Absorbance detector and method for in vitro determination of food glycemic index
By designing slidable sample components and screw motor drive in the absorbance detector, multi-position detection is achieved, solving the problems of limitations and low accuracy of detection data caused by the position fixation of the test tube, and improving the detection accuracy.
Patent Information
- Application Number
- CN202411466231.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2024-12-24
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the existing absorbance detector, the test tube is fixed, and the optical path can only acquire images in a fixed light-transmitting part, resulting in limited detection data and low accuracy.
A slidable sample assembly is designed, combining screws and motor drives to realize multi-position detection of sample assembly. The optical path can acquire images in multiple positions, and overcome detection errors caused by settlement through oblique detection.
The representativeness and accuracy of the detection data are improved, the settlement error is overcome, and more accurate detection results are achieved.
Smart Images
Figure CN118961599B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to detection equipment and relates to the technical field of absorbance detection, in particular to an absorbance detector and a method for in vitro determination of the glycemic index of food. Background Art
[0002] Absorbance detector is a relatively simple measurement technology. There is only one light path between the sample and the light source. A filter is usually used to select the appropriate wavelength and the absorbance of the sample is determined by measuring the intensity of light after passing through or reflecting the sample. This instrument is suitable for measuring some physical and chemical properties related to the sample, such as measuring the concentration of the liquid, reaction rate, and color.
[0003] The Chinese patent application number 201710057381.0 discloses an absorbance detection system, including a support mechanism, a light source mechanism, an imaging mechanism and a processor. The support mechanism has at least two light outlets and at least one light inlet; at least two mounting cavities and at least one reference cavity are provided on the support mechanism, one end of the mounting cavity and the reference cavity are connected to the light inlet, and the other end is respectively connected to the light outlet in one-to-one correspondence; the mounting cavity is used to insert a light-transmitting container; the light source mechanism is used to provide a light source of the required color to the mounting cavity and the reference cavity through the light inlet; the imaging mechanism is used to take images of the solution to be detected and the reference cavity after being irradiated by the light source through the light outlet; the processor obtains the absorbance value of the solution to be detected in the mounting cavity according to the image information obtained by the imaging mechanism.
[0004] However, the test tube is installed on the support mechanism, and the position of the test tube is fixed. The optical path can only acquire images at the fixed light-transmitting part, so the detection data is relatively limited and the accuracy of the detection data is low. Summary of the invention
[0005] The purpose of the present invention is to provide an absorbance detector and a method for in vitro determination of the glycemic index of food, so as to solve the problem in the above background technology that the existing test tube is fixed in position, the optical path can only acquire images at the fixed light-transmitting part, and the detection data is relatively limited.
[0006] The technical solution adopted by the present invention is as follows: an absorbance detector comprises a detection box, a light emitting part is arranged on the top of the detection box; a filter assembly is arranged on the top of the detection box, the filter assembly is located downstream of the light emitting part, and the filter assembly is used to select light of a required radiation band emitted by the light emitting part; a supporting mechanism is arranged at the bottom of the detection box, the supporting mechanism comprises a screw rod, the screw rod is rotatably connected to the detection box, and the screw rod is driven by a first motor; a limit head is arranged at the upper end of the screw rod; a cone is threadedly connected to the screw rod, a guide rod is slidably connected to the cone, and the guide rod is connected to the bottom of the detection box; a slide groove is arranged on the inclined surface of the cone, a sample assembly is slidably connected to the slide groove, and the sample assembly is used to fill the liquid to be tested, and the sample assembly is located downstream of the filter assembly; an inner tube body is arranged at the bottom of the detection box, a guide hole is arranged on the side wall of the inner tube body, the guide hole is arranged obliquely, and the guide hole is slidably adapted to the sample assembly; a light receiving part is arranged at the bottom of the detection box, and the light receiving part is located downstream of the sample assembly, and the light receiving part is opposite to the light emitting part.
[0007] The detection box comprises a shell, an upper port of the shell is provided with a top cover, and a lower port of the shell is provided with a bottom cover.
