Component content detection method, system and device for food compound emulsifier

Abstract

The invention relates to the technical field of content detection, in particular to a component content detection method, system and device for a food compound emulsifier. The method comprises the following steps: screening overlapping peaks from a liquid chromatogram of a sample; selecting a parent ion peak according to the sharpness and the mass-to-charge ratio of the ion peak in the mass spectrum of the overlapped peak, and determining the corresponding component of the overlapped peak according to the difference between the molecular mass corresponding to the parent ion peak of the overlapped peak and the molecular mass of the component of the sample and the mass-to-charge ratio corresponding to the ion peak in the mass spectrum of the overlapped peak; determining components corresponding to the chromatographic peaks except the overlapping peaks based on the retention time; and combining the signal intensity of the chromatographic peak with the signal intensity of the ion peak of each corresponding component to obtain the content ratio of each component of the sample. According to the method, the overlapping peaks representing multiple components are qualitatively analyzed, then the sample components are quantitatively analyzed by considering the mass spectrum specificity and the chromatographic global distribution, and the accuracy and the reliability of content analysis of the components of the sample are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of content detection, and specifically relates to a method, system and device for detecting the component content of food compound emulsifiers. Background Art

[0002] Food compound emulsifiers are products made by mixing multiple emulsifier components in specific proportions. The main emulsifier components include: monoglycerides, diglycerides, fatty acid esters, phospholipids, polysorbates, sorbitan esters, etc. If the content of emulsifier components deviates from the standard, it may affect the emulsifying performance or introduce harmful substances, threatening food safety. Therefore, it is necessary to detect the content of emulsifier components that make up food compound emulsifiers to ensure the quality of food compound emulsifiers and compliance with relevant food safety standards.

[0003] Existing methods usually use high performance liquid chromatography to obtain the chromatogram of food compound emulsifiers, and calculate the content of its corresponding components in the whole sample based on the area of chromatographic peaks in the chromatogram. However, compound emulsifiers contain multiple components with similar chemical structures, and the polarity differences of these components may make it difficult to separate components with similar chemical structures on the high performance liquid chromatography column, which may cause chromatographic peak overlap in the chromatogram and reduce the accuracy of detecting the component content of food compound emulsifiers. Summary of the Invention

[0004] In order to solve the technical problem that it is difficult to separate multiple components with similar chemical structures in compound emulsifiers on the high performance liquid chromatography column, resulting in a low accuracy rate for detecting the component content of food compound emulsifiers, the purpose of the present invention is to provide a method, system and device for detecting the component content of food compound emulsifiers. The specific technical solutions adopted are as follows:

[0005] The present invention proposes a method for detecting the component content of food compound emulsifiers, and the method includes:

[0006] Obtain the chromatographic peaks in the liquid chromatogram of the compound emulsifier sample to be tested, as well as the mass spectrum and retention time of each chromatographic peak. The sample is composed of different components;

[0007] Screen overlapping peaks from the liquid chromatogram according to the symmetry, morphological smoothness and retention time of the chromatographic peaks;

[0008] According to the sharpness and mass-to-charge ratio of the ion peaks in the mass spectrum of each overlapping peak, select the parent ion peak of each overlapping peak; according to the difference between the molecular mass corresponding to the parent ion peak of each overlapping peak and the molecular masses of the components that make up the sample, and the mass-to-charge ratio corresponding to the ion peaks in the mass spectrum of the overlapping peak, select the corresponding component of each overlapping peak from the components that make up the sample; determine the components corresponding to the chromatographic peaks other than the overlapping peaks in the liquid chromatogram based on the retention time;

[0009] Based on the signal intensity of each chromatographic peak and the signal intensity of the ion peak corresponding to each component, obtain the content ratio of each component constituting the sample.

