A pressure-controlled, temperature-controlled, delayed constant-temperature sterilization process for glutinous rice cakes

Abstract

This invention relates to the field of food processing technology and discloses a controlled-pressure, temperature-controlled, delayed-temperature sterilization process for glutinous rice cakes. The process includes: treating steamed glutinous rice with high-density carbon dioxide; sealing and pounding the rice into shape before vacuum packaging; preheating with pulsed microwaves; placing the rice in a rotating sterilizer, where it is heated and pressurized simultaneously; accumulating the F0 value in real time during constant-temperature sterilization, automatically terminating when a preset value is reached; and cooling after three-stage gradient backpressure cooling. This invention inactivates microorganisms through high-density carbon dioxide pretreatment before shaping, combined with microwave heating and rotating uniform-temperature sterilization, using the F0 value as a precise sterilization endpoint. Multi-stage backpressure cooling prevents bag breakage and tissue collapse, achieving commercial sterility without chemical preservatives, maintaining the glutinous rice cake's chewy texture and white color, delaying starch aging, and significantly extending its shelf life at room temperature.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a pressure-controlled, temperature-controlled, delayed constant-temperature sterilization process for glutinous rice cakes. Background Technology

[0002] Currently, the main methods of sterilization are as follows: High temperature and high pressure sterilization method: Usually, high temperature sterilization at 121℃ for 20-30 minutes is used. Although the sterilization is thorough, it will cause the glutinous rice starch to be over-gelatinized, making the glutinous rice cake soft, sticky, and losing its original chewiness and elasticity, resulting in a serious decline in taste.

[0003] Pasteurization: This method uses a low temperature of 70-75℃ for 45-60 minutes to sterilize the food. Although it can preserve the taste well, the sterilization is not thorough and cannot kill thermophilic Bacillus. It requires repeated sterilization, resulting in low production efficiency and a shelf life of only 1-3 months.

[0004] Adding chemical preservatives: This method extends shelf life by adding chemical preservatives such as sodium dehydroacetate and propylparaben. However, as consumers become more health-conscious and demand for additive-free, all-natural foods increases, products with added chemical preservatives are becoming less and less popular in the market.

[0005] Microwave sterilization: This method uses the thermal and non-thermal effects of microwaves to sterilize, resulting in fast sterilization speed. However, it suffers from uneven heating and the potential for cold spots that lead to incomplete sterilization.

[0006] Furthermore, during the sterilization process, vacuum-packed glutinous rice cakes are prone to bulging and rupture due to the excessive pressure difference between the inside and outside of the packaging bag, resulting in a high product scrap rate. Therefore, developing a sterilization process that can solve the above problems has become an urgent technical issue to be addressed in the industrial production of glutinous rice cakes. Summary of the Invention

[0007] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a pressure-controlled, temperature-controlled, delayed constant-temperature sterilization process for glutinous rice cakes.

[0008] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A pressure-controlled, temperature-controlled, delayed-temperature sterilization process for glutinous rice cakes includes the following steps: S1. The steamed glutinous rice is treated with high-density carbon dioxide. S2. The glutinous rice treated with high-density carbon dioxide is sealed, pounded, and shaped to make glutinous rice cakes. After cooling, it is vacuum-packed in a clean environment. S3. Microwave-assisted preheating of vacuum-packed glutinous rice cakes to raise the center temperature of the glutinous rice cakes; S4. Place the preheated glutinous rice cake in a sterilizer with a rotating cage, rotate and inject hot water, continue to heat up and pressurize simultaneously, and control the pressure difference between the inside and outside of the packaging bag within the preset range. S5. Sterilize by rotating the constant temperature at the sterilization temperature, and accumulate the F0 value in real time. When the F0 value at the coldest point reaches the preset target value, the constant temperature will be automatically terminated. S6. Perform multi-stage gradient back pressure cooling to gradually reduce the temperature and pressure until it is finally restored to normal pressure; S7. Remove from the pot and let cool to obtain the finished product.

[0009] Furthermore, in step S1, the high-density carbon dioxide treatment temperature is 30-50℃, the pressure is 5-20MPa, the treatment time is 15-45min, and the pressure is released to atmospheric pressure in stages after the treatment is completed.