[0008] The driving part comprises a fixed seat, the center of which is provided with a light hole, the light hole and the rotating shaft are gap-matched, the lower end of the fixed seat is connected to the detection box, the top surface of the fixed seat is provided with a circular hole, and the number of the circular holes is at least 2; a sliding column is slidably connected to the circular hole, a strip plate is provided on the top of the sliding column, a third spring is sleeved on the side wall of the sliding column, and the third spring is located between the strip plate and the fixed seat in an elastically connected manner; a limiting column is provided on the top surface of the strip plate, the cross-sectional shape of the limiting column is T-shaped, and a pointer is provided on the side of the strip plate; a dividing plate is provided on the side wall of the rotating shaft, and a plurality of limiting openings are opened on the side wall of the dividing plate, the limiting openings are concentric with the through hole, and the limiting openings are slidably adapted to the small diameter section of the limiting column; a guide strip is provided on the upper side wall of the rotating shaft, a cover shell is slidably connected to the guide strip, and a pressure rod is provided on the side wall of the cover shell; a concave cavity is provided on the bottom surface of the cover shell; the bottom edge of the cover shell is against the large diameter section of the limiting column, and the outer side wall of the cover shell has a second scale line, which is used in conjunction with the pointer; a stopper is provided on the top surface of the rotating shaft.
[0009] A method for in vitro determination of the glycemic index of food for use with the absorbance detector comprises the following steps: (1) accurately weighing a food sample containing 100 mg to 500 mg of carbohydrates and vortexing to simulate the oral chewing process; (2) continuously oscillating in a water bath constant temperature oscillator to simulate the gastrointestinal peristalsis process; (3) adjusting the pH value of the digestive juice by adding HCl and NaOH solutions to simulate the digestive environment of the human stomach and intestines; (4) finally digesting the food to be tested into glucose by adding one or more digestive enzymes in the digestion step, detecting the absorbance of glucose, and obtaining a hydrolysis-digestion curve, and calculating the glycemic index (eGI value) by software integral fitting and theoretical relationship.
[0010] The beneficial effects of the present invention are as follows: by setting up a sliding sample assembly, the optical path can acquire images at multiple positions, the detection data is more representative, and the oblique detection of the sample assembly can overcome the detection error caused by sedimentation, thereby further improving the accuracy of the detection data. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is a schematic diagram of the main cross-sectional structure of this application.
[0012] Figure 2 Schematic diagram of the three-dimensional structure of a cone.
[0013] Figure 3 Schematic diagram of the cone structure from top view.
[0014] Figure 4 This is a schematic diagram of the main structure of the detection box.
[0015] Figure 5 It is a schematic diagram of the three-dimensional structure of the filter component.
[0016] Figure 6 It is a schematic diagram of the main cross-sectional structure of the turntable.
[0017] Figure 7 Schematic diagram of the three-dimensional structure of the filter.
[0018] Figure 8 This is a schematic diagram of the main cross-sectional structure of the sample component.
[0019] Fig. 9 It is a schematic diagram of the main cross-sectional structure of the pull rope.
[0020] Fig.10 It is a schematic diagram of the main structure of the pull rope.
[0021] Fig.11 It is a schematic diagram of the main cross-sectional structure of the scraper.
[0022] Fig.12 It is a schematic diagram of the three-dimensional structure of the ring gear.
[0023] Fig.13 Schematic diagram of the three-dimensional structure of the cantilever.
[0024] Fig.14 This is a schematic diagram of the main structure of the cantilever rotated 90° on the lens.
[0025] Fig.15 It is a schematic diagram of the main cross-sectional structure of the sponge strip.
[0026] Fig.16 This is a schematic diagram of the main structure of the peristaltic pump and degassing device.
[0027] Fig.17It is a schematic diagram of the main cross-sectional structure of the degassing device.
[0028] Fig.18 It is a schematic diagram of the main cross-sectional structure of the plug.
[0029] Fig.19 It is a schematic diagram of the main cross-sectional structure of the injection component.
[0030] Fig. 20 Schematic diagram of the exploded structure of the injection component.
[0031] Fig.21 It is a flow chart of the LED control unit and the photodiode control unit.
[0032] Fig. 22 It is a schematic diagram of the main structure of the fixed seat.
[0033] Fig.23 It is a schematic diagram of the main cross-sectional structure of the cover.
[0034] Fig.24 It is a schematic diagram of the three-dimensional structure of the dividing plate.
[0035] Fig.25 This is a schematic diagram of the main cross-sectional structure of the limit post being disengaged after the cover shell moves downward.
