and other flavor substances in spices, or the sterilization is not thorough and cannot meet food safety supervision requirements; some chemical sterilization methods may also leave behind toxic and harmful substances.

[0003] Traditional mechanical pulverization relies on high-speed friction to generate high temperatures, which further exacerbates the loss of flavor substances. Moreover, the pulverization process is mostly open or semi-open, which easily introduces external impurities, leading to a decrease in the purity of spice powder. At the same time, there are problems such as uneven particle size and large batch quality differences, which cannot meet the standardization requirements of industrial production.

[0004] Sterilized spices are prone to absorbing moisture and becoming damp, which not only increases the risk of secondary contamination but also affects the subsequent pulverization effect, leading to powder clumping and poor flowability. At the same time, non-standard raw material pretreatment and failure to differentiate treatment according to the characteristics of different spices further affect the quality of the final product. Summary of the Invention

[0005] The purpose of this invention is to provide a process for steam sterilization and clean pulverization of spice raw materials to solve one or more problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a process for steam sterilization and clean pulverization of spice raw materials, comprising the following specific steps: Furthermore, in the raw material pretreatment stage, spice raw materials are selected, and intelligent grading and screening equipment is used to establish grading standards based on the characteristics of the raw materials, dividing the raw materials into 3-5 grades. The raw materials are then fed into a closed-loop clean screening system. Through multi-stage clean filtration, mechanical impurities in the raw materials are removed. At the same time, negative pressure air separation and electrostatic impurity removal are used to separate light impurities and fine dust in the raw materials. Finally, the graded raw materials are subjected to low-temperature air drying. A moisture content linkage control mode is adopted to precisely control the moisture content at 8%-12% according to the characteristics of different grades of raw materials. At the same time, a trace amount of natural antioxidants is introduced during the air drying process.

[0007] Furthermore, the steam pretreatment stage is based on the grading results of the raw material pretreatment stage. According to the characteristics of different grades and types of spices, a differentiated steam pretreatment and parameter linkage control process is adopted. For spices with high volatile oil content and low heat resistance, a low-temperature saturated steam pretreatment at 85-90℃ is used for 5-8 minutes, while controlling the steam flow rate at 0.3-0.5 m / s. For spices with low volatile oil content and high heat resistance, a saturated steam pretreatment at 95-100℃ is used for 10-12 minutes, while controlling the steam flow rate at 0.6-0.8 m / s. Inert gas is introduced during the pretreatment process to form a closed steam environment; an online detection module for the pretreatment effect is set up to detect the number of microorganisms and the amount of volatile oil residue on the surface of the raw materials in real time. If the standard is not met, the steam temperature and time parameters are automatically adjusted.

[0008] The online detection module adopts multi-point synchronous detection. Three sets of detection probes are set at the feed end, middle and discharge end of the pretreatment chamber. The detection frequency is once every 10 seconds. The data is uploaded to the process control system in real time to ensure that the detection results can truly reflect the pretreatment status of the entire batch of raw materials and avoid parameter adjustment deviations caused by single-point detection.

[0009] Furthermore, in the vacuum sterilization stage, the pretreated spices are fed into a vacuum sterilization tank. After the tank door is closed, a vacuum is drawn to -0.08 to -0.09 MPa to completely remove air from the intercellular spaces of the spices. Then, high-pressure saturated steam at 105-110℃ is introduced to maintain the tank pressure at 0.12-0.15 MPa. Sterilization is performed using a vacuum pressure-changing pulse and intelligent temperature control combined sterilization mode. Based on the initial tank pressure of 0.12-0.15 MPa, the pressure is alternately increased by 0.02 MPa and decreased by 0.02 MPa every 3 minutes. At the same time, the temperature fluctuation range during the pulse process is dynamically adjusted according to the type and grade of the spices, lasting for 15-20 minutes. The pressure changes cause the spice cells to repeatedly contract and expand, enhancing the steam penetration sterilization effect. After sterilization, a gradient depressurization mode is adopted to slowly release the pressure inside the tank, while using a vacuum environment to remove residual steam. A flavor retention detection module is set up after sterilization to detect the loss rate of volatile oils in real time and automatically adjust the variable pulse parameters for the next batch.

[0010] Furthermore, in the low-temperature drying stage, the sterilized spices are immediately sent into a low-temperature vacuum drying tank, maintaining a vacuum degree of -0.07 to -0.08 MPa inside the tank. The drying temperature is controlled at 45-55℃, and a gradient temperature and dynamic moisture content control drying mode is adopted. The temperature is 45℃ for the first 10 minutes, then rises to 50℃ for the middle 20 minutes, and finally rises to 55℃ for the last 10 minutes, with a total drying time of 40 minutes. The final moisture content is controlled at 5%-7% depending on the type of spice. During the drying process, a small amount of volatile oil volatilized from the spices is collected by a condensation recovery device. A volatile oil refill control module is set up so that the recovered volatile oil is added back to the pulverized powder in proportion according to the flavor requirements of different spices. At the same time, a trace amount of β-cyclodextrin is added to form a flavor encapsulation system.

[0011] Flavor encapsulation employs a closed, low-speed stirring method, with the stirring speed controlled at 30-50 r / min and the stirring time at 5-8 min. This allows the recovered volatile oil and β-cyclodextrin to fully combine and form a stable encapsulation structure. The encapsulated flavor substances are less prone to volatilization and oxidation during subsequent pulverization, packaging, and storage, thus preserving the natural flavor of the spices for a long time.

