Ultrahigh pressure jet flow combined thermal sterilization system and thermal sterilization method thereof

Abstract

The invention relates to the technical field of food sterilization equipment, in particular to an ultrahigh-pressure jet flow combined thermal sterilization system and a thermal sterilization method thereof.The system sequentially comprises a preheating module, an ultrahigh-pressure jet flow module, a steam direct injection module, a heat preservation module, a flash evaporation module and a cooling module; the ultrahigh-pressure jet flow combined thermal sterilization method adopting the system is suitable for pasteurization working conditions, UHT sterilization working conditions and ultrahigh-temperature super-instantaneous sterilization working conditions. According to the method, the principle of ultrahigh-pressure jet flow is adopted, firstly, the ultrahigh-pressure jet flow can bring instant temperature rise of 40-60 DEG C, the ultrahigh-pressure jet flow is a temperature rise mode of converting pure mechanical energy into internal energy, and a preset sterilization temperature is reached in an extremely short time, so that the loss of active ingredients and flavor of a product in the temperature rise process is reduced; meanwhile, by utilizing an extremely strong cavitation effect generated by ultrahigh-pressure jet flow, a jet flow wall breaking effect is generated on microorganisms, a non-thermal sterilization effect is achieved, and the obvious effects of reducing the thermal sterilization intensity and maintaining the nutrition, flavor and taste of the raw materials are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of food sterilization equipment, and in particular to an ultra-high pressure jet combined thermal sterilization system and a thermal sterilization method thereof. Background Art

[0002] In the process of food processing and storage, sterilization is a key link to ensure product safety and extend shelf life. Traditionally, sterilization processes are based on the principle of heat treatment inactivation. Heat treatment is mainly used to kill microorganisms and inactivate enzymes. The effectiveness of heat treatment and its impact on product quality are mainly related to the combination of temperature and time, the heating method used, and the pretreatment conditions of the materials. Heat sterilization is the most widely used sterilization method in the food industry. The essence of traditional heat sterilization technology is to rely on burning fuel or resistance heating to provide heat energy on the outside of the food, and transfer the heat energy to the inside of the food through conduction and convection, so as to achieve the purpose of sterilization and enzyme inactivation. At present, there are four main types of heat sterilization treatment: preheating sterilization, pasteurization, ultra-high temperature instantaneous sterilization, and maintenance sterilization. Now countries around the world have formed a relatively unified production model, mainly pasteurization and Ultra-high temperature instantaneous sterilization (UHT) sterilization.

[0003] However, traditional thermal sterilization technologies rely on indirect or direct heat conduction for heating and temperature rise. Limited by the efficiency of heat conduction, the material will be exposed to additional heat, resulting in loss of food nutrients and deterioration of flavor and taste. For example, the active protein components in milk, including α-lactalbumin, β-lactoglobulin and lactoferrin, are the essence of milk. They have important functions such as resisting the invasion of pathogens such as bacteria, activating the body's immune response, and maintaining the health of the body. They are collectively referred to as the "natural active nutrition" of milk. However, during the heat treatment and sterilization process of milk, these active ingredients will be damaged to varying degrees. Therefore, the sterilization process of milk is constantly being improved to continuously reduce the damage to active ingredients while meeting the shelf life requirements. However, due to the limitations of traditional heat transfer methods, it is difficult to achieve both sterilization effect and active ingredient retention. At the same time, due to the existence of heat transfer surfaces, thermal damage and slagging will also occur, resulting in the occurrence of pipe sticking, which requires the production line to be stopped and cleaned regularly, resulting in a large amount of material loss.

[0004] Therefore, it is necessary to develop a new generation of non-thermal sterilization technology to reduce the intensity of thermal sterilization while maintaining food quality, which has become an urgent problem to be solved in the current industry. Among them, ultra-high pressure jet technology is an emerging non-thermal sterilization technology. Its cavitation effect can produce jet wall breaking effect on microorganisms. However, ultra-high pressure jet technology has always remained in the laboratory research stage and is still a long way from being truly put into industrial application. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention aims to provide an ultra-high pressure jet combined thermal sterilization system and a thermal sterilization method thereof.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0007] An ultra-high pressure jet combined thermal sterilization system, the system sequentially comprises a preheating module, an ultra-high pressure jet module, a steam direct injection module, a heat preservation module, a flash evaporation module and a cooling module;

[0008] The preheating module is used to heat the material to a preheating temperature to obtain a preheated material;

[0009] The ultra-high pressure jet module is used to perform high-speed jet on the preheated material, so that the temperature of the preheated material is increased to obtain a heated material;

[0010] The steam direct injection module includes a steam direct injection mixer, which is used to heat the heated material to the sterilization temperature to obtain the sterilization temperature material. Different heating temperatures correspond to steam direct injection mixers with different structures.