[0036] In the figure: 1, detection box; 2, light emitting part; 3, filter assembly; 4, support mechanism; 5, screw; 6, first motor; 7, limit head; 8, cone; 9, guide rod; 10, slide groove; 11, sample assembly; 12, inner tube; 13, guide hole; 14, light receiving part; 15, shell; 16, top cover; 17, bottom cover; 18, rotating shaft; 19, driving part; 20, second motor; 21, turntable; 22, through hole; 23, ring groove; 24, slot; 25, positioning bolt; 26, filter Optical sheet; 27, lens; 28, pipe clamp; 29, connecting bolt; 30, support rod; 31, short board; 32, sphere; 33, sample tube; 34, end cap; 35, liquid tube; 36, hose; 37, pipe joint; 38, countersunk hole; 39, tension spring; 40, scraper; 41, pull rope; 42, guide tube; 43, handle; 44, shaft; 45, gear; 46, gear ring; 47, third motor; 48, cantilever; 49, bump; 50, T-bar; 51, sponge strip; 52, first spring spring; 53, scraper; 54, first pipeline; 55, peristaltic pump; 56, second pipeline; 57, first valve; 58, degassing device; 59, barrel cover; 60, third pipeline; 61, vacuum pump; 62, barrel; 63, fourth pipeline; 64, second valve; 65, feed pipe; 66, plug; 67, second spring; 68, U-shaped seat; 69, injection assembly; 70, carrier; 71, slide rail; 72, slider; 73, carrier plate; 74, U-port; 75, micro-injector; 76 , screw; 77, first scale line; 78, detector control unit; 79, LED control unit; 80, photodiode control unit; 81, amplifier unit; 82, A / D converter; 83, fixing seat; 84, light hole; 85, round hole; 86, sliding column; 87, strip plate; 88, third spring; 89, limit column; 90, pointer; 91, dividing plate; 92, limit opening; 93, guide strip; 94, cover; 95, pressure rod; 96, concave cavity; 97, second scale line; 98, stop seat. DETAILED DESCRIPTION
[0037] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0038] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0039] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.
[0040] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0041] like Figure 1~Figure 3As shown in the first embodiment, an absorbance detector includes a detection box 1, a light emitting part 2 is installed on the top of the detection box 1, and the light emitting part 2 is preferably an LED lamp, and the light source emitted is white light, which is convenient for absorbing the wavelength light required by different solutions to be detected; a filter component 3 is installed on the top of the detection box 1, and the filter component 3 is located downstream of the light emitting part 2. The filter component 3 is used to select the light of the required radiation band emitted by the light emitting part 2; a support mechanism 4 is installed at the bottom of the detection box 1, and the support mechanism 4 includes a screw 5, which is rotatably connected to the detection box 1, and the screw 5 is arranged vertically upward, and the screw 5 Driven by the first motor 6, the first motor 6 is connected to the detection box 1, and the first motor 6 is preferably a servo motor; the upper end of the screw 5 is threadedly connected to a limit head 7, and the limit head 7 is used to limit the rising position of the cone 8; the screw 5 is threadedly connected to a cone 8, and the shape of the cone 8 is preferably a circular rotating part; the cone 8 is slidably connected to a guide rod 9, the number of the guide rods 9 is at least 2, the guide rods 9 are connected to the bottom of the detection box 1, and the guide rods 9 are used to guide the cone 8 to move in the up and down directions; the inclined surface of the cone 8 is provided with a slide groove 10, and the slide groove 10 is inclined upward (viewed from left to right), and the shape of the slide groove 10 is preferably The slide 10 is arc-shaped, and a sample assembly 11 is slidably connected to the slide 10. The sample assembly 11 is used to fill the liquid to be tested, and the sample assembly 11 is located downstream of the filter assembly 3; an inner tube body 12 is installed at the bottom of the detection box 1. The shape of the inner tube body 12 is a circular tube. A guide hole 13 is opened on the side wall of the inner tube body 12. The guide hole 13 is arranged obliquely. The guide hole 13 is slidably adapted to the sample assembly 11, so that the sample assembly 11 is tilted downward (viewed from left to right); a light receiving part 14 is installed at the bottom of the detection box 1. The light receiving part 14 is preferably a photodiode for receiving light. The light receiving part 14 is located at the sample assembly 11. Downstream of the component 11, the light receiving part 14 is opposite to the light emitting part 2; the adjustment process of the sample component 11: the screw 5 is driven to rotate by the first motor 6, and the guiding effect of the guide rod 9 is cooperated to make the cone 8 move up or down, thereby pushing the sample component 11 to slide in the guide hole 13, and different heights can produce different measurement results; in this application, by setting a slidable sample component 11, the optical path can acquire images at multiple positions, and the detection data is more representative. In addition, the oblique detection of the sample component 11 can overcome the detection error caused by sedimentation, thereby further improving the accuracy of the detection data.
