CN118961599B - Absorbance detector and method for in vitro determination of food glycemic index - Google Patents

Abstract

The application relates to the technical field of absorbance detection, and discloses an absorbance detector and a method for measuring food glycemic index in vitro, comprising a detection box, wherein the top of the detection box is provided with a luminous part; the top of the detection box is provided with a light filtering component, and the light filtering component is positioned at the downstream of the light emitting part; the bottom of the detection box is provided with a supporting mechanism, the supporting mechanism is connected with a sample assembly in a sliding way, the sample assembly is used for filling liquid to be detected, and the sample assembly is positioned at the downstream of the filtering assembly; the application can acquire images at multiple positions by arranging the slidable sample assembly, the detection data is more representative, the sample assembly can obliquely detect, detection errors caused by sedimentation can be overcome, and the accuracy of the detection data is further improved.

Description

Absorbance detector and method for in vitro determination of food glycemic index

Technical Field

The invention belongs to detection equipment, relates to the technical field of absorbance detection, and particularly relates to an absorbance detector and a method for in-vitro determination of food glycemic index.

Background

The suction detector is a relatively simple measurement technique. There is only one optical path between the sample and the light source, and a filter is typically used to select the appropriate wavelength and to determine the absorbance of the sample by measuring the intensity of light transmitted or reflected from the sample. The instrument is suitable for measuring certain physical and chemical properties associated with the sample, such as measuring the concentration of the liquid, the reaction rate, and the color, among others.

The chinese patent with application number 201710057381.0 discloses a detection system for absorbance, which comprises a supporting mechanism, a light source mechanism, an imaging mechanism and a processor. The light source mechanism is used for providing light sources with required colors for the installation cavity and the reference cavity through the light inlet, the imaging mechanism is used for shooting images of the solution to be detected and the reference cavity after the light sources are irradiated through the light outlet respectively, and the processor obtains absorbance values of the solution to be detected in the installation cavity according to image information obtained by the imaging mechanism.

But test tube grafting is installed on supporting mechanism, and the position of test tube is fixed, and the light path can only carry out image acquisition at fixed printing opacity part, and detection data is comparatively limited, and detection data's precision is lower.

Disclosure of Invention

The invention aims to provide an absorbance detector and a method for measuring the glycemic index of food in vitro, which solve the problems that the conventional test tube proposed in the background art is fixed in position, an optical path can only acquire images at a fixed light transmission part, and detection data is limited.

The absorbance detector comprises a detection box, wherein a light emitting part is arranged at the top of the detection box, a filtering component is arranged at the top of the detection box and positioned at the downstream of the light emitting part, the filtering component is used for selecting light of a required radiation wave band emitted by the light emitting part, a supporting mechanism is arranged at the bottom of the detection box and comprises a screw rod which is rotationally connected with the detection box and is driven by a first motor, a limit head is arranged at the upper end of the screw rod, a cone is connected onto the screw rod in a threaded manner, a guide rod is connected onto the cone in a sliding manner and is connected with the bottom of the detection box, a chute is formed in the inclined surface of the cone, a sample component is connected onto the chute in a sliding manner and is used for filling liquid to be detected, the sample component is positioned at the downstream of the filtering component, an inner pipe body is arranged at the bottom of the detection box, a guide hole is formed in the side wall of the inner pipe body and is obliquely arranged, the guide hole is in sliding fit with the sample component, a light receiving part is arranged at the bottom of the detection box, the light receiving part is positioned at the downstream of the sample component, and the light receiving part is opposite to the light emitting part.

The detection box comprises a shell, wherein the upper port of the shell is provided with a top cover, and the lower port of the shell is provided with a bottom cover.