[0012] Furthermore, in the clean pulverization stage, the dried spices are fed into a closed-loop low-temperature pulverization system, where liquid nitrogen is used to assist in cooling. The cooling rate is dynamically adjusted based on the volatile oil release characteristics of the spices to maintain the temperature of the pulverization chamber at -10~0℃. The pulverizing system adopts a fully enclosed design, completely isolated from the external environment. The pulverizing chamber and discharge pipe are made of food-grade stainless steel and have undergone steam sterilization in advance. An online cleanliness real-time detection module is set up to detect the impurity content and microbial quantity in the pulverizing chamber and pipe in real time. If the cleanliness does not meet the standard, the machine will automatically stop for secondary steam sterilization. After sterilization, the pulverizing system is purged with sterile air to replace residual steam at a pressure of 0.02 MPa for 10 minutes. After sterilization, the system is sealed and stored until feeding, with a storage time not exceeding 2 hours to avoid secondary contamination of the system.

[0013] Based on downstream product demand, the grinding speed can be adjusted to achieve different particle sizes from 30 to 120 mesh. A particle size uniformity detection module is set up. If the particle size deviation exceeds ±5 mesh, the speed is automatically adjusted. The dust generated during the grinding process is collected by a closed-loop recycling device, screened, and then re-grinded for reuse.

[0014] Furthermore, in the purification and testing stage, the pulverized spice powder is fed into a grading and purification device, which employs a triple purification method of sieving, air separation, and electrostatic impurity removal. First, a precision sieving machine is used to screen out powder that meets the target particle size; then, negative pressure air separation is used to separate fine impurities and residual dust from the powder; finally, electrostatic impurity removal is used to remove fine metal impurities and hair from the powder.

[0015] The purified powder was then subjected to multi-level aseptic testing. Microbial rapid detection technology and high performance liquid chromatography were used to detect microbial indicators, including total bacterial count, mold, and pathogenic bacteria, as well as quality indicators, including volatile oil content and heavy metal content. Powder that failed the test was sent back to the sterilization process for secondary processing. At the same time, the test data were recorded and encrypted for storage.

[0016] Furthermore, in the aseptic packaging and storage stage, the qualified spice powder is sent to the aseptic packaging workshop. The packaging equipment has been sterilized by ultraviolet light and steam in advance. The powder is put into a food-grade aseptic packaging bag by vacuum nitrogen filling and aseptic sealing. After vacuuming, nitrogen gas is filled in and sealed. At the same time, a food-grade desiccant is added to the packaging bag. During the packaging process, a unique blockchain traceability identifier is configured on the packaging bag and connected to the blockchain traceability module, binding the entire process data, including the origin of raw materials, grading parameters, pretreatment parameters, sterilization parameters, particle size, test results, and packaging time. The traceability code is dynamically updated, and environmental parameters during the storage of finished products are uploaded to the traceability system in real time. After packaging, the finished products are sent to the finished product warehouse for low-temperature storage. An intelligent temperature and humidity control module is used to monitor the storage environment in real time. If the temperature and humidity exceed the standard, the control equipment will be automatically activated. At the same time, a regular sampling inspection mechanism for finished products is established, with a sampling inspection rate of no less than 5% for each batch of finished products. The sampling inspection data is updated to the traceability system in sync.

[0017] The beneficial effects of this invention are as follows: 1. This invention addresses the differences in volatile oil content and heat resistance among various spices by employing differentiated steam pretreatment combined with vacuum pressure pulse and intelligent temperature control for synergistic sterilization. First, a vacuum is drawn to remove air from the cells, enhancing steam penetration. Then, pressure pulses cause the cells to repeatedly expand and contract, killing stubborn microorganisms such as spores and molds. After sterilization, the total bacterial count meets the standard and there are no chemical sterilization residues. The entire process is conducted with inert gas to isolate oxygen. During the low-temperature drying stage, volatile oils are condensed, recovered, and added back in proportion. Combined with β-cyclodextrin, a flavor encapsulation system is formed. With the addition of a flavor retention detection module for dynamic parameter adjustment, the loss of volatile oils is minimized, thus meeting food safety sterilization requirements while fully preserving the natural aroma and flavor of the spices.

[0018] 2. This invention employs a closed-loop low-temperature pulverization system, using liquid nitrogen to maintain the pulverization chamber at -10~0℃, avoiding accelerated loss of flavor substances due to high-speed frictional heat generation; the system uses a fully enclosed food-grade stainless steel design and is pre-sterilized with steam, coupled with an online real-time cleanliness detection module, automatically stopping for secondary sterilization if the cleanliness does not meet the standard, avoiding external impurities and microbial contamination; by dynamically adjusting the pulverization speed, precise pulverization of 30-120 mesh is achieved, with particle size uniformity deviation controlled within ±5 mesh, and pulverized dust is recycled and reused in a closed loop, improving raw material utilization; thus significantly improving the purity and particle size consistency of spice powder.

[0019] 3. The raw materials of this invention employ intelligent grading and screening, negative pressure air separation, and electrostatic impurity removal for dual purification. Low-temperature air drying with precise humidity control and the addition of natural antioxidants avoid quality defects caused by non-standard raw material pretreatment. After sterilization, the raw materials are immediately vacuum dried at low temperature with gradient temperature control to maintain the moisture content at 5%-7%, preventing moisture absorption, re-wetting, and secondary contamination. The purification stage employs triple purification through sieving, air separation, and electrostatic impurity removal, with multi-level aseptic testing to strictly control microbial and heavy metal indicators. Aseptic packaging uses vacuum nitrogen filling and sealing for dual protection, and is equipped with a blockchain traceability module to bind full-process data. The finished product is stored intelligently at low temperature and regularly sampled. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the overall process of the present invention. Figure 2 This is a flowchart of the vacuum sterilization process of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figures 1 to 2 As shown, this embodiment of the invention provides a process for steam sterilization and clean pulverization of spice raw materials, including the following specific steps: In this embodiment of the invention, the raw material pretreatment stage selects spice raw materials, such as Sichuan pepper, star anise, cinnamon, cumin, etc., and uses intelligent grading and screening equipment to establish grading standards based on raw material characteristics such as volatile oil content and heat resistance, and divides the raw materials into 3-5 grades to avoid uneven sterilization and excessive differences in particle size caused by mixing raw materials with different particle sizes and characteristics. The intelligent grading and screening system works collaboratively through multiple modules including online visual inspection, weight sensing, and texture detection. It uses four core indicators—spice particle size, volatile oil content, texture softness / hardness, and initial moisture content—as the grading criteria. The system has a built-in database of grading standards for different spices and automatically and accurately divides the raw materials into 3-5 grades. Each grade is automatically bound to a complete set of process parameters, including steam pretreatment, vacuum sterilization, low-temperature drying, and clean pulverization. The grading accuracy error is controlled within ±5%.

