An apparatus and method for extracting polyphenols from grapes while obtaining raisins

Abstract

The application provides a device and method for extracting polyphenol solution and obtaining raisin products simultaneously, and is applied to the technical field of food processing, and the method comprises the following steps: placing grapes in a low-temperature environment, taking out the grapes when the temperature of the center of the grapes is reduced to a first preset temperature to obtain pretreated grapes; placing the pretreated grapes into an extraction liquid device, irradiating the pretreated grapes with microwaves according to a preset power for a first preset time to obtain pre-dehydrated grapes, collecting the leached liquid in the wrapping of inert gas and storing the leached liquid at a second preset temperature to obtain polyphenol solution and pre-dehydrated grapes; conveying the pre-dehydrated grapes to a raisin product obtaining device through a sealed conveying belt pipeline, generating vibration while alternately irradiating the pre-dehydrated grapes with microwaves and infrared light, and uniformly and quickly heating the grapes to obtain raisin products; the application does not use extraction reagents to extract grape polyphenols, and can quickly obtain raisin products with antioxidant components, and can improve the economic benefits of the grape industry.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food processing, in particular to a device and method for extracting polyphenols from grapes and obtaining raisins at the same time. BACKGROUND

[0002] Grape is a perennial deciduous vine of the family Vitaceae and genus Vitis, and is a seasonal fruit with high water content and sugar content, and thus is not resistant to storage. Therefore, fresh grapes must be consumed or processed quickly, and the processing of raisins is a common processing method. However, the surface of the grape has a waxy layer that hinders the evaporation of water from the grape. Therefore, the grape is often pretreated before being dried, and the pretreatment of the surface of the grape helps the grape to release water and speeds up the drying process, thereby reducing energy consumption and helping to maintain the quality of the final product at a high level.

[0003] There are many methods for pretreating the skin of the grape, such as physical rubbing, using chemical additives, bleaching, and ultrasonic waves. However, some pretreatment techniques are invasive, such as chemical additives, which can cause food safety problems due to the residues left after treatment. When surface rubbing is used, the grape appears to have a darker color, which is not attractive in terms of sensory appeal. The use of bleaching, high-humidity hot air impingement bleaching, ultrasonic waves, and osmotic dehydration can cause the final product to lose its nutritional and sensory qualities, as some of the soluble nutrients of the grape are lost during these treatments, and high temperatures can cause the grape to crack. In this sense, it is important to find a pretreatment method for drying grapes that is less invasive, safer, and preserves the nutrients of the grape.

[0004] Another problem with the processing of grapes into raisins is the low added value. About 5 kg of fresh grapes are needed to make 1 kg of raisins, but the price of 1 kg of raisins is not necessarily equivalent to the price of 5 kg of fresh grapes. Because the added value of raisins is low, farmers prefer to sell fresh grapes and only use the excess grapes for drying.

[0005] Grapes contain a large amount of polyphenol compounds, which have strong antioxidant activity and are a good free radical scavenger and lipid peroxidation inhibitor, and also have good protection for the cardiovascular system. Studies by domestic and foreign scholars have shown that polyphenol solutions also have anticancer, anti-radiation, antimicrobial, and cell proliferation-promoting effects, and are a grape product with high added value. Therefore, extracting polyphenol solutions from grapes has excellent practical value and economic benefits.

[0006] Therefore, the present application proposes a device and method for extracting polyphenols from grapes and obtaining raisins at the same time. SUMMARY

[0007] In view of the deficiencies of the prior art, in order to solve the problems of chemical reagent residue caused by current raisin pretreatment, grape quality mutation, and low added value of raisins produced from grapes, the present application provides a method which aims to extract grape polyphenol solution without using an extractant and simultaneously obtain raisin products. Fresh grapes are first subjected to low-temperature freezing treatment, and then the frozen grapes are placed in a microwave magnetic field. Since electromagnetic waves can penetrate the surface and interior of the grapes, the in-situ water in the grape cells is heated and expanded, and the cells are ruptured, thereby causing the water molecules in the grapes to evaporate and obtaining pre-dehydrated grapes. At the same time, the polyphenols in the grapes are extracted through water diffusion, and collected at the bottom of the device by gravity. Then the pre-dehydrated grapes are sent into a container for drying by a conveying device, which is subjected to alternating heating by microwaves and infrared light, and finally two kinds of products, grape polyphenol extract and raisins, are obtained simultaneously. The device can minimize the time and energy consumption of raisin production, and better utilize raw materials, thereby maximizing the added value of grapes.

