CN108936139A - A kind of preparation method and equipment of bananas juice - Google Patents

Abstract

The invention discloses a banana juice preparation process, which comprises: removing the head and tail and peeling the screened bananas; coarsely beating the banana pulp to obtain a banana coarse pulp; transporting the banana coarse pulp to a nitrogen positive pressure through a closed pipeline The airtight pipeline type microwave treatment device carries out microwave sterilization and deactivation treatment during the flow process; the banana crude pulp is transported by a screw propeller while stirring and extruding in front of the microwave treatment device; the banana crude pulp after the above sterilization and deactivation treatment is Put the finely beaten banana pulp into the blending tank for stirring and blend according to the required beverage types, and add water to make banana juice; use a high-pressure homogenizer to homogenize the banana juice; The vacuum degassing process is carried out on the homogenized banana juice; the banana juice after the vacuum degassing is further sterilized; and the further sterilized banana juice is aseptically packed in a closed space.

Description

A kind of preparation method and equipment of banana juice

technical field

The invention relates to a method for preparing banana juice prone to browning, in particular to a banana juice preparation process provided with a microwave heating process and a pipeline type microwave sterilization and inactivation equipment capable of preventing banana browning.

Background technique

Banana is suitable for a wide range of people, has very high medicinal and edible health value, and is one of the fruit products with the most significant economic benefits in the domestic and foreign markets. At present, the area of cultivated bananas in South China is constantly increasing, and the output is gradually improving. It has become a large number of cultivated fruit trees in various provinces in South China. However, the production period of bananas is concentrated, and due to the impact of storage, transportation and sales, further processing of bananas is the main means to ease the contradiction between production and sales.

During the processing of bananas, the product quality is affected to a great extent due to its susceptibility to browning. Therefore, in recent years, the use of various technologies to prevent banana browning has become the focus of research in this field. Enzymatic browning of bananas requires three conditions: an appropriate phenolic substrate, phenoloxidase, and oxygen. Methods to control enzymatic browning range from traditional heating, pH adjustment to biotechnology applications, and research continues. The current methods of controlling enzymatic browning can be divided into three categories: physical control, chemical control and biotechnology control. Among them, physical control methods include microwave treatment, hot air treatment, hot water steam treatment, etc. Chemical control includes citric acid, malic acid, ascorbic acid, sulfur oxide addition, etc. Biological control technology includes onion extract, plant protease, honey, The addition of lactic acid bacteria and so on.

Because microwave treatment has the advantages of easy operation and control, high treatment efficiency and good effect, it has attracted extensive research. In the prior art, the microwave treatment process can be divided into four methods: (1) using microwave technology alone to inactivate enzymes; (2) using berry enzymes (or compound enzymes) to assist microwave inactivating enzymes; (3) using color-protecting agents Auxiliary microwave inactivation of enzymes; (4) Use pressure or heating to inactivate enzymes in assisted microwave inactivation of enzymes. Representative prior art, such as Yunnan Banana Research Institute has studied a preparation method of anti-browning banana juice, the preparation process includes: banana sorting→peeling→microwave enzyme elimination→pulping→filtration→homogenization→ Vacuum degassing → sterilization → filling → cooling → finished product. However, this technology uses microwave inactivation treatment first, followed by beating and preparation, and the tunnel type microwave inactivation device cannot completely isolate oxygen and there are inhomogeneities in the microwave, resulting in low efficiency of the microwave treatment process, incomplete inactivation of enzymes, and anti-browning. The transformation effect is not good.

Judging from the public information of products and relevant publications on the market, the prior art does not yet solve the problem of enzymatic browning well, and the processed banana juice is unsatisfactory no matter the color and luster product, appearance or flavor and mouthfeel. Therefore, there is an urgent need in this area for a microwave anti-browning treatment method, pulping equipment, and process that can be safer and more efficient, and can effectively control banana browning through thorough enzyme deactivation.

Contents of the invention

The invention provides a banana juice microwave treatment process, which can efficiently solve the browning problem in the finishing process of banana drinks. In the present invention, beating is performed before enzymes are inactivated by microwaves, and microwave treatment processes such as nitrogen positive pressure operation are used for the slurry, thereby improving the efficiency of the treatment process and improving the treatment effect.