The driving part comprises a fixing seat, wherein the center of the fixing seat is provided with a light hole, the light hole is in clearance fit with a rotating shaft, the lower end of the fixing seat is connected with a detection box, the top surface of the fixing seat is provided with round holes, the number of the round holes is at least 2, a sliding column is connected to the round holes in a sliding mode, a slat is arranged at the top of the sliding column, a third spring is sleeved on the side wall of the sliding column and is arranged between the slat and the fixing seat in an elastic connection mode, the top surface of the slat is provided with a limit column, the cross section of the limit column is T-shaped, the side edge of the slat is provided with a pointer, the side wall of the rotating shaft is provided with an index plate, the side wall of the index plate is provided with a plurality of limit ports, the limit ports are concentric with the through holes, the limit ports are in sliding fit with the small-diameter section of the limit column, the upper side wall of the rotating shaft is provided with a conducting bar, the conducting bar is connected with a housing in a sliding mode, the side wall of the housing is provided with a compression bar, the bottom surface of the housing is provided with a concave cavity, the bottom surface of the housing is propped against the large-diameter section of the limit column, the outer side wall of the housing is provided with a second scale mark, the second scale mark is matched with the pointer for use, and the top surface of the rotating shaft is provided with a baffle.

A method for in-vitro determination of food glycemic index by using the absorbance detector comprises the following steps of (1) accurately weighing food samples containing 100-500 mg of carbohydrate, simulating an oral chewing process by vortex, 2) continuously oscillating in a water bath constant temperature oscillator to simulate a gastrointestinal peristalsis process, (3) adjusting the pH value of digestive juice by adding HCl and NaOH solution to simulate the digestive environment of human stomach and intestinal tracts, and (4) finally digesting the food to be detected into glucose by adding one or more digestive enzymes in the digestion step, detecting the absorbance of the glucose, and calculating the glycemic index (eGI values) by software integral fitting and theoretical relation of a hydrolysis digestion curve.

The application has the beneficial effects that by arranging the sample assembly capable of sliding, the optical path can acquire images at multiple positions, the detection data is more representative, and the sample assembly is obliquely detected, so that the detection error caused by sedimentation can be overcome, and the accuracy of the detection data is further improved.

Drawings

Fig. 1 is a schematic view of a front view in cross section.

Fig. 2 is a schematic perspective view of a cone.

Fig. 3 is a schematic top view of a cone.

Fig. 4 is a schematic diagram of the front view structure of the inspection box.

Fig. 5 is a schematic perspective view of a filter assembly.

Fig. 6 is a schematic view of a sectional front view of the turntable.

Fig. 7 is a schematic perspective view of a filter.

Fig. 8 is a schematic view of a front cross-sectional structure of a sample assembly.

Fig. 9 is a schematic view of a sectional front view of a pull cord.

Fig. 10 is a schematic diagram of a front view of a pull cord.

Fig. 11 is a schematic view of a front sectional structure of the wiper blade.

Fig. 12 is a schematic perspective view of the ring gear.

Fig. 13 is a schematic perspective view of a cantilever.

Fig. 14 is a schematic diagram of the front view configuration of the cantilever rotated 90 ° on the lens.

Fig. 15 is a schematic view of a cross-sectional front view of a sponge strip.

FIG. 16 is a schematic diagram showing the front view of peristaltic pump and degasser.

FIG. 17 is a schematic view showing a schematic cross-sectional front view of a deaerator.

Fig. 18 is a schematic view of a front view cross-sectional structure of the plug.

Fig. 19 is a schematic view of a front view cross-section of the sample injection assembly.

Fig. 20 is a schematic diagram of an exploded view of a sample assembly.

Fig. 21 is a schematic flow chart of the LED control section and the photodiode control section.

Fig. 22 is a schematic front view of the fixing base.

Fig. 23 is a schematic sectional front view of the casing.

Fig. 24 is a schematic perspective view of the index plate.

Fig. 25 is a schematic sectional front view showing the release of the stopper post after the housing has been moved down.