[0042] like Figure 4 As shown, as an optimization of the first embodiment, the detection box 1 includes a shell 15, the shape of the shell 15 is tubular, the upper port of the shell 15 is fixed with a top cover 16 by bolts, and the top cover 16 is used to install the light receiving part 14 and the filter component 3; the lower port of the shell 15 is fixed with a bottom cover 17 by bolts, and the bottom cover 17 is used to install the support mechanism 4 and the inner tube body 12. By providing a detachable top cover 16 and bottom cover 17, disassembly and maintenance are facilitated.
[0043] like Figure 3As shown, as an optimization of the first embodiment, considering that sample detection requires multiple comparative experimental groups, if only one sample component 11 is set, multiple liquid inlet and outlet operations are required, which increases the number of cleaning times. At the same time, the detection error caused by cleaning is also increased. The number of slide slots 10 is at least 2. The number of slide slots 10 in this embodiment is 8, and the 8 slide slots 10 are arranged at equal angles. A sample component 11 is installed in each slide slot 10, and each sample component 11 can add different comparative samples. According to the number of sample components 11, the number of light-emitting parts 2 and light-receiving parts 14 is increased to 8; by setting up multiple sample components 11, data collection of multiple groups of samples can be performed at one time.
[0044] like Figure 5 and Figure 6 As shown, as an optimization of the first embodiment, the filter assembly 3 includes a rotating shaft 18, the rotating shaft 18 is rotatably connected to the top cover 16, the upper end of the rotating shaft 18 is connected to a driving part 19, the driving part 19 is a second motor 20, the second motor 20 is connected to the top cover 16, and the second motor 20 is preferably a servo motor; the lower end of the rotating shaft 18 is connected to a rotating disk 21 by bolts, and the end surface of the rotating disk 21 is provided with a plurality of through holes 22, and the number of the through holes 22 in this embodiment is 8, 8 The through holes 22 are arranged at equal angles, and the through holes 22 are used to form a light path between the light emitting part 2 and the light receiving part 14. The side wall of the turntable 21 is provided with an annular groove 23, and the annular groove 23 cuts the through hole 22 into two identical parts, and the side wall of the annular groove 23 is provided with a slot 24, and the slot 24 corresponds to the through hole 22 one by one. The slot 24 is fixed with a filter 26 by a positioning bolt 25. The eight filters 26 are respectively a red filter, a green filter, a blue filter, a near Infrared filter, 0° polarizing film, 45° polarizing film, 90° polarizing film and a blank film; or the filter 26 is a filter 26 of different wavelengths; the switching process of the filter 26: the second motor 20 drives the rotating shaft 18 to rotate, and then drives the turntable 21 to rotate, so as to realize the switching of the filter 26. When the filter 26 wheel is in a certain state, each filtering channel corresponds to the position of the 8 light receiving parts 14 respectively, and different targets are imaged with different detection channels at the same time; after the filter 26 rotates once, each target is imaged with another detection channel at the same time. When the turntable 21 rotates 7 times, that is, completes one circle of rotation, each target completes the imaging of 8 channels respectively, and each target area completes multi-spectral and polarization detection respectively; through the advantages of multi-channel filtering, simultaneous detection of different areas, and rapid rotation, after one circle of rotation, each target area completes full-color, multi-spectral and polarization detection respectively.
[0045] like Figure 7As shown, as an optimization of the first embodiment, the filter 26 includes a lens 27, and the side wall of the lens 27 is connected with a pipe hoop 28, and the height of the pipe hoop 28 is preferably flush with the height of the lens 27. The pipe hoop 28 is tightened by a connecting bolt 29, and the side wall of the pipe hoop 28 is connected with a support rod 30. The number of the support rods 30 is 2, and the two support rods 30 are distributed on both sides of the notch of the pipe hoop 28. The side walls of the support rods 30 are connected with short plates 31, and there is a movable gap between the two short plates 31. The short plates 31 are used to insert into the slots 24, and the short plates 31 are connected to the positioning bolts 25. By providing a detachable filter 26, disassembly and cleaning are facilitated.
