Health tea irradiation sterilization process
By establishing a model of the relationship between irradiation dose and sterilization effect, accurately measuring the D10 value of the target microorganisms, and dynamically adjusting the irradiation dose, the problems of loss of active ingredients and incomplete sterilization in the sterilization of health tea were solved, achieving efficient and economical sterilization effect and protection of active ingredients.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HARBIN SIBO TECHNOLOGY CO LTD
- Filing Date
- 2026-04-30
- Publication Date
- 2026-07-14
Smart Images
Figure CN122375652A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of food irradiation sterilization technology, and more specifically to an irradiation sterilization process for health-preserving tea. Background Technology
[0002] Health-preserving teas, a type of health beverage primarily composed of medicinal and edible ingredients, have experienced rapid growth in domestic and international markets in recent years. Common ingredients in health-preserving teas include cassia seeds, hawthorn, lotus leaves, goji berries, and chrysanthemum. These medicinal and edible ingredients are highly susceptible to microbial contamination during planting, harvesting, drying, storage, and transportation. The microorganisms that contaminate health-preserving teas mainly include bacteria such as Bacillus and Escherichia coli, and fungi such as molds and yeasts. Among these, Bacillus, due to its ability to form spores, possesses strong heat and radiation resistance, making it a key target for microbial control in health-preserving teas.
[0003] Existing sterilization methods for health-preserving teas mainly include three types: high-temperature steam sterilization, chemical fumigation, and irradiation sterilization. High-temperature steam sterilization typically involves treatment at 121°C for 30 minutes. This method can effectively kill most microorganisms, but the high temperature can destroy heat-sensitive active ingredients in health-preserving teas, such as total flavonoids, polysaccharides, and volatile oils, leading to a decrease in the efficacy of the tea. High-temperature treatment can also affect the color and flavor of the tea, causing an irradiation-related off-flavor. Chemical fumigation methods involve fumigation treatment using ethylene oxide, sulfur, etc. While this method has a certain sterilization effect, the residue of chemical reagents poses safety hazards. Ethylene oxide has been identified as a carcinogen by the World Health Organization, and many countries and regions have restricted its use in food.
[0004] Irradiation sterilization is a cold sterilization technology that uses radiation or electron beams to destroy the DNA of microorganisms, killing them without raising the temperature. The "Technical Guidelines for Irradiation Sterilization of Traditional Chinese Medicine" issued by the National Medical Products Administration allows the use of irradiation sterilization for traditional Chinese medicine, but requires that the irradiation dose be minimized to reduce the impact on active ingredients while ensuring sterilization effectiveness. However, the microbial contamination levels and radiation resistance of different health-preserving tea raw materials vary significantly. Current technologies often use fixed doses, such as 5 kGy or 10 kGy, for a one-size-fits-all irradiation approach. This can lead to problems such as insufficient dose resulting in incomplete sterilization or excessive dose damaging active ingredients.
[0005] Health-preserving teas, as products with both medicinal and edible properties, have unique characteristics: a complex microbial contamination spectrum, a high proportion of Bacillus subtilis that is radiation-resistant; the active ingredients, total flavonoids and polysaccharides, are sensitive to radiation; and the raw materials are sourced from diverse sources with large fluctuations in contamination levels (10). 2 -10 5 (CFU / g). These unique characteristics dictate that health-preserving teas cannot simply follow the fixed-dosage regimens used for food irradiation. Summary of the Invention
[0006] The purpose of this invention is to provide an irradiation sterilization process for health-preserving tea. This invention establishes an irradiation dose-sterilization effect relationship model to accurately determine the dose D required to kill 90% of the target microorganisms. 10 The value, combined with the initial contamination level, is used to calculate the minimum effective irradiation dose, so as to maximize the protection of the effective components of the health tea while ensuring sterilization compliance.