In the figure, 1, a detection box; 2, a light-emitting part; 3, a light filtering component; 4, support mechanism, 5, screw, 6, first motor, 7, limit head, 8, cone, 9, guide rod, 10, slide, 11, sample assembly, 12, inner tube, 13, guide, 14, light receiving portion, 15, housing, 16, top, 17, bottom, 18, spindle, 19, drive, 20, second motor, 21, turntable, 22, through-hole, 23, ring groove, 24, slot, 25, positioning bolt, 26, filter, 27, lens, 28, ferrule, 29, connecting bolt, 30, strut, 31, short plate, 32, sphere, 33, sample tube, 34, end cap, 35, feed tube, 36, hose, 37, tube, 38, counterbore, 39, tension spring, 40, wiper, 41, pull cord, 42, catheter, 43, handle, 44, shaft, 45, gear, 46, ring gear, 47, third motor, 48, cantilever, 49, bump, 50, T-shaped rod, 51, sponge strip, 52, first spring, 53, scraper strip, 54, first conduit, 55, valve, 62, valve, 68, valve, 60, valve, plug, valve, 60, valve, plug, valve, plug, 46, valve plug, valve, 46, valve plug, valve, 46, valve plug, 46, valve plug, 46, and valve plug, 46, and valve pins, 46, and valve, 46, and a ring, 46, and a 18, 46, 18, the device comprises a slat, 88, a third spring, 89, a limit post, 90, a pointer, 91, an index plate, 92, a limit opening, 93, a conducting bar, 94, a housing, 95, a compression bar, 96, a concave cavity, 97, a second scale mark, 98 and a baffle seat.

Detailed Description

Embodiments of the present invention will now be described in detail, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements throughout or elements having like or similar functions, and the embodiments described below by referring to the drawings are exemplary only for the purpose of explaining the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," "third," "fourth" and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated.

In the description of the present invention, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example, and that the specific meaning of the terms in the present invention will be understood to those skilled in the art in specific cases.

As shown in fig. 1 to 3, in a first embodiment, an absorbance detector includes a detection box 1, a light emitting portion 2 is installed at the top of the detection box 1, the light emitting portion 2 is preferably an LED lamp, and a light source emitted by the light emitting portion is white light, so that light with wavelengths required by different solutions to be detected can be absorbed conveniently; a filter component 3 is arranged at the top of the detection box 1, the filter component 3 is positioned at the downstream of the light-emitting part 2, and the filter component 3 is used for selecting light of a required radiation wave band emitted by the light-emitting part 2; the bottom of the detection box 1 is provided with a supporting mechanism 4, the supporting mechanism 4 comprises a screw 5, the screw 5 is rotationally connected with the detection box 1, the screw 5 is vertically upwards arranged, the screw 5 is driven by a first motor 6, the first motor 6 is connected with the detection box 1, and the preferred first motor 6 is a servo motor; the upper end of the screw 5 is in threaded connection with a limit head 7, the limit head 7 is used for limiting the ascending position of a cone 8, the screw 5 is in threaded connection with the cone 8, the shape of the cone 8 is preferably a round rotating member, the cone 8 is in sliding connection with guide rods 9, the number of the guide rods 9 is at least 2, the guide rods 9 are connected with the bottom of the detection box 1, the guide rods 9 are used for guiding the cone 8 to move up and down, a chute 10 is formed on the inclined surface of the cone 8, the chute 10 is inclined upwards (seen from left to right), the shape of the chute 10 is preferably arc-shaped, a sample assembly 11 is in sliding connection with the chute 10, the sample assembly 11 is used for filling liquid to be detected, the sample assembly 11 is positioned at the downstream of the filtering assembly 3, an inner tube 12 is arranged at the bottom of the detection box 1, the inner tube 12 is in a round tube shape, the side wall of the inner tube 12 is provided with guide holes 13, the guide holes 13 are in inclined arrangement, the guide holes 13 are in sliding fit with the sample assembly 11, the application discloses a sample assembly 11, which comprises a sample assembly 11, a light receiving part 14, a sample assembly 11 adjusting process, a light path and a light receiving part, wherein the light receiving part 14 is arranged at the bottom of the detection box 1 (seen from left to right), the light receiving part 14 is preferably a light receiving photodiode, the light receiving part 14 is positioned at the downstream of the sample assembly 11, the light receiving part 14 is opposite to the light emitting part 2, the sample assembly 11 is driven by a first motor 6 to rotate, the cone 8 moves upwards or downwards under the guiding action of a guide rod 9, and then the sample assembly 11 is pushed to slide in a guide hole 13, different heights can generate different measuring results, the light path can acquire images at multiple positions by arranging the sample assembly 11 which can slide, the detection data is more representative, the detection error caused by sedimentation can be overcome, and the accuracy of the detection data can be further improved.