[0010] Further, the screening of overlapping peaks from the liquid chromatogram includes:

[0011] Calculate the absolute value of the difference between the time intervals from the highest point of the chromatographic peak to the two peak boundaries respectively, and record it as the symmetry;

[0012] Extract the response value sequence of all time points within each peak boundary from the highest point of the chromatographic peak, obtain the first-order difference sequence of the response value sequence, and take the sum of the number of changes in the signs of adjacent two elements in the first-order difference sequence corresponding to the two peak boundaries of the chromatographic peak as the morphological smoothness;

[0013] Obtain the retention time of the chromatographic peak and the standard retention times of all components constituting the sample, and record the minimum value among the differences between all standard retention times and the retention time of the chromatographic peak as the retention time offset;

[0014] According to the symmetry, the morphological smoothness and the retention time offset, obtain the overlapping determination index of the chromatographic peak; record the chromatographic peak with the overlapping determination index greater than the preset overlapping threshold in the liquid chromatogram as the overlapping peak.

[0015] Further, the selection of the parent ion peak of each overlapping peak includes:

[0016] Take the ratio of the peak value to the peak width of the ion peak as the sharpness, and obtain the peak intensity of the ion peak according to the mass-to-charge ratio corresponding to the ion peak and the sharpness; select the ion peak corresponding to the peak intensity greater than the preset intensity threshold from the mass spectrum of each overlapping peak as the parent ion peak of each overlapping peak.

[0017] Further, the selection of the component corresponding to each overlapping peak from the components constituting the sample includes:

[0018] For each overlapping peak, perform deconvolution processing on the parent ion peak of the overlapping peak to obtain a single-charged ion peak, and obtain the molecular mass corresponding to each single-charged ion peak, the molecular masses of all components constituting the sample, and the standard mass-to-charge ratios of the fragments;

[0019] Calculate the differences between the molecular masses corresponding to each single-charged ion peak of the overlapping peak and the molecular masses of all components constituting the sample, select the minimum difference as the target mass difference corresponding to the single-charged ion peak, and take the component corresponding to the target mass difference as the target component of the single-charged ion peak;

[0020] Based on the difference between the standard mass-to-charge ratio of the fragments of the target component of the single-charge ion peak of the overlapping peak and the mass-to-charge ratio corresponding to the ion peak in its mass spectrum, and the target mass difference, obtain the component matching degree between each single-charge ion peak of the overlapping peak and its target component; select the target component corresponding to the component matching degree greater than the preset matching threshold from the component matching degrees between all single-charge ion peaks of the overlapping peak and their target components as the corresponding component of the overlapping peak.

[0021] Further, the method for obtaining the component matching degree includes:

[0022] Calculate the difference between each standard mass-to-charge ratio of the fragments of the target component of each single-charge ion peak of the overlapping peak and the mass-to-charge ratio corresponding to the remaining ion peaks except the parent ion peak in its mass spectrum, and select the ion peak corresponding to the minimum difference as the fragment ion peak of the target component;

[0023] Take the sum of the differences corresponding to all fragment ion peaks of the target component of each single-charge ion peak of the overlapping peak as the ion difference degree between each single-charge ion peak of the overlapping peak and its target component;

[0024] Perform negative correlation and normalization processing on the product of the target mass difference and the ion difference degree to obtain the component matching degree between each single-charge ion peak of the overlapping peak and its target component.

[0025] Further, the method for obtaining the content proportion of each component constituting the sample includes:

[0026] Judge whether each chromatographic peak in the liquid chromatogram is an overlapping peak. If so, select the parent ion peak of each corresponding component from the mass spectrum of each chromatographic peak, record the parent ion peak and the fragment ion peak of each corresponding component of the chromatographic peak as the analysis ion peak, and take the ratio of the sum of the ion intensities of the analysis ion peaks of each corresponding component of the chromatographic peak to the sum of the ion intensities of all analysis ion peaks in the mass spectrum of the corresponding chromatographic peak as the overlapping proportion of each corresponding component of each chromatographic peak; take the ratio of the signal intensity of each chromatographic peak to the sum of the signal intensities of all chromatographic peaks in the liquid chromatogram as the chromatographic proportion; the product of the overlapping proportion and the chromatographic proportion is used as the content proportion of each corresponding component of each chromatographic peak;

[0027] If not, take the chromatographic proportion as the content proportion of the corresponding component of each chromatographic peak.