[0023] It is then sent to a closed-loop clean screening system, where mechanical impurities such as mud, hair, and twigs are removed from the raw materials through a multi-stage clean filtration process. At the same time, a combination of negative pressure air separation and electrostatic impurity removal is used to separate light impurities and fine dust from the raw materials. The negative pressure air classifier has an air pressure control of -0.03 to -0.05 MPa and an air velocity of 1.5 to 2.5 m / s, effectively separating light impurities such as straw, broken leaves, and dust from the raw materials. The electrostatic purification voltage is set to 10-15 kV, which removes fine dust and lint impurities from the surface of the raw materials through electrostatic adsorption. After purification, the cleanliness of the raw materials meets the feeding requirements for subsequent steam pretreatment and vacuum sterilization, with no mechanical impurities or light impurities remaining.

[0024] Finally, the graded raw materials are subjected to low-temperature air drying. A moisture content linkage control mode is adopted. According to the characteristics of different grades of raw materials, the moisture content is precisely controlled at 8%-12%, raw materials with high volatile oil content are controlled at 8%-10%, and raw materials with strong heat resistance are controlled at 10%-12%. At the same time, a trace amount of natural antioxidant is introduced during the air drying process. The natural antioxidant is rosemary extract, with an addition amount of 0.01%-0.03%, to inhibit the premature oxidation of flavor substances.

[0025] The moisture content linkage control adopts a PID closed-loop intelligent control algorithm, which consists of four core modules: a real-time sensing unit, a deviation calculation unit, a parameter output unit, and a closed-loop feedback unit. The algorithm input data includes the grade of spice raw materials, initial moisture content, real-time moisture content from online sensors, graded target moisture content ranges, temperature and humidity of the drying chamber, and thickness of the raw material layer. The algorithm output data includes the drying temperature adjustment, the circulating air velocity correction value, the dynamic adjustment value of the drying time, and the precise replenishment amount of natural antioxidants. The algorithm collects moisture content detection data in real time, performs difference calculation with the target moisture content, and dynamically adjusts the drying parameters according to the proportional-integral-derivative control logic to strictly control the error between the actual moisture content and the target value within ±0.5%. At the same time, it links with the natural antioxidant addition module to achieve coordinated intelligent control of precise moisture content control and antioxidant protection of flavor substances.

[0026] The temperature for low-temperature air drying is controlled at 35-40℃, the circulating air speed is controlled at 1.0-1.5m / s, a uniform spreading air drying mode is adopted, the spreading thickness does not exceed 5cm, and the natural antioxidant is evenly applied to the surface of the raw material through atomized spraying, with the spraying pressure controlled at 0.1-0.2MPa to ensure uniform coverage of the antioxidant without local accumulation or missed spraying.

[0027] In this embodiment of the invention, the steam pretreatment stage is based on the grading results of the raw material pretreatment stage. According to the characteristics of different grades and types of spices, a differentiated steam pretreatment and parameter linkage control process is adopted. For spices with high volatile oil content and low heat resistance, such as Sichuan pepper and bay leaves, a low-temperature saturated steam pretreatment at 85-90℃ is used for 5-8 minutes, while the steam flow rate is controlled at 0.3-0.5 m / s to reduce the erosion and loss of flavor substances. For spices with low volatile oil content and high heat resistance, such as cinnamon and star anise, a saturated steam pretreatment at 95-100℃ is used for 10-12 minutes, and the steam flow rate is controlled at 0.6-0.8 m / s to improve the pretreatment sterilization effect. Nitrogen gas is introduced during the pretreatment process to create a closed steam environment, reducing the contact between spices and oxygen and preventing the loss of flavor substances through oxidation. At the same time, it also initially kills some microorganisms on the surface of the raw materials. An online detection module for the pretreatment effect is set up to detect the number of microorganisms on the surface of the raw materials (total colony count ≤1000 cfu / g) and the amount of volatile oil residue in real time. If the standard is not met, the steam temperature and time parameters are automatically adjusted.

[0028] The adaptive parameter tuning employs a multivariate fuzzy control algorithm, which comprises five core components: a data acquisition module, a fuzzification processing module, a fuzzy rule reasoning module, a defuzzification output module, and a parameter iteration module. The algorithm's input data includes spice type, raw material grade, total microbial colony count on the raw material surface detected online, real-time residual volatile oil content, oxygen content in the closed steam environment, pretreatment duration, and real-time steam temperature and flow rate. The algorithm's output data includes steam temperature correction amplitude, steam flow rate adjustment ratio, and pretreatment time extension / shortening thresholds. Based on a pre-built fuzzy rule library of spice characteristics, the algorithm fuzzifies the multi-dimensional detection data and derives the optimal control parameters through rule reasoning. Independent control rules are established for two types of raw materials: those with high volatile oil content and low heat resistance, and those with low volatile oil content and high heat resistance. If the parameters are not met, the algorithm automatically iterates and adjusts the process parameters.

[0029] The inert gas used is food-grade nitrogen, with an injection flow rate controlled at 5-8 m³ / h. The oxygen content in the closed steam environment is maintained below 3% throughout the process. The ambient oxygen concentration is monitored in real time by an online oxygen content detection module. When the oxygen content exceeds the standard, the nitrogen injection flow rate is automatically increased to ensure that the spices are pretreated in a low-oxygen environment, preventing the oxidation and destruction of flavor substances such as volatile oils, while improving the sterilization stability of steam pretreatment.