As shown in fig. 4, as an optimization of the first embodiment, the detection box 1 includes a casing 15, the casing 15 is tubular, a top cover 16 is fixed on an upper port of the casing 15 through bolts, the top cover 16 is used for installing the light receiving part 14 and the light filtering component 3, a bottom cover 17 is fixed on a lower port of the casing 15 through bolts, the bottom cover 17 is used for installing the supporting mechanism 4 and the inner pipe body 12, and the detachable top cover 16 and the detachable bottom cover 17 are arranged, so that disassembly, assembly and maintenance are facilitated.

As shown in fig. 3, as an optimization of the first embodiment, considering that a plurality of comparison experiment sets are needed for sample detection, if only 1 sample assembly 11 is provided, a plurality of liquid feeding and discharging operations are needed, the number of cleaning times is increased, meanwhile, the detection error caused by cleaning is also increased, the number of sliding grooves 10 is at least 2, the number of sliding grooves 10 is 8 in the embodiment, the 8 sliding grooves 10 are arranged at equal angles, one sample assembly 11 is arranged in each sliding groove 10, each sample assembly 11 can be added with different comparison samples according to the number of sample assemblies 11, so that the number of light emitting parts 2 and light receiving parts 14 is increased to 8, and the data acquisition of a plurality of groups of samples can be performed at one time by arranging a plurality of sample assemblies 11.

As shown in fig. 5 and 6, as an optimization of the first embodiment, the optical filter assembly 3 includes a rotating shaft 18, the rotating shaft 18 is rotatably connected with the top cover 16, a driving part 19 is connected to the upper end of the rotating shaft 18, the driving part 19 is a second motor 20, the second motor 20 is connected with the top cover 16, and the preferred second motor 20 is a servo motor; the lower end of the rotating shaft 18 is connected with a rotating disc 21 through bolts, a plurality of through holes 22 are formed in the end face of the rotating disc 21, the number of the through holes 22 is 8, the 8 through holes 22 are arranged at equal angles, the through holes 22 are used for forming a light path between the light emitting part 2 and the light receiving part 14, annular grooves 23 are formed in the side walls of the rotating disc 21, the annular grooves 23 cut the through holes 22 into two parts which are the same up and down, slots 24 are formed in the side walls of the annular grooves 23, the slots 24 are in one-to-one correspondence with the through holes 22, optical filters 26 are respectively fixed in the slots 24 through positioning bolts 25, and the 8 optical filters 26 are respectively a red optical filter, a green optical filter, a blue optical filter, a near infrared optical filter, a 0-degree polarizing plate, a 45-degree polarizing plate, a 90-degree polarizing plate and an empty plate; or the optical filter 26 is an optical filter 26 with different wavelengths, the optical filter 26 is switched, the second motor 20 drives the rotating shaft 18 to rotate so as to drive the rotary table 21 to rotate, thus realizing the switching of the optical filter 26, when the optical filter 26 works in a certain state, each optical filtering channel corresponds to the positions of 8 light receiving parts 14 one by one respectively, different targets are imaged by different detection channels at the same time, after the optical filter 26 rotates once, each target is imaged by another detection channel at the same time respectively, when the rotary table 21 rotates 7 times, namely, after completing one rotation, each target completes the imaging of 8 channels respectively, each target region completes multispectral and polarization detection respectively, and through multichannel optical filtering, the detection of different regions can be simultaneously and respectively carried out, and the device has the advantage of fast rotation, and after one rotation, each target area respectively completes full color, multispectral and polarization detection.

As shown in fig. 7, as an optimization of the first embodiment, the optical filter 26 includes a lens 27, a pipe hoop 28 is connected to a side wall of the lens 27, preferably, the height of the pipe hoop 28 is flush with the height of the lens 27, the pipe hoop 28 is screwed down by a connecting bolt 29, the side wall of the pipe hoop 28 is connected with a number of struts 30, 2 struts 30 are distributed on two sides of a notch of the pipe hoop 28, a movable gap is formed between two short plates 31,2 connected to the side wall of the struts 30, the short plates 31 are used for being inserted into the slots 24, the short plates 31 are connected with the positioning bolts 25, and the detachable optical filter 26 is convenient to detach and clean.