[0007] The objective of this invention is achieved through the following technical solution:
[0008] An irradiation sterilization process for health-preserving tea, comprising the following steps: Step S1: Detect the initial microbial contamination level of the health tea sample and obtain N0;
[0009] Step S2: Isolate the radiation-resistant strain from the sample and determine the D of the radiation-resistant strain. 10 value;
[0010] Step S3: Establish a model for the relationship between irradiation dose and sterilization effect; Step S4: Calculate the required minimum radiation dose D: Step S5: Irradiate the target dose at a safety margin multiple of the calculated minimum irradiation dose; Step S6: After irradiation, perform microbial re-examination and detect the content of effective ingredients to verify the process; It also includes step S7: establishing a dynamic quality control system; Step S1 includes the following steps: Step S11: Take a sample of the health-preserving tea, add sterile saline solution, homogenize, and then dilute. Step S12: Determine the initial contamination level N0 by measuring the total bacterial count, counting molds and yeasts, and counting coliform bacteria.
[0011] Step S2 includes the following steps: Step S21: Spread the diluted health tea sample onto plate counting agar, and after cultivation, pick colonies of different morphologies for purification. The purified strains were irradiated with 2kGy, 4kGy and 6kGy of cobalt-60 rays respectively, and the strains that still survived at 6kGy were selected as radiation-resistant strains. Step S22: Prepare a bacterial suspension from the purified radiation-resistant strain, spread it evenly on a plate counting agar plate, place the plate in a cobalt-60 irradiation device, and receive irradiation doses of 0, 1, 2, 3, 4, 5, and 6 kGy respectively. After irradiation, incubate and count the number of colonies.
[0012] Step S23: After data processing, determine the D of the radiation-resistant strain. 10 value.
[0013] In step S23, D10 =-D / log 10 (N / N0); where the irradiation dose is D, N is the number of colonies after irradiation, N0 is the number of colonies in the unirradiated control, and the survival rate is N / N0.
[0014] In step S3, based on the first-order kinetic model of microbial radiation extinguishing activity, the survival rate has an exponential relationship with the irradiation dose: N=N010 (-D / D10) Logarithmic form: log 10 (N)=log 10 (N0)-D / D 10 Among them, the number of surviving microorganisms after N irradiation (CFU / g); the initial number of microorganisms at N0 (CFU / g); the irradiation dose at D (kGy); and D 10 The dose required to kill 90% of microorganisms is kGy.
[0015] Step S4 includes the following steps: based on the target sterility level N target From N=N010(-D / D) 10 Solve for the required dose D = D 10 log 10 (N0 / N target ).
[0016] The target sterility level N target The values were: total bacterial count 1000 CFU / g; molds and yeasts 100 CFU / g; coliforms 10 CFU / g.
[0017] In step S5, the safety margin is 1 to 1.2.
[0018] Step S6 specifically involves taking samples of the same batch of health-preserving tea, subjecting them to irradiation with the model-calculated dose and the comparative dose, and comparing the detection indicators.
[0019] Step S7 specifically involves: testing N0 for each batch of raw materials, calculating the required irradiation dose for that batch, and taking a mixed sample after irradiation to verify D. 10 Values were monitored to track changes in radiation-resistant bacterial flora; an irradiation dose control chart was established, and D was reassessed when several consecutive batches of N0 exceeded the mean of 2. 10 .
[0020] The beneficial effects of this invention are as follows: This invention establishes a model to accurately determine the D of target microorganisms by irradiation dose-sterilization effect. 10The minimum effective irradiation dose is calculated based on the initial contamination level. Compared to the traditional fixed-dose method of 5 kGy, this invention reduces the irradiation dose to 1.6 kGy, a reduction of 68%, maximizing the protection of the effective components of the health tea while ensuring sterilization compliance. Specifically, after treatment using this method, the total flavonoid retention rate reaches 96.5%, an increase of 11.3 percentage points compared to the 85.2% of the traditional fixed-dose method; the total polysaccharide retention rate reaches 94.2%, an increase of 13.9 percentage points compared to the 80.3% of the traditional method. This indicates that by precisely controlling the irradiation dose, this invention significantly reduces the damage to the heat-sensitive active ingredients in the health tea, better preserving its efficacy.