[0030] In this embodiment of the invention, during the vacuum sterilization stage, the pretreated spices are fed into a vacuum sterilization tank. After the tank door is closed, a vacuum is drawn to -0.08 to -0.09 MPa to completely remove air from the intercellular spaces of the spices and enhance steam penetration. Subsequently, high-pressure saturated steam at 105-110℃ is introduced to maintain the tank pressure at 0.12-0.15 MPa. Sterilization is performed using a vacuum pressure-changing pulse and intelligent temperature control synergistic sterilization mode. Based on the initial tank pressure of 0.12-0.15 MPa, the pressure is alternately increased by 0.02 MPa and decreased by 0.02 MPa every 3 minutes. At the same time, the temperature fluctuation range during the pulse process is dynamically adjusted according to the type and grade of the spices. The temperature fluctuation of raw materials with high volatile oil content is controlled within ±1℃, and the fluctuation of raw materials with strong heat resistance is controlled within ±2℃. This process is continued for 15-20 minutes. Through pressure changes, the spice cells repeatedly contract and expand, enhancing the steam penetration sterilization effect and killing stubborn microorganisms such as spores and molds within the cells. The high-pressure saturated steam is introduced at a rate of 0.8-1.0 m³ / min, using a bottom-uniform steam distribution method to ensure even distribution of steam within the sterilization tank. The vacuum level is monitored in real time by two sets of vacuum sensors at the top and bottom of the tank, with the monitoring data displayed and uploaded synchronously. The vacuum pump operating power is automatically adjusted when the vacuum level deviation exceeds ±0.005 MPa.

[0031] The variable pressure pulse operation is executed continuously without interruption. After each pulse pressure adjustment, the temperature and pressure are maintained for 30 seconds to ensure that the steam fully penetrates into the spice cells. Temperature fluctuations are synchronized with the pressure pulses. When the pressure increases, the temperature rises slightly in sync, and when the pressure decreases, the temperature drops slightly in sync. Through the coordinated changes in pressure and temperature, deep-seated stubborn microorganisms such as spores and molds are killed.

[0032] The variable pressure pulse operation and high-pressure saturated steam supply are synchronized throughout the process. While the pressure rises and falls, the steam continuously, stably and evenly fills the inside of the sterilization tank, allowing the spice cells to contract and expand repeatedly in accordance with the pressure pulses. The steam penetrates deeply into the cells and interstitial spaces as the cells expand and contract, breaking through the limitation of traditional steam sterilization which only acts on the surface of the raw materials. It kills stubborn microorganisms such as spores and molds hidden inside at the cellular level. No chemical sterilizing agents are added during the entire sterilization process, so there is no risk of chemical residues. It not only meets the microbial control requirements for food safety production, but also protects the natural structure of the spices to the greatest extent.

[0033] After sterilization, a gradient depressurization mode is adopted to slowly release the pressure inside the tank at a depressurization rate of 0.01 MPa / min. This avoids sudden pressure changes that could cause damage to the spice structure and loss of flavor substances. At the same time, a vacuum environment is used to remove residual steam and reduce the spice's moisture absorption. The gradient depressurization process is carried out in three stages at a constant speed. In the first stage, the pressure inside the tank is reduced from 0.12-0.15 MPa to 0.08-0.10 MPa at a constant speed, with a depressurization time of 3 minutes. In the second stage, the pressure is reduced to 0.03-0.05 MPa at a constant speed, with a depressurization time of 4 minutes. In the third stage, the pressure is slowly reduced to atmospheric pressure, with a depressurization time of 5 minutes. Throughout the process, a vacuum suction state is maintained to continuously remove residual vapor, ensuring that the spices do not absorb moisture or damage their cell structure during the depressurization process, while also preventing a large amount of flavor substances from escaping due to sudden pressure changes.

[0034] A flavor retention detection module is set up after sterilization to detect the loss rate of volatile oils in real time and automatically adjust the variable pulse parameters for the next batch.

[0035] The vacuum pressure pulse and intelligent temperature control employ a multi-objective collaborative optimization algorithm, which consists of a pressure pulse control module, a temperature dynamic adjustment module, a flavor real-time monitoring module, a multi-objective optimization module, and a parameter backtracking optimization module. The algorithm's input data includes spice type, raw material grade, real-time pressure and temperature inside the sterilization tank, sterilization time, real-time volatile oil loss rate, spore and mold kill rate, and cell penetration efficiency detection value. The algorithm's output data includes pulse pressure rise / fall amplitude, pulse interval time, temperature fluctuation range, total sterilization time, and gradient depressurization rate. The algorithm uses 100% microbial kill rate and minimum volatile oil loss rate as its dual core optimization objectives, dynamically matching pressure pulse and temperature control strategies. Alternating pressure changes cause repeated contraction and expansion of spice cells, enhancing the steam penetration sterilization effect. Simultaneously, it constrains the temperature and pressure fluctuation range based on flavor retention detection data. For unqualified batches, the algorithm automatically backtracks process parameters and iteratively optimizes the control scheme for the next batch.

[0036] The flavor retention detection module uses near-infrared spectroscopy for online detection. A dedicated detection probe is set at the sterilization outlet, which can quickly determine the amount of volatile oil residue without sampling and calculate the real-time loss rate. The detection time is no more than 5 seconds, and the detection data is directly fed back to the collaborative optimization algorithm.