A kind of banana juice preparation technology, comprising:

The screened bananas are removed from the head and tail and peeled;

Roughly beating banana pulp to obtain banana coarse pulp;

The banana coarse pulp is transferred to a nitrogen positive pressure closed pipeline microwave treatment device through a closed pipeline, and microwave sterilization and inactivation treatment is carried out during the flow process;

Carrying out fine beating treatment to the banana coarse pulp after the above-mentioned sterilization and inactivation treatment;

Put the finely beaten banana slurry into the blending tank and stir it according to the type of beverage required, and add water to make banana juice;

Utilize high-pressure homogenizer to carry out homogenization to banana juice;

Carry out the vacuum degassing process to the banana juice after the homogenization;

Further sterilize the banana juice after vacuum degassing;

The banana juice after further sterilization is carried out aseptic canning in a closed space.

Preferably, the rough beating process does not add any water, and the banana meat is transported in the form of slurry in the closed pipeline while being stirred and sent to microwave heating. Preferably, nitrogen gas is injected into the pipeline to isolate The action of air prevents the oxidative browning of the banana puree; further preferably, the banana coarse pulp is stirred while being pushed and conveyed by a screw-type material pusher in a closed pipeline.

Preferably, the nitrogen pressure in the microwave treatment process is controlled at 1.2 to 1.5 times the atmospheric pressure, the nitrogen flow rate is at 4-10m³/min and the flow direction is the same as that of the banana slurry; further preferably, the nitrogen is in the The inlet side of the pipeline type microwave processing device is charged, and a nitrogen pressure relief means is provided on the outlet side of the microwave processing device.

Preferably, the high-pressure homogeneous process is twice, preferably the first pressure-40MPa, the second pressure 50-80MPa;

As mentioned above, preferably, the sterilization temperature is 80-85°C, and the preferred time is 5-8 seconds;

As mentioned above, preferably, the entire filling equipment for the above-mentioned canning is a closed space; the preferred filling temperature is 80-85°C.

Preferably, the above-mentioned pulping can use a colloid mill for pulping. When pulping, the preferred material:water volume ratio=1:2.0-3.0; when putting the material, it is more preferred to add citric acid, D-iso Sodium ascorbate, and the control pH value is 2.2-3.0.

Preferably, the microwave treatment process is divided into a main treatment section and a heat preservation treatment section, and the microwave power, microwave density, and heating time of the main treatment section are greater than the microwave power, microwave density, and heating time of the heat preservation section; preferably, the The microwave power of the microwave treatment in the main treatment section is 60-12OKW, such as 85KW, the microwave frequency is 2000-2800MHz, such as 2450MHz, and the sterilization and inactivation time is 5-10 minutes; the microwave power of the microwave treatment in the heat preservation section is 20-6OKW, such as 45KW, and the microwave frequency is 2000 -2800MHz, such as 2450MHz, the sterilization and inactivation time is 3-8 minutes; the specific power density is 4-8W/g, preferably 6 W/g; more preferably, the temperature at the end of the two-stage microwave treatment is 75-93°C , preferably 88°C.

A kind of banana juice that utilizes aforementioned process to obtain.

A product using the aforementioned banana juice as a raw material.

Solution 1 of a pipeline-type microwave processing device applied to the aforementioned process, which includes: a microwave heating pipeline, the microwave heating pipeline includes a conveying inner pipe and a conveying outer pipe, and a material is formed between the conveying inner pipe and the conveying outer pipe. a plurality of microwave generators arranged on the outside of the conveying outer pipe; and a material pusher connected to the material inlet of the microwave heating pipeline, and the material enters the microwave from the material inlet under the promotion of the material pusher. The heating pipeline is processed under the action of a microwave field: the microwave heating pipeline is a closed type, the material pusher is a screw type material pusher driven by a frequency conversion motor, and a nitrogen filling device is installed at the material inlet of the microwave heating pipeline , so that the material is under positive pressure in the microwave heating pipeline; the plurality of microwave generators are arranged at intervals along the axial direction of the microwave heating pipeline, and each microwave generator forms microwave reflection in the circumferential direction of the outer conveying pipe The metal ring cavity and the magnetron of each microwave generator can be controlled individually.