[0021] Traditional fixed-dosage regimens fail to consider batch-to-batch variations in the initial contamination levels of raw materials for health teas, nor are they adapted to the radiation resistance of the dominant radiation-resistant bacteria (Bacillus) in the teas. This results in low-contamination batches experiencing excessive irradiation and loss of active ingredients, while high-contamination batches suffer from insufficient dosage and incomplete sterilization. This invention is based on a first-order kinetic model of microbial radiation sterilization activity, using the formula D=D 10 log 10 (N0 / N target The minimum effective dose required for each batch of raw materials is precisely calculated. This batch-specific dosage calculation method overcomes the drawbacks of the traditional fixed-dose, one-size-fits-all approach, avoiding insufficient or excessive irradiation due to varying initial contamination levels. When the initial contamination level of the raw materials is low, the calculated dose is correspondingly reduced; when the contamination level is high, the calculated dose is appropriately increased but remains well below the fixed dose of 5 kGy. This dynamic adjustment mechanism ensures the reliability of sterilization effects while minimizing irradiation dose.
[0022] This invention significantly reduces the negative impact of irradiation treatment on the active ingredients of health-promoting teas by substantially lowering the irradiation dose, increasing the retention rate of active ingredients by 15 to 20 percentage points. This technological effect has significant practical implications: for health-promoting tea products with total flavonoids and total polysaccharides as their main active ingredients, increased retention of active ingredients means enhanced health benefits, contributing to improved market competitiveness and consumer satisfaction. Furthermore, increased retention of active ingredients also extends the product's shelf life, as total flavonoids and total polysaccharides possess antioxidant properties, inhibiting microbial growth and delaying quality deterioration.
[0023] This invention establishes a comprehensive dynamic quality control system, including initial contamination level testing for each batch of raw materials, calculation of irradiation dose according to formula, post-irradiation sampling verification, and periodic verification. 10 The initial pollution level N0 is monitored in real time using XR control charts. If multiple consecutive batches of data exceed the mean control limit of 2, the D control is activated promptly. 10The value is reassessed. This dynamic adjustment mechanism can effectively adapt to changes in microbial contamination levels and radiation-resistant bacterial composition caused by factors such as changes in raw material sources, seasonal differences, and fluctuations in storage conditions, ensuring the stability and consistency of sterilization effects during long-term production. Attached Figure Description
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.
[0025] Figure 1 This is a schematic diagram of the irradiation sterilization process for health-preserving tea according to the present invention; Figure 2 This is a schematic diagram of the inactivation curve of the present invention; Figure 3 This is a schematic diagram illustrating the establishment of a dynamic quality control system according to the present invention; Figure 4 This is the XR diagram of irradiation dose control according to the present invention; Figure 5 This is a comparison chart of dynamic dosage calculation and total flavonoid retention rate of different batches of raw materials in Example 2 of the present invention. Detailed Implementation
[0026] The present invention will now be described in further detail with reference to the accompanying drawings.
[0027] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms "a," "say," and "this" used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms used herein refer to and / or include any or all possible combinations of one or more associated listed items.
[0028] It should be noted that the method described in this invention is specifically designed for the characteristics of health-preserving tea products. The raw materials for health-preserving teas (cassia seeds, hawthorn, lotus leaves, etc.) are mostly plant roots, stems, leaves, and fruits, which are easily contaminated by soil microorganisms during planting and harvesting. Among these, Bacillus subtilis, due to its ability to form spores, is radiation-resistant and a key target for sterilization control. Simultaneously, the total flavonoids and polysaccharides, the active ingredients in health-preserving teas, are sensitive to radiation; excessive radiation can lead to a decrease in efficacy. This invention establishes a D... 10 The quantitative relationship between N0 and the target substance, health tea, enables precise dosage control.