[0011] The heat preservation module is used to keep the sterilization temperature material warm to obtain the heat preservation material;

[0012] The flash evaporation module is used to cool down the insulation material and remove the moisture added by the steam direct injection module. The insulation material stays in the pipeline from the insulation module to the flash evaporation module for no more than 0.2 seconds to obtain a cooling material.

[0013] The cooling module is used to cool the temperature-reducing material to room temperature and enter the next process;

[0014] The ultra-high pressure jet combined thermal sterilization system is suitable for pasteurization conditions, UHT sterilization conditions, and ultra-high temperature ultra-instantaneous sterilization conditions.

[0015] An ultra-high pressure jet combined thermal sterilization method, using the above-mentioned ultra-high pressure jet combined thermal sterilization system,

[0016] The preheating module heats the material to a preheating temperature to obtain a preheated material;

[0017] The ultra-high pressure jet module performs high-speed jetting on the preheated material, so that the temperature of the preheated material is increased to obtain a heated material;

[0018] The steam direct injection module heats the heated material to a sterilization temperature to obtain a sterilization temperature material;

[0019] The heat preservation module keeps the sterilization temperature material warm to obtain the heat preservation material;

[0020] The flash evaporation module cools down the heat-insulating material and removes the moisture added by the steam direct injection module to obtain a flash evaporation material;

[0021] The cooling module cools the flash vaporized material to room temperature and enters the next process;

[0022] The ultra-high pressure jet combined thermal sterilization method is suitable for pasteurization conditions, UHT sterilization conditions, and ultra-high temperature ultra-instantaneous sterilization conditions.

[0023] Preferably, the preheating temperature is 10-40°C.

[0024] Preferably, the heating temperature of the ultra-high pressure jet module is 62-95°C.

[0025] Preferably, the sterilization temperature is 135-157°C.

[0026] Preferably, the insulation time is 3-20s.

[0027] Preferably, the flash evaporation module cools the insulation material to 55-65°C.

[0028] Preferably, under pasteurization conditions, the material passes through the ultra-high pressure jet module, the heat preservation module and the cooling module in sequence;

[0029] The material directly enters the ultra-high pressure jet module to be jet heated to 62-85° C. to obtain heated material;

[0030] The heated material directly enters the insulation module and is kept warm for 10-20 seconds to obtain the insulation material;

[0031] The insulation material directly enters the cooling module to be cooled to room temperature and enters the next process.

[0032] Preferably, under UHT sterilization conditions, the material enters the preheating module, ultra-high pressure jet module, steam direct injection module, heat preservation module, flash evaporation module and cooling module in sequence;

[0033] The material enters the preheating module and is heated to a preheating temperature of 10-20°C to obtain a preheated material;

[0034] The preheated material enters the ultra-high pressure jet module for high-speed jetting, so that the preheated material is heated to 62-85° C. to obtain a heated material;

[0035] The heated material enters the steam direct injection module and is heated to a sterilization temperature of 135-145° C. to obtain a sterilization temperature material;

[0036] The sterilization temperature material enters the insulation module for insulation for 3-10 seconds to obtain insulation material;

[0037] The heat-insulating material enters the flash evaporation module to be cooled to 55-65° C., and the moisture added by the steam direct injection module is removed to obtain a flash evaporation material;

[0038] The flash evaporated material enters the cooling module to be cooled to room temperature and enters the next process.

[0039] Preferably, under ultra-high temperature and ultra-instantaneous sterilization conditions, the material sequentially enters the preheating module, ultra-high pressure jet module, steam direct injection module, flash evaporation module and cooling module;

[0040] The material enters the preheating module and is heated to a preheating temperature of 30-40°C to obtain a preheated material;

[0041] The preheated material enters the ultra-high pressure jet module for high-speed jetting, so that the preheated material is heated to 85-95° C. to obtain a heated material;

[0042] The heated material enters the steam direct injection module and is heated to a sterilization temperature of 152-157° C. to obtain a sterilization temperature material;

[0043] The heat-insulating material enters the flash evaporation module to be cooled to 55-65° C., and the moisture added by the steam direct injection module is removed to obtain a flash evaporation material;

[0044] The flash evaporated material enters the cooling module to cool to room temperature and enters the next process

[0045] The beneficial effects of the present invention are:

[0046] The present invention adopts the principle of ultra-high pressure jet. Firstly, the ultra-high pressure jet can bring about an instantaneous temperature rise of 40-60°C. It is a heating method that converts pure mechanical energy into internal energy. It reaches the predetermined sterilization temperature in a very short time, thereby reducing the loss of active ingredients and flavor of the product during the heating process. At the same time, the extremely strong cavitation effect generated by the ultra-high pressure jet is utilized to produce a jet wall breaking effect on microorganisms, which has a non-thermal sterilization effect, and has a significant effect on reducing the intensity of thermal sterilization and maintaining the nutrition, flavor and taste of the raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0048] Figure 1 Schematic diagram of the entire system and process flow of the present invention