[0028] Further, the method for obtaining the peak intensity includes:

[0029] Calculate the difference between the mass-to-charge ratio corresponding to each ion peak in each mass spectrum and the minimum value of the mass-to-charge ratios corresponding to all ion peaks, and perform normalization processing on the product of the difference and the sharpness to obtain the peak intensity of each ion peak in each mass spectrum.

[0030] Furthermore, the remaining chromatographic peaks in the liquid chromatography diagram except for the overlapping peaks correspond to one component.

[0031] A component content detection system for food compound emulsifiers, the system comprising:

[0032] A data acquisition module for obtaining the chromatographic peaks in the liquid chromatography diagram of the compound emulsifier sample to be tested, as well as the mass spectrometry diagram and retention time of each chromatographic peak, the sample being composed of different components;

[0033] An overlapping peak screening module for screening overlapping peaks from the liquid chromatography diagram according to the symmetry, morphological smoothness and retention time of the chromatographic peaks;

[0034] A qualitative analysis module for selecting the parent ion peak of each overlapping peak according to the sharpness and mass-to-charge ratio of the ion peaks in the mass spectrometry diagram of each overlapping peak; selecting the corresponding component of each overlapping peak from the components composing the sample according to the difference between the molecular mass corresponding to the parent ion peak of each overlapping peak and the molecular masses of the components composing the sample, as well as the mass-to-charge ratio corresponding to the ion peaks in the mass spectrometry diagram of the overlapping peak; determining the components corresponding to the chromatographic peaks in the liquid chromatography diagram except for the overlapping peaks based on the retention time;

[0035] A quantitative analysis module for obtaining the content ratio of each component composing the sample according to the signal intensity of each chromatographic peak and the signal intensity of the ion peaks corresponding to each component.

[0036] A component content detection device for food compound emulsifiers, the device comprising a processor, and when the processor executes, the steps of a component content detection method for food compound emulsifiers as described above are realized.

[0037] The present invention has the following beneficial effects:

[0038] In the embodiments of the present invention, the sample may have overlapping chromatographic peaks in the liquid chromatography due to the presence of components with similar chemical structures, which affects the qualitative and quantitative analysis of the sample. It is necessary to screen out the overlapping peaks representing multiple components from the liquid chromatography. The parent ion is the direct evidence of the molecular weight and elemental composition, and the ions other than the parent ion provide structural details. The two together provide the structural information of the components. By combining the molecular mass of the parent ion peak with the mass-to-charge ratio of the remaining ion peaks, a multi-dimensional structural fingerprint is formed to uniquely identify the components, select the components corresponding to the overlapping peaks, improve the accuracy of selecting the components corresponding to the overlapping peaks, and provide technical support for the accurate analysis of the compound emulsifier. Directly identify the components corresponding to the chromatographic peaks other than the overlapping peaks according to the retention time. This solution combines the signal intensity of the chromatographic peaks and the ion intensity distribution of the mass spectrometry, considers the mass spectrometry specificity and the global chromatographic distribution, analyzes the content ratio of each component in the sample of the compound emulsifier to be measured, makes the quantitative analysis closer to the true value, and significantly improves the accuracy and reliability of the content analysis of each component of the compound emulsifier sample with similar chemical structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0040] Figure 1 It is a flowchart of the steps of a method for detecting the component content of a compound emulsifier for food provided by an embodiment of the present invention;

[0041] Figure 2 It is a flowchart of a method for obtaining the components corresponding to the overlapping peaks provided by an embodiment of the present invention;

[0042] Figure 3 It is a system structure diagram of a system for detecting the component content of a compound emulsifier for food provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, describe in detail the specific embodiments, structures, features and effects of a method, system and device for detecting the component content of a compound emulsifier for food proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs.

[0045] The following specifically describes the specific solutions of a method, system, and device for detecting the component content of a food compound emulsifier provided by the present invention in conjunction with the accompanying drawings.