[0029] Example 1 like Figure 1 As shown below, the steps and functions of the irradiation sterilization process for health-preserving tea will be explained in detail.
[0030] An irradiation sterilization process for health-preserving tea, comprising the following steps: Step S1: Detect the initial microbial contamination level of the health tea sample and obtain N0; Take 25g of a health-preserving tea sample, such as a compound health-preserving tea mainly composed of cassia seed, hawthorn, and lotus leaf, add 225mL of sterile physiological saline, homogenize for 2 minutes, and prepare a 1:10 dilution. Perform total bacterial count determination according to GB 4789.2 using plate counting agar and incubate at 36℃ for 48h; perform mold and yeast count according to GB 4789.15 using Bengal red agar and incubate at 28℃ for 5 days; and perform coliform count according to GB 4789.3 using VRBA plates.
[0031] Determining the initial contamination level N0 is a prerequisite for calculating the required irradiation dose. The microbial contamination levels of different batches of health tea vary considerably, typically around 10. 2 -10 5 CFU / g must be measured in person.
[0032] Each sample was tested in triplicate, and the results were taken as the logarithmic mean. Detection limits: Total bacterial count 10 CFU / g, mold 10 CFU / g.
[0033] Obtain accurate N0 values in CFU / g to provide basic data for subsequent dose calculations.
[0034] Step S2: Isolate the radiation-resistant strain from the sample and determine the D of the radiation-resistant strain. 10 value; Step S21: Isolation of dominant radiation-resistant strains; Diluted samples of the health-preserving tea were spread onto plate counting agar and incubated at 36°C for 48 hours. Colonies of different morphologies were then picked and purified. The purified strains were irradiated with 2 kGy, 4 kGy, and 6 kGy of cobalt-60 rays, respectively. Strains that survived at 6 kGy were selected as the dominant radiation-resistant strains. 16S rDNA sequencing identified the most common radiation-resistant bacteria in the health-preserving tea as *Bacillus subtilis* and *Bacillus pumilus*.
[0035] Step S22: Prepare a bacterial suspension (approximately 10 μL) from the purified Bacillus subtilis. 6 -10 7 The CFU / mL concentration was evenly spread onto plate counting agar plates, with three plates per dose. The plates were placed in a cobalt-60 irradiation device and subjected to irradiation doses of 0, 1, 2, 3, 4, 5, and 6 kGy (with a fixed dose rate of 2 kGy / h, calibrated using a silver dichromate dosimeter). After irradiation, the plates were incubated at 36°C for 48 h, and the colony count was then performed.
[0036] Step S23: After data processing, determine the D of the radiation-resistant strain. 10 value.
[0037] In step S23, D 10 =-D / log 10 (N / N0); where the irradiation dose is D, N is the number of colonies after irradiation, N0 is the number of colonies in the unirradiated control, and the survival rate is N / N0.
[0038] like Figure 2 As shown, with the irradiation dose D (kGy) as the x-axis, log 10 Plot the inactivation curve with (N / N0) as the ordinate; perform linear regression on the linear portion to obtain the equation: log 10 (N / N0) = -kD;D 10 Value = 1 / k; D 10 The dose required to kill 90% of microorganisms.
[0039] Typical measured data are shown in the table below: Irradiation dose (kGy) viable colony count (CFU / plate) <![CDATA[Survival rate N / N0]]> <![CDATA[log 10 (N / N0)]]> 0 <![CDATA[2.310 6 ]]> 1 0 1 <![CDATA[1.210 5 ]]> 0.052 -1.28 2 <![CDATA[6.510 3 ]]> 0.0028 -2.55 3 <![CDATA[3.610 2 ]]> 0.00016 -3.80 4 20 <![CDATA[8.710 -6 ]]> -5.06 5 1 <![CDATA[4.310 -7 ]]> -6.36 6 0 <![CDATA[<10 -6 ]]> -6.90 Linear regression was performed on the dose data of 1-4 kGy: log 10 (N / N0) = -1.26D + 0.08 (R = 0.998), therefore D 10 =1 / 1.26=0.79kGy.