[0037] In this embodiment of the invention, during the low-temperature drying stage, the sterilized spices are immediately fed into a low-temperature vacuum drying tank, maintaining a vacuum level of -0.07 to -0.08 MPa. The drying temperature is controlled at 45-55°C, employing a gradient temperature increase and dynamic moisture content control drying mode. The temperature is 45°C for the first 10 minutes, then increases to 50°C for the middle 20 minutes, and finally increases to 55°C for the last 10 minutes, with a total drying time of 40 minutes. The final moisture content is controlled at 5%-7% depending on the type of spice, with 5%-6% for raw materials with high volatile oil content and 6%-7% for raw materials with strong heat resistance. The low-temperature vacuum drying chamber maintains a vacuum level continuously through a variable frequency vacuum pump, with the vacuum level fluctuation range controlled within ±0.005MPa. The gradient heating uses intelligent electric heating combined with a heat exchange plate to control the temperature, with a temperature control accuracy of ±1℃. The heating process is uniform and stable, without sudden temperature rises or falls, thus avoiding flavor loss or uneven drying of spices due to temperature fluctuations.

[0038] The moisture content is detected in real time using an online microwave moisture analyzer. A detection point is set at the discharge end of the drying tank, and the moisture content data is collected every 30 seconds. The data is directly linked to the drying control system, and the drying process is automatically stopped when the target moisture content is reached.

[0039] A real-time closed-loop linkage mechanism is formed by gradient heating and dynamic moisture content control. The system automatically adjusts the heating rate based on online moisture content detection data. When the moisture content decreases too quickly, the system automatically reduces the heating amplitude and extends the constant temperature time to prevent spices from cracking, peeling, and excessive loss of volatile oils. When the moisture content decreases too slowly, the system slightly increases the heating amplitude and accelerates the drying process, balancing drying efficiency and flavor retention. For raw materials with high volatile oil content, flavor protection is prioritized, and for raw materials with high heat resistance, drying efficiency is appropriately increased. This ensures that each spice can be dehydrated under suitable drying conditions, resulting in a uniform moisture content after drying, without localized over-drying or excessive moisture.

[0040] During the drying process, a small amount of volatile oil volatilized from the spices is collected through a condensation recovery device. A volatile oil refill control module is set up so that, according to the flavor requirements of different spices, the recovered volatile oil is refilled into the pulverized powder at a ratio of 0.5%-1.0%, and at the same time, a trace amount of β-cyclodextrin is added at a ratio of 0.1%-0.2% to form a flavor encapsulation system.

[0041] The volatile oil recovery and encapsulation process employs an intelligent proportioning control algorithm, which consists of a condensation recovery monitoring module, a component analysis module, a proportioning calculation module, and a backfilling execution module. The algorithm's input data includes spice type, real-time volatile oil recovery amount, initial volatile oil content of raw materials, target flavor intensity of powder, and optimal β-cyclodextrin encapsulation ratio. The algorithm's output data includes volatile oil backfilling ratio, β-cyclodextrin addition amount, and encapsulation mixing speed and time. The algorithm dynamically calculates the optimal backfilling and encapsulation parameters based on the flavor characteristics of different spices, ensuring full utilization of the recovered volatile oil and stable flavor, forming a stable flavor encapsulation system, and avoiding the loss of flavor substances during subsequent pulverization and storage.

[0042] The condensation recovery device adopts a tubular low-temperature condensation structure, with the condensation temperature controlled at 0-5℃ and the condensation wind speed controlled at 1.0-1.5m / s. It efficiently collects the volatile oil that escapes during the drying process through low-temperature condensation, with a volatile oil recovery efficiency of not less than 90%. The purity and moisture content of the recovered volatile oil are monitored in real time through an online component detection module.

[0043] In this embodiment of the invention, the dried spices are fed into a closed-loop low-temperature pulverization system during the clean pulverization stage. The system uses liquid nitrogen to assist in cooling and dynamically adjusts the cooling rate based on the volatile oil release characteristics of the spices. The cooling rate is 5°C / min for raw materials with high volatile oil content and 3°C / min for raw materials with strong heat resistance, so that the temperature of the pulverization chamber is maintained at -10~0°C, thus avoiding the loss of flavor substances caused by frictional heat generation during the pulverization process. Liquid nitrogen is evenly introduced through the atomizing nozzle at the top of the pulverizing chamber. The flow rate is adjusted in real time according to the chamber temperature, and the flow rate range is controlled between 2-5 L / min. The fully enclosed system uses double sealing gaskets to ensure airtightness, and the sealing pressure is maintained at 0.05 MPa. Airtightness is tested regularly to ensure that no external air enters and no powder leaks during the pulverizing process.

[0044] The closed-loop circulation system constructs a complete aseptic processing flow, including sealed feeding, low-temperature pulverization, sealed discharge, closed-loop dust recovery, and aseptic return for re-pulverization. The real-time cleanliness detection module is electrically interlocked with the pulverizing host and liquid nitrogen temperature control system. Once the number of microorganisms or impurities in the pulverizing chamber or pipeline is detected to exceed the standard, the equipment will immediately and automatically stop and start a closed secondary steam sterilization program. The sterilization process is completed entirely within the closed system, preventing contamination from spreading to qualified powder. At the same time, the low-oxygen environment continuously protects volatile oils from oxidation. After dust recovery, it is aseptically tested and reused, which not only ensures the cleanliness and particle size uniformity of the powder, but also greatly improves the utilization rate of raw materials.

[0045] The pulverizing system adopts a fully enclosed design, completely isolated from the external environment. The pulverizing chamber and discharge pipe are made of food-grade stainless steel and have undergone steam sterilization in advance. An online cleanliness real-time detection module is set up to detect the impurity content and microbial quantity in the pulverizing chamber and pipe in real time. If the cleanliness does not meet the standard, the machine will automatically stop for secondary steam sterilization to avoid contamination by external impurities. Based on downstream product demand, the grinding speed can be adjusted to achieve different particle sizes from 30 to 120 mesh. A particle size uniformity detection module is set up. If the particle size deviation exceeds ±5 mesh, the speed is automatically adjusted. The dust generated during the grinding process is collected by a closed-loop recycling device, screened, and then re-grinded for reuse, thereby improving the utilization rate of raw materials.