[0010] Furthermore, the segmented pressure relief specifically involves: first reducing the pressure to 3-5 MPa at a rate of 0.5-0.8 MPa / min, maintaining it for 5 minutes, and then reducing it to atmospheric pressure at a rate of 1.0-1.5 MPa / min.

[0011] Furthermore, in step S2, the vacuum degree of the vacuum packaging is -0.08 to -0.10 MPa, and the packaging bag is a high-temperature retort pouch.

[0012] Furthermore, in step S3, microwave-assisted preheating brings the center temperature of the glutinous rice cake to 50-65℃ and the surface temperature to ≤70℃; the microwave frequency is 890-940MHz, the power density is 0.5-2.0W / g, the pulse mode is used, and the duty cycle is 30-70%.

[0013] Furthermore, in step S4, the rotation speed of the rotating cage is 1-5 rpm, the temperature of the injected hot water is 85-95℃, the temperature is increased to 105-115℃ at a rate of 1.0-2.0℃ / min, and the pressure is increased to 0.12-0.18MPa simultaneously, controlling the pressure difference between the inside and outside of the packaging bag to ≤0.05MPa.

[0014] Furthermore, in step S5, the sterilization temperature is 105-115℃, the pressure is 0.12-0.18MPa, and the constant temperature is automatically terminated when the coldest point F0 value reaches 2.0-5.0min.

[0015] Furthermore, the multi-stage gradient backpressure cooling in step S6 is specifically a three-stage process: the first stage cools to 85-90℃, the pressure drops to 0.08-0.10MPa, and is maintained for 3-8 minutes; the second stage cools to 60-65℃, the pressure drops to 0.02-0.04MPa, and is maintained for 2-5 minutes; the third stage cools to 40-50℃ and restores normal pressure.

[0016] Furthermore, in step S6, during the first stage of cooling, water at 70-80°C is injected into the vessel and hot water is simultaneously discharged. At the same time, pressure is precisely replenished by compressed air to achieve counter-pressure cooling.

[0017] (iii) Beneficial technical effects This invention discloses a pressure-controlled, temperature-controlled, and time-delayed constant-temperature sterilization process for glutinous rice cakes. High-density carbon dioxide treatment before molding is used to allow carbon dioxide to fully penetrate the glutinous rice matrix under low-temperature and pressurized conditions. This inactivates a large number of microbial vegetative cells and some spores through non-thermal effects such as lowering intracellular pH and disrupting cell membrane structure, thus weakening the heat resistance of residual spores. Microwave pulse heating is used to preheat the vacuum-packed glutinous rice cakes, causing simultaneous heating of the center and surface. This eliminates the temperature gradient inherent in traditional conductive heating, significantly shortens the time of the subsequent hot water heating stage, and reduces the problem of starch gelatinization and textural damage caused by excessive surface heating. The glutinous rice cakes are slowly tumbled in hot water by a rotating cage, effectively avoiding the localized under- or over-sterilization caused by dead zones in static sterilization. During the constant temperature process, the sterilization intensity F0 value is calculated in real time, and the automatic termination of the constant temperature is based on the F0 value reaching the preset target at the coldest point. This transforms the endpoint control of heat treatment from a traditional fixed-time mode to a precise determination mode based on lethal dose, ensuring commercial sterility while preventing the deterioration of the glutinous rice cakes' elasticity and flavor due to excess heat input. The cooling stage employs a three-stage gradient backpressure cooling method. By gradually reducing the temperature and simultaneously adjusting the pressure, the pressure difference between the inside and outside of the packaging bag is always kept at an extremely low level. This prevents the instantaneous boiling and vaporization of internal moisture, tissue collapse, and packaging breakage caused by sudden pressure drops, maintaining the product's full, smooth appearance and dense, uniform texture. Compared with single high-temperature and high-pressure sterilization or pasteurization, the sterilization process of this invention not only meets the safety requirements of commercial sterility and long-term room temperature storage without the addition of any chemical preservatives, but also preserves the unique elasticity, white color and natural rice aroma of glutinous rice cake to the greatest extent, significantly delays starch retrogradation, and ensures stable quality during the shelf life. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 A pressure-controlled, temperature-controlled, delayed-temperature sterilization process for glutinous rice cakes includes the following steps: S1. Place the steamed glutinous rice in a high-pressure container and treat it with high-density carbon dioxide: treatment temperature 30℃, pressure 5MPa, treatment time 15min; after treatment, depressurize in stages to atmospheric pressure, first at a rate of 0.5MPa / min to 3MPa, maintain for 5min, and then at a rate of 1.0MPa / min to atmospheric pressure. S2. The glutinous rice treated with high-density carbon dioxide is sealed, pounded, and shaped to make glutinous rice cakes. After cooling, they are vacuum-packed in a clean environment. The vacuum degree of the vacuum packaging is -0.08MPa, and the packaging bag is a high-temperature retort bag. S3. Microwave-assisted preheating of vacuum-packed glutinous rice cakes to achieve a center temperature of 50℃ and a surface temperature ≤70℃; the microwave frequency is 890MHz, the power density is 0.5W / g, the pulse mode is used, and the duty cycle is 30%. S4. Place the preheated glutinous rice cake in a sterilizer with a rotating cage, rotate it at 1 rpm, pour in 85°C hot water and completely immerse the product, continue to heat it to 105°C at a rate of 1.0°C / min, and simultaneously introduce clean compressed air to pressurize it to 0.12MPa, and control the pressure difference between the inside and outside of the packaging bag to ≤0.05MPa. S5. Sterilize by rotating at 105℃ and 0.12MPa, and accumulate the F0 value in real time. The constant temperature will be automatically terminated when the F0 value at the coldest point reaches 2.0min. S6. Perform multi-stage gradient backpressure cooling: The first stage cools to 85℃ and the pressure drops to 0.08MPa, maintaining this for 3 minutes; the second stage cools to 60℃ and the pressure drops to 0.02MPa, maintaining this for 2 minutes; the third stage cools to 40℃ and restores atmospheric pressure. During the first stage cooling process, 70℃ water is injected into the vessel and hot water is simultaneously discharged. At the same time, compressed air is used to precisely replenish the pressure to achieve backpressure cooling. S7. Remove from the pot and let cool to obtain the finished product.