[0040] Step S3: Establish a model for the relationship between irradiation dose and sterilization effect; Based on a first-order kinetic model of microbial radiation extinguishing activity, the survival rate exhibits an exponential relationship with the irradiation dose: N=N010 (-D / D10) Logarithmic form: log 10 (N)=log 10 (N0)-D / D 10 Among them, the number of surviving microorganisms after N irradiation (CFU / g); the initial number of microorganisms at N0 (CFU / g); the irradiation dose at D (kGy); and D 10 The dose required to kill 90% of microorganisms is kGy.
[0041] Step S4: Calculate the required minimum irradiation dose D: based on the target sterility level N. target From N=N010(-D / D) 10 Solve for the required dose D = D 10 log 10 (N0 / N target ).
[0042] Target sterility level N target The values were: total bacterial count 1000 CFU / g; molds and yeasts 100 CFU / g; coliforms 10 CFU / g.
[0043] Step S5: Irradiate the patient at a safety margin multiple of the calculated minimum irradiation dose; the safety margin is 1 to 1.2. The initial total bacterial count of the health tea was N0 = 510. 4 CFU / g, target N target =1000 CFU / g, D 10 =0.79kGy, then D=0.79log 10 (510 4 / 10 3 ) = 0.79log 10 (50) = 0.791.699 = 1.34 kGy. Considering a safety margin (1.2 times), the actual dose is 1.6 kGy. The traditional fixed dose of 5 kGy is 3.1 times the dose of this model, which will cause unnecessary loss of active ingredients.
[0044] Compared with existing technologies, this process has the following advantages: Accuracy: Traditional fixed-dose models do not consider differences in initial contamination levels; this model is based on measured N0 and D. 10 Calculate the minimum dose that exactly achieves the target sterility level.
[0045] Economic efficiency: By avoiding excessive irradiation, the cost of irradiating each kg of health tea is reduced by about 50%.
[0046] Protecting active ingredients: Irradiation dose is positively correlated with the degradation of active ingredients. This model increases the retention rate of total flavonoids and polysaccharides by more than 15%.
[0047] Adaptive adjustment: It can dynamically adjust according to the initial contamination of each batch of raw materials, realizing a batch-specific policy.
[0048] Step S6: After irradiation, perform microbial re-examination and effective ingredient content detection to verify the process; take samples of the same batch of health tea and irradiate them with the model-calculated dose and the control dose respectively, and compare the detection indicators.
[0049] The core of this invention lies in establishing an adaptive irradiation dose model tailored to the characteristics of health-preserving tea: (1) Regarding the microbial contamination spectrum of health tea: Bacillus was preferentially screened as an indicator bacterium because it has a high proportion in health tea and is highly resistant to radiation. Its D value was measured. 10 The value represents the worst-case scenario.
[0050] (2) To address the fluctuations in raw materials for health tea: N0 is measured for each batch, and the dosage is dynamically calculated to achieve a one-batch-one-policy approach.
[0051] (3) Regarding the protection of active ingredients in health tea: the model ensures that the dosage reaches the target sterility level and avoids excessive irradiation.
[0052] As shown in the table below, samples of the same batch of health tea were irradiated with 0, 1.6, 2.5, 3.5, 5.0, and 7.0 kGy respectively, and their microbial indicators, total flavonoids, total polysaccharides, and sensory quality were tested. Irradiation dose (kGy) Total bacterial count (CFU / g) Mold and yeast (CFU / g) Total flavonoid retention rate (%) Total polysaccharide retention rate (%) Sensory rating (out of 10) 0 <![CDATA[5.210 4 ]]> 2.110 100 100 9.2 1.6 (Model Calculation) 850 45 96.5 94.2 9.0 2.5 120 8 93.1 90.5 8.7 3.5 15 0 88.6 85.3 8.3 5.0 (Traditional Fixed) 0 0 81.2 77.8 7.5 7.0 0 0 72.5 68.4 6.8
[0053] The model calculated that after sterilization at a dose of 1.6 kGy, the total bacterial count was 850 CFU / g (<1000), and the mold and yeast count was 45 CFU / g (<100), meeting the standards. The total flavonoid retention rate was 96.5%, the total polysaccharide retention rate was 94.2%, and there was almost no change in sensory characteristics. Although the traditional 5 kGy method achieves thorough sterilization, it results in significant loss of active ingredients. This model improves the retention rate of active ingredients by 15-20 percentage points while ensuring sterilization compliance.