[0046] The intelligent particle size adjustment adopts a model predictive control algorithm, which consists of an online particle size detection module, a crushing prediction model module, a speed adjustment module, an error correction module, and a temperature and pressure linkage module. The algorithm input data includes the target crushing mesh size, the real-time detection value of the online particle size analyzer, the real-time temperature of the crushing chamber, the liquid nitrogen cooling rate, the hardness and brittleness of the spice raw material, and the feeding speed. The algorithm output data includes the adjustment amount of the crushing spindle speed, the matching value of the feeding speed, the adjustment amount of the crushing gap, and the liquid nitrogen replenishment rate. Based on the low-temperature crushing particle size prediction model of spices, the algorithm compares the deviation between the target particle size and the actual particle size in real time, predicts the speed adjustment range in advance, and stably controls the particle size uniformity deviation of the powder within ±5 mesh. At the same time, it links with the liquid nitrogen temperature control system to ensure that the crushing temperature is constant in the range of -10~0℃.

[0047] The dust closed-loop recycling adopts a combination of negative pressure dust collection and precision filtration. The dust collection air pressure is controlled at -0.04~-0.06MPa, and the filtration accuracy reaches more than 200 mesh. The collected dust is first confirmed to be free of pollution by rapid microbial testing, and then sent into the crushing chamber for re-crushing through a closed return material device. The recycled dust is only used for the production of powder of the same batch and specification and is not mixed with raw materials from other batches.

[0048] In this embodiment of the invention, the purification and testing stage involves feeding the pulverized spice powder into a grading and purification device. A triple purification process of sieving, air separation, and electrostatic purification is employed. First, a precision sieving machine selects powders that meet the target particle size, removing excessively coarse or fine impurities. Then, negative pressure air separation separates fine impurities and residual dust from the powder. Finally, electrostatic purification removes fine metallic impurities and hair from the powder, further improving its cleanliness. The triple purification process employs unified process parameters. The precision screening machine uses a high-frequency vibrating screening mode, with the screen mesh size matching the target pulverization mesh size. The screening frequency is controlled at 30-50Hz, and the screening time is 5-8 minutes. The negative pressure air classifier has an air pressure controlled at -0.02~-0.03MPa and an air classifier speed of 2-3m / s, separating and removing light impurities such as dust and fragments from the powder. The electrostatic purification process has a voltage controlled at 15-20kV and a purification speed of 1.5-2.0m / s, effectively removing fine metal shavings, hair, and fibrous impurities. The purified powder meets food-grade sterile standards.

[0049] The triple purification equipment and the multi-level aseptic testing equipment are directly connected through a fully enclosed food-grade stainless steel pipeline. The purified qualified powder is directly transported to the testing station in a closed positive pressure environment. The entire process does not come into contact with the outside air, is not exposed to non-clean environments, and is not directly handled by humans. This completely avoids the risk of secondary contamination with microorganisms, dust, hair, metal shavings, and other impurities after purification. The testing station is also in a Class 10,000 clean environment, and the test data is uploaded to the system in real time and stored in encrypted form.

[0050] The purified powder was then subjected to multi-stage aseptic testing. Microbial rapid detection technology and high-performance liquid chromatography were used to test microbial indicators such as total bacterial count, mold, and pathogenic bacteria, as well as quality indicators such as volatile oil content and heavy metal content, to ensure that the total bacterial count of the powder was ≤100 cfu / g and that there were no pathogenic bacteria. For powders that failed the test, they were sent back to the sterilization process for secondary processing. At the same time, the test data were recorded and encrypted for storage.

[0051] The rapid microbial detection method uses immunofluorescence rapid detection. Before detection, the powder sample is aseptically homogenized. The detection time is controlled within 15-20 minutes. The pathogenic bacteria detection covers Salmonella, Staphylococcus aureus and Escherichia coli. The test results are uploaded in real time and stored for future reference.

[0052] Non-conforming powder is stored separately in a sealed container with the reason for non-conformity clearly marked. During secondary processing, it enters a vacuum sterilization process separately, using appropriate sterilization parameters for enhanced treatment. After processing, it re-enters the purification and testing stage. Only after passing the test can it proceed to the next process. Non-conforming powder will never flow into the next stage.

[0053] In this embodiment of the invention, during the aseptic packaging and storage stage, the qualified spice powder is sent to the aseptic packaging workshop. The packaging equipment has undergone double sterilization treatment with ultraviolet light and steam in advance. The powder is packaged into a food-grade aseptic packaging bag using a double packaging method of vacuum nitrogen filling and aseptic sealing. After vacuuming, nitrogen gas is filled in and the bag is sealed. At the same time, montmorillonite desiccant is added to the packaging bag at a dosage of 0.5%-1.0% to prevent the powder from absorbing moisture and oxidizing, thus extending the shelf life. The packaging equipment is sterilized by irradiating with ultraviolet light for 30 minutes, followed by sterilization with 100℃ saturated steam for 15 minutes. After sterilization, it is allowed to cool to room temperature before use. The aseptic packaging workshop is a Class 10,000 cleanroom with an ambient temperature controlled at 18-25℃ and a relative humidity controlled at 45%-60%. The laminar flow purification device is turned on throughout the process to avoid introducing microorganisms or impurities during the packaging process.

[0054] The desiccant is packaged in an independent, breathable small package and placed on top of the powder inside the packaging bag, without direct contact with the powder. After sealing, a seal integrity test is performed using a negative pressure leak detection method. The leak detection pressure is -0.05MPa, and if there is no leakage after holding the pressure for 30 seconds, it is considered qualified, ensuring that the sealing performance meets the standards.