A pipeline-type microwave processing device scheme 2 applying the aforementioned technology, which includes: a tube shell made of metal materials, a microwave heating pipeline made of non-metallic materials arranged in the tube shell, and a microwave heating tube set on the inner wall of the tube shell The microwave generator on the outer wall side of the microwave heating pipeline, the material pusher arranged in the microwave heating pipeline in the microwave field of the microwave generator, the material enters the microwave heating pipeline from the material inlet, and acts on the microwave field The material is pushed to the material outlet by the material pusher. The microwave heating pipeline is a closed type, and the flow power of the fluid in it comes from the material pusher arranged on the material inlet side, which is a screw type material pusher and is driven by frequency conversion. Driven by a motor, a nitrogen filling device is installed on the material inlet side of the microwave heating pipeline where it is located, so that the material is pushed to the discharge port of the microwave processing device by the material pusher in the microwave heating pipeline under positive pressure; The microwave generator includes a plurality of microwave emitting units arranged along the material conveying direction, and each microwave emitting unit forms one or more microwave emitting points distributed circumferentially on the outer peripheral side of the microwave heating pipeline, and each microwave The emitting points are arranged with independent magnetrons and drive circuits for emitting microwaves; each microwave emitting unit and each microwave emitting point can be independently controlled.

Further preferably, the microwave power can be adjusted by using the voltage applied to the microwave emission point, and the microwave heating time can be adjusted by controlling the conveying speed of the material.

The second preferred embodiment of the pipeline type microwave processing device is further preferably, each microwave emitting unit includes 2-8 microwave emitting points uniformly distributed in the circumferential direction, preferably an even number, further preferably, the microwave emitting points are arranged symmetrically, further preferably along the In the pushing direction of the material, the microwave emission points of each section of the microwave emission unit are reduced section by section or unit by unit. As one of the preferred embodiments, the microwave emission unit is divided into four sections, each section has a unit, and each unit emission point is 8, 6, 4, 2; as the second preferred embodiment, the microwave emitting unit is divided into two sections, each section has one unit, and each unit has 8, 4 emitting points.

The second preferred embodiment of the above-mentioned pipeline type microwave processing device is further preferably arranged in a staggered arrangement along the banana conveying direction, and the emission points of the plurality of microwave emission units are arranged in a staggered manner; in another exemplary embodiment, the plurality of microwave emission units The launch point is arranged in a spiral along the banana conveying direction as a whole, and the spiral direction is the same as the pushing direction of the screw-type banana conveyor.

In the second preferred embodiment of the above pipeline microwave processing device, it is further preferred that the microwave heating pipeline is made of soft silicone material.

The second preferred embodiment of the above-mentioned pipeline type microwave processing device is further preferred, and the screw type material pusher is preferably a shaftless screw pusher.

The second preferred embodiment of the above-mentioned pipeline microwave processing device is further preferred, the nitrogen charging device sends nitrogen spirally and tangentially into the microwave heating pipeline, and the conveying direction of nitrogen is the same as the conveying direction of bananas. In an exemplary embodiment, the outlet end of the microwave heating pipeline is provided with a nitrogen pressure release device, so that the banana slurry is discharged from the microwave heating pipeline before being transported to the storage device through the microwave heating pipeline.

The second preferred embodiment of the pipeline type microwave processing device is further preferred. The pipeline type microwave sterilization and deactivation equipment also includes a banana pretreatment section without a microwave generating device, and the pretreatment section is connected to the pipeline type microwave sterilization. The entrance of the living equipment allows the bananas to be processed in advance and then enter the microwave heating pipeline equipped with a microwave generating device and a screw material pusher. The pretreatment section can be pretreated according to the type of banana and the state of the banana to ensure the effect of microwave treatment. The processing section is set up as a closed pipeline with an auger. In another exemplary embodiment, the banana pretreatment section is provided with a spray humidifier to prevent the banana solid product from being too dry and losing its crispness during the microwave heating process.

The second preferred embodiment of the pipeline type microwave processing device is further preferred. The pipeline type microwave sterilization and deactivation equipment also includes a control system, and the control system includes a banana temperature monitoring unit. The temperature monitoring unit includes a set of microwave The temperature sensors used to monitor the temperature of the bananas between the transmitting units; the control unit also includes a microwave control unit, which is used to control the start-up and heating time of the multi-stage microwave generator, each microwave transmitting unit, and microwave transmitting points. The control unit also includes a motor control unit of the screw material pusher, which is used to control the speed at which bananas are pushed in the microwave heating pipeline. Further preferably, the microwave control system also includes a central microprocessor, which can adjust the microwave power and/or microwave density and/or the material delivery speed of the motor when the banana temperature monitored by the temperature monitoring unit is not within the set range. Further preferably, the microwave control system also includes a pressure control unit, which is used to control the nitrogen filling volume and nitrogen flow rate of the nitrogen filling device. Further preferably, the nitrogen flow rate added by the nitrogen filling device is 4-10m ² /min . Further preferably, the control system also includes a preset system, so that the microwave control unit and the screw material pusher motor control unit can automatically apply preset microwave power, microwave density and microwave For heating time, the banana parameter is at least temperature, and may also be banana type, temperature, humidity, viscosity, sugar content, flow rate, etc.