[0054] As shown in the table below, the advantages of this process over existing technologies are as follows: Scientific and precise: based on the biomechanical model of microbial inactivation, rather than empirical values.
[0055] Protecting active ingredients: The retention rate of total flavonoids increased by 14.6%, and the retention rate of total polysaccharides increased by 15.7%.
[0056] Cost savings: Irradiation dose is reduced by 50-70%, resulting in a cost reduction of approximately 50%.
[0057] Quality controllable: Dynamically adjust dosage to adapt to raw material fluctuations and avoid quality accidents.
[0058] Compliant with regulations: Meets the minimum effective dose requirements of the "Technical Guidelines for Irradiation Sterilization of Traditional Chinese Medicine". Comparison items Traditional fixed-dose regimen (5 kGy) The present invention uses a model method (dynamic dosing). Dosage determination basis Experience points (uniform standard) <![CDATA[Measured N0 + D 10 Calculation]]> Initial pollution level considerations no yes Average radiation dose 5.0kGy 1.5-2.5kGy Sterilization pass rate 100% 100% Average retention rate of total flavonoids 81.2% 95.8% Average retention rate of total polysaccharides 77.8% 93.5% Sensory quality (odor) Relatively obvious (7.5 points) No impact (9.0 points) Irradiation cost (RMB / kg) 2.5 0.8-1.3
[0059] It also includes step S7: establishing a dynamic quality control system; such as Figure 3 As shown, each batch of incoming raw materials is tested for N0, according to the formula D=1.2D. 10 log 10 (N0 / 1000) Calculate the required irradiation dose for this batch; after irradiation, take 3 samples from each batch for re-inspection; take mixed samples monthly for verification. 10 Values are used to monitor changes in radiation-resistant bacterial communities. For example... Figure 4 As shown, an irradiation dose control chart (XR chart) was established. When three consecutive batches of N0 exceeded the mean of 2, the D was re-evaluated. 10 .
[0060] Example 2 This embodiment is used to specifically demonstrate how the present invention achieves the best balance between sterilization effect and retention of active ingredients when facing batches of health tea raw materials with different initial contamination levels (N0) through a batch-by-batch dynamic dosage calculation model.
[0061] The raw materials for health-preserving teas are mostly agricultural products, and their initial microbial load (N0) is greatly affected by the climate of the place of origin, the harvest season, the drying method, and the storage and transportation conditions. Actual test data shows that the initial total bacterial count (N0) of different batches of mixed cassia seed and hawthorn raw materials can fluctuate by up to two orders of magnitude (10^6). 3 Up to 10 5 (CFU / g). If a traditional fixed dosage (e.g., 5 kGy) is used, low-contamination batches will suffer unnecessary radiolytic loss of active ingredients, while high-contamination batches may face the risk of insufficient dosage leading to sterilization failure.
[0062] Raw material sampling and NO determination: Three representative batches of health tea raw materials (batch numbers: 20241021-A, 20241028-B, 20241105-C) were selected, and their initial microbial contamination level NO was determined according to the method described in step S1. The actual test results are as follows: Batch A (low-contamination batch): N0=2.810 3 CFU / g Batch B (Regularly Contaminated Batch): N0=5.210 4 CFU / g (same as data in Example 1) Batch C (highly contaminated batch): N0=3.510 5 CFU / g D 10 Value confirmation: Following step S2 for isolation and identification, the dominant radiation-resistant bacterial group in these three batches of raw materials was Bacillus subtilis, and its D value was measured. 10 The value is stable at 0.79 kGy.