As shown in fig. 8, as an optimization of the first embodiment, the sample assembly 11 includes a sphere 32, the sphere 32 is adapted to the chute 10, a sample tube 33 is screwed on the sphere 32, an end cap 34 is connected to an upper port of the sample tube 33, a liquid tube 35 is connected to a lower side wall of the sample tube 33, the liquid tube 35 is connected to a pipe joint 37 through a hose 36, the pipe joint 37 is provided on the detection box 1, and a liquid to be detected is injected into or discharged from the sample tube 33 through the hose 36.

As shown in fig. 9 to 11, 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, the cleaning effect of circulating water flushing is poor, a counter bore 38 is formed in the inner bottom surface of the sample tube 33, a tension spring 39 is installed in the counter bore 38, the upper end of the tension spring 39 is connected with a scraping blade 40, the scraping blade 40 is conical, the scraping blade 40 is made of rubber, the liquid inlet and outlet of the liquid tube 35 is not affected when the scraping blade 40 is in a low position, the upper end of the scraping blade 40 is connected with a pull rope 41, the pull rope 41 penetrates out of the end cover 34, the pull rope 41 slides on the end cover 34, meanwhile, a gap between the pull rope 41 and the end cover 34 serves as a ventilation channel, the pull rope 41 positioned outside the end cover 34 is spiral, the tension spring has good retractility, a conduit 42 is installed on the side wall of the detection box 1, the conduit 42 is slidingly connected with the pull rope 41 positioned outside the conduit 42, the handle 43 is connected with the end of the pull rope 41, the scraping blade 40 in the sample tube 33 is enabled to move upwards by pulling the handle 43, the hanging wall liquid in the sample tube 33 is enabled to be reset by loosening the pull rope 41 and 39.

As shown in fig. 12 to 15, as an optimization of the first embodiment, considering that stains exist on the upper surface and the lower surface of the lens 27 for a long time and timing cleaning is required, the top surface of the turntable 21 is rotationally connected with a shaft lever 44, the upper end of the shaft lever 44 is connected with a gear 45, a plurality of gears 45 are driven by a gear ring 46, one shaft lever 44 is connected with a third motor 47, and the third motor 47 is connected with the turntable 21; the side wall of the shaft lever 44 is connected with cantilever 48, the number of the cantilever 48 is 2, 2 cantilevers 48 are vertically symmetrically arranged, gaps between the cantilevers 48 are larger than the thickness of the lens 27, bumps 49 are arranged on the end face of the cantilever 48 at equal intervals, T-shaped rods 50 are connected to the bumps 49, large-diameter sections of the T-shaped rods 50 are slidably connected with sponge strips 51, the sponge strips 51 are used for cleaning the upper surface and the lower surface of the lens 27, the sponge strips 51 protrude out of the cantilever 48, small-diameter sections of the T-shaped rods 50 are sleeved with first springs 52, the first springs 52 are located between the sponge strips 51 and the bumps 49 in an elastic connection mode, the bottom of the cantilever 48 is of an oblique angle structure, scraping strips 53 are arranged on the inclined surfaces of the cantilever 48 at equal intervals, the scraping strips 53 are made of rubber, the scraping strips 53 are elastically matched with the lens 27, the shaft lever 44 is driven to rotate through a third motor 47, the sponge strips 51 start to clean the lens 27 for the second time, and the definition of the lens 27 is guaranteed.