Further, the canned banana juice is sold, and hydrogen is added when canned, and the flow rate of adding hydrogen is 35-90L/min, preferably the flow rate of hydrogen is 40-80L/min, more preferably the flow rate of hydrogen is 50-70L/min, the preferred liquid flow rate pressure is 3-6 kg. The addition of hydrogen can help the body excrete excess metabolic waste, remove harmful free radicals, and thus delay aging.

The above-mentioned preferred implementation modes or optimization measures can also be combined arbitrarily.

Description of drawings

Embodiments of the present disclosure will be more fully understood from the detailed description given below and the accompanying drawings according to the embodiments of the disclosure. In the drawings, like reference numbers may indicate identical or functionally similar elements.

Fig. 1 is the flow chart of the preferred embodiment of banana juice preparation process of the present invention.

Fig. 2 is a schematic structural diagram of a preferred embodiment of the microwave processing device of the present invention.

Fig. 3 is a schematic circuit diagram of a microwave generator with a preferred embodiment of the present invention.

Fig. 4 is an example diagram of the control procedure of the microwave heating of the microwave generator according to the preferred embodiment of the present invention.

Fig. 5 shows a schematic diagram of the banana pulp temperature and corresponding color after the microwave heating treatment of the present invention.

Detailed ways

The invention provides a pipeline type microwave sterilization and deactivation equipment capable of effectively inactivating and inhibiting enzymatic browning of bananas, a banana pulping device equipped with the microwave processing device, a pulping method and obtained banana products. It should be understood that these examples are provided by way of explanation and nothing herein should be construed as limiting the full scope of the invention.

Banana juice preparation technique of the present invention, general inventive thinking comprises:

The screened bananas are removed from the head and tail and peeled;

Roughly beating banana pulp to obtain banana coarse pulp;

The banana coarse pulp is transferred to a nitrogen positive pressure closed pipeline microwave treatment device through a closed pipeline, and microwave sterilization and inactivation treatment is carried out during the flow process;

Carrying out fine beating treatment to the banana coarse pulp after the above-mentioned sterilization and inactivation treatment;

Put the finely beaten banana slurry into the blending tank and stir it according to the type of beverage required, and add water to make banana juice;

Utilize high-pressure homogenizer to carry out homogenization to banana juice;

Carry out the vacuum degassing process to the banana juice after the homogenization;

Further sterilize the banana juice after vacuum degassing;

The banana juice after further sterilization is carried out aseptic canning in a closed space.

The most important features of adopting the above-mentioned anti-browning banana juice preparation process are: 1) To overcome technical prejudice, before the microwave heating treatment of the banana pulp, it is first beaten into a coarse pulp, which will in turn sterilize and inactivate more thoroughly. 2) A closed nitrogen positive pressure environment is used to completely isolate oxygen to avoid slurry oxidation; 3) The slurry is heated by microwaves while being conveyed, so that the treatment is more complete and no dead ends are left; 4) The processing efficiency of the existing technology is greatly improved, and it can In a short period of time, a banana juice product with stable color can be obtained, and the product can maintain a color difference change of less than 15% within 30 minutes, which provides a strong guarantee for the high-quality preparation of banana-related products.

Below in conjunction with accompanying drawing 1 explanation banana juice optimal preparation process discusses juice making method: the original juice content of banana juice is greater than 20%.

1. Banana pretreatment

Optionally use Williams bananas as an ingredient. The best bananas are completely yellow and ripe, pH=5.3-5.5, Bx=20, no damage, no rotten fruit, no bad fruit, remove the head and tail.

2. Coarse beating

Preferably adopt the banana peeling juice extractor produced by Leading Light Industry Machinery Co., Ltd., Xinxiang City, Henan Province, and put the bananas into the machine for beating. Bananas are first separated from the skin and flesh, and after being beaten by a beater, they are transported from the discharge port through the pipeline to the screw conveyor of the microwave pipeline type sterilization and deactivation device in the form of slurry. Nitrogen is injected into the pipeline to isolate the air and prevent oxidation and browning of the banana puree.