[0046] Example 1:

[0047] The present invention provides a method for detecting the component content of a food compound emulsifier. Please refer to Figure 1 , which shows a flowchart of the steps of a method for detecting the component content of a food compound emulsifier provided by an embodiment of the present invention. The method includes:

[0048] Step S1: Obtain the chromatographic peaks in the liquid chromatogram of the compound emulsifier sample to be tested, as well as the mass spectrum and retention time of each chromatographic peak. The sample is composed of different components.

[0049] The compound emulsifier to be tested is a product made by mixing multiple emulsifier components. Inject the compound emulsifier sample to be tested into a high-performance liquid chromatography-mass spectrometry (HPLC-MS) system. After separation by the chromatographic column, each component flows out of the chromatographic column in sequence according to the retention time. Detectors such as ultraviolet detectors and diode array detectors monitor the chromatographic effluent in real time to generate a liquid chromatogram. Each chromatographic peak represents one or more components. Then, the components separated by chromatography are directly introduced into the ion source of the mass spectrometer. The components are ionized to form charged ions, and the ions are separated according to the mass-to-charge ratio by a mass analyzer such as a quadrupole. The detector records the ion signal to generate the mass spectrum corresponding to each chromatographic peak in the liquid chromatogram.

[0050] It should be noted that each chromatographic peak corresponds to a mass spectrum, which contains the molecular ion peak and fragment ion peak of the component corresponding to the chromatographic peak. The horizontal and vertical axes of the liquid chromatogram represent the retention time and the detector response value at the characteristic retention time in sequence. The horizontal and vertical axes of the mass spectrum represent the mass-to-charge ratio of the ions and the ion abundance at a specific mass-to-charge ratio in sequence. The HPLC-MS system can directly obtain the retention time of each chromatographic peak in the liquid chromatogram. The ion peaks in the mass spectrum are extracted by mass spectrometry data processing software such as MassHunter and Xcalibur.

[0051] Step S2: Screen for overlapping peaks from the liquid chromatogram according to the symmetry, morphological smoothness, and retention time of the chromatographic peaks.

[0052] In a chromatogram, normally each peak represents a component. However, due to the similar characteristics of multiple components, the overlapping peaks resulting from the superposition of corresponding peak signals represent multiple components. The overlapping peaks will cause errors in the detection of the content of each component in the sample. Therefore, it is necessary to screen the overlapping peaks from the liquid chromatogram. A normal chromatographic peak representing a single component usually has a clear symmetric shape and a relatively smooth line; the overlapping peaks representing multiple components will have the peak signals superposed on each other due to the too small difference in retention times of multiple components. The peak of the high-concentration component may mask the signal of the low-concentration component, resulting in the offset of the peak apex or the bifurcation of the peak shape, so that the overlapping peaks show asymmetry and a lower degree of line smoothness. At the same time, since different chromatographic peaks correspond to different components in the sample, each chromatographic peak corresponds to a retention time, but the overlapping peaks representing multiple components will cause the retention time to shift. For example, the overlapping peak representing lecithin and monoglyceride will expand the original retention time. Therefore, by combining the symmetry of the chromatographic peak, the shape smoothness and the retention time, the overlapping peaks representing multiple components can be screened from the chromatographic peaks according to the morphological characteristics of the chromatographic peak and the shift of the retention time.

[0053] Step S3: According to the sharpness and mass-to-charge ratio of the ion peaks in the mass spectrum of each overlapping peak, select the parent ion peak of each overlapping peak; according to the difference between the molecular weight corresponding to the parent ion peak of each overlapping peak and the molecular weights of the components constituting the sample, and the mass-to-charge ratio corresponding to the ion peaks in the mass spectrum of the overlapping peak, select the corresponding components of each overlapping peak from the components constituting the sample.