[0063] Dynamic dose calculation (batch-by-batch): Setting the target sterility level N target = 1000 CFU / g, with a safety margin of 1.1, according to the formula D=1.1D 10 log 10 (N0 / N target Calculate the required irradiation dose for each batch.
[0064] Calculated dose for batch A: D_A = 1.10.79log 10 (2.810 3 / 10 3 = 0.39kGy (rounded to 0.5kGy for irradiation) Calculated dose for batch B: D_B = 1.10.79log 10 (5.210 4 / 10 3 = 1.49kGy (rounded to 1.5kGy for irradiation) Calculated dose for batch C: D_C = 1.10.79log10 (3.510 5 / 10 3 = 2.21kGy (rounded to 2.2kGy for irradiation) Comparative experiment and effect verification: The above three batches of raw materials were divided into two parts. One part was treated with the dynamic dose calculated in this invention, and the other part was treated with the traditional fixed dose of 5 kGy. After irradiation, the total bacterial count and total flavonoid retention rate were detected according to step S6.
[0065] The table below shows a comparison of the treatment effects of the dynamic dosing method of this invention and the traditional fixed dosing method: batch <![CDATA[Initial N0 (CFU / g)]]> Handling method Irradiation dose (kGy) Post-irradiation bacterial colonies (CFU / g) Sterilization determination Total flavonoid retention rate (%) A (Low pollution) <![CDATA[2.810 3 ]]> Dynamic Dosage of the Invention 0.5 420 qualified 98.2 A (Low pollution) <![CDATA[2.810 3 ]]> Traditional fixed dose 5.0 0 qualified 80.1 B (Standard) <![CDATA[5.210 4 ]]> Dynamic Dosage of the Invention 1.5 780 qualified 96.8 B (Standard) <![CDATA[5.210 4 ]]> Traditional fixed dose 5.0 0 qualified 81.5 C (High Pollution) <![CDATA[3.510 5 ]]> Dynamic Dosage of the Invention 2.2 950 qualified 94.5 C (High Pollution) <![CDATA[3.510 5 ]]> Traditional fixed dose 5.0 0 qualified 80.8 Achieving precise batch-specific control: Faced with initial contamination levels differing by two orders of magnitude (batch A and batch C), the model of this invention automatically adjusts the irradiation dose from 0.5 kGy to 2.2 kGy. For the low-contamination batch A, the dose is significantly reduced to avoid excessive irradiation; for the high-contamination batch C, the dose is moderately increased to ensure thorough sterilization.
[0066] Significant benefits in protecting active ingredients: Under the premise of ensuring that all batches of raw materials meet the microbiological indicators, the three batches of raw materials using the dynamic dosage of this invention have an average total flavonoid retention rate of up to 96.5%, which is much higher than the 80.8% of the traditional fixed dosage method. Especially in the low-contamination batch A, the dosage of this invention is only 1 / 10 of the fixed dosage, and the total flavonoid retention rate is increased by 18.1 percentage points.
[0067] It should be noted that the safety margin multiple in this embodiment is 1.1, which is based on the D of these three batches of raw materials. 10 The value determination shows good reproducibility and high process stability; in Example 1, 1.2 is taken as a conventional conservative value. The safety margin multiple can be flexibly selected within the limited range of 1 to 1.2 according to the actual process control level.
[0068] Compliance with regulatory guidelines and cost control: This embodiment verifies that the present invention fully meets the core requirement of the "Guiding Principles for Irradiation Sterilization Technology of Traditional Chinese Medicine" to minimize the irradiation dose while ensuring the sterilization effect.
[0069] like Figure 5 As shown in the bar chart, the significant numerical differences between the dynamic and fixed doses of the present invention under different contamination levels and the corresponding advantages in retaining active ingredients are clearly demonstrated.