3. Sterilization, enzyme inactivation

Utilize the microwave pipeline type sterilization and deactivation device according to the present invention, banana pulp is sterilized, wherein the operating parameters of the microwave generator are as follows: the microwave power is 80KW, the microwave frequency is 2450MHz, and the microwave power density is 6W/g. The active time is 8 minutes; the microwave power of heat preservation treatment is 60KW, the microwave density is 6W/g, the microwave frequency is 2450MHz, the sterilization and inactivation time is 6 minutes, and the temperature after deactivation is 88°C; the banana crude pulp has been treated with microwave deactivation;

After the slurry enters the pipeline, the air is completely isolated, thereby avoiding the browning of bananas during the production process.

See below for the specific pipeline microwave processing device.

4. Fine beating

It is preferred to use JMF-120 colloid mill produced by Guangzhou Food Machinery Equipment Factory for beating, the rotation speed is 2800 rpm, and the particle size is 13.75-15 μm (micron). When beating, material: water = 1:2.5; while putting in the material, add citric acid and D-sodium erythorbate in the form of spray (citric acid and D-sodium erythorbate are dissolved in water in advance); liquid pH=2.5- 2.7 To achieve the effect of preventing browning; cycle beating three times.

5. Prepare banana juice according to the type of beverage

Put the beaten material into the blending tank, which is produced by Shanghai Dacheng Experimental Equipment Co., Ltd.; while stirring, blend according to the type of beverage, and add water to blend the material into banana juice; stir for 10 minutes.

6. Homogenization

Preferably, the 40-10S homogenizer produced by Shanghai Donghua High Pressure Homogenizer Factory is used for continuous homogenization twice, the first time is carried out under the pressure of 25-30MPa, and the second time is carried out under the pressure of 60-65MPa.

7. Vacuum, degassing

The DC-TJG-50 vacuum degasser produced by Shanghai Dacheng Experimental Equipment Co., Ltd. is preferred, and the parameter of vacuum degassing is 0.045MPa.

8. Sterilization

The DC-UHT-20 tube type sterilizer produced by Shanghai Dacheng Experimental Equipment Co., Ltd. is preferably used, the sterilization temperature is 80-85°C, and the sterilization time is 5 seconds.

9. Canning

The DC-GZS aseptic filling room produced by Shanghai Dacheng Experimental Equipment Co., Ltd. is preferred. The entire filling equipment is a closed space; the filling temperature is 80-85°C.

Compared with the existing microwave tunnel type sterilization device, the microwave pipeline type sterilization and deactivation device, system and method of the present invention have the following advantages:

1. No preheating is required, the time is short, the speed is fast, the sterilization and inactivation are uniform and thorough, so that more nutrients and flavors of food can be retained.

2. Compared with the conventional method of low-temperature sterilization, the product is not easy to coke and can maintain active ingredients.

3. Energy saving, microwave power conversion efficiency is generally above 70%, microwave is directly sterilizing food itself without being heated, so there is no heat damage.

4. The equipment is simple, saves space and has a high degree of automation.

5. The whole process of slurry is carried out in a closed environment without contact with air, etc., thus avoiding secondary pollution. There is no secondary pollution in the whole processing process.

Below in conjunction with accompanying drawing 2-4 illustrate the preferred pipeline type microwave treatment device that banana juice adopts and control method. Schematically set forth the microwave processing device adopted by the banana juice of the present invention and have the preferred embodiment and specific implementation of the microwave processing device. It should be pointed out that, excluding obvious conflicts that can be determined by those skilled in the art, the preferred modes can be combined arbitrarily, and are not limited to the limited preferred embodiments given below, and the process links and technical means that are not particularly limited in this application , which means that this application does not make special requirements.

Also, "material" is a generic term, referring to bananas when the product or method is specific to them.