[0046] like Figure 8 As shown, as an optimization of the first embodiment, the sample assembly 11 includes a sphere 32, the sphere 32 is adapted to the slide 10, a sample tube 33 is threadedly connected to the sphere 32, an upper port of the sample tube 33 is connected to an end cap 34, a lower side wall of the sample tube 33 is connected to a liquid tube 35, the liquid tube 35 is connected to a pipe joint 37 through a hose 36, the pipe joint 37 is arranged on the detection box 1, and the liquid to be tested is injected into or discharged from the sample tube 33 by setting the hose 36.
[0047] like Figure 9~Figure 11 As shown, as an optimization of the first embodiment, considering that the sample tube 33 needs to be cleaned after the liquid to be tested is discharged, and the cleaning effect of circulating water flushing is poor, a countersunk hole 38 is opened on the inner bottom surface of the sample tube 33, and a tension spring 39 is installed in the countersunk hole 38. The upper end of the tension spring 39 is connected to a scraper 40. The scraper 40 is conical in shape and made of rubber. When the scraper 40 is in a low position, it does not affect the inlet and outlet of the liquid feed pipe 35. The upper end of the scraper 40 is connected to a pull rope 41, which passes through the end cover 34, and the pull rope 41 passes through the end cover 34. 1 slides on the end cover 34, and the gap between the pull rope 41 and the end cover 34 serves as a ventilation channel. The pull rope 41 located outside the end cover 34 is spiral and has good elasticity. A conduit 42 is installed on the side wall of the detection box 1. The conduit 42 is slidably connected with the pull rope 41. The end of the pull rope 41 located outside the conduit 42 is connected with a handle 43. By pulling the handle 43, the scraper 40 in the sample tube 33 moves up to remove the wall liquid in the sample tube 33. When the pull rope 41 is released, the tension spring 39 automatically resets the scraper 40.
[0048] like Figures 12 to 15As shown, as an optimization of the first embodiment, considering that the upper and lower surfaces of the lens 27 will have stains for a long time and need to be cleaned regularly, the top surface of the turntable 21 is rotatably connected to a shaft 44, and the upper end of the shaft 44 is connected to a gear 45. The multiple gears 45 are driven by a gear ring 46, and a third motor 47 is connected to one of the shafts 44, and the third motor 47 is connected to the turntable 21; the side wall of the shaft 44 is connected to a cantilever 48, the number of the cantilever 48 is 2, and the two cantilevers 48 are symmetrically arranged up and down, and the gap between the cantilevers 48 is greater than the thickness of the lens 27; the end surface of the cantilever 48 is installed with equidistantly arranged protrusions 49, and the protrusion 49 is connected to a T-shaped rod 50, and the large diameter section of the T-shaped rod 50 A sponge strip 51 is slidably connected, and the sponge strip 51 is used to clean the upper and lower surfaces of the lens 27. The sponge strip 51 protrudes from the cantilever 48. The small diameter section of the T-bar 50 is sleeved with a first spring 52. The first spring 52 is elastically connected and is located between the sponge strip 51 and the protrusion 49. The bottom of the cantilever 48 is an oblique structure, and equidistantly arranged scraping strips 53 are installed on the inclined surface of the cantilever 48. The scraping strips 53 are made of rubber, and the scraping strips 53 elastically cooperate with the lens 27. The shaft 44 is driven to rotate by the third motor 47, and then the cantilever 48 is driven to start rotating. The sponge strip 51 cleans the lens 27 for the first time, and the scraping strip 53 cleans the lens 27 for the second time, thereby ensuring the clarity of the lens 27.