As shown in fig. 16 to 20, as an optimization of the first embodiment, the lower end of the pipe joint 37 is connected with a first pipe 54, the free end of the first pipe 54 is connected with a peristaltic pump 55, the inlet end of the peristaltic pump 55 is connected with a second pipe 56, the side wall of the second pipe 56 is connected with a first valve 57, and the free end of the second pipe 56 is connected with a degassing device 58; the degasser 58 comprises a barrel cover 59 arranged at the waist of a second pipeline 56, the barrel cover 59 is positioned below a first valve 57, the barrel cover 59 is connected with a vacuum pump 61 through a third pipeline 60, the bottom surface of the barrel cover 59 is connected with a barrel 62, the bottom surface of the barrel 62 is provided with a fourth pipeline 63, the fourth pipeline 63 is provided with a second valve 64, the fourth pipeline 63 is used for discharging a detected sample, the upper side wall of the barrel 62 is connected with a feed pipe 65, the feed pipe 65 is connected with a plug 66 in a sliding manner, one end of the plug 66 is connected with a second spring 67, the free end of the second spring 67 is connected with a U-shaped seat 68, the U-shaped seat 68 is connected with the inner wall of the barrel 62, the side wall of the barrel 62 is provided with a sample injection assembly 69, the sample injection assembly 69 comprises a carrier 70 arranged on the barrel 62, the carrier 70 is provided with a slide rail 71, the slide rail 71 is connected with a slide block 72 in a sliding manner, the slide block 72 is connected with a carrier 73, the carrier 73 is provided with a U-port 74, the U-port 74 is inserted with a micro-injector 75, the micro-injector 75 is used for extending into the feed pipe 65, the slide block 66 is pushed into the slide block 62, one end of the slide block 66 is connected with a set of the slide block 66, the slide block 72 is connected with a screw 77, the first screw 72 is connected with the screw thread 77, and the first screw 72 is provided with a screw thread 77, and the first screw driver is provided with a screw 72 is used for displaying the displacement.

As shown in fig. 21, as an optimization of the embodiment, the detector control section 78 is further included, and the detector control section 78 includes an LED control section 79 and a photodiode control section 80, the LED control section 79 supplying a driving current to the light emitting section 2, and the photodiode control section 80 acquiring a signal from the light receiving section 14 via an amplifier section 81 and an a/D converter 82.

As shown in fig. 22 to 25, in the second embodiment, unlike the first embodiment, considering that the driving portion 19 is the first motor 6, errors easily occur in the rotation number of the motor, and the rotation number deviates from the center of the lens, the driving portion 19 includes a fixing seat 83, the fixing seat 83 is in a cable roll shape, a light hole 84 is formed in the center of the fixing seat 83, the light hole 84 is in clearance fit with the rotating shaft 18, the lower end of the fixing seat 83 is connected with the detection box 1, a circular hole 85 is formed in the top surface of the fixing seat 83, and the number of the circular holes 85 is at least 2; the round hole 85 is connected with a sliding column 86 in a sliding way, the top of the sliding column 86 is connected with a slat 87, the side wall of the sliding column 86 is sleeved with a third spring 88, the third spring 88 is arranged between the slat 87 and a fixed seat 83 in a sliding way, the top surface of the slat 87 is connected with a limit column 89, the section of the limit column 89 is T-shaped, the upper end of the limit column 89 is of a round corner structure, the side edge of the slat 87 is connected with a pointer 90, the side wall of the rotating shaft 18 is fixedly connected with an index plate 91, the side wall of the index plate 91 is provided with limit ports 92 which are arranged at equal angles, the number of the limit ports 92 is 8, the limit ports 92 are concentric with the through hole 22, the limit ports 92 are in sliding fit with a small diameter section of the limit column 89, the upper side wall of the rotating shaft 18 is provided with a guide bar 93, a housing 94 is connected onto the guide bar 93 in a sliding way, the side wall of the housing 94 is connected with a compression bar 95 in a threaded way, the bottom surface of the housing 94 is provided with a cavity 96, a movable clearance is arranged between the top surface of the cavity 96 and the index plate 91, the bottom edge of the housing 94 abuts against a large diameter section of the limit column 89, the housing 94 is provided with a second scale mark 97, the outer side wall of the housing 94 is provided with a second scale mark 97, the second scale mark 97 is matched with the pointer 90, the pointer is used for displaying the position of the second scale mark 97, the second scale mark 97 is matched with the pointer, the position is used for displaying the position of the compression bar 98, the position of the compression bar 98 is used for displaying the compression bar 98, which is used for the compression of the compression bar is used, the cover 94 pushes the limit post 89 to move downwards until the limit post 89 is separated from the index plate 91, and then the cover 94 is rotated to the position of the next through hole 22, so that the optical filter 26 is switched, the center of the lens corresponds to the center of each optical path, no error exists in the switching, and the accuracy of detection data is improved.

