Multi-bit Detection Device Integrating Ultrasonic Machining and Optical Sensing Detection and Its Application

Abstract

The present invention belongs to the technical fields of food processing and food safety detection, and particularly relates to a multi-position detection device integrating ultrasonic processing and optical sensing detection and its application. First, a detection device integrating ultrasonic processing and optical sensing detection is designed using a fermenter, an ultrasonic device, and a near-infrared spectroscopy system; then, a novel nanosensor sensitive to the characteristic aroma components during the ultrasonic treatment of the mixed fermentation broth is placed in the detection tank of the detection device, reacts with the gas volatilized from the mixed fermentation broth, and the change in the spectral transmittance of the sensor before and after the reaction is detected using a near-infrared spectrometer to construct a PLS quantitative prediction model for the polyphenol content during the ultrasonic fermentation process. The present invention combines the physical processing characteristics of ultrasonic technology that can improve the fermentation efficiency of liquid foods and the high sensitivity and high specificity of the novel nano-optical sensor, realizing the rapid in-situ determination of the polyphenol content during the fermentation process of the mixed fermentation broth under the stress of the ultrasonic field using the novel nano-optical sensing technology.

Description

Technical Field

[0001] The present invention relates to the technical fields of food processing and food safety detection, and particularly relates to a multi-position detection device integrating ultrasonic processing and optical sensing detection and its application, specifically applied to the in-situ detection of polyphenols during the ultrasonic fermentation process of a mixed fermentation broth. Background Art

[0002] The fermentation of a mixed fermentation broth is accompanied by complex chemical changes in the internal substances, which comprehensively form the unique color, aroma, and taste qualities of the fermentation product. Most of the existing mixed fermentation broth fermentation processes still remain in the natural fermentation process stage. The enzymatic oxidation reaction is greatly interfered by external factors and has low efficiency. At present, physical processing technologies such as infrared, microwave, and ultrasound have been successfully applied in food fermentation. Therefore, the use of ultrasonic technology in the black tea fermentation process is bound to promote the enzymatic oxidation reaction process and improve the fermentation efficiency. In addition, most of the existing mixed fermentation broth fermentation process is controlled by artificial experience, with low informatization and intelligence levels, resulting in unstable product quality and high processing costs. Real-time perception of the dynamic changes in aroma during the fermentation process of a mixed fermentation broth is a key means for studying the fermentation of a mixed fermentation broth. Usually, expert sensory evaluation is an important means for judging the aroma changes during the black tea fermentation process, but expert sensory judgment is subjective, has poor repeatability, and cannot accurately describe the characteristic aroma molecules generated during the black tea fermentation process.

[0003] Currently, domestic and foreign scholars have analyzed the changes and composition ratios of aroma components during the black tea fermentation process through headspace solid-phase microextraction (HS-SPME) method and gas chromatography-mass spectrometry (GC-MS). However, the GC-MS technology is relatively slow and obviously cannot meet the requirements for in-situ monitoring of the aroma during the fermentation process of a mixed fermentation broth. Therefore, on the basis of studying the fermentation process of a mixed fermentation broth under the stress of an ultrasonic physical field, the advantages of optical sensors in the field of rapid detection, such as being simple and not easily affected by environmental factors, are combined with the advantages of nanotechnology, such as strong specificity and high sensitivity, to break through the problem of real-time online monitoring of the changes in aroma components. Because the essence of fermentation is an enzymatic oxidation reaction mainly based on polyphenolic compounds, generating a large number of aldehydes, acids, ketones, etc. compounds, the aroma changes during the fermentation process of a mixed fermentation broth are related to the changes in the content of tea polyphenols, and the in-situ detection of the polyphenol content during the fermentation process of a mixed fermentation broth is carried out, and a device integrating an ultrasonic fermentation processing system and an optical sensing detection system is designed to realize the real-time monitoring of the fermentation process of a mixed fermentation broth. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention aims to solve one of the problems existing in the above-mentioned prior art; to provide a multi-position detection device integrating ultrasonic processing and optical sensing detection and its application to the in-situ detection of polyphenols in the ultrasonic fermentation process of mixed fermentation broth; the present invention combines the cavitation effect and mechanical effect of the ultrasonic process to improve the activity of fermentation bacteria, the rapid and simple detection performance of optical sensors, and the advantages of strong specificity and high sensitivity of nanotechnology in the detection field, so as to improve the informatization and intelligent level of the fermentation and processing technology of tea mixed fermentation broth.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention first provides a multi-position detection device integrating ultrasonic processing and optical sensing detection, including a slit ultrasonic device, an input pipeline, an output pipeline, an ultrasonic tank, a peristaltic pump I, a peristaltic pump II, a fermentation tank, a fermentation tank main console, a pH detector, a temperature sensor, a data line, an air filter, a spectrometer, a detection tank, a light shield, an optical fiber cable I, an optical fiber cable II, a light source, a computer and an ultrasonic pipeline;

[0007] The slit ultrasonic device includes a control panel, an ultrasonic generator and an ultrasonic transducer; the control panel is electrically connected to the ultrasonic generator and the ultrasonic transducer for control purposes;

[0008] The fermentation tank main console is also provided with a pH detector and a temperature sensor, wherein the other end of the pH detector is connected to the fermentation tank for monitoring the pH value of the internal substances during the fermentation process of the fermentation tank; the temperature sensor is connected to the fermentation tank through an air filter for monitoring the temperature of the internal substances during the fermentation process of the fermentation tank;

[0009] One end of the input pipeline is connected to the fermentation tank, and the other end is connected to the ultrasonic tank; one end of the output pipeline is connected to the fermentation tank, and the other end is connected to the ultrasonic tank; a peristaltic pump I is provided on the input pipeline, and a peristaltic pump II is provided on the output pipeline; valves are also provided on both the input pipeline and the output pipeline for controlling the opening and closing of the pipeline;

[0010] The slit ultrasonic device is connected to the outer wall of the ultrasonic tank through an ultrasonic pipeline; the slit ultrasonic device controls the ultrasonic frequency, power density and ultrasonic time through the control panel;

[0011] One side of the fermentation tank is connected to the detection tank through an air pipe, and there is also a light shield above the detection tank; one end of the detection tank is connected to a light source through an optical fiber cable I, the other end is connected to a spectrometer through an optical fiber cable II, and the spectrometer is electrically connected to a computer through a data line.

[0012] Preferably, a condensation device is provided at the lower end of the fermentation tank main console, and a condensation pipeline is provided at the bottom end of the fermentation tank, which are respectively connected to the condensation device through a condensation pipe and a return pipe.

[0013] Preferably, the fermenter is cylindrical.

[0014] Preferably, there are 6 ultrasonic transducers, which are located inside the ultrasonic generator.

[0015] Preferably, the detection tank is square in shape.

[0016] The device includes three parts: a fermentation system, an ultrasonic-assisted fermentation system, and a near-infrared spectroscopy detection system; the fermentation system is composed of a fermenter, a main control console of the fermenter, a pH detector, and a temperature sensor; the main body is the fermenter, which is controlled by the main control console of the fermenter. There are a pH detector and a temperature sensor on the main control console of the fermenter to monitor the pH and temperature during the fermentation process.

[0017] The ultrasonic-assisted fermentation system is composed of a slit ultrasonic device, a control panel, an ultrasonic generator, ultrasonic transducers, an input pipeline, an output pipeline, an ultrasonic tank, a peristaltic pump I, a peristaltic pump II, and an ultrasonic pipeline; during ultrasonic fermentation, the slit ultrasonic device is turned on, and the control panel is adjusted to a certain ultrasonic frequency, ultrasonic density, and ultrasonic time. The fermentation material is pumped into the ultrasonic tank through the input pipeline by the peristaltic pump I for ultrasonic treatment, and then pumped into the fermenter through the output pipeline by the peristaltic pump II after ultrasonic treatment. This process is completed based on the ultrasonic generator and ultrasonic transducers.

[0018] The near-infrared spectroscopy detection system is composed of a spectrometer, a detection tank, a light-shielding cover, an optical fiber cable, and a light source; to detect the change of aroma components during the fermentation process of the material, the near-infrared spectroscopy detection system collects the spectral changes after the reaction of the material with the optical sensor in real time. Specifically, the optical sensor is placed in the detection tank, the near-infrared spectrum is collected by the spectrometer, and the computer controls the collection process and records and saves the data, finally realizing the in-situ detection of polyphenols in the ultrasonic fermentation of the mixed fermentation broth based on the new type of nano-optical sensor.

[0019] The multi-position detection device based on the integration of ultrasonic processing and optical sensing detection is used for the in-situ detection of polyphenols during the ultrasonic fermentation process of the mixed fermentation broth, including the following steps:

[0020] Step 1, ultrasonic fermentation treatment of the tea soup

[0021] First, sucrose and distilled water are mixed to obtain a sucrose medium; then the tea fungus liquid and the sucrose medium are mixed and placed in a container, covered with gauze, and fermented at room temperature for a period of time to obtain a fermented tea fungus liquid;

[0022] Next, take tea powder, mix it with the fermented tea fungus liquid and water to obtain a mixed fermentation liquid, put it into a fermentation tank, then start the ultrasonic generator and ultrasonic transducer, set the ultrasonic conditions through the control panel, with the ultrasonic frequency being 23 - 28 kHz, the ultrasonic time being 12 - 60 min, and the power density being 20 - 40 W / L; at the same time, open the valve on the input pipeline, use peristaltic pump 1 to flow the materials in the fermentation tank into the ultrasonic tank through the input pipeline. When the ultrasonic tank is filled with materials, close the valve on the input pipeline and peristaltic pump 1; perform ultrasonic treatment on the materials in the ultrasonic tank through the ultrasonic pipeline. After ultrasonic treatment, open the valve on the output pipeline, and pump it back into the fermentation tank through the action of peristaltic pump 2. After all the materials in the ultrasonic tank are pumped out, close the valve on the output pipeline and peristaltic pump 2;

[0023] Then, according to the same operation, open the valve on the input pipeline again, use peristaltic pump 1 to flow the materials in the fermentation tank into the ultrasonic tank through the input pipeline for ultrasonic treatment, and then pump it back into the fermentation tank after ultrasonic treatment; repeat this many times;

[0024] Step two, construction of a novel nano - optical sensor

[0025] (1) During the fermentation process of the mixed fermentation liquid, take out the mixed fermentation liquid from the fermentation tank at regular intervals to measure the volatile organic components (VOC); use a triple - quadrupole gas chromatography - mass spectrometer (TQ - 8040) for headspace solid - phase microextraction - gas chromatography - mass spectrometry (GC - MS) to analyze the change rules of the aroma components in the fermentation liquid at different ultrasonic fermentation stages. Use analysis of variance to screen out linalool, 3 - hexenyl isovalerate, and geraniol as the characteristic volatile gases during the ultrasonic fermentation process of the mixed fermentation liquid;

[0026] (2) The chemical materials sensitive to the characteristic aroma linalool in the mixed fermentation liquid fermentation process are 8 - (4 - nitrophenyl) - 4,4 - difluoro - 2,6 - dibromoboron dipyrromethane (NO2Br2BDP), the material sensitive to 3 - hexenyl isovalerate is bis[8 - phenyldipyrromethane] nickel(II) ((HBDP)2Ni(II)); the chemical material sensitive to geraniol is 8 - (4 - carbazolylphenyl) - 4,4 - difluoroboron dipyrromethane (pCarBDP);

[0027] Emulsify and fuse with the nanomaterials poly(styrene - acrylic acid) (PSA), porous silica nanoparticles (PSN), and metal - organic framework materials (MOF) to finally obtain a novel nano - optical sensor;

[0028] Step three, detection of tea polyphenols

[0029] Place the novel nano-optical sensor prepared in Step 2 in the detection cell, cover the detection cell with a light shield, turn on the light source, and collect the near-infrared spectra of the mixed fermentation broth at different fermentation time stages after ultrasonic treatment through a spectrometer; simultaneously measure the polyphenol value corresponding to the fermentation time stage, and establish a partial least squares (GA-PLS) model for the tea polyphenol content based on the polyphenol value and the near-infrared spectrum; finally, by measuring the near-infrared spectrum of an unknown sample and substituting it into the model, quantitative detection of tea polyphenols can be achieved.

[0030] Further, in Step 1, the volume ratio of sucrose to distilled water is 1:10; the volume ratio of the tea fungus liquid to the sucrose medium is 1:5; the volume ratio of tea powder, fermented tea fungus liquid, and water is 1:10:100; the tea fungus liquid is commercially available, specifically Kombucha black tea fungus; the tea powder is green tea powder.

[0031] Further, in Step 1, the ultrasonic frequency is 23 kHz, the ultrasonic time is 24 min, and the power density is 40 W / L.

[0032] Further, in Step 2, the fermentation time of the mixed fermentation broth is 7 days, and the interval is 12 h each time.

[0033] Further, in Step 3, when collecting with a near-infrared spectrometer, the integration time of the near-infrared reflection mode is set to 4 milliseconds, the average scan time is 5 milliseconds, and the smoothness is 10.

[0034] The present invention also provides the application of the synthesis of nano materials PSA, PSN, and MOF in modifying a chemical response material on a color-sensitive sensor. Based on the RGB signals before and after the reaction of the nano-optical sensing extraction sensor with the mixed fermentation broth at different fermentation stages under certain ultrasonic conditions, a chromatogram of the mixed fermentation broth at different fermentation time periods is established according to the RGB characteristic values to distinguish the dynamic changes of the aroma during the ultrasonic fermentation process of the mixed fermentation broth.

[0035] The multi-bit detection device based on the integration of ultrasonic processing and optical sensing detection of the present invention can not only detect tea polyphenols, but also be used for the detection of aroma components. The aroma components during the fermentation process of the mixed fermentation broth are detected using the above-mentioned novel nano-optical sensor. The detection method includes the following steps:

[0036] (1) Construction of the nano-optical sensing detection system

[0037] Construct an optical sensor to capture the characteristic aroma components volatilized during the ultrasonic fermentation process of the mixed fermentation broth, screen out the characteristic chemical response materials with good response to the aroma characteristics according to the change of the RGB signal before and after the sensor detection, and prepare a novel nano-optical sensor by combining nano materials PSA, PSN, and MOF;

[0038] (2) Aroma Recognition during the Ultrasonic Fermentation Process of Mixed Fermentation Broth Based on Nano-Optical Sensing

[0039] React the novel nano-optical sensor with the mixed fermentation broth at different fermentation stages under certain ultrasonic conditions. According to the change of RGB signals before and after the sensor reaction, draw a chromatogram to identify the dynamic change of aroma during the ultrasonic fermentation process of the mixed fermentation broth.

[0040] Furthermore, the optical sensor is composed of 12 porphyrin compounds including TPP, TPPF, TPPCl, etc. and 12 boron dipyrromethene compounds including BDP-F, pCarBDP, NO2Br2BDP, etc. According to the RGB difference values before and after the reaction of the optical sensor with the characteristic aroma components linalool, 3-hexenyl isovalerate, and geraniol screened out during the fermentation process of the mixed fermentation broth, the sensitive chemical response materials are determined to be NO2Br2BDP, (HBDP)2Ni(II), and pCarBDP respectively. Modifying the chemical response materials with nanomaterials (PSA, PSN, and MOF) can improve the adsorption performance of capturing volatile organic compounds. The hydrothermally synthesized metal-organic framework (MOF) has more adsorption sites, which can improve the selectivity of the material. Polystyrene-acrylic acid (PSA) can increase the specific surface area of the reactants. In addition, the porous silica nanospheres (PSN) with a higher porosity have an enhanced gas enrichment effect.

[0041] Furthermore, use near-infrared spectroscopy to obtain the nano-color-sensitive sensing spectral data of the mixed fermentation broth at different fermentation stages under ultrasonic field stress. For the spectral preprocessing of the near-infrared spectral data, the standard normal variate (SNV) preprocessing tool was used. The interval partial least squares (Si-PLS) calculation was performed on the data to effectively quantify the relevant information variables captured in the spectral interval. The variable selection chemometric methods with good modeling performance, such as ACO-PLS, GA-PLS, and CARS-PLS, have been applied to quantify the tea polyphenol content in samples with different concentration gradients. Then, ACO-PLS, GA-PLS, and CARS-PLS were applied in comparison to further screen variables and construct an optimal prediction model for the polyphenol content of the extract of the mixed fermentation broth during the fermentation process.

[0042] The present invention discloses the following technical effects:

[0043] 1. The present invention discloses that there is a significant difference in the polyphenol content between the non-ultrasonic-treated samples and the ultrasonic-treated samples (P < 0.05). Under the optimized ultrasonic frequency of 23 kHz, treatment time of 24 min, and ultrasonic power density of 40 W / L, compared with the control fermentation experiment on the 5th day, the proposed method increased the polyphenol consumption rate by 35.57%, 11.34%, and 16.09% respectively, providing a new idea for the ultrasonic processing method of the mixed fermentation broth fermentation.

[0044] 2. The method of the present invention has good specificity and sensitivity. The nanomaterial MOF for constructing the novel nano-optical sensor has more adsorption sites, which can improve the selectivity of the material; the nanostructure of the nanomaterial PSA can increase the specific surface area of the reactants. In addition, the nanomaterial PSN with a higher porosity has an enhanced gas enrichment effect.

[0045] 3. A new method based on near-infrared spectroscopy and a nano-optical sensor using MOF, PSA, and PSN are used to detect the polyphenol content; the comparative study of the prediction models applied to the spectral data shows that GA-PLS obtains the best results compared with the ACO-PLS and CARS-PLS algorithm models. As a robust prediction model, GA-PLS successfully captures the relevant information and eliminates the uninformative variables related to the polyphenols under study. Finally, the correlation coefficient of the prediction is 0.9988, and the RMSEP value is 0.0264 mg / kg. The current work shows great potential for the aroma analysis of tea extracts using an ultrasonic-assisted fermentation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic structural diagram of a multi-bit detection device integrating ultrasonic processing and optical sensing detection; Reference numerals: 1 - slit ultrasonic device, 2 - control panel, 3 - ultrasonic generator, 4 - ultrasonic transducer, 5 - input pipe, 6 - output pipe, 7 - ultrasonic tank, 8-1 peristaltic pump one, 8-2 peristaltic pump two, 9 - fermentation tank, 10-1 condenser, 10-2 reflux pipe, 11 - main control of the fermentation tank, 12 - pH detector, 13 - temperature sensor, 14 - data line, 15 - air filter, 16 - spectrometer, 17 - detection tank, 18 - light shield, 19-1 optical fiber cable one, 19-2 optical fiber cable two, 20 - light source, 21 - computer, 22 - ultrasonic pipe.

[0047] Figure 2 It is the influence of ultrasonic power on the polyphenol consumption rate during the fermentation process of the mixed fermentation broth.

[0048] Figure 3 It is the influence of ultrasonic time on the polyphenol consumption rate during the fermentation process of the mixed fermentation broth.

[0049] Figure 4 It is the influence of ultrasonic density on the polyphenol consumption rate during the fermentation process of the mixed fermentation broth.

[0050] Figure 5 It is the response diagram of the chemical response material to the aroma of tea extract during the ultrasonic fermentation process; a is the schematic diagram of the principle of optical sensing detection of volatile substances, b is the response result of linalool, c is the response result of 3-hexenyl isovalerate, and d is the response result of geraniol.

[0051] Figure 6 Electron microscopy characterization images and ultraviolet-visible spectroscopy images of nanomaterials PSA, PSN, and MOF; a is the transmission electron microscopy image of MOF, b is the transmission electron microscopy image of PSN, c is the transmission electron microscopy image of PSA, d is the ultraviolet-visible spectrum of nano-sized NO2Br2BDP, e is the ultraviolet-visible spectrum of nano-sized pCarBDP, and f is the ultraviolet-visible spectrum of nano-sized (HBDP)2Ni(II).

[0052] Figure 7 Models for predicting the polyphenol content of the fermented liquid under ultrasonic treatment; a is Si-GA-PLS, b is Si-CARS-PLS, and c is Si-ACO-PLS. Detailed implementation manners

[0053] The various exemplary implementation manners of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0054] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0055] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0056] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the specification of the present invention, which are obvious to those skilled in the art. Other implementation manners obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are only exemplary.

[0057] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0058] In order to further verify the detection of polyphenol content during the fermentation process in the mixed fermentation broth by the method constructed in the present invention, in the embodiments of the present invention, only the mixed fermentation broth brewed from green tea powder of summer and autumn tea is taken as an example. However, the pathogenic bacteria targeted by the present invention are not limited to the extract of tea powder. The green tea powder is provided by Nanjing Rongdian Food Technology Co., Ltd., and the Kombucha black tea fungus is purchased from Anqing Mingxun Tuosen Trading Co., Ltd. (Anhui, China).

[0059] The device includes three parts: a fermentation system, an ultrasonic-assisted fermentation system, and a near-infrared spectroscopy detection system; the fermentation system is composed of a fermentation tank 9, a main control console 11 of the fermentation tank, a pH detector 12, and a temperature sensor 13; the main body is the fermentation tank 9, which is controlled by the main control console 11 of the fermentation tank. The main control console 11 of the fermentation tank is equipped with a pH detector 12 and a temperature sensor 13 to monitor the pH and temperature during the fermentation process.

[0060] The ultrasonic-assisted fermentation system is composed of a slit ultrasonic device 1, a control panel 2, an ultrasonic generator 3, an ultrasonic transducer 4, an input pipeline 5, an output pipeline 6, an ultrasonic tank 7, a peristaltic pump 8-1, a peristaltic pump 8-2, and an ultrasonic pipeline 22; during ultrasonic fermentation, the slit ultrasonic device 1 is turned on, and the control panel 2 is adjusted to a certain ultrasonic frequency, ultrasonic density, and ultrasonic time. The fermentation material is pumped into the ultrasonic tank 7 through the input pipeline 5 by the peristaltic pump 8-1 for ultrasonic treatment, and then pumped into the fermentation tank 9 through the output pipeline 6 by the peristaltic pump 8-2. This process is completed based on the ultrasonic generator 3 and the ultrasonic transducer 4.

[0061] The near-infrared spectroscopy detection system is composed of a spectrometer 16, a detection tank 17, a light-shielding cover 18, an optical fiber cable, and a light source 20; in order to detect the change of aroma components during the fermentation process of the material, the near-infrared spectroscopy detection system real-time collects the spectral changes after the reaction of the material with the optical sensor. Specifically, the optical sensor is placed in the detection tank 17, the near-infrared spectrum is collected by the spectrometer 16, and the computer 21 controls the collection process and records and saves the data, finally realizing the in-situ detection of polyphenols in the ultrasonic fermentation of the mixed fermentation broth based on the novel nano-optical sensor.

[0062] Specifically, a multi-position detection device integrating ultrasonic processing and optical sensing detection includes a slit ultrasonic device 1, an input pipeline 5, an output pipeline 6, an ultrasonic tank 7, a peristaltic pump 8-1, a peristaltic pump 8-2, a fermentation tank 9, a condenser 10-1 and a reflux pipe 10-2, a main console 11 of the fermentation tank, a pH detector 12, a temperature sensor 13, a data line 14, an air filter 15, a spectrometer 16, a detection tank 17, a light-shielding cover 18, an optical cable 19-1, an optical cable 19-2, a light source 20, a computer 21 and an ultrasonic pipeline 22; wherein the fermentation tank 9 is cylindrical and is internally provided with a stirring device; the slit ultrasonic device 1 includes a control panel 2, an ultrasonic generator 3 and an ultrasonic transducer 4; wherein there are 6 ultrasonic transducers 4, which are located inside the ultrasonic generator 3; the control panel 2 is electrically connected to the ultrasonic generator 3 and the ultrasonic transducer 4 for realizing the control function;

[0063] The main console 11 of the fermentation tank is internally provided with a condensing device. The bottom end of the fermentation tank 9 is provided with a condensing pipeline, which is respectively connected to the condensing device through the condenser 10-1 and the reflux pipe 10-2; the main console 11 of the fermentation tank is also provided with a pH detector 12 and a temperature sensor 13. The other end of the pH detector 12 is connected to the fermentation tank 9 for monitoring the pH value of the internal substance during the fermentation process of the fermentation tank 9; the temperature sensor 13 is connected to the fermentation tank 9 through the air filter 15 for monitoring the temperature of the internal substance during the fermentation process of the fermentation tank 9;

[0064] One end of the input pipeline 5 is communicated with the fermentation tank 9, and the other end is communicated with the ultrasonic tank 7; one end of the output pipeline 6 is communicated with the fermentation tank 9, and the other end is communicated with the ultrasonic tank 7; a peristaltic pump 8-1 is arranged on the input pipeline 5, and a peristaltic pump 8-2 is arranged on the output pipeline 6; valves are also arranged on both the input pipeline 5 and the output pipeline 6 for controlling the opening and closing of the pipeline.

[0065] The slit ultrasonic device 1 is communicated with the outer wall of the ultrasonic tank 7 through the ultrasonic pipeline 22; wherein the slit ultrasonic device 1 realizes the control of the ultrasonic frequency, power density and ultrasonic time through the control panel 2;

[0066] One side of the fermentation tank 9 is connected to the detection tank 17 through an air pipe. The detection tank 17 is square in shape; there is also a light-shielding cover 18 above the detection tank 17; one end of the detection tank 17 is connected to the light source 20 through the optical cable 19-1, and the other end is connected to the spectrometer 16 through the optical cable 19-2. The spectrometer 16 is electrically connected to the computer 21 through the data line 14.

[0067] II: Selection of ultrasonic fermentation parameters

[0068] First, mix sucrose and distilled water in a volume ratio of 1:10 to obtain a sucrose culture medium;

[0069] Weigh 20 g of green tea powder and prepare 2 L of tea fermentation broth with sucrose medium. Add it to the fermentation tank 9 and add 200 mL of Kombucha black tea fungus to obtain a mixed fermentation broth. Set the ultrasonic conditions through the control panel 2, then start the ultrasonic generator 3 and the ultrasonic transducer 4, and perform ultrasonic peristalsis (for 30 minutes) at a constant ultrasonic power density (100 W / L). Use ultrasonic treatments at different frequencies (20, 23, 25, 28, 33, and 40 kHz) to stimulate the fermentation of the mixed fermentation broth to explore the optimal ultrasonic frequency, and use the non - ultrasonic - treated group as the control group.

[0070] Figure 2 Regarding the effect of ultrasonic power on the polyphenol consumption rate during the fermentation of the mixed fermentation broth, it can be seen from the figure that the ultrasonic frequency of 23 kHz is the optimal ultrasonic frequency for ultrasonic fermentation of the mixed fermentation broth.

[0071] Based on this, find the optimal ultrasonic time at different ultrasonic times of 6, 12, 24, 48, and 60 min respectively; Figure 3 Regarding the effect of ultrasonic time on the polyphenol consumption rate during the fermentation of the mixed fermentation broth, it can be seen from the figure that the treatment time of 24 min is the optimal ultrasonic time for ultrasonic fermentation of the mixed fermentation broth.

[0072] Finally, conduct a single - factor optimization experiment on ultrasonic power density at different power densities of 20, 40, 60, 80, and 100 W / L to explore the optimal ultrasonic power.

[0073] Figure 4 Regarding the effect of ultrasonic density on the polyphenol consumption rate during the fermentation of the mixed fermentation broth, it can be seen from the figure that the ultrasonic power density treatment of 40 W / L is the optimal ultrasonic power density for ultrasonic fermentation of the mixed fermentation broth.

[0074] Start the slit ultrasonic device 1 through the control panel 2. The test conditions are a fermentation temperature of 30 °C and natural pH. Compare different ultrasonic frequencies of 20, 23, 25, 28, 33, and 40 kHz. The result shows that 23 kHz is the best. Compared with the control fermentation experiment (without ultrasonic treatment), the polyphenol consumption rate under this condition has increased by 35.57%; compare different power densities of 20, 40, 60, 80, and 100 W / L. The ultrasonic power density of 40 W / L is the best. Compared with the control fermentation experiment (without ultrasonic treatment), the polyphenol consumption rate under this condition has increased by 11.34%; compare different treatment times of 6, 12, 24, 48, and 60 min. The ultrasonic treatment time of 24 min is the best. Compared with the control fermentation experiment (without ultrasonic treatment), the polyphenol consumption rate under this condition has increased by 16.09%.

[0075] III: Detection method for polyphenol content during the ultrasonic fermentation of Kombucha by an optical sensing spectroscopy device based on ultrasonic fermentation:

[0076] Step 1, ultrasonic fermentation treatment of tea soup

[0077] Mix sucrose and distilled water at a volume ratio of 1:10 to obtain a sucrose medium. Mix Kombucha black tea fungus and the sucrose medium at a volume ratio of 1:5, place them in a container, cover it with gauze, and ferment at room temperature for one week to ferment the tea fungus liquid to obtain Kombucha black tea fungus tea fungus liquid.

[0078] Prepare a tea powder fermentation liquid according to the volume ratio of tea powder: Kombucha black tea fungus tea fungus liquid: water of 1:10:100 and put it into the fermentation tank 9. Then start the ultrasonic generator 3 and the ultrasonic transducer 4, set the ultrasonic conditions through the control panel 2, with an ultrasonic frequency of 23 kHz, an ultrasonic time of 24 min, and a power density of 40 W / L; at the same time, open the valve on the input pipeline 5, and use the peristaltic pump 8-1 to flow the material in the fermentation tank 9 into the ultrasonic tank 7 through the input pipeline 5. When the ultrasonic tank is filled with material, close the valve on the input pipeline 5 and the peristaltic pump 8-1; perform ultrasonic treatment on the material in the ultrasonic tank 7 through the ultrasonic pipeline 22. After ultrasonic treatment, open the valve on the output pipeline 6, and pump it back into the fermentation tank 9 through the action of the peristaltic pump 8-2 via the output pipeline 6. After the material in the ultrasonic tank 7 is pumped out, close the valve on the output pipeline 6 and the peristaltic pump 8-2;

[0079] Then, according to the same operation, open the valve on the input pipeline 5 again, use the peristaltic pump 8-1 to flow the material in the fermentation tank 9 into the ultrasonic tank 7 for ultrasonic treatment, and then pump it back into the fermentation tank 9 after ultrasonic treatment; repeat this many times;

[0080] Step 2, construction of a new type of nano-optical sensor

[0081] (1) Aroma analysis of ultrasonic-fermented tea extract:

[0082] During the fermentation of the mixed fermentation liquid, accurately take 6 mL of tea extract fermentation liquid from the fermentation tank 9 every 12 hours to measure the volatile organic components (VOCs), in triplicate. Use a triple quadrupole gas chromatography-mass spectrometer (TQ-8040) for headspace solid-phase microextraction-gas chromatography-mass spectrometry (GC-MS) analysis, summarize the change rules of the aroma components in the mixed fermentation liquid at different ultrasonic fermentation stages, and use analysis of variance to screen out linalool, 3-hexenyl isovalerate, and geraniol as the characteristic volatile gases during the ultrasonic fermentation process of the mixed fermentation liquid;

[0083] (2) Screening of chromogenic materials sensitive to the characteristic aroma components of ultrasonic fermentation of the mixed fermentation liquid: Figure 5Response diagram of chemical response materials to the aroma of tea extract during ultrasonic fermentation; where a is the schematic diagram of optical sensing for detecting volatile substances, b is the response result of linalool, c is the response result of 3-hexenyl isovalerate, and d is the response result of geraniol.

[0084] According to the RGB difference values before and after the reaction of the characteristic aroma components linalool, 3-hexenyl isovaleric acid, and geraniol screened out during the fermentation process of the optical sensor and the mixed fermentation broth, the respective sensitive chemical response materials are determined; the chemical material sensitive to linalool is NO2Br2BDP, the material sensitive to 3-hexenyl isovaleric acid is (HBDP)2Ni(II); the chemical material sensitive to geraniol is pCarBDP.

[0085] (3) Construction of a new type of nano-optical sensor (using conventional methods):

[0086] Utilize the surface microstructure of PSA to help increase the specific surface area of the reactants, the high porosity gas enrichment effect of PSN to enhance the adsorption of the material, and the fact that MOF has more adsorption sites to improve the selectivity of the material. The chemical materials NO2Br2BDP sensitive to the characteristic aroma linalool during the fermentation process of the mixed fermentation broth, the material (HBDP)2Ni(II) sensitive to 3-hexenyl isovaleric acid, and pCarBDP sensitive to geraniol are emulsified and fused with the nanomaterials PSA, PSN, and MOF (modified and reconstructed by emulsion polymerization, suspension polymerization, and dispersion polymerization respectively) to obtain a new type of nano-optical sensor.

[0087] Figure 6 Electron microscopy characterization diagram and ultraviolet-visible spectroscopy diagram of the nanomaterials; a is the transmission electron microscopy diagram of MOF, b is the transmission electron microscopy diagram of PSN, c is the transmission electron microscopy diagram of PSA, e is the ultraviolet-visible spectrum of the nanosized NO2Br2BDP, d is the ultraviolet-visible spectrum of the nanosized (HBDP)2Ni(II), and e is the ultraviolet-visible spectrum of the nanosized pCarBDP.

[0088] Step three, quantitative detection of tea polyphenols

[0089] (1) Aroma recognition during the ultrasonic fermentation of the mixed fermentation broth based on nano-optical sensing:

[0090] Place the new type of nano-optical sensor prepared in step two in the detection tank 17, cover the detection tank 17 with the light-shielding cover 18, turn on the light source 20, and collect the near-infrared spectra of the tea powder fermentation broth at different fermentation time stages after ultrasonic treatment through the spectrometer 16.

[0091] The novel nano-optical sensor was reacted with the odor of the mixed fermentation broth at different fermentation stages (ultrasonic fermentation for 0, 1, 2, 3, 4, 5, 6, 7 days), and the RGB signal changes before and after the sensor reaction were calculated.

[0092] (2) Determination of polyphenols: The polyphenol value of the mixed fermentation broth was measured daily according to the national standard method (GB / T 21733-2008).

[0093] Accurately weigh 2 g of the fermentation broth and put it into a 25 mL volumetric flask. Then add 4 mL of water, 5 mL of ferrous tartrate solution, and use PBS buffer to complete the solution mixing to the 25.0 mL mark; use a 10 mm cuvette to measure the absorbance (A1), and deduct the reagent blank value at 540 nm. The preparation method of the reagent blank solution is to transfer the accurately weighed (2 g) fermentation broth to a 25 mL volumetric flask, then add 4 mL of water, and adjust the volume to 25 mL with PBS buffer; measure the absorbance (A2) after deducting the reagent blank. The calculation formula for the content of tea polyphenols is as follows

[0094]

[0095] Where X is the content of tea polyphenols in the sample (mg / kg); A1 is the absorbance after the test solution is colored; A2 is the absorbance of the background color of the test solution; the integer 1.957 means that under the condition of 0.50 absorbance, the polyphenol content in 1 mL of tea solution is equivalent to 1.957 mg; K is the dilution factor; m is the mass (g) of the test solution during the weighing measurement.

[0096] (3) Establish a discrimination model for the polyphenol content during the ultrasonic fermentation of the mixed fermentation broth: Based on the near-infrared spectra of the mixed fermentation broth at different fermentation stages (ultrasonic fermentation for 0, 1, 2, 3, 4, 5, 6, 7 days) collected by the novel nano-optical sensor, for the spectral preprocessing of the near-infrared spectral data, the SNV preprocessing tool was used; then the Si-PLS algorithm was used to establish the ACO-PLS, GA-PLS, and CARS-PLS models for the content of tea polyphenols respectively, and the best quantitative detection method for tea polyphenols during the ultrasonic fermentation of the mixed fermentation broth was obtained by comparing with the traditional method. Compared with the ACO-PLS and CARS-PLS algorithm models, GA-PLS obtained the best results.

[0097] Figure 7 It is a model for predicting the polyphenol content of the mixed fermentation broth under ultrasonic treatment; where a is Si-GA-PLS, b is Si-CARS-PLS, and c is Si-ACO-PLS. As a robust prediction model, GA-PLS successfully captured the relevant information and eliminated the informationless variables related to the polyphenols studied. Finally, the predicted correlation coefficient was 0.9988, and the RMSEP value was 0.0264 mg / kg.

[0098] Table 1 Comparison between the new method for detecting the content of tea polyphenols during the fermentation process of mixed fermentation broth based on the new nano-optical sensor of the present invention and the national standard method

[0099]

[0100]

[0101] The current innovative work combines nano-optical sensors with near-infrared spectroscopy for the rapid detection and quantification of polyphenols, and studies the potential extraction of the dynamic changes of aroma components during the fermentation process of mixed fermentation broth based on nano-optical sensors with chemically selective colorants.

[0102] The present invention explores the effects of different ultrasonic-assisted factors on the change of polyphenol consumption rate during the fermentation process of tea extracts and the non-ultrasonic treatment as a control group. The results show that the polyphenol consumption rate increases under the ultrasonic conditions of an ultrasonic frequency of 28 kHz, a treatment time of 24 min, and an ultrasonic power density of 40 W / L. The nano-optical sensor based on metal-organic frameworks described in the present invention has more adsorption sites, which can enhance the adsorption of volatile organic compounds. The polystyrene-acrylic microstructure provides a specific surface area for the reactants. In addition, the porous silica nanospheres with a higher porosity adopted have improved gas enrichment effects. The nano-optical sensor exhibits good performance and has a "chromatogram" for the identification of aroma components during the fermentation process of tea extracts.

[0103] Based on the established quantitative prediction model of polyphenols, the present invention explores the feasibility of in-situ imaging of the fermentation degree of the extract of the mixed fermentation broth after ultrasonic treatment using a nano-optical sensor. Therefore, on the basis of studying the formation of aroma during the fermentation process of the mixed fermentation broth under the stress of the ultrasonic physical field, this method breaks through the problem of real-time online monitoring of the changes in aroma components, and can realize the intelligent control of the fermentation process of the mixed fermentation broth, so as to improve the informatization and intelligent level of the processing technology of the mixed fermentation broth, and ultimately promote the healthy and sustainable development of the entire mixed fermentation broth fermentation industry.

[0104] Note: The above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention; therefore, although this specification has described the present invention in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced; and all technical solutions and their improvements that do not depart from the spirit and scope of the present invention shall be covered within the scope of the claims of the present invention.

Claims

1. A multi-position detection device integrating ultrasonic machining and optical sensing detection, characterized in that, It includes a slit ultrasonic device (1), an input pipeline (5), an output pipeline (6), an ultrasonic tank (7), a peristaltic pump I (8-1), a peristaltic pump II (8-2), a fermentation tank (9), a main control console of the fermentation tank (11), a pH detector (12), a temperature sensor (13), a data line (14), an air filter (15), a spectrometer (16), a detection tank (17), a light-shielding cover (18), an optical cable I (19-1), an optical cable II (19-2), a light source (20), a computer (21) and an ultrasonic pipeline (22); The slit ultrasonic device (1) includes a control panel (2), an ultrasonic generator (3) and an ultrasonic transducer (4); the control panel (2) is electrically connected to the ultrasonic generator (3) and the ultrasonic transducer (4) for control; The main control console of the fermentation tank (11) is also provided with a pH detector (12) and a temperature sensor (13), wherein the other end of the pH detector (12) is connected to the fermentation tank (9) for monitoring the pH value of the internal substance during the fermentation process of the fermentation tank (9); the temperature sensor (13) is connected to the fermentation tank (9) through the air filter (15) for monitoring the temperature of the internal substance during the fermentation process of the fermentation tank (9); One end of the input pipeline (5) communicates with the fermentation tank (9), and the other end communicates with the ultrasonic tank (7); one end of the output pipeline (6) communicates with the fermentation tank (9), and the other end communicates with the ultrasonic tank (7); a peristaltic pump I (8-1) is provided on the input pipeline (5), and a peristaltic pump II (8-2) is provided on the output pipeline (6); valves are also provided on both the input pipeline (5) and the output pipeline (6) for controlling the opening and closing of the pipeline; The slit ultrasonic device (1) communicates with the outer wall of the ultrasonic tank (7) through the ultrasonic pipeline (22); wherein the slit ultrasonic device (1) controls the ultrasonic frequency, power density and ultrasonic time through the control panel (2); One side of the fermentation tank (9) is connected to the detection tank (17) through an air delivery pipe, and there is also a light-shielding cover (18) above the detection tank (17); one end of the detection tank (17) is connected to the light source (20) through the optical cable I (19-1), and the other end is connected to the spectrometer (16) through the optical cable II (19-2), and the spectrometer (16) is electrically connected to the computer (21) through the data line (14).

2. The multi-bit detection device integrating ultrasonic machining and optical sensing detection according to claim 1, characterized in that, A condensation device is arranged inside the main control console of the fermentation tank (11), and a condensation pipeline is arranged at the bottom end of the fermentation tank (9), and the condensation pipeline is respectively connected to the condensation device through a condenser pipe (10-1) and a return pipe (10-2).

3. A multi-position detection device integrating ultrasonic machining and optical sensing detection according to claim 2, characterized in that, The fermentation tank (9) is cylindrical.

4. The multi-position detection device integrating ultrasonic machining and optical sensing detection according to claim 1, characterized in that, Six ultrasonic transducers (4) are provided inside the ultrasonic generator (3).

5. A multi-bit detection device integrating ultrasonic machining and optical sensing detection according to claim 1, characterized in that, The detection tank (17) is square in shape.

6. Use of a multi - detection device integrating ultrasonic processing and optical sensing detection according to any one of claims 1 - 5 for in - situ detection of polyphenols during the ultrasonic fermentation of a mixed fermentation broth, characterized in that, It includes the following steps: Step 1, ultrasonic fermentation treatment of tea soup; First, sucrose and distilled water are mixed to obtain a sucrose culture medium; then the tea fungus liquid and the sucrose culture medium are mixed and placed in a container, covered with gauze, and fermented at room temperature for a period of time to obtain a fermented tea fungus liquid; Take the tea powder and mix it with the fermented tea fungus liquid and water to obtain a mixed fermentation liquid, which is put into a fermentation tank (9). Then, start the ultrasonic generator (3) and the ultrasonic transducer (4), and set the ultrasonic conditions through the control panel (2). The ultrasonic frequency is 23 - 28 kHz, the ultrasonic time is 12 - 60 min, and the power density is 20 - 40 W / L. At the same time, open the valve on the input pipeline (5), and use the peristaltic pump one (8 - 1) to flow the materials in the fermentation tank (9) into the ultrasonic tank (7) through the input pipeline (5). When the ultrasonic tank is filled with materials, close the valve on the input pipeline (5) and the peristaltic pump one (8 - 1). Carry out ultrasonic treatment on the materials in the ultrasonic tank (7) through the ultrasonic pipeline (22). After ultrasonic treatment, open the valve on the output pipeline (6), and pump the materials back into the fermentation tank (9) through the action of the peristaltic pump two (8 - 2) via the output pipeline (6). When all the materials in the ultrasonic tank (7) are pumped out, close the valve on the output pipeline (6) and the peristaltic pump two (8 - 2). Then, according to the same operation, open the valve on the input pipeline (5) again, and use the peristaltic pump one (8 - 1) to flow the materials in the fermentation tank (9) into the ultrasonic tank (7) for ultrasonic treatment, and then pump them back into the fermentation tank (9) after ultrasonic treatment; repeat this process multiple times; Step two, construction of a new type of nano - optical sensor; (1) During the fermentation process of the mixed fermentation liquid, take out the mixed fermentation liquid from the fermentation tank (9) at regular intervals to measure the volatile organic components. A triple - quadrupole gas chromatography - mass spectrometer is used for headspace solid - phase microextraction - gas chromatography - mass spectrometry combined technology to analyze the change law of the aroma components of the fermentation liquid at different ultrasonic fermentation stages. Through variance analysis, linalool, 3 - hexenyl isovalerate, and geraniol are selected as the characteristic volatile gases during the ultrasonic fermentation process of the mixed fermentation liquid; (2) The chemical materials sensitive to the characteristic aroma linalool in the fermentation process of the mixed fermentation liquid are 8 - (4 - nitrophenyl) - 4,4 - difluoro - 2,6 - dibromoboron dipyrromethane and the material sensitive to 3 - hexenyl isovalerate, bis[8 - phenyldipyrromethane] nickel(II); the chemical material sensitive to geraniol is 8 - (4 - carbazolylphenyl) - 4,4 - difluoroboron dipyrromethane; Use the nanomaterials poly(styrene - acrylic acid), porous silica nanoparticles, and metal - organic framework materials for emulsification and fusion to finally obtain a new type of nano - optical sensor; Step three, detection of tea polyphenols; Place the new type of nano - optical sensor prepared in step two in the detection tank (17), cover the detection tank (17) with a light - shielding cover (18), turn on the light source (20), and collect the near - infrared spectra of the mixed fermentation liquid after ultrasonic treatment at different fermentation time stages through the spectrometer (16). At the same time, measure the polyphenol value corresponding to the fermentation time stage, establish a partial least - squares model for the tea polyphenol content based on the polyphenol value and the near - infrared spectra. Finally, by measuring the near - infrared spectra of unknown samples and substituting them into the model, the quantitative detection of tea polyphenols can be achieved.

7. The use according to claim 6, wherein In Step 1, the volume ratio of sucrose to distilled water is 1:10; the volume ratio of the tea fungus solution to the sucrose medium is 1:5; the volume ratio of tea powder, fermented tea fungus solution, and water is 1:10:100; the tea fungus solution is commercially available, specifically Kombucha black tea fungus; the tea powder is green tea powder.

8. The use according to claim 6, wherein In Step 1, the ultrasonic frequency is 23 kHz, the ultrasonic time is 24 min, and the power density is 40 W / L.

9. The use according to claim 6, characterized in that, In Step 2, the fermentation time of the mixed fermentation broth is 7 days, with an interval of 12 h each time.

10. The use according to claim 6, wherein In Step 3, when using the near-infrared spectrometer (16) for collection, the integration time in the near-infrared reflection mode is set to 4 milliseconds, the average scanning time is 5 milliseconds, and the smoothness is 10.

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