[0020] Example 2 A pressure-controlled, temperature-controlled, delayed-temperature sterilization process for glutinous rice cakes includes the following steps: S1. Place the steamed glutinous rice in a high-pressure container and treat it with high-density carbon dioxide: treatment temperature 35℃, pressure 8MPa, treatment time 20min; after treatment, depressurize in stages to atmospheric pressure, first at a rate of 0.6MPa / min to 4MPa, maintain for 5min, and then at a rate of 1.2MPa / min to atmospheric pressure. S2. The glutinous rice treated with high-density carbon dioxide is sealed, pounded, and shaped to make glutinous rice cakes. After cooling, they are vacuum-packed in a clean environment. The vacuum degree of the vacuum packaging is -0.09MPa, and the packaging bag is a high-temperature retort bag. S3. Microwave-assisted preheating of vacuum-packed glutinous rice cakes to achieve a center temperature of 55℃ and a surface temperature ≤70℃; the microwave frequency is 900MHz, the power density is 1W / g, the pulse mode is used, and the duty cycle is 40%. S4. Place the preheated glutinous rice cake in a sterilizer with a rotating cage, rotate it at 2 rpm, pour in 90℃ hot water and completely immerse the product, continue to heat it to 110℃ at a rate of 1.5℃ / min, and simultaneously introduce clean compressed air to pressurize it to 0.15MPa, and control the pressure difference between the inside and outside of the packaging bag to ≤0.05MPa. S5. Sterilize by rotating at 110℃ and 0.15MPa, and accumulate the F0 value in real time. The constant temperature will be automatically terminated when the F0 value at the coldest point reaches 3.0min. S6. Perform multi-stage gradient backpressure cooling: The first stage cools to 88℃ and the pressure drops to 0.09MPa, maintaining for 5 minutes; the second stage cools to 60℃ and the pressure drops to 0.03MPa, maintaining for 3 minutes; the third stage cools to 45℃ and restores atmospheric pressure; during the first stage cooling process, 72℃ water is injected into the vessel and hot water is simultaneously discharged, while compressed air is used to precisely replenish the pressure to achieve backpressure cooling. S7. Remove from the pot and let cool to obtain the finished product.