[0055] During the packaging process, a unique blockchain traceability identifier is configured on the packaging bag and connected to the blockchain traceability module, binding full-process data, including information such as raw material origin, grading parameters, pretreatment parameters, sterilization parameters, particle size, test results, and packaging time. The traceability code is dynamically updated, and the temperature and humidity during the finished product storage process are uploaded to the traceability system in real time. The intelligent temperature and humidity control system employs an LSTM deep learning prediction algorithm. This algorithm comprises an environmental perception module, a time-series data processing module, a trend prediction module, a control execution module, and a blockchain on-chain module. Input data includes real-time warehouse temperature and humidity, historical environmental time-series data, finished product shelf-life requirements, desiccant status in packaging bags, temperature difference between the inside and outside of the warehouse, and seasonal humidity trends. Output data includes refrigeration equipment start / stop commands, dehumidification equipment operating power, ventilation system adjustment parameters, and airflow distribution adjustment values ​​within the warehouse. The algorithm mines the time-series characteristics of environmental data through a long short-term memory network to accurately predict temperature and humidity trends, triggering control actions in advance to prevent temperature and humidity from exceeding limits. All algorithm control commands, equipment execution results, and real-time environmental data are synchronously written to the blockchain traceability module, binding them to data from raw material grading, pretreatment, sterilization, crushing, and testing. This achieves intelligent control and irreversible traceability throughout the entire process from production to storage, ensuring stable and traceable product quality.

[0056] The intelligent temperature and humidity control system is deeply integrated with the finished product shelf life prediction algorithm. When the temperature and humidity of the storage environment approach the safety threshold, the system will automatically increase the operation intensity of the refrigeration and dehumidification equipment and issue graded warnings. The warning information, control measures, and execution results are all synchronously written into the blockchain traceability module, forming a complete traceability chain with the data of the entire production process. At the same time, the system will dynamically predict the shelf life of the finished product based on environmental changes. Abnormal situations will be automatically recorded and management personnel will be notified to handle them. Both regulators and consumers can query complete production, testing, storage, and control data through the traceability mark. The whole process is transparent and traceable, and the data is tamper-proof, which comprehensively ensures the safety and quality stability of the finished product storage.

[0057] The blockchain traceability module adopts a food industry consortium blockchain architecture, automatically writing data at every stage of the entire process, from raw material entry, grading and screening, steam pretreatment, vacuum sterilization, low-temperature drying, clean pulverization, purification and testing, to aseptic packaging. Each package's unique traceability identifier is bound to all process parameters, test results, and equipment operating status of the corresponding batch. Once the data is written, it cannot be tampered with. Consumers and regulators can scan the traceability identifier to query the entire production and storage data, achieving full transparency and traceability from raw materials to finished products.

[0058] After packaging, the finished products are sent to the finished product warehouse for low-temperature storage at a temperature of 0-10℃. An intelligent temperature and humidity control module is used to monitor the storage environment in real time. If the temperature and humidity exceed the standard, the control equipment will be automatically activated to avoid environmental factors from affecting product quality. At the same time, a regular sampling inspection mechanism for finished products is established, with a sampling inspection rate of no less than 5% for each batch of finished products. The sampling inspection data is updated to the traceability system in sync.

[0059] Differentiated steam pretreatment adopts a zoned temperature and speed control mode, with spices of different characteristics undergoing corresponding processes in independent pretreatment chambers without interference, ensuring that each type of raw material can be matched with the most suitable pretreatment conditions, taking into account both sterilization effect and flavor preservation.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for steam sterilization and clean pulverization of spice raw materials, characterized in that, The specific steps include the following: In the raw material pretreatment stage, spice raw materials are selected, and graded screening and impurity removal are completed in combination with the characteristics of the raw materials. The graded raw materials are then subjected to low-temperature air drying. While controlling the moisture content of the raw materials during low-temperature air drying, trace amounts of natural antioxidants are introduced. In the steam pretreatment stage, based on the raw material grading results and combined with the characteristics of spices, differentiated steam pretreatment is adopted. Inert gas is introduced to form a closed pretreatment environment, and the pretreatment process parameters are monitored online and dynamically adjusted. During the vacuum sterilization stage, the pretreated spices are sent into the vacuum sterilization tank, and after vacuuming, high-pressure saturated steam is introduced. The sterilization mode is a combination of vacuum pressure pulse and intelligent temperature control. After sterilization, gradient depressurization is adopted, and the flavor retention after sterilization is detected online and the subsequent process parameters are adjusted accordingly. In the low-temperature drying stage, the sterilized spices are sent into a low-temperature vacuum drying tank and a drying mode with gradient temperature rise and dynamic control of moisture content is adopted to recover the volatile oils that escape during the drying process and construct a flavor encapsulation system. In the clean pulverization stage, the dried spices are fed into a closed-loop low-temperature pulverization system, which uses liquid nitrogen for assisted cooling. The closed-loop low-temperature pulverization system adopts a fully enclosed and sterile design, and monitors the cleanliness and particle size uniformity of the pulverization process online, and recycles and reuses the pulverized dust in a closed loop. During the purification and testing stage, the pulverized powder is sent to a grading and purification equipment. The cleanliness of the powder is improved through a triple purification process. The quality indicators are verified through multi-level aseptic testing. Unqualified powder is processed again and the test data is encrypted and stored. During the aseptic packaging and storage stage, qualified powder is sent into an aseptic packaging environment, using a double aseptic packaging method, equipped with a blockchain traceability module, and employing intelligent temperature and humidity control and regular sampling inspection mechanisms to complete the storage of finished products.

2. The process for steam sterilization and clean pulverization of spice raw materials according to claim 1, characterized in that, The raw material pretreatment stage uses intelligent grading and screening equipment combined with raw material characteristics to establish grading standards, dividing the raw materials into 3-5 grades; The raw materials are then fed into a closed-loop clean screening system, where mechanical impurities are removed through a multi-stage filtration process. At the same time, light impurities and fine dust are separated by a combination of negative pressure air separation and electrostatic dust removal. Finally, the graded raw materials are air-dried at low temperature, using a moisture content linkage control mode to keep the moisture content between 8% and 12% according to the grade of the raw materials. A trace amount of natural antioxidant is introduced during the air-drying process.