[0054] The core principle of mass spectrometry is to ionize sample molecules into ions, separate and identify the ions according to the mass-to-charge ratio. Different components have differences in ion composition and mass-to-charge ratio. In this step, qualitative analysis of the corresponding components of the overlapping peaks is carried out based on the mass spectrometry information of the overlapping peaks. The mass spectrum of the overlapping peak representing multiple components is the superposition of the ion signals of these co-flow components. The ions come from the contributions of these components, but it is not clear which components these ions constitute, that is, which components the overlapping peaks correspond to. Generally, the molecules constituting a certain component are mainly divided into parent ions and characteristic fragment ions. The parent ion is the direct evidence of the molecular weight and elemental composition. The characteristic fragment ions provide structural details, and the two correspond to different mass-to-charge ratios. The two together provide the structural information of the component. Therefore, the combination of the mass-to-charge ratios of the parent ion and the characteristic fragment ions is sufficient to uniquely determine each emulsifier component constituting the sample of the compound emulsifier to be measured.

[0055] In the mass spectrum of the overlapping peak, the parent ions and characteristic fragment ions of different components are arranged in a mixed manner. The parent ion peak generally has a sharp peak shape. The characteristic fragment ions represent a part of the molecule or some groups, making the sharpness of the corresponding peaks weaker. At the same time, the parent ion represents the charged state peak when the whole molecule has not undergone cleavage, so that the mass-to-charge ratio of the parent ion is larger than that of the characteristic fragment ions. The parent ion peak in the mass spectrum of the overlapping peak can be selected according to the sharpness and mass-to-charge ratio of the ion peaks.

[0056] The mass-to-charge ratio of the precursor ion corresponding to different components is unique. However, for components with similar structures, such as the precursor ions or characteristic fragment ions of fatty acid esters with different chain lengths, their mass-to-charge ratios are relatively close and difficult to distinguish. By directly comparing the difference between the molecular mass corresponding to the precursor ion peak of the overlapping peak and the theoretical molecular mass of the known emulsifier component, high-precision matching is used to determine the component corresponding to the overlapping peak. However, relying on the precursor ion peak may lead to misjudgment of isomers or homologues, resulting in the inability to determine the uniquely corresponding component based on the characteristics of the precursor ion peak. Therefore, it is necessary to combine the fragment ion information, that is, the mass-to-charge ratio corresponding to the ion peak in the mass spectrum of the overlapping peak, for verification. By combining the molecular mass of the precursor ion peak with the mass-to-charge ratio of the ion peak, that is, the characteristic fragment ion, a multi-dimensional structural fingerprint is formed to uniquely identify the component, improving the accuracy of selecting the component corresponding to the overlapping peak and providing technical support for the precise analysis of compound emulsifiers.

[0057] The remaining chromatographic peaks in the liquid chromatography diagram except for the overlapping peaks represent one component, and its corresponding component can be directly identified according to the retention time. In one implementation of the embodiment of the present invention, the standard retention time of each component of the sample is obtained, and the absolute value of the difference between the retention time of each of the remaining chromatographic peaks in the liquid chromatography diagram and the standard retention time of all components is calculated. The component corresponding to the minimum absolute value of the difference is used as the component corresponding to each of the remaining chromatographic peaks. Among them, for the analysis of a single emulsifier component by high performance liquid chromatography-mass spectrometry, its retention time is directly obtained and recorded as the standard retention time of the corresponding component.

[0058] Step S4: Obtain the content ratio of each component constituting the sample according to the signal intensity of each chromatographic peak and the signal intensity of the ion peak corresponding to each component.

[0059] The above steps complete the qualitative analysis of the chromatographic peaks in the liquid chromatography diagram. This step needs to complete the quantitative analysis of the components corresponding to the chromatographic peaks. The overlapping peak area representing multiple components cannot distinguish the contributions of each component, which is likely to lead to quantitative deviation; in the case where the mass spectrometry response factor of a certain component is low, using only mass spectrometry data may underestimate its content; this solution combines the signal intensity of the chromatographic peak and the mass spectrometry ion intensity distribution, that is, the signal intensity of the ion peak corresponding to each component of the chromatographic peak, to analyze the content ratio of each component in the sample of the compound emulsifier to be measured. Considering both the mass spectrometry specificity and the global chromatographic distribution, the quantitative analysis is closer to the true value, significantly improving the accuracy and reliability of the content analysis of each component in the sample of compound emulsifiers with similar chemical structures.