Further, a method for measuring the glycemic index of food in vitro by the absorbance detector is provided, which comprises the following steps of (1) accurately weighing the food sample containing 100-500 mg of carbohydrate, and simulating the chewing process of the oral cavity by vortex; the method is particularly suitable for detecting the glycemic index of milk products (such as milk powder, yoghourt, national special milk products and the like) with complex ingredients in a batching table, has no unified method special for predicting the GI value in vitro digestion of the milk products at present, has the advantages of small consumption, simple operation, short period, low cost and the like, and can meet the requirements of high-throughput low-GI raw material screening, product research and development and other work of milk product production enterprises.

Although the present invention has been described in detail with reference to the foregoing examples, it will be apparent to those skilled in the art that the foregoing embodiments may be modified and practiced in the field of the invention, and that certain modifications, equivalents, improvements and substitutions may be made thereto without departing from the spirit and principles of the invention.

Claims (10)

1. The absorbance detector comprises a detection box (1), and is characterized in that a light emitting part (2) is arranged at the top of the detection box (1), a light filtering component (3) is arranged at the top of the detection box (1), the light filtering component (3) is arranged at the downstream of the light emitting part (2), the light filtering component (3) is used for selecting light of a required radiation wave band emitted by the light emitting part (2), a supporting mechanism (4) is arranged at the bottom of the detection box (1), the supporting mechanism (4) comprises a screw rod (5), the screw rod (5) is rotationally connected with the detection box (1), the screw rod (5) is driven by a first motor (6), a limit head (7) is arranged at the upper end of the screw rod (5), a cone (8) is connected onto the screw rod (5) in a threaded manner, a guide rod (9) is connected with the bottom of the detection box (1) in a sliding manner, a sliding groove (10) is formed in the inclined plane of the cone (8), a sample component (11) is connected onto the sliding groove (10), an inner tube to be detected is used for filling liquid, the sample component (11) is arranged in the inner tube, the sample component (11) is arranged at the downstream of the light filtering component (3), a guide hole (12) is formed in the bottom of the detection box (1), a guide hole (12) is formed in the bottom of the detection box (12), the guide hole (13) is in sliding fit with the sample assembly (11), the bottom of the detection box (1) is provided with a light receiving part (14), the light receiving part (14) is positioned at the downstream of the sample assembly (11), and the light receiving part (14) is opposite to the light emitting part (2).

2. An absorbance detector according to claim 1 wherein the number of slide channels (10) is at least 2, each slide channel (10) having a sample assembly (11) disposed therein, each sample assembly (11) being capable of adding a different reference sample.

3. The absorbance detector of claim 1, wherein the light filtering component (3) comprises a rotating shaft (18), the rotating shaft (18) is rotationally connected with the top cover (16), a driving part (19) is arranged at the upper end of the rotating shaft (18), a rotating disc (21) is arranged at the lower end of the rotating shaft (18), a plurality of through holes (22) are formed in the end face of the rotating disc (21), the through holes (22) are used for forming light paths between the light emitting part (2) and the light receiving part (14), annular grooves (23) are formed in the side walls of the rotating disc (21), slots (24) are formed in the side walls of the annular grooves (23), the slots (24) are in one-to-one correspondence with the through holes (22), and light filters (26) are fixed in the slots (24) through positioning bolts (25).

4. An absorbance detector according to claim 3 wherein the optical filter (26) comprises a lens (27), a pipe hoop (28) is arranged on the side wall of the lens (27), the pipe hoop (28) is screwed down by a connecting bolt (29), a supporting rod (30) is arranged on the side wall of the pipe hoop (28), the number of the supporting rods (30) is 2, a short plate (31) is arranged on the side wall of the supporting rod (30), and the short plate (31) is connected with the positioning bolt (25).