[0049] like Figures 16 to 20As shown, as an optimization of the first embodiment, the lower end of the pipe joint 37 is connected to a first pipe 54, the free end of the first pipe 54 is connected to a peristaltic pump 55, the inlet end of the peristaltic pump 55 is connected to a second pipe 56, the side wall of the second pipe 56 is connected to a first valve 57, and the free end of the second pipe 56 is connected to a degassing device 58; the degassing device 58 includes a barrel cover 59 provided at the waist of the second pipe 56, the barrel cover 59 is located below the first valve 57, and the barrel cover 59 is connected to a vacuum pump 61 through a third pipe 60; the bottom surface of the barrel cover 59 is connected to a material barrel 62, the bottom surface of the material barrel 62 is installed with a fourth pipe 63, the fourth pipe 63 is installed with a second valve 64, and the fourth pipe 63 is used to discharge the sample after the test; the upper side wall of the material barrel 62 is connected to a feeding pipe 65, and a plug 66 is slidably connected to the feeding pipe 65, One end of the plug 66 is connected to a second spring 67, and the free end of the second spring 67 is connected to a U-shaped seat 68, and the U-shaped seat 68 is connected to the inner wall of the barrel 62; an injection assembly 69 is installed on the side wall of the barrel 62, and the injection assembly 69 includes a carrier 70 arranged on the barrel 62, and a slide rail 71 is installed on the carrier 70, and a slider 72 is slidably connected to the slide rail 71, and a carrier plate 73 is connected to the slider 72, and a U-port 74 is provided on the carrier plate 73, and a micro-injector 75 is plugged into the U-port 74. The needle of the micro-injector 75 is used to extend into the feed pipe 65, and then push the plug 66 into the barrel 62, and one group of sliders 72 is threadedly connected to a lead screw 76, and the lead screw 76 drives the slider 72 to move; a first scale line 77 is provided on the slide rail 71, and the first scale line 77 is used to display the entry length of the micro-injector 75.
[0050] like Fig.21 As shown, as an optimization of the first embodiment, it also includes a detector control unit 78, and the detector control unit 78 includes: an LED control unit 79 and a photodiode control unit 80, the LED control unit 79 supplies the driving current to the light emitting unit 2; the photodiode control unit 80 obtains the signal from the light receiving unit 14 via the amplifier unit 81 and the A / D converter 82.
[0051] like Figures 22 to 25As shown, the second embodiment is different from the first embodiment in that, considering that the driving unit 19 is the first motor 6, the number of rotations of the motor is prone to error and deviates from the center of the lens, the driving unit 19 includes a fixed seat 83, the shape of the fixed seat 83 is a cable roller, the center of the fixed seat 83 has a light hole 84, the light hole 84 and the rotating shaft 18 are clearance-matched, the lower end of the fixed seat 83 is connected to the detection box 1, the top surface of the fixed seat 83 has a circular hole 85, the number of the circular holes 85 is at least 2; the circular hole 85 is slidably connected to a sliding post 8 6. The top of the slide post 86 is connected to a strip plate 87, and the side wall of the slide post 86 is sleeved with a third spring 88, which is elastically connected between the strip plate 87 and the fixed seat 83; the top surface of the strip plate 87 is connected to a limit column 89, the cross-section of the limit column 89 is T-shaped, and the upper end of the limit column 89 is a rounded structure, and the side of the strip plate 87 is connected to a pointer 90; the side wall of the rotating shaft 18 is fixedly connected to a dividing plate 91, and the side wall of the dividing plate 91 is provided with limit openings 92 arranged at equal angles, and the number of the limit openings 92 is 8 The limiting opening 92 is concentric with the through hole 22, and the limiting opening 92 is slidably adapted to the small diameter section of the limiting column 89; the upper side wall of the rotating shaft 18 has a guide bar 93, and a cover 94 is slidably connected to the guide bar 93, and a pressure rod 95 is threadedly connected to the side wall of the cover 94; the bottom surface of the cover 94 has a concave cavity 96, and there is a movable gap between the top surface of the concave cavity 96 and the dividing plate 91; the bottom edge of the cover 94 is against the large diameter section of the limiting column 89, and the outer side wall of the cover 94 has a second scale line 97, and the second scale line 97 cooperates with the pointer 90 In use, the second scale line 97 is used to display the position of a certain through hole 22; the top surface of the rotating shaft 18 is threadedly connected with a stop seat 98, and the stop seat 98 is used to limit the position of the cover shell 94; during the rotation process: the pressure rod 95 is pressed down, so that the cover shell 94 pushes the limit column 89 to move downward until the limit column 89 is disengaged from the dividing plate 91, and then the cover shell 94 is rotated to the next through hole 22 position, thereby realizing the switching of the filter 26. The center of the lens corresponds to the center of each optical path. There is no error in such switching, which improves the accuracy of the detection data.