[0060] Preferably, in some possible implementation manners of the embodiments of the present invention, the method for screening overlapping peaks includes: calculating the absolute value of the difference between the time intervals from the highest point of the chromatographic peak to the two peak boundaries, which is denoted as the symmetry degree; extracting the response value sequence of all time points within each peak boundary from the highest point of the chromatographic peak, obtaining the first-order difference sequence of the response value sequence, and taking the sum of the change times of the signs of adjacent two elements in the first-order difference sequence corresponding to the two peak boundaries of the chromatographic peak as the morphological smoothness; obtaining the retention time of the chromatographic peak and the standard retention times of all components constituting the sample, and taking the minimum value among the differences between all standard retention times and the retention time of the chromatographic peak as the retention time deviation degree; obtaining the overlapping determination index of the chromatographic peak according to the symmetry degree, the morphological smoothness, and the retention time deviation degree; and recording the chromatographic peaks in the liquid chromatogram with the overlapping determination index greater than the preset overlapping threshold as overlapping peaks.

[0061] It should be noted that in this embodiment, the symmetry of the chromatographic peak is measured by the time difference between the peak point of the chromatographic peak and the left and right endpoints. The smaller the symmetry degree, the more obvious the symmetry characteristics of the chromatographic peak, and the smaller the possibility of being an overlapping peak. For a chromatographic peak with a relatively smooth shape, the response values at the time points within the peak point to the left and right endpoints show an increasing or decreasing trend. The signs of the elements in the first-order difference sequence of the response value sequence should be the same, that is, the smaller the change times of the signs of adjacent two elements in the first-order difference sequence, the more obvious the monotonic trend of the response value sequence. Then, the smaller the morphological smoothness, the smoother the line of the chromatographic peak, and the smaller the possibility of being an overlapping peak. The standard retention time corresponding to the component with the smallest difference from the retention time of each chromatographic peak may be the main component corresponding to the chromatographic peak. The greater the difference between the two, the greater the deviation of the retention time of each chromatographic peak from the retention time of the corresponding main component, and the greater the retention time deviation degree, the greater the possibility that the chromatographic peak is an overlapping peak generated by the superposition of peak signals. Therefore, the symmetry degree, the morphological smoothness, and the retention time deviation degree are all positively correlated with the overlapping determination index. In the embodiments of the present invention, the product of the symmetry degree, the morphological smoothness, and the retention time deviation degree of each chromatographic peak is normalized to obtain the overlapping judgment index corresponding to the chromatographic peak. The greater the overlapping judgment index of the chromatographic peak, the greater the possibility of being an overlapping peak representing multiple components.

[0062] It should be noted that in the embodiments of the present invention, the Norm function is used for normalization processing. Other normalization methods can also be selected, such as function transformation, maximum-minimum normalization, etc. The normalization method is not limited herein.

[0063] In one implementation manner of the embodiments of the present invention, the preset overlapping threshold is set to 0.85.

[0064] Preferably, in some possible implementation manners of the embodiments of the present invention, the method for screening the parent ion peak includes: taking the ratio of the peak value of the ion peak to the peak width as the sharpness, and obtaining the peak intensity of the ion peak according to the mass-to-charge ratio corresponding to the ion peak and the sharpness; selecting the ion peak corresponding to the peak intensity greater than the preset intensity threshold from the mass spectrum of each overlapping peak as the parent ion peak of each overlapping peak. It should be noted that since the more significant the sharpness and the larger the mass-to-charge ratio indicate the higher the intensity of the ion peak, and the greater the possibility that it is the parent ion peak of the overlapping peak, the above difference and sharpness are both positively correlated with the peak intensity. In the embodiments of the present invention, calculate the difference between the mass-to-charge ratio corresponding to each ion peak in each mass spectrum and the minimum value of the mass-to-charge ratios corresponding to all ion peaks, and perform normalization processing on the product of the difference and the sharpness to obtain the peak intensity of each ion peak in each mass spectrum. Among them, maximum-minimum normalization is used for normalization processing, and other normalization methods can also