[0070] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
Claims
1. An irradiation sterilization process for health-preserving tea, characterized in that: The method includes the following steps: Step S1: Detect the initial microbial contamination level of the health tea sample and obtain N0; Step S2: Isolate the radiation-resistant strain from the sample and determine the D of the radiation-resistant strain. 10 value; Step S3: Establish a model for the relationship between irradiation dose and sterilization effect; Step S4: Calculate the required minimum radiation dose D: Step S5: Irradiate the target dose at a safety margin multiple of the calculated minimum irradiation dose; Step S6: After irradiation, perform microbial re-examination and detection of effective ingredient content to verify the process.
2. The irradiation sterilization process for health-preserving tea according to claim 1, characterized in that: Step S1 includes the following steps: Step S11: Take a sample of the health-preserving tea, add sterile saline solution, homogenize, and then dilute. Step S12: Determine the initial contamination level N0 by measuring the total bacterial count, counting molds and yeasts, and counting coliform bacteria.
3. The irradiation sterilization process for health-preserving tea according to claim 1, characterized in that: Step S2 includes the following steps: Step S21: Spread the diluted health tea sample onto plate counting agar, and after cultivation, pick colonies of different morphologies for purification. The purified strains were irradiated with 2kGy, 4kGy and 6kGy of cobalt-60 rays respectively, and the strains that still survived at 6kGy were selected as radiation-resistant strains. Step S22: Prepare a bacterial suspension from the purified radiation-resistant strain, spread it evenly on a plate counting agar plate, place the plate in a cobalt-60 irradiation device, and receive irradiation doses of 0, 1, 2, 3, 4, 5, and 6 kGy respectively. After irradiation, incubate and count the number of colonies. Step S23: After data processing, determine the D of the radiation-resistant strain. 10 value.
4. The irradiation sterilization process for health-preserving tea according to claim 3, characterized in that: In step S23, D 10 =-D / log 10 (N / N0); where the irradiation dose is D, N is the number of colonies after irradiation, N0 is the number of colonies in the unirradiated control, and the survival rate is N / N0.
5. The irradiation sterilization process for health-preserving tea according to claim 1, characterized in that: In step S3, based on the first-order kinetic model of microbial radiation extinguishing activity, the survival rate has an exponential relationship with the irradiation dose: N=N010 (-D / D10) Logarithmic form: log 10 (N)=log 10 (N0)-D / D 10 Among them, the number of surviving microorganisms after N irradiation (CFU / g); the initial number of microorganisms after N0 irradiation (CFU / g); the irradiation dose of D (kGy); and D 10 The dose required to kill 90% of microorganisms is kGy.
6. The irradiation sterilization process for health-preserving tea according to claim 1, characterized in that: Step S4 includes the following steps: based on the target sterility level N target From N=N010(-D / D) 10 Solve for the required dose D = D 10 log 10 (N0 / N target ).
7. The irradiation sterilization process for health-preserving tea according to claim 6, characterized in that: The target sterility level N target The values were: total bacterial count 1000 CFU / g; molds and yeasts 100 CFU / g; coliforms 10 CFU / g.
8. The irradiation sterilization process for health-preserving tea according to claim 1, characterized in that: In step S5, the safety margin is 1 to 1.
2.
9. The irradiation sterilization process for health-preserving tea according to claim 1, characterized in that: Step S6 specifically involves taking samples of the same batch of health-preserving tea, subjecting them to irradiation with the model-calculated dose and the comparative dose, and comparing the detection indicators.
10. The irradiation sterilization process for health-preserving tea according to claim 1, characterized in that: It also includes step S7: establishing a dynamic quality control system; testing N0 for each batch of raw materials, calculating the required irradiation dose for that batch, and taking a mixed sample after irradiation to verify D. 10 Values were monitored to track changes in radiation-resistant bacterial flora; an irradiation dose control chart was established, and D was reassessed when several consecutive batches of N0 exceeded the mean of 2. 10 .