[0008] To achieve the above object, the present application provides the following technical scheme:

[0009] The present application provides a device for extracting polyphenol solution and simultaneously obtaining raisin products, comprising:

[0010] The extraction liquid device comprises a microwave cavity, a cooling cavity, a first material container, a funnel, and a liquid collector. The microwave cavity is connected to the cooling cavity through the funnel, the first material container is fixed above the conical collection part of the funnel, and the liquid collector is below the conduit of the funnel.

[0011] The dry product obtaining device comprises a drying cavity, a second material container, a vibrating device, an infrared generating device, a microwave generating device, a moisture removal device, and a control system. The vibrating device is connected to the bottom of the drying cavity through a vibrating connecting rod, and is separated by a baffle. The infrared generating device is above the second material container and is separated by a microwave shielding device. The microwave generating device is on the side wall of the drying cavity. The moisture removal device is connected to the outside of the dry product obtaining device and the drying cavity.

[0012] The extraction liquid device and the dry product obtaining device are connected by a conveying device. The conveying device conveys the first material container to above the dry product obtaining device, and pours the material in the first material container into the second material container.

[0013] The extraction liquid device is used to extract phenolic substances in grapes, and the process includes: putting pretreated grapes into the first material container, irradiating the first preset time according to the preset power by using microwave, making the water and phenolic substances seep out of the cell membrane to obtain pre-dehydrated grapes, collecting the phenolic substance solution in the conical collecting part of the funnel by gravity, and then collecting in the liquid collecting container after condensation through the conduit of the funnel, and storing at a preset temperature to obtain a polyphenol solution.

[0014] The conveying device conveys the pre-dehydrated grapes to the second material container of the dry product obtaining device, and alternately heats for a second preset time by using microwave and infrared. During the heating process, vibration is generated. The alternating heating process is as follows: the upper limit temperature, the middle limit temperature and the lower limit temperature of the grapes are set, when the temperature of the grapes is lower than the lower limit temperature, the microwave is heated at a first preset power and the infrared is heated at a second preset power at the same time, when the temperature of the grapes is between the lower limit temperature and the middle limit temperature, the infrared generating device is turned off and the microwave is heated alone at the first preset power, when the temperature of the grapes is between the middle limit temperature and the upper limit temperature, the infrared generating device is turned off and the microwave is heated alone at a third preset power, and when the temperature is higher than the upper limit temperature, the microwave and infrared are both stopped heating, and when the water content in the grapes is less than 15%, the dried grape product is obtained.

[0015] Further, the first material container has a plurality of holes with a preset diameter at the bottom, and the upper half of the top cover has a sealed space containing low-temperature liquid nitrogen. The bottom of the container is circular and has a diameter smaller than the diameter of the funnel collecting part by a preset size.

[0016] Further, the rear wall of the microwave cavity is openable, and the gas composition in the cooling cavity is mixed inert gas.

[0017] Further, the conveying device includes a conveyor belt and a sealed pipeline connected to the microwave cavity and the drying cavity at both ends. After the rear wall of the microwave cavity and the front wall of the drying cavity are opened, the conveying device conveys the pre-dehydrated grapes to the drying cavity.

[0018] Further, the dry product obtaining device includes a vibration device, a drying cavity, an exhaust device, and a control system.

[0019] The vibration device includes a vibration connecting rod, a vibration motor, a vibration base, and a shock-absorbing spring. The vibration base is connected to the dry product obtaining device at the bottom, the shock-absorbing spring is connected between the vibration base and the vibration motor, there is a partition plate between the vibration motor and the drying cavity, and the second material container is connected through the vibration connecting rod.