[0049] Figure 2 Schematic diagram of pasteurization working conditions

[0050] Figure 3 Schematic diagram of UHT sterilization working conditions

[0051] Figure 4 Schematic diagram of ultra-high temperature and ultra-instantaneous sterilization working conditions DETAILED DESCRIPTION

[0052] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the following embodiments are provided only for the purpose of illustration and are not intended to limit the scope of the present invention. Those skilled in the art may make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0053] The purpose of the present invention is to provide an ultra-high pressure jet combined thermal sterilization system and a thermal sterilization method thereof. The system is modularly designed and comprises a preheating module, an ultra-high pressure jet module, a steam direct injection module, a heat preservation module, a flash evaporation module and a cooling module in sequence, and can realize a variety of different working conditions including pasteurization, UHT sterilization and ultra-high temperature instantaneous sterilization.

[0054] 2) First, the material is heated to the preheating temperature of 10-40℃ through the preheating module. It does not pass through the preheating module under pasteurization conditions. Then the material enters the ultra-high pressure jet module for high-speed jetting. During the high-speed jetting process, the temperature of the material rises to 62-95℃, and most of the microorganisms are killed. Next, the material enters the steam direct injection module and is heated to the sterilization temperature of 135-157℃ through the steam direct injection mixer. After reaching the sterilization temperature, the material enters the insulation module for insulation. After insulation, the material enters the flash evaporation module for cooling and removing the moisture added by the steam direct injection module. Finally, after the material is cooled to room temperature in the cooling module, it enters the subsequent process. The advantage of modular design is that a variety of different sterilization conditions can be achieved through one system: 1) pasteurization conditions; 2) UHT sterilization conditions; 3) ultra-high temperature and ultra-instantaneous sterilization conditions.

[0055] Example 1: Pasteurization conditions

[0056] Under pasteurization conditions, the material does not pass through the preheating module, steam direct injection module and flash module. The material directly enters the ultra-high pressure jet module for jet heating. According to the different sterilization intensity, the temperature can be raised to 62-85°C by adjusting the jet pressure, the jet pressure is 200-280MPa, preferably the jet pressure is 250MPa, and the temperature reaches 69°C. Then it directly enters the insulation module for 10-20s, and finally enters the cooling module to cool to room temperature.

[0057] The outlet temperature of the milk material and the killing of microorganisms under different jet pressures are shown in Table 1. It can be seen that as the jet pressure increases, the sterilization effect continues to increase. When the jet pressure reaches 230MPa, the outlet temperature of the material is only 62°C, and the killing effect of coliform group and total bacterial count is equivalent to the pasteurization condition of 72°C / 15s. When the jet pressure reaches 250MPa, the outlet temperature of the material is only 69°C, and the killing effect of coliform group and total bacterial count is equivalent to the pasteurization condition of 85°C / 15s. Therefore, the pasteurization temperature can be significantly reduced by the method of the present invention.

[0058] Table 1

[0059]

[0060] Since the temperature of the jet treatment is relatively low, the inactivation of active substances caused by heat is greatly reduced. Milk treated with 250MPa high-pressure jet has obvious advantages in retaining active substances compared with pasteurization. The results of active substance detection are shown in Table 2:

[0061] Table 2

[0062]

[0063] Example 2: UHT sterilization conditions

[0064] In the UHT sterilization condition, first, the material is heated to a preheating temperature of 10-20°C through the preheating module, and then the material enters the ultra-high pressure jet module for high-speed jetting, and the temperature is raised to 62-85°C. The jet pressure is 200-280MPa, and the preferred jet pressure is 250MPa. Next, the material enters the steam direct injection module and is heated to a sterilization temperature of 135-145°C through a steam direct injection mixer. After reaching the sterilization temperature, the material enters the insulation module for insulation for 3-10s. After insulation, the material enters the flash evaporation module for cooling and removing the moisture added by the steam direct injection. Finally, after the material is cooled to room temperature in the cooling module, it enters the subsequent process.

[0065] Example 3: Ultra-high pressure ultra-instantaneous sterilization

[0066] In the ultra-high temperature and ultra-instantaneous sterilization condition, first, the material is heated to a preheating temperature of 30-40°C through the preheating module, and then the material enters the ultra-high pressure jet module for high-speed jetting and is heated to 85-95°C. Next, the material enters the steam direct injection module and is heated to a sterilization temperature of 152-157°C through the steam direct injection mixer. After reaching the sterilization temperature, the material enters the flash module directly without passing through the insulation module to cool down to 55-65°C, and removes the moisture added by the steam direct injection. The material stays in the pipeline from the steam direct injection mixer to the flash module for no more than 0.2s. Finally, after the material is cooled to room temperature in the cooling module, it enters the subsequent process.