3. The process for steam sterilization and clean pulverization of spice raw materials according to claim 2, characterized in that, The steam pretreatment stage employs differentiated steam pretreatment and parameter linkage control processes based on the characteristics of different grades and types of spices: for spices with high volatile oil content and low heat resistance, a low-temperature saturated steam pretreatment at 85-90℃ is used for 5-8 minutes, with the steam flow rate controlled at 0.3-0.5 m / s; for spices with low volatile oil content and high heat resistance, a saturated steam pretreatment at 95-100℃ is used for 10-12 minutes, with the steam flow rate controlled at 0.6-0.8 m / s. During the pretreatment process, inert gas is introduced to form a closed steam environment, and the number of microorganisms and the amount of residual volatile oil on the surface of the raw materials are monitored in real time by an online detection module. If the preset standards for the number of microorganisms and the amount of residual volatile oil are not met, the steam temperature and treatment time parameters are automatically adjusted.

4. The process for steam sterilization and clean pulverization of spice raw materials according to claim 3, characterized in that, The vacuum sterilization stage, depending on the type and grade of the spices, involves closing the vacuum sterilization tank door and first drawing a vacuum to -0.08 to -0.09 MPa to remove air from the intercellular spaces of the spices; then, high-pressure saturated steam at 105-110℃ is introduced to maintain the pressure inside the tank at 0.12-0.15 MPa, with a total sterilization time of 15-20 minutes.

5. The process for steam sterilization and clean pulverization of spice raw materials according to claim 4, characterized in that, The vacuum pressure-pulse and intelligent temperature control synergistic sterilization mode uses an initial pressure of 0.12-0.15 MPa in the tank as a reference. Every 3 minutes, the pressure is alternately increased by 0.02 MPa and decreased by 0.02 MPa, while the temperature fluctuation range during the pulse process is dynamically adjusted according to the type and grade of spices. The pressure changes cause the spice cells to repeatedly contract and expand to enhance the steam penetration sterilization effect. After sterilization, the pressure in the tank is slowly released in a gradient depressurization mode, while residual steam is discharged using the vacuum environment. The flavor retention detection module detects the volatile oil loss rate in real time and automatically adjusts the pressure-pulse parameters for the next batch.

6. The process for steam sterilization and clean pulverization of spice raw materials according to claim 5, characterized in that, The low-temperature drying stage maintains a vacuum level of -0.07 to -0.08 MPa inside the low-temperature vacuum drying tank, and adopts a gradient temperature rise and dynamic moisture content control drying mode: the temperature is 45℃ for the first 10 minutes, the temperature is raised to 50℃ for the middle 20 minutes, and the temperature is raised to 55℃ for the last 10 minutes, with a total drying time of 40 minutes. The final moisture content is controlled at 5%-7% depending on the type of spice. During the drying process, the volatile oils released from the spices are collected by a condensation recovery device. The recovered volatile oils are added back to the pulverized powder in proportion through the volatile oil return control module. At the same time, a trace amount of β-cyclodextrin is added to form a flavor encapsulation system.

7. The process for steam sterilization and clean pulverization of spice raw materials according to claim 6, characterized in that, The clean pulverization stage uses liquid nitrogen-assisted cooling, and the cooling rate is dynamically adjusted based on the volatile oil release characteristics of spices to maintain the pulverization chamber temperature at -10~0℃. The closed-loop low-temperature pulverization system adopts a fully enclosed design, completely isolated from the external environment. The pulverization chamber and the discharge pipe are made of food-grade stainless steel and have been steam sterilized in advance. The online cleanliness real-time detection module monitors the impurity content and microbial quantity in the pulverization chamber and pipe. If the cleanliness does not meet the standard, the machine will automatically stop for secondary steam sterilization.

8. The process for steam sterilization and clean pulverization of spice raw materials according to claim 7, characterized in that, The clean pulverization stage adjusts the pulverization speed according to the downstream product requirements to prepare powders of different particle sizes from 30 to 120 mesh. The particle size is monitored by a particle size uniformity detection module, and the speed is automatically adjusted when the particle size deviation exceeds ±5 mesh. The dust generated during the pulverization process is collected by a closed-loop recycling device, screened, and then pulverized again for reuse.

9. The process for steam sterilization and clean pulverization of spice raw materials according to claim 8, characterized in that, The purification and testing stage employs a triple purification method: sieving, air separation, and electrostatic purification. First, a precision sieving machine is used to screen out powders that meet the target particle size. Then, negative pressure air separation is used to separate fine impurities and residual dust from the powder. Finally, electrostatic purification is used to remove fine metal impurities and hair from the powder. Subsequently, rapid microbial detection technology and high-performance liquid chromatography are used to test the microbial and quality indicators of the purified powder. Unqualified powders are sent back to the vacuum sterilization stage for secondary processing, and the test data is encrypted and stored.

10. The process for steam sterilization and clean pulverization of spice raw materials according to claim 9, characterized in that, The packaging equipment used in the aseptic packaging and storage stage undergoes dual sterilization treatment with ultraviolet light and steam in advance. It adopts a dual packaging method of first vacuuming and nitrogen filling, and then aseptic sealing. The powder is put into a food-grade aseptic packaging bag, vacuumed and then filled with nitrogen to seal. At the same time, a food-grade desiccant is added to the packaging bag. During packaging, a unique blockchain traceability identifier is configured for the packaging bag, which is linked to the entire production process data of raw material grading, pretreatment, sterilization, crushing and testing. Environmental parameters during the storage of finished products are uploaded to the traceability system in real time. The finished products are stored at low temperatures, and the storage environment is monitored in real time through an intelligent temperature and humidity control module. Microbiological and physicochemical indicators are regularly sampled and tested, with a sampling rate of no less than 5% for each batch of finished products. The sampling data is updated to the traceability system in real time.

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