[0020] The second material container is placed in the drying cavity and connected with the vibration device through a vibration connecting rod, the left and right side walls of the drying cavity are embedded with microwave generating devices, the upper wall is embedded with infrared generating devices, the rear wall has dense exhaust holes, and the other side wall has a preset distance from the shell of the dried product obtaining device and is connected with an exhaust device;

[0021] The exhaust device connects the drying cavity with the external space, and an air inducer is arranged at the upper outlet to induce the air in the drying cavity to the outside;

[0022] The drying cavity and the infrared generating device are provided with microwave shielding devices;

[0023] The control system adjusts the microwave generating device, the infrared generating device, the exhaust device and the vibration device according to a preset program to complete the drying of the pre-dehydrated grapes.

[0024] A method for extracting a polyphenol solution and obtaining a dried grape product simultaneously, comprising:

[0025] A pretreatment step: placing the grapes in a low-temperature environment and taking them out when the temperature of the center of the grapes is reduced to a first preset temperature to obtain pretreated grapes;

[0026] A polyphenol solution extraction step: irradiating the pretreated grapes with microwaves at a preset power for a first preset time to obtain pre-dehydrated grapes, collecting the leached liquid in an inert gas package and storing it at a second preset temperature to obtain a polyphenol solution;

[0027] A dried product obtaining step: pre-dehydrated grapes are heated in an inert gas package using microwaves and infrared alternately for a second preset time, and the pre-dehydrated grapes are vibrated at the same time, the alternating heating process is as follows: the upper limit temperature, the middle limit temperature and the lower limit temperature of the pre-dehydrated grapes are set, when the temperature of the pre-dehydrated grapes is lower than the lower limit temperature, the microwave is heated at a first preset power and the infrared is heated at a second preset power at the same time, when the temperature of the pre-dehydrated grapes is between the lower limit temperature and the middle limit temperature, the infrared generating device is disconnected and the microwave is heated alone at a first preset power, when the temperature of the pre-dehydrated grapes is between the middle limit temperature and the upper limit temperature, the infrared generating device is disconnected and the microwave is heated alone at a third preset power, and when the temperature is higher than the upper limit temperature, the microwave and infrared are all stopped heating; when the moisture content in the grapes is less than 15%, a dried grape product is obtained.

[0028] The present application provides a device for extracting a polyphenol solution and obtaining a dried grape product simultaneously, which has the following beneficial effects:

[0029] (1) through the grape first freeze pretreatment, the cell wall and cell membrane of grape is easy to break, then use microwave irradiation, the liquid in the cell is extracted from the cell membrane, and then through the gravity of the grape polyphenol solution in the inert gas is surrounded in the collection, in low temperature environment, the extraction efficiency of grape polyphenol solution is accelerated, and there is no any reagent residue, at the same time, the polyphenol material in the solution is prevented from being oxidized;

[0030] (2) through microwave and infrared alternating irradiation and vibration at the same time, the pre-dehydrated grape is quickly removed from the excess water, the antioxidant substances and antioxidant activity in the grape are retained, and the dried grape product with rich nutrition and easy preservation is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The structure diagram of the device for extracting polyphenol solution and obtaining dried grape product according to an embodiment of the present application is shown in the figure.

[0032] Figure 2 The flow chart of the method for extracting polyphenol solution and obtaining dried grape product according to an embodiment of the present application is shown in the figure.

[0033] The purpose, function features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. EMBODIMENT

[0034] It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0036] REFERENCE Figure 1 The structure diagram of the device for extracting polyphenol solution and obtaining dried grape product according to an embodiment of the present application is shown in the figure.

[0037] The present application provides a device for extracting polyphenol solution and obtaining dried grape product, comprising: an extraction liquid device, a dried product obtaining device, and a conveying device.