As shown in Figure 2, the preferred embodiment of the microwave processing device 1 of the present embodiment includes a microwave heating pipeline 222, a microwave generator 13 arranged on the outside of the microwave heating pipeline, a material pusher 224 connected to the material inlet of the microwave heating pipeline, and a connecting Material storage device 23 to the material outlet of the microwave heating pipeline. The material 211 is processed by banana coarse pulp preparation equipment (not shown) and then transported to the screw propeller 224 through a closed pipeline, where it is stirred evenly and pushed to the microwave heating pipeline 222 . The material pusher 224 is preferably a screw-type material pusher (a piston-type material pusher or a scraper-type material pusher is also acceptable, but relatively speaking, we find that the screw-type material pusher works best). In order to better control the temperature of the microwave heating, the screw-type material pusher is preferably driven by a frequency conversion motor 221, so that the pushing speed of the material 211 can be adjusted during the microwave treatment. In order to increase the material pushing capacity and material handling capacity, the screw propeller can also be further optimized as a rodless screw propeller. In order to better realize the pushing effect of the material pusher, the pusher forms a conical pushing surface on its pushing side facing the microwave heating equipment.

In order to improve the effect of microwave inactivating enzymes, the microwave heating pipeline is airtight, and the nitrogen positive pressure device 22 is filled with nitrogen at the material inlet to maintain the positive pressure in the pipeline and have a flow rate in the same delivery direction as the material. Preferably, the nitrogen pressure added by the nitrogen positive pressure device is controlled at 1.2 to 1.5 times the atmospheric pressure, and the nitrogen flow rate is at 4-10m³/min. Further preferably, a nitrogen pressure relief device 26 is also provided on the outlet side of the microwave heating pipeline, so that the nitrogen gas from the pipeline microwave treatment device is discharged from the nitrogen pressure relief device connected to the microwave heating pipeline before the material is transported to the storage device through the microwave heating pipeline.

In order to improve temperature control accuracy, the pipeline type microwave processing device of the present invention preferably includes a plurality of microwave generators. Preferably, the microwave heating pipe 222 has a length of about 10 meters, and 40-60 microwave generators are preferably evenly spaced along its axial direction, more preferably about 45-55 microwave generators, and more preferably 50 microwave generators. Each microwave generator respectively forms a metal ring cavity for microwave reflection in the circumferential direction of the microwave heating pipeline, and each microwave generator can be individually controlled.

Fig. 2 schematically shows a cross-sectional view of microwave heating pipes and microwave generator parts according to a preferred embodiment of the present invention. As shown in FIG. 2 , the microwave heating pipeline 222 includes an inner conveying pipe 121 and an outer conveying pipe 122 , and an annular cavity 100 for accommodating materials is formed between the inner conveying pipe and the outer conveying pipe. The microwave generator 13 is arranged circumferentially around the outer conveying pipe, which includes a reflective metal shell 11 , a heat-resistant plastic shell 123 , a microwave stirrer 136 , a magnetron 133 , a high voltage diode 134 and a transformer 135 .

The delivery inner tube 121 and the delivery outer tube 122 are made of materials that do not produce microwave shielding and microwave absorption. Preferably, both the delivery inner tube and the delivery outer tube are made of soft silicone.

The magnetron 133 generates microwaves, and the microwave stirrer 136 can heat the materials in a circular direction with microwaves.

As shown in the partially enlarged view in FIG. 2 , the conveying inner pipe 121 has a conical structure at the material inlet, so as to facilitate the material entering the annular chamber 100 . The material 211 enters the annular cavity 100 between the conveying inner pipe 121 and the conveying outer pipe 122, where it is subjected to microwave heating treatment. The pipeline type microwave processing device of the present invention also includes a material temperature monitoring unit (not shown), which can be arranged between the microwave generators 13 to monitor the temperature of the material. Preferably, the microwave generator inlet, outlet and microwave A temperature sensor is arranged between two generators.

Fig. 3 is a schematic circuit diagram of a microwave generator according to a preferred embodiment of the present invention. It can be seen from Figure 3 that the microwave emission of the magnetron of the microwave generator is determined by the voltage at both ends of the input, and the magnitude of the voltage is related to the current at the output side. In this embodiment, multiple thermal switches 137 control the circuit current on the output side (two are shown in the figure, 1371/1372). Multiple thermal switches can be implemented individually or in combination to change the current in the circuit. Then change the voltage amount and microwave power applied to the microwave generator.