[0067] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0068] Finally, it should be noted that the above description is only a preferred example of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An ultra-high pressure jet combined thermal sterilization system, characterized in that: The system includes a preheating module, an ultra-high pressure jet module, a steam direct injection module, a heat preservation module, a flash evaporation module and a cooling module in sequence; The preheating module is used to heat the material to a preheating temperature to obtain a preheated material; The ultra-high pressure jet module is used to perform high-speed jet on the preheated material, so that the temperature of the preheated material is increased to obtain a heated material; The steam direct injection module includes a steam direct injection mixer, which is used to heat the heated material to the sterilization temperature to obtain the sterilization temperature material. Different heating temperatures correspond to steam direct injection mixers with different structures. The heat preservation module is used to keep the sterilization temperature material warm to obtain the heat preservation material; The flash evaporation module is used to cool down the heat-insulating material and remove the moisture added by the steam direct injection module to obtain a cooling material; The cooling module is used to cool the temperature-reducing material to room temperature and enter the next process; The ultra-high pressure jet combined thermal sterilization system is suitable for pasteurization conditions, UHT sterilization conditions, and ultra-high temperature ultra-instantaneous sterilization conditions.

2. An ultra-high pressure jet combined thermal sterilization method, using the ultra-high pressure jet combined thermal sterilization system according to claim 1, characterized in that: The preheating module heats the material to a preheating temperature to obtain a preheated material; The ultra-high pressure jet module performs high-speed jetting on the preheated material, so that the temperature of the preheated material is increased to obtain a heated material; The steam direct injection module heats the heated material to a sterilization temperature to obtain a sterilization temperature material; The heat preservation module keeps the sterilization temperature material warm to obtain the heat preservation material; The flash evaporation module cools down the insulation material and removes the moisture added by the steam direct injection module. The insulation material stays in the pipeline from the insulation module to the flash evaporation module for no more than 0.2 seconds to obtain a flash evaporation material. The cooling module cools the flash vaporized material to room temperature and enters the next process; The ultra-high pressure jet combined thermal sterilization method is suitable for pasteurization conditions, UHT sterilization conditions, and ultra-high temperature ultra-instantaneous sterilization conditions.

3. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: The preheating temperature is 10-40°C.

4. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: The heating temperature of the ultra-high pressure jet module is 62-95°C.

5. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: The sterilization temperature is 135-157°C.

6. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: The insulation time is 3-20s.

7. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: The flash module cools the insulation material to 55-65°C.

8. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: Under pasteurization conditions, the material passes through the ultra-high pressure jet module, the heat preservation module and the cooling module in sequence; The material directly enters the ultra-high pressure jet module to be jet heated to 62-85° C. to obtain heated material; The heated material directly enters the insulation module and is kept warm for 10-20 seconds to obtain the insulation material; The insulation material directly enters the cooling module to be cooled to room temperature and enters the next process.

9. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: Under the UHT sterilization condition, the material enters the preheating module, the ultra-high pressure jet module, the steam direct injection module, the heat preservation module, the flash evaporation module and the cooling module in sequence; The material enters the preheating module and is heated to a preheating temperature of 10-20°C to obtain a preheated material; The preheated material enters the ultra-high pressure jet module for high-speed jetting, so that the preheated material is heated to 62-85° C. to obtain a heated material; The heated material enters the steam direct injection module and is heated to a sterilization temperature of 135-145° C. to obtain a sterilization temperature material; The sterilization temperature material enters the insulation module for insulation for 3-10 seconds to obtain insulation material; The heat-insulating material enters the flash evaporation module to be cooled to 55-65° C., and the moisture added by the steam direct injection module is removed to obtain a flash evaporation material; The flash evaporated material enters the cooling module to be cooled to room temperature and enters the next process.

10. The ultra-high pressure jet combined thermal sterilization method according to claim 2, characterized in that: Under the ultra-high temperature and ultra-instantaneous sterilization conditions, the material enters the preheating module, the ultra-high pressure jet module, the steam direct injection module, the flash evaporation module and the cooling module in sequence; The material enters the preheating module and is heated to a preheating temperature of 30-40°C to obtain a preheated material; The preheated material enters the ultra-high pressure jet module for high-speed jetting, so that the preheated material is heated to 85-95° C. to obtain a heated material; The heated material enters the steam direct injection module and is heated to a sterilization temperature of 152-157° C. to obtain a sterilization temperature material; The heat-insulating material enters the flash evaporation module to be cooled to 55-65° C., and the moisture added by the steam direct injection module is removed to obtain a flash evaporation material; The flash evaporated material enters the cooling module to be cooled to room temperature and enters the next process.

Images