[0038] In one embodiment, the extraction liquid device is the front end of the whole device, the frozen pre-processed grapes are put into the extraction liquid device, the conveying device is in the middle, connecting the microwave cavity and the drying cavity, the pre-dehydrated grapes are conveyed to the drying cavity through the sealed pipeline for dehydration treatment; the whole device selects different power microwave generating devices and different size containers according to needs, and in this embodiment, the material container can hold up to 1000 kg of grapes.

[0039] The extraction liquid device comprises a microwave cavity, a cooling cavity, a first material container, a funnel and a liquid collection container, the microwave cavity is connected to the cooling cavity through the funnel, the first material container is fixed above the conical collection part of the funnel, and the liquid collector is below the pipeline of the funnel;

[0040] The extraction liquid device is used to extract water from grapes, and the process comprises the following steps: putting the pre-processed grapes into the first material container, irradiating the first pre-set time using the microwave according to the pre-set power, making the water seep out of the cell membrane to obtain pre-dehydrated grapes, collecting the water in the conical collection part of the funnel through gravity, and then condensing and collecting in the liquid collection container through the pipeline of the funnel, and storing the polyphenol solution at a pre-set temperature;

[0041] In specific implementation, as shown in the leftmost part, the extraction liquid device is shown, the upper half is the microwave cavity, the front wall is glass, the middle is provided with a container containing pre-processed grapes, the lower half is the condensing device and the collection container, and the front wall is transparent glass for checking whether the extraction liquid process is normal; Figure 1

[0042] The device for obtaining dried products comprises a drying cavity, a second material container, a vibrating device, an infrared generating device, a microwave generating device, a moisture removal device and a control system, the vibrating device is connected below the drying cavity through a vibrating connecting rod, and the middle is separated by a baffle, the infrared generating device is above the second material container and separated by a microwave shielding device, the microwave generating device is on the side wall of the drying cavity, and the moisture removal device connects the outside of the device for obtaining dried products and the drying cavity;

[0043] Further, the device for obtaining dried products comprises a vibrating device, a drying cavity, an air exhaust device and a control system.

[0044] The vibrating device comprises a vibrating connecting rod, a vibrating motor, a vibrating base and a damping spring, the vibrating base is connected to the device for obtaining dried products at the bottom, the damping spring is connected between the vibrating base and the vibrating motor, the vibrating motor is separated from the drying cavity by a baffle, and the vibrating connecting rod is connected to the second material container. ​

[0045] The second material container is placed in the drying cavity and connected with the vibration device through a vibration connecting rod, the left and right side walls of the drying cavity are embedded with microwave generating devices, the upper wall is embedded with infrared generating devices, the back wall has dense exhaust holes, and the other side wall has a preset distance from the shell of the dried product obtaining device and is connected with an exhaust device;

[0046] The exhaust device connects the drying cavity with the external space, and an air inducer is arranged at the upper outlet of the exhaust device.

[0047] The drying cavity and the infrared generating device are provided with a microwave shielding device.

[0048] The control system adjusts the microwave generating device, the infrared generating device, the exhaust device and the vibration device according to a preset program to complete the drying of the pre-dehydrated grapes.