In order to better realize the control of microwave heating time, heating power, power density and material delivery speed, a control system is also designed in the preferred embodiment of the present invention. Preferably, the pipeline type microwave processing device further includes a control system 17, which includes the aforementioned material temperature monitoring unit 171, and the temperature monitoring unit includes a temperature sensor 1711 arranged between a plurality of microwave generators to monitor the temperature of the material ; The control unit also includes a microwave control unit 172, which is used to individually control the startup and heating time of multiple microwave generators. Further preferably, the microwave control system further includes a central microprocessor 174, which can adjust microwave power and/or microwave density and/or motor material delivery speed when the temperature of the material monitored by the temperature monitoring unit is not within the set range. Further preferably, the microwave control system also includes a pressure control unit 175, which installs an Yali monitor on the nitrogen valve to monitor the nitrogen level in the pipeline microwave processing device, so as to control the nitrogen filling amount and nitrogen flow of the nitrogen positive pressure device speed. Further preferably, the control system also includes a preset system 176, so that the microwave control unit and the screw material pusher motor control unit can automatically apply preset microwave power, microwave density and Microwave heating time, the material parameters can be material type, temperature, humidity, viscosity, sugar content, etc. As a result, the temperature of the material can not only be monitored timely and accurately, but also can be precisely controlled by microwave power, microwave heating time, microwave power density, and material pushing speed. In a specific embodiment, the microwave density can be adjusted by changing the current value. The microwave heating time and the material delivery speed can be realized together by adjusting the material delivery speed through the frequency of the motor, and of course other methods understandable by those skilled in the art can also be used.

Fig. 4 schematically shows the preferred microwave heating control method and process of this embodiment: start of operation → power on the main switch → automatic operation of the system → setting of process parameters required for microwave heating (according to the amount of material, the flow of material and the required control Material temperature (set microwave power, power density, nitrogen pressure, adjust) → turn on the required number and power of microwave generators according to the set parameters → turn on the nitrogen positive pressure device and start filling nitrogen, the pressure is 1.2 times ~ 1.5 times the atmospheric pressure → The temperature sensor and air pressure monitor start to monitor the material temperature and nitrogen pressure → the banana coarse pulp is prepared and transported to the microwave heating equipment → microwave heating to sterilize the enzyme → store the processed banana puree.

Preferably, we found that the effect is better under the control of these parameter ranges: configure three-phase five-wire 380V±10%, 50Hz±1% AC, and the capacity is not less than 220KVA. Control the microwave power density to 4-8W/g, the material flow rate to 2-4t/h, and the temperature to be controlled at 75°C~93°C. Further preferably, the total power of the entire generator does not exceed 146kW; the microwave power density is 6W/g ;The material flow rate is 3t/h; the temperature is controlled at 75°C~88°C, the total power of the entire generator is ≤146kW, so that the power can be adjusted steplessly, and the rated output power of each microwave emission point is 1200W, with a total of 50 emission points. The power density is 6w/g.

In actual operation, the positive pressure pipeline microwave treatment device is preferably first implemented with a microwave power of 60-120kW, a power density of 6w/g, a frequency of 2450MHZ, and a sterilization and inactivation time of 5-10 minutes. When the material is monitored in the microwave treatment device When the temperature reaches the predetermined temperature of 75°C~93°C, preferably 75°C~88°C, the microwave processing device will automatically switch to the constant temperature section, and control the microwave power of the microwave processing device to 20-60KW, 6w/g, frequency 2450MHZ, time 3-8 Minutes to keep the temperature of the material at 75°C to 93°C, preferably 75°C to 88°C, more preferably 88°C. Based on this design, this disposal method not only avoids damage to the quality of the material caused by excessive temperature rise of the material, but also avoids unnecessary waste of energy.

The above detailed descriptions of the embodiments are not exhaustive descriptions of all embodiments contemplated by the inventors to be within the scope of the specification.

Indeed, those skilled in the art will appreciate that certain elements of the above-described embodiments can be variously combined or eliminated to create further embodiments, and such further embodiments fall within the scope and teachings of the present description. It will also be apparent to those skilled in the art that the above-described embodiments can be combined in whole or in part to create additional embodiments that fall within the scope and teachings of this description.

Thus, while specific embodiments have been described for illustrative purposes, various equivalent embodiments are possible, which fall within the scope of the description, as those skilled in the relevant art will recognize. The embodiments provided herein do not limit the present invention to the implementations described above and shown in the accompanying drawings. Accordingly, the reactions of the above-described embodiments shall be determined by the appended claims.