[0021] Example 3 A pressure-controlled, temperature-controlled, delayed-temperature sterilization process for glutinous rice cakes includes the following steps: S1. Place the steamed glutinous rice in a high-pressure container and treat it with high-density carbon dioxide: treatment temperature 40℃, pressure 10MPa, treatment time 30min; after treatment, depressurize in stages to atmospheric pressure, first at a rate of 0.6MPa / min to 4MPa, maintain for 5min, and then at a rate of 1.2MPa / min to atmospheric pressure. S2. The glutinous rice treated with high-density carbon dioxide is sealed, pounded, and shaped to make glutinous rice cakes. After cooling, it is vacuum-packed in a clean environment. The vacuum degree of the vacuum packaging is -0.10MPa, and the packaging bag is a high-temperature retort bag. S3. Microwave-assisted preheating of vacuum-packed glutinous rice cakes to achieve a center temperature of 60℃ and a surface temperature ≤70℃; the microwave frequency is 930MHz, the power density is 1.5W / g, the pulse mode is used, and the duty cycle is 50%. S4. Place the preheated glutinous rice cake in a sterilizer with a rotating cage, rotate it at 3 rpm, pour in 85°C hot water and completely immerse the product, continue to heat it to 115°C at a rate of 2.0°C / min, and simultaneously introduce clean compressed air to pressurize it to 0.16MPa, and control the pressure difference between the inside and outside of the packaging bag to ≤0.05MPa. S5. Sterilize by rotating at 115℃ and 0.15MPa, and accumulate the F0 value in real time. The constant temperature will be automatically terminated when the F0 value at the coldest point reaches 5.0 min. S6. Perform multi-stage gradient backpressure cooling: The first stage cools to 90℃, the pressure drops to 0.10MPa, and is maintained for 8 minutes; the second stage cools to 60℃, the pressure drops to 0.03MPa, and is maintained for 5 minutes; the third stage cools to 50℃ and restores atmospheric pressure; during the first stage cooling process, 80℃ water is injected into the vessel and hot water is discharged simultaneously, while the pressure is precisely replenished by compressed air to achieve backpressure cooling. S7. Remove from the pot and let cool to obtain the finished product.

[0022] Example 4 A pressure-controlled, temperature-controlled, delayed-temperature sterilization process for glutinous rice cakes includes the following steps: S1. Place the steamed glutinous rice in a high-pressure container and treat it with high-density carbon dioxide: treatment temperature 45℃, pressure 18MPa, treatment time 40min; after treatment, depressurize in stages to atmospheric pressure, first at a rate of 0.5MPa / min to 5MPa, maintain for 5min, and then at a rate of 1.5MPa / min to atmospheric pressure. S2. The glutinous rice treated with high-density carbon dioxide is sealed, pounded, and shaped to make glutinous rice cakes. After cooling, they are vacuum-packed in a clean environment. The vacuum degree of the vacuum packaging is -0.08MPa, and the packaging bag is a high-temperature retort bag. S3. Microwave-assisted preheating of vacuum-packed glutinous rice cakes to achieve a center temperature of 50℃ and a surface temperature ≤70℃; the microwave frequency is 915MHz, the power density is 2.0W / g, the pulse mode is used, and the duty cycle is 50%. S4. Place the preheated glutinous rice cake in a sterilizer with a rotating cage, rotate it at 4 rpm, pour in 90℃ hot water and completely immerse the product, continue to heat it to 105℃ at a rate of 1.0℃ / min, and simultaneously introduce clean compressed air to pressurize it to 0.12MPa, and control the pressure difference between the inside and outside of the packaging bag to ≤0.05MPa. S5. Sterilize by rotating at 110℃ and 0.15MPa, and accumulate the F0 value in real time. The constant temperature will be automatically terminated when the F0 value at the coldest point reaches 3.0min. S6. Perform multi-stage gradient backpressure cooling: The first stage cools to 90℃ and the pressure drops to 0.08MPa, maintaining for 5 minutes; the second stage cools to 60℃ and the pressure drops to 0.03MPa, maintaining for 2 minutes; the third stage cools to 50℃ and restores atmospheric pressure; during the first stage cooling process, 70℃ water is injected into the vessel and hot water is simultaneously discharged, while compressed air is used to precisely replenish the pressure to achieve backpressure cooling. S7. Remove from the pot and let cool to obtain the finished product.