[0049] In specific implementation, for example, Figure 1 The right side part, 1 is a vibrating bed base for connecting the bottom of the dried product obtaining device and fixing the vibration device, 2 is a damping spring for reducing the influence of the vibration device on the dried product obtaining device, so that the dried product obtaining device shakes weakly in the working room, 3 is a vibration motor which generates vibration after being connected to electricity and can adjust the frequency, 4 is a vibration-assisting flexible bending piece which makes the second material container softer when vibrating to prevent the pre-dehydrated grapes from being vibrated out of the container, 5 is the second material container for loading the pre-dehydrated grapes for drying and dehydrating treatment, 6 and 11 are microwave sources for irradiating the cavity with microwaves from the side walls of the drying cavity, 7 is a display screen for displaying the step of the drying treatment, 8 is an exhaust pipe for removing the water vapor evaporated in the drying process through an air inducer 18, 9 is a moisture exhaust hole for assisting moisture removal, 10 is a drying cavity, 12 is a vibration connecting rod connecting the material container in the drying cavity and the vibration motor in the vibration cavity, 13 is a damping spring rubber for reducing noise when the vibration motor vibrates, 14 is an empty cavity for reducing the vibration influence of the vibration motor on the entire device, 15 is a support frame of the vibration cavity, 16 is a software control system for adjusting the microwave generating device, the infrared generating device, the vibration device and controlling the drying process, 17 is an integral part of the moisture removal device, 18 is an air inducer above the exhaust device for guiding the air in the drying cavity to the outside, 19 is a tubular infrared generating device, 20 is an infrared temperature sensor for measuring the temperature of the generated infrared rays in real time, 21 is an infrared heating device, 22 is an infrared device temperature sensor, 23 is a microwave shielding device, 24 is the back wall of the drying cavity, and 25 is the pre-dehydrated grapes placed in the empty container.

[0050] The extraction liquid device is connected with the dry product obtaining device through the conveying device, and the conveying device conveys the first material container to above the dry product obtaining device and pours the material in the first material container into the second material container;

[0051] The conveying device conveys the pre-dehydrated grapes into the second material container of the dry product obtaining device, and the second material container is heated by microwave and infrared alternately for a second preset time, and vibration is generated during the heating process, the alternately heating process is as follows: the upper limit temperature, the middle limit temperature and the lower limit temperature of the grapes are set, when the temperature of the grapes is lower than the lower limit temperature, the microwave and the infrared are heated simultaneously at a first preset power and a second preset power, when the temperature of the grapes is between the lower limit temperature and the middle limit temperature, the infrared generating device is turned off, and the microwave is heated alone at the first preset power, when the temperature of the grapes is between the middle limit temperature and the upper limit temperature, the infrared generating device is turned off, and the microwave is heated alone at a third preset power, and when the temperature of the grapes is higher than the upper limit temperature, the microwave and the infrared are all stopped, and the dry grape product is obtained.

[0052] Further, the first material container has a plurality of holes with a preset diameter at the bottom, and the upper half of the top cover has a sealed space filled with low-temperature liquid nitrogen, the bottom of the container is circular and has a diameter smaller than the diameter of the funnel collection part by a preset size.

[0053] Further, the rear wall of the microwave cavity is openable, and the gas composition in the cooling cavity is mixed inert gas.

[0054] Further, the conveying device comprises a conveying belt and a sealed pipeline connected with the microwave cavity and the drying cavity at two ends, and the conveying device conveys the pre-dehydrated grapes to the drying cavity after the rear wall of the microwave cavity and the front wall of the drying cavity are opened.

[0055] In specific implementation, as Figure 1 The middle part is sealed by the outer wall 9, and the inert gas devices 11 and 14 can remove the air in the conveying device and flush in the inert gas, the support frame 8 of the conveying belt, and the pulley 17 and the pulley device 10.

[0056] Reference Figure 2 A flowchart of a method for extracting a polyphenol solution and obtaining a dry grape product simultaneously is provided in the present application;

[0057] A method for extracting a polyphenol solution and obtaining a dry grape product simultaneously, the steps comprising:

[0058] The pre-treatment step: the grapes are placed in a low-temperature environment, and are taken out when the temperature of the center of the grapes is reduced to a first preset temperature, and the pre-treated grapes are obtained.

[0059] The step of obtaining the polyphenol solution: irradiating the pretreated grape with the microwave at a preset power for a first preset time to obtain pre-dehydrated grape, collecting the leached liquid in the wrapping of inert gas and storing at a second preset temperature to obtain the polyphenol solution;

[0060] The step of obtaining the dried product: alternately heating the pre-dehydrated grape with the microwave and the infrared for a second preset time in the wrapping of inert gas, vibrating the pre-dehydrated grape during the heating, the alternately heating process being: setting the upper limit temperature, the middle limit temperature and the lower limit temperature of the pre-dehydrated grape, when the temperature of the pre-dehydrated grape is lower than the lower limit temperature, simultaneously heating with the microwave at a first preset power and the infrared at a second preset power, when the temperature of the pre-dehydrated grape is between the lower limit temperature and the middle limit temperature, disconnecting the infrared generating device and heating with the microwave at the first preset power alone, when the temperature of the pre-dehydrated grape is between the middle limit temperature and the upper limit temperature, disconnecting the infrared generating device and heating with the microwave at a third preset power alone, and when the temperature is higher than the upper limit temperature, stopping heating with the microwave and the infrared; obtaining the dried grape product after complete dehydration.

[0061] In one embodiment, 100 kg of grapes are put into a cold storage for pretreatment, and when the temperature of the center of the grape is reduced to -18 degrees Celsius, the grape is taken out of the cold storage, then the pretreated grape is put into the first material container of the extraction liquid device, the microwave is used for pretreatment of the grape, the cell membrane and cell wall of the grape are broken, the liquid in the grape cells is leached out, and under the action of gravity, the liquid flows to the lower funnel, the lower half of the funnel is provided with a condensing device, the grape juice is cooled to 4 degrees Celsius when flowing through the condensing device, and the polyphenol extraction liquid is collected and stored at low temperature, the pre-dehydrated grape is conveyed to the drying cavity of the dried product obtaining device by a conveying belt, the microwave and the infrared are alternately heated for 30 hours, the pre-dehydrated grape is vibrated during the heating, the alternately heating process being: setting the upper limit temperature of the pre-dehydrated grape to be 65 degrees Celsius, the middle limit temperature to be 63 degrees Celsius and the lower limit temperature to be 60 degrees Celsius, when the temperature of the pre-dehydrated grape is lower than 60 degrees Celsius, simultaneously heating with the microwave at 15 kw / kg and the infrared at 10 kw, when the temperature of the pre-dehydrated grape is between 60 and 63 degrees Celsius, disconnecting the infrared generating device and heating with the microwave at 17 kw / kg alone, when the temperature of the pre-dehydrated grape is between 63 and 65 degrees Celsius, disconnecting the infrared generating device and heating with the microwave at 13 kw / kg alone, and when the temperature is higher than 65 degrees Celsius, stopping heating with the microwave and the infrared; when the water content in the grape is less than 15%, the dried grape product is obtained.

[0062] Example test: Take 100 kg of grapes, first put into the cold storage for pretreatment, when the temperature of the center of the grape is reduced to -18℃, the grape can be taken out of the warehouse, then the pretreated grape is put into the first material container of the extraction liquid device, the grape pretreatment is carried out, the microwave frequency is adjusted to 380 W, the treatment time is 10 minutes, the cell membrane and cell wall of the grape are broken, the liquid in the grape cells is leached out, and under the action of gravity, it flows to the lower funnel, the lower half of the funnel is provided with a condensing device, which cools the grape juice to 4℃ when it flows through, and then a container is used to collect the polyphenol solution and keep the storage temperature between 3 and 6℃. The pre-dewatered grape contains 50% of water. The pre-dewatered grape is conveyed to the drying cavity of the dry product obtaining device by the conveying belt, and the pre-dewatered grape is vibrated while being heated, and is heated by microwave and infrared alternately for 36h, so that the water content of the grape is reduced to less than 15%, and the dried grape product is obtained.

[0063] Comparative test 1: hot air hot drying grape dehydration test, take 100 kg of grapes, dry the grapes by drying room, and store the sample in the dryer at each weighing interval, so that the grape will not be externally hygroscopic. In order to speed up the pre-dewatering process and promote the release of water in the grape fruit, the grape is heated at 50℃, and weighed every 30 minutes. According to the drying kinetics, when the water content in the grape is reduced to less than 15%, the dried grape product is obtained, and the drying time required by this test is 74 hours.

[0064] Comparative test 2: freeze-drying grape dehydration test, weigh 100 kg of grapes and store them at -18℃ for 24 hours. After freezing, freeze-drying is carried out at -41℃ and 31 Pa to dehydrate the grapes until the water content in the grapes is reduced to less than 15%. The drying time required by this experiment is 84 hours.

[0065] Example and comparative experiment polyphenol solution and phenolic substance content in dried grape product

[0066] The experiment proves that the microwave pretreatment shortens the drying time of raisins, when the raisin products are obtained, the microwave pretreatment plus microwave and infrared alternate heating takes 36.16 hours, hot air heating takes 74 hours, and freeze drying takes 84 hours, which shows that the microwave pretreatment plus microwave and infrared alternate heating process can greatly shorten the drying time of raisins and improve the drying efficiency. Through the comparison of the polyphenol solution and the polyphenol content in the raisin products in the implementation example and the comparative experiment, it can be seen that the total phenol content, total flavonoid content and anthocyanin content in the raisin sample of the implementation example have no obvious difference with the raisin sample obtained by the comparative experiment 2 (vacuum freeze drying); compared with the raisin sample obtained by the comparative experiment 2 (hot air drying), the polyphenol content in the raisin sample of the implementation example is obviously increased; and the implementation example can obtain a solution rich in polyphenols. The method for extracting grape polyphenols and obtaining raisin products simultaneously can produce two products simultaneously: raisin products and polyphenol extracts, and the polyphenol extracts can be added to different products, which has great potential in the food or pharmaceutical industry.

[0067] In summary, the method for extracting grape polyphenols and obtaining raisin products simultaneously has the characteristics of high efficiency, economy and environmental protection, and can reduce the production cost of enterprises, and can be used for large-scale production of raisins and grape extracts rich in polyphenols, and fully exert the economic value and edible value of grapes.

[0068] It should be noted that in this paper, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, device, article or method including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, device, article or method. Without more limitation, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, device, article or method including the element.

[0069] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation made by using the content of the specification and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present application.

[0070] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An apparatus for extracting a polyphenol solution and simultaneously obtaining raisin products, comprising: A liquid extraction apparatus, a dry product acquisition apparatus, and a conveying device are characterized by: The liquid extraction device includes: a microwave cavity, a cooling cavity, a first material container, a funnel, and a liquid collection container. The microwave cavity is connected to the cooling cavity above the funnel. The first material container is fixed above the conical collection part of the funnel. The liquid collection container is below the conical guide tube of the funnel. The device for obtaining dried products includes: a drying chamber, a second material container, a vibration device, an infrared generator, a microwave generator, a dehumidification device, and a control system. The vibration device is connected to the drying chamber below by a vibration connecting rod and is separated by a baffle in the middle. The infrared generator is above the second material container and is separated by a microwave shielding device in the middle. The microwave generator is located on the side wall of the drying chamber. The dehumidification device is connected to the outside of the device for obtaining dried products and the drying chamber. The liquid extraction device and the dry product acquisition device are connected through the conveying device. The conveying device conveys the first material container to the top of the dry product acquisition device and pours the material in the first material container into the second material container. The liquid extraction device is used to extract antioxidant phenolic substances from grapes. The process includes: placing pretreated grapes into the first material container, irradiating them with microwaves at a preset power for a first preset time to cause water and phenolic substances to seep out from the cell membrane to obtain pre-dehydrated grapes, collecting the phenolic substance solution in the conical collection part of the funnel by gravity, condensing it through the conduit of the funnel and collecting it in the liquid collection container, and storing it at a preset temperature to obtain a polyphenol solution. The conveying device transfers the pre-dehydrated grapes to the second material container of the dried product obtaining device. Microwave and infrared heating are used alternately for a second preset time, generating vibrations during the heating process. The alternating heating process is as follows: An upper limit temperature, a middle limit temperature, and a lower limit temperature are set for the grapes. When the grape temperature is detected to be below the lower limit temperature, microwave heating is performed simultaneously at a first preset power and infrared heating at a second preset power. When the grape temperature is between the lower limit temperature and the middle limit temperature, the infrared generator is disconnected, and microwave heating is performed alone at the first preset power. When the grape temperature is between the middle limit temperature and the upper limit temperature, the infrared generator is disconnected, and microwave heating is performed alone at a third preset power. When the grape temperature is above the upper limit temperature, both microwave and infrared heating are stopped, resulting in dried raisin product.

2. The apparatus for extracting polyphenol solution and simultaneously obtaining raisin products according to claim 1, characterized in that, The first material container has a preset number of holes of a preset diameter at the bottom, and the upper part of the top cover has a sealed space containing cryogenic liquid nitrogen. The bottom of the container is circular, and its diameter is smaller than the preset size of the diameter of the funnel collection part.

3. The apparatus for extracting polyphenol solution and simultaneously obtaining raisin products according to claim 1, characterized in that, The rear wall of the microwave cavity can be opened and closed, and the gas composition in the cooling cavity is a mixture of inert gases.

4. The apparatus for extracting polyphenol solution and simultaneously obtaining raisin products according to claim 1, characterized in that, The conveying device includes a conveyor belt and a sealed pipe, both ends of which are connected to the microwave cavity and the drying cavity. After the rear wall of the microwave cavity and the front wall of the drying cavity are opened, the conveying device conveys the pre-dehydrated grapes to the drying cavity.

5. The apparatus for extracting polyphenol solution and simultaneously obtaining raisin products according to claim 1, characterized in that, The device for obtaining dried products also includes an exhaust system; The vibration device includes a vibration connecting rod, a vibration motor, a vibration base, and a shock-absorbing spring. The vibration base is connected to the dry product acquisition device at the bottom. The shock-absorbing spring is connected to the vibration motor at the vibration base. The vibration motor is separated from the drying chamber by a partition and is connected to the second material container through the vibration connecting rod. The drying chamber contains the second material container and is connected to the vibration device via a vibration connecting rod. Microwave generators are embedded in the left and right side walls of the drying chamber, an infrared generator is embedded in the upper wall, and the rear wall has dense dehumidification holes. The other side wall is at a predetermined distance from the outer shell of the dry product acquisition device and is connected to the exhaust device. The exhaust device connects the drying chamber to the outside space, and there is an exhaust fan at the upper outlet, which introduces the air inside the drying chamber into the outside. A microwave shielding device is provided between the drying chamber and the infrared generator. The control system adjusts the microwave generator, infrared generator, exhaust device, and vibration device according to a preset program to dry the pre-dehydrated grapes.

6. A method for extracting a polyphenol solution and simultaneously obtaining raisin products, characterized in that, The method is performed using the apparatus described in any one of claims 1-5 for extracting a polyphenol solution and simultaneously obtaining raisin products, the method comprising: Pretreatment steps: Place the grapes in a low-temperature environment, and remove them when the temperature at the center of the grapes drops to the first preset temperature to obtain pretreated grapes; Steps for obtaining polyphenol solution: The pretreated grapes are irradiated with microwaves at a preset power for a first preset time to obtain pre-dehydrated grapes. The leached liquid is collected in an inert gas atmosphere and stored at a second preset temperature to obtain polyphenol solution. Steps for obtaining dried grapes: Pre-dehydrated grapes are wrapped in an inert gas atmosphere and heated alternately with microwaves and infrared radiation for a second preset time. The grapes are vibrated during heating. The alternating heating process involves setting an upper, middle, and lower temperature limit for the pre-dehydrated grapes. When the temperature of the pre-dehydrated grapes is below the lower limit, microwaves are used at a first preset power and infrared radiation at a second preset power simultaneously. When the temperature of the pre-dehydrated grapes is between the lower and middle limits, the infrared generator is disconnected, and microwaves heat only at the first preset power. When the temperature of the pre-dehydrated grapes is between the middle and upper limits, the infrared generator is disconnected, and microwaves heat only at a third preset power. When the temperature is above the upper limit, both microwave and infrared heating are stopped. When the grape moisture content is less than 15%, dried grapes are obtained.

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