Claims (9)

1. a kind of bananas juice preparation process, comprising: removed to handle the banana after screening with peeling end to end；By banana pulp into The thick mashing of row, obtains banana and slightly starches；Banana is slightly starched and is transferred to positive pressure of nitrogen sealed pipe type microwave treatment via closed conduit Device carries out microwave disinfection inactivation treatment in flow process；It is thin that banana after above-mentioned sterilization inactivation treatment is slightly starched to progress Mashing processing；Banana slurry after thin mashing is handled well is put into and stirs in blend tank and is adjusted according to required drink variety Match, and adds water at bananas juice；Homogeneous is carried out to bananas juice using high pressure homogenizer；Vacuum outgas is implemented to the bananas juice after homogeneous Process；Bananas juice after vacuum outgas is further sterilized；Bananas juice after further sterilization is subjected to nothing in confined space Bacterium is canned.

2. bananas juice preparation process as described in claim 1, it is characterised in that: the thick pulping process does not add any water Point, the banana meat is sent by what is stirred while conveying to microwave heating in the closed conduit in the form of slurries, excellent By injection nitrogen in the pipeline of choosing, playing isolation air effect prevents banana raw juice oxidizing brown stain；It is further preferred that described Banana slightly starch in closed conduit by screw material pusher realize on one side pushes convey while mixing effect.

3. the bananas juice preparation process as described in any one of aforementioned claim, it is characterised in that: in the microwave processing process Nitrogen pressure control in 1.2 ~ 1.5 times of atmospheric pressure, nitrogen flow rate is defeated in 4-10m3/min and flow direction and banana slurry Send direction identical；It is further preferred that the nitrogen is filled in the pipeline type microwave processing unit feed inlet side, at microwave It manages device discharge port side and is equipped with nitrogen pressure release means.

4. the bananas juice preparation process as described in any one of aforementioned claim, it is characterised in that: the high-pressure homogeneous process is It is secondary, preferably first time pressure -40MPa, second of pressure 50-80MPa.

5. the technique as described in any one of aforementioned claim, it is characterised in that: the sterilization temperature is 80-85 DEG C, preferably when Between be 5-8 seconds.

6. the technique as described in any one of aforementioned claim, it is characterised in that: above-mentioned canned entire filling apparatus is closed Space；It is preferred that canned temperature is 80-85 DEG C.

7. the technique as described in any one of aforementioned claim, it is characterised in that: colloid mill mashing, slurrying can be used in above-mentioned slurrying When, preferred feed: water volume ratio=1:2.0-3.0；While being put into material, more preferably in the form of spray be added citric acid, D-araboascorbic acid sodium, and controlling pH value is 2.2-3.0.

8. the technique as described in any one of aforementioned claim, it is characterised in that: the microwave processes process is divided into main place Manage section and isothermal holding section, the main process task section microwave power, microwave density, heating time are greater than soaking zone microwave power, micro- Bomi degree, heating time；Preferably, the microwave power 60-12OKW of the main process task section microwave treatment, such as 85KW, Microwave Frequency Rate 2000-2800MHz, such as 2450MHz are sterilized inactivation time 5-10 minutes；The microwave power 20- of soaking zone microwave treatment 6OKW, such as 45KW, microwave frequency 2000-2800MHz, such as 2450MHz are sterilized inactivation time 3-8 minutes；Specific implementation Power density is 4-8W/g, preferably 6 W/g；It is highly preferred that temperature at the end of two sections of microwave treatments is 75-93 DEG C, preferably 88 ℃。

9. a kind of pipeline type microwave processing unit applied to any one of the claim 1-8 technique, comprising: microwave adds Heat pipeline, the microwave heating pipeline include conveying inner tube and conveying outer tube, are formed and are used between conveying inner tube and conveying outer tube Accommodate the annular chamber of material；The multiple microwave generators being located on the outside of the conveying outer tube；And it is connected to the microwave heating The material pusher of the material inlet of pipeline, the material enter microwave heating by material inlet under the promotion of material pusher Pipeline is handled under microwave field action, it is characterised in that: the microwave heating pipeline is closed, the material push Device is screw material pusher and is driven by variable-frequency motor, and nitrogen charging device is arranged at the material inlet of microwave heating pipeline, Make material in the microwave heating pipeline under barotropic state；The multiple microwave generator along microwave heating pipeline axis It is arranged to interval, and each microwave generator is respectively in the circumferential metal ring cavity for forming microwave reflection of conveying outer tube, each microwave hair The magnetron of raw device can be controlled individually.