5. The absorbance detector of claim 1 wherein the sample assembly (11) comprises a sphere (32), the sphere (32) is matched with the chute (10), a sample tube (33) is arranged on the sphere (32), an end cover (34) is arranged at the upper port of the sample tube (33), a feed liquid tube (35) is arranged on the lower side wall of the sample tube (33), the feed liquid tube (35) is connected with a pipe joint (37) through a hose (36), and the pipe joint (37) is arranged on the detection box (1).

6. The absorbance detector of claim 5, wherein a counter bore (38) is formed in the inner bottom surface of the sample tube (33), a tension spring (39) is arranged in the counter bore (38), a wiper blade (40) is arranged at the upper end of the tension spring (39), a pull rope (41) is arranged at the upper end of the wiper blade (40), the pull rope (41) penetrates out of the end cover (34), the pull rope (41) slides on the end cover (34), a guide pipe (42) is arranged on the side wall of the detection box (1), the guide pipe (42) is in sliding connection with the pull rope (41), and a handle (43) is arranged at the end of the pull rope (41) positioned outside the guide pipe (42).

7. The absorbance detector of claim 3, wherein the top surface of the turntable (21) is rotatably connected with a shaft lever (44), the upper end of the shaft lever (44) is provided with a gear (45), the gears (45) are driven by a gear ring (46), one shaft lever (44) is provided with a third motor (47), the third motor (47) is connected with the turntable (21), the side wall of the shaft lever (44) is provided with a cantilever (48), the end surface of the cantilever (48) is provided with a bump (49), the bump (49) is provided with a T-shaped rod (50), the large diameter section of the T-shaped rod (50) is slidably connected with a sponge strip (51), the sponge strip (51) is used for cleaning the upper surface and the lower surface of the lens (27), the sponge strip (51) protrudes out of 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 arranged between the sponge strip (51) and the bump (49) in an elastic connection mode, the bottom of the cantilever (48) is of an oblique angle structure, the cantilever (48) is provided with a scraping strip (53), and the scraping strip (53) is elastically matched with the lens (27).

8. The absorbance detector according to claim 5, wherein the lower end of the pipe joint (37) is provided with a first pipeline (54), the free end of the first pipeline (54) is provided with a peristaltic pump (55), the inlet end of the peristaltic pump (55) is provided with a second pipeline (56), the side wall of the second pipeline (56) is provided with a first valve (57), the free end of the second pipeline (56) is provided with a degassing device (58), the degassing device (58) comprises a barrel cover (59) arranged at the waist of the second pipeline (56), the barrel cover (59) is positioned below the first valve (57), the barrel cover (59) is connected with a vacuum pump (61) through a third pipeline (60), the bottom surface of the barrel cover (59) is provided with a barrel (62), the bottom surface of the barrel (62) is provided with a fourth pipeline (63), the fourth pipeline (63) is provided with a second valve (64), the upper side wall of the barrel (62) is provided with a feed pipe (65), one end of the second pipeline (56) is provided with a plug (66) in a sliding connection, the free end of the second spring (67) is provided with a U-shaped plug (68), and the free end of the second spring (67) is provided with a U-shaped plug (68) is provided with a barrel assembly (68) which is connected with the side wall of the barrel (62).

9. The absorbance detector according to claim 1, further comprising a detector control unit (78), wherein the detector control unit (78) comprises 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) acquires a signal from the light receiving unit (14) via the amplifier unit (81) and the A/D converter (82).

10. A method for in vitro determination of food glycemic index by using the absorbance detector according to any one of claims 1 to 9 is characterized by comprising the following steps of (1) accurately weighing the food sample containing 100-500 mg of carbohydrate, performing vortex simulation on the food sample to simulate the chewing process of an oral cavity, (2) performing continuous oscillation in a water bath constant temperature oscillator to simulate the gastrointestinal peristalsis process, (3) adjusting the pH value of digestive juice by adding HCl and NaOH solution to simulate the digestive environment of human stomach and intestinal tracts, and (4) finally digesting the food to be detected into glucose by adding one or more digestive enzymes in the digestion step, performing absorbance detection on the glucose, and calculating the glycemic index by using software integral fitting and theoretical relation to obtain a hydrolysis digestion curve.