[0023] Example 5 A pressure-controlled, temperature-controlled, delayed-temperature sterilization process for glutinous rice cakes includes the following steps: S1. Place the steamed glutinous rice in a high-pressure container and treat it with high-density carbon dioxide: treatment temperature 50℃, pressure 20MPa, treatment time 45min; after treatment, depressurize in stages to atmospheric pressure, first at a rate of 0.8MPa / min to 5MPa, maintain for 5min, and then at a rate of 1.5MPa / min to atmospheric pressure. S2. The glutinous rice treated with high-density carbon dioxide is sealed, pounded, and shaped to make glutinous rice cakes. After cooling, it is vacuum-packed in a clean environment. The vacuum degree of the vacuum packaging is -0.10MPa, and the packaging bag is a high-temperature retort bag. S3. Microwave-assisted preheating of vacuum-packed glutinous rice cakes to achieve a center temperature of 65℃ and a surface temperature ≤70℃; the microwave frequency is 940MHz, the power density is 2.0W / g, the pulse mode is used, and the duty cycle is 70%. S4. Place the preheated glutinous rice cake in a sterilizer with a rotating cage, rotate it at 5 rpm, pour in 95℃ hot water and completely immerse the product, continue to heat it to 115℃ at a rate of 2.0℃ / min, and simultaneously introduce clean compressed air to pressurize it to 0.18MPa, and control the pressure difference between the inside and outside of the packaging bag to ≤0.05MPa. S5. Sterilize by rotating at 115℃ and 0.18MPa, and accumulate the F0 value in real time. The constant temperature will be automatically terminated when the F0 value at the coldest point reaches 5.0 min. S6. Perform multi-stage gradient backpressure cooling: The first stage cools to 90℃ and the pressure drops to 0.10MPa, maintaining for 8 minutes; the second stage cools to 65℃ and the pressure drops to 0.04MPa, maintaining for 5 minutes; the third stage cools to 50℃ and restores atmospheric pressure; during the first stage cooling process, 80℃ water is injected into the vessel and hot water is simultaneously discharged, while compressed air is used to precisely replenish the pressure to achieve backpressure cooling. S7. Remove from the pot and let cool to obtain the finished product.

[0024] Comparative Example 1: Step S1 is omitted, and the process proceeds directly to the S2 forming and packaging stage. The remaining processes are the same as in Example 3.

[0025] Comparative Example 2: The sterilization vessel in step S4 does not have a rotation function, and the rest of the process is the same as in Example 3.

[0026] Comparative Example 3: In step S5, the real-time accumulation of F0 value and automatic termination function are not set, and the rest of the process is the same as in Example 3.

[0027] Comparative Example 4: In step S6, the multi-stage gradient back pressure cooling was cancelled and replaced with single-stage direct cooling: After the constant temperature was completed, the temperature was directly reduced to 45℃ at a rate of 2.5℃ / min, and the pressure was simultaneously reduced linearly from 0.15MPa to atmospheric pressure within 8min. The rest of the process was the same as in Example 3.

[0028] Performance testing: 1. Commercial sterility testing Methods: According to GB 4789.26-2023 "National Food Safety Standard - Microbiological Examination of Food - Commercial Sterility Test", 30 bags of samples were taken from each example and comparative example and placed in a constant temperature incubator at 37℃ for 10 days to observe whether the bags swelled. Smears of samples before and after incubation were stained and examined under a microscope to compare the changes in the number of microorganisms. The pH value was measured and the pH changes before and after incubation were compared.

[0029] Judgment criteria: If there is no swelling of the bag after heat preservation, the pH change is ≤0.3, and there is no microbial growth under microscopic examination, it is judged as commercially sterile and qualified.

[0030] 2. Quantitative test of bactericidal efficacy Methods: 30 bags of samples were taken from each of the embodiments and comparative examples and placed in constant temperature incubators at 37℃ and 55℃, respectively. The swelling of the bags was observed on days 7, 14, 21, 30, 45, 60 and 90.

[0031] Judgment criteria: Record the time of first bag expansion and the 90-day bag expansion rate.

[0032] Table 1. Results of bactericidal performance test

[0033] As shown in the table above, although Comparative Example 1 passed the commercial sterility test (10 days), its bag expansion rate after 90 days of accelerated sterilization at 55℃ was 3 / 30, slightly higher than the 0 / 30 of Example 3. This indicates that high-density carbon dioxide treatment is effective in sterilization. Comparative Example 2, with a bag expansion rate of 8 / 30 after 90 days of accelerated sterilization at 55℃, significantly higher than the other groups, indicates insufficient local sterilization. Comparative Example 3 showed good sterilization effect; however, not setting an F0 value would result in excessive heat load and poor temperature control. Direct cooling in Comparative Example 4 would lead to a larger pressure difference between the inside and outside of the packaging, affecting the sterility barrier during storage.

[0034] 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 pressure-controlled, temperature-controlled, delayed, constant-temperature sterilization process for glutinous rice cakes, characterized in that, Includes the following steps: S1. The steamed glutinous rice is treated with high-density carbon dioxide. S2. The glutinous rice treated with high-density carbon dioxide is sealed, pounded, and shaped to make glutinous rice cakes. After cooling, it is vacuum-packed in a clean environment. S3. Microwave-assisted preheating of vacuum-packed glutinous rice cakes to raise the center temperature of the glutinous rice cakes; S4. Place the preheated glutinous rice cake in a sterilizer with a rotating cage, rotate and inject hot water, continue to heat up and pressurize simultaneously, and control the pressure difference between the inside and outside of the packaging bag within the preset range. S5. Sterilize by rotating at the sterilization temperature and accumulate the F0 value in real time. When the F0 value at the coldest point reaches the preset target value, the constant temperature will be automatically terminated. S6. Perform multi-stage gradient back pressure cooling to gradually reduce the temperature and pressure until it is finally restored to normal pressure; S7. Remove from the pot and let cool to obtain the finished product.

2. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 1, characterized in that, In step S1, the high-density carbon dioxide treatment is carried out at a temperature of 30-50℃, a pressure of 5-20MPa, and a treatment time of 15-45min. After the treatment is completed, the pressure is released in stages to atmospheric pressure.

3. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 2, characterized in that, The segmented pressure relief is specifically as follows: first, the pressure is reduced to 3-5 MPa at a rate of 0.5-0.8 MPa / min, maintained for 5 minutes, and then reduced to normal pressure at a rate of 1.0-1.5 MPa / min.

4. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 1, characterized in that, In step S2, the vacuum degree of vacuum packaging is -0.08 to -0.10 MPa, and the packaging bag is a high-temperature retort pouch.

5. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 1, characterized in that, In step S3, microwave-assisted preheating brings the center temperature of the glutinous rice cake to 50-65℃ and the surface temperature to ≤70℃. The microwave frequency is 890-940MHz, the power density is 0.5-2.0W / g, the pulse mode is used, and the duty cycle is 30-70%.

6. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 1, characterized in that, In step S4, the rotating cage rotates at a speed of 1-5 rpm, the injected hot water temperature is 85-95℃, the temperature is increased to 105-115℃ at a rate of 1.0-2.0℃ / min, and the pressure is simultaneously increased to 0.12-0.18MPa, controlling the pressure difference between the inside and outside of the packaging bag to ≤0.05MPa.

7. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 1, characterized in that, In step S5, the sterilization temperature is 105-115℃ and the pressure is 0.12-0.18MPa. The constant temperature is automatically terminated when the coldest point F0 value reaches 2.0-5.0min.

8. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 1, characterized in that, The multi-stage gradient backpressure cooling in step S6 is specifically in three stages: the first stage cools to 85-90℃ and the pressure drops to 0.08-0.10MPa, maintaining for 3-8 minutes; the second stage cools to 60-65℃ and the pressure drops to 0.02-0.04MPa, maintaining for 2-5 minutes; the third stage cools to 40-50℃ and restores normal pressure.

9. The pressure-controlled temperature-controlled time-delayed constant temperature sterilization process for glutinous rice cakes according to claim 1, characterized in that, In step S6, during the first stage of cooling, water at 70-80°C is injected into the reactor and hot water is discharged simultaneously. At the same time, pressure is precisely replenished by compressed air to achieve counter-pressure cooling.

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