[0052] Furthermore, a method for determining the glycemic index of food in vitro using the above absorbance detector is proposed, comprising the following steps: (1) accurately weighing a food sample containing 100 mg to 500 mg of carbohydrates and vortexing to simulate the oral chewing process; (2) continuously oscillating at a certain speed in a water bath constant temperature oscillator to simulate the gastrointestinal peristalsis process; (3) adjusting the pH value of the digestive juice by adding HCl and NaOH solutions of a certain concentration and volume to simulate the digestive environment of the human stomach and intestines; (4) adding one or more digestive enzymes (amylase, pepsin, The food to be tested is finally digested into glucose by pancreatic enzymes, amyloglucosidase, and the absorbance of glucose is detected. The hydrolysis digestion curve is obtained and the glycemic index (eGI value) is calculated by software integral fitting and theoretical relationship. This method is particularly suitable for the glycemic index detection of dairy products with complex ingredients in the ingredient list (such as milk powder, yogurt, ethnic dairy products, etc.). At present, there is no unified method specifically for predicting the GI value of dairy products in vitro digestion. This method also has the advantages of small dosage, simple operation, short cycle, and low cost. It can meet the needs of dairy product manufacturers for high-throughput low GI raw material screening and product development.
[0053] Although the present invention has been described in detail with reference to the aforementioned examples, it is still possible for those skilled in the art to make and modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. An absorbance detector, comprising a detection box (1), characterized in that: A light emitting portion (2) is provided on the top of the detection box (1); a filter assembly (3) is provided on the top of the detection box (1), the filter assembly (3) is located downstream of the light emitting portion (2), and the filter assembly (3) is used to select light of a desired radiation band emitted by the light emitting portion (2); a support mechanism (4) is provided on the bottom of the detection box (1), the support mechanism (4) comprises a screw rod (5), the screw rod (5) is rotatably connected to the detection box (1), and the screw rod (5) is driven by a first motor (6); a limit head (7) is provided on the upper end of the screw rod (5); a cone (8) is threadedly connected to the screw rod (5), a guide rod (9) is slidably connected to the cone (8), and the guide rod (9) is connected to the detection box ( 1) are connected at the bottom; a slide groove (10) is provided on the inclined surface of the cone (8), a sample assembly (11) is slidably connected to the slide groove (10), the sample assembly (11) is used to fill the liquid to be tested, and the sample assembly (11) is located downstream of the filter assembly (3); an inner tube body (12) is provided at the bottom of the detection box (1), a guide hole (13) is provided on the side wall of the inner tube body (12), the guide hole (13) is arranged obliquely, and the guide hole (13) is slidably matched with the sample assembly (11); a light receiving portion (14) is provided at the bottom of the detection box (1), the light receiving portion (14) is located downstream of the sample assembly (11), and the light receiving portion (14) is opposite to the light emitting portion (2).
2. An absorbance detector according to claim 1, characterized in that: The number of the chutes (10) is at least two, each chutes (10) is provided with a sample assembly (11), and each sample assembly (11) can be added with different comparison samples.
3. An absorbance detector according to claim 1, characterized in that: The filter assembly (3) comprises a rotating shaft (18), the rotating shaft (18) being rotatably connected to the top cover (16), the upper end of the rotating shaft (18) being provided with a driving portion (19); the lower end of the rotating shaft (18) being provided with a rotating disk (21), the end surface of the rotating disk (21) being provided with a plurality of through holes (22), the through holes (22) being used to form a light path between the light emitting portion (2) and the light receiving portion (14), the side wall of the rotating disk (21) being provided with an annular groove (23), the side wall of the annular groove (23) being provided with a slot (24), the slot (24) being in one-to-one correspondence with the through holes (22), and a filter (26) being fixed in the slot (24) by a positioning bolt (25).
4. An absorbance detector according to claim 3, characterized in that: The filter (26) comprises a lens (27), a side wall of the lens (27) is provided with a pipe hoop (28), the pipe hoop (28) is tightened by a connecting bolt (29), a side wall of the pipe hoop (28) is provided with a support rod (30), the number of the support rods (30) is two, and a side wall of the support rod (30) is provided with a short plate (31), the short plate (31) is connected to the positioning bolt (25).
5. An absorbance detector according to claim 1, characterized in that: The sample assembly (11) comprises a sphere (32), the sphere (32) being adapted to fit the slide groove (10), a sample tube (33) being provided on the sphere (32), an end cap (34) being provided at the upper end of the sample tube (33), a liquid feed tube (35) being provided at the lower side wall of the sample tube (33), the liquid feed tube (35) being connected to a pipe joint (37) via a hose (36), and the pipe joint (37) being provided on the detection box (1).
6. An absorbance detector according to claim 5, characterized in that: The inner bottom surface of the sample tube (33) is provided with a countersunk hole (38), a tension spring (39) is provided in the countersunk hole (38), a scraper (40) is provided at the upper end of the tension spring (39), a pull rope (41) is provided at the upper end of the scraper (40), the pull rope (41) passes through the end cover (34), and the pull rope (41) slides on the end cover (34), a conduit (42) is provided on the side wall of the detection box (1), the conduit (42) is slidably connected to the pull rope (41), and a handle (43) is provided at the end of the pull rope (41) located outside the conduit (42).
7. An absorbance detector according to claim 3, characterized in that: The top surface of the rotating disk (21) is rotatably connected to a shaft (44), the upper end of the shaft (44) is provided with a gear (45), and the plurality of gears (45) are driven by a gear ring (46), one of the shafts (44) is provided with a third motor (47), and the third motor (47) is connected to the rotating disk (21); a cantilever (48) is provided on the side wall of the shaft (44); a convex block (49) is provided on the end surface of the cantilever (48), and a T-shaped rod (50) is provided on the convex block (49), and the large diameter of the T-shaped rod (50) is The section is slidably connected with a sponge strip (51), the sponge strip (51) is used to clean the upper and lower surfaces of the lens (27), the sponge strip (51) protrudes outside the cantilever (48), the small diameter section of the T-shaped rod (50) is sleeved with a first spring (52), the first spring (52) is elastically connected and is located between the sponge strip (51) and the protrusion (49), the bottom of the cantilever (48) is an oblique angle structure, and a scraping strip (53) is provided on the inclined surface of the cantilever (48), and the scraping strip (53) is elastically matched with the lens (27).
8. An absorbance detector according to claim 5, characterized in that: A first pipe (54) is provided at the lower end of the pipe joint (37); a peristaltic pump (55) is provided at the free end of the first pipe (54); a second pipe (56) is provided at the inlet end of the peristaltic pump (55); a first valve (57) is provided on the side wall of the second pipe (56); and a degassing device (58) is provided at the free end of the second pipe (56); the degassing device (58) comprises a barrel cover (59) provided at the waist of the second pipe (56); the barrel cover (59) is located below the first valve (57); and the barrel cover (59) is connected to a vacuum pump (60) via a third pipe (60). 61); a material barrel (62) is provided on the bottom surface of the barrel cover (59); a fourth pipe (63) is provided on the bottom surface of the material barrel (62); a second valve (64) is provided on the fourth pipe (63); a feed pipe (65) is provided on the upper side wall of the material barrel (62); a plug (66) is slidably connected to the feed pipe (65); a second spring (67) is provided at one end of the plug (66); a U-shaped seat (68) is provided at the free end of the second spring (67); the U-shaped seat (68) is connected to the inner wall of the material barrel (62); a sample injection assembly (69) is provided on the side wall of the material barrel (62).
9. An absorbance detector according to claim 1, characterized in that: The device also includes a detector control unit (78), which includes an LED control unit (79) and a photodiode control unit (80). The LED control unit (79) supplies a driving current to the light-emitting unit (2); and the photodiode control unit (80) obtains a signal from the light-receiving unit (14) via an amplifier unit (81) and an A / D converter (82).
10. A method for measuring the glycemic index of food in vitro using the absorbance detector according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: (1) accurately weighing a food sample containing 100 mg to 500 mg of carbohydrates and vortexing the sample to simulate the oral chewing process; (2) continuously oscillating the sample in a water bath constant temperature oscillator to simulate the gastrointestinal motility process; (3) adjusting the pH value of the digestive juice by adding HCl and NaOH solutions to simulate the digestive environment of the human stomach and intestines; and (4) finally digesting the food to be tested into glucose by adding one or more digestive enzymes in the digestion step, detecting the absorbance of the glucose, and obtaining a hydrolysis-digestion curve, which is then integrated and fitted by software and the glycemic index is calculated by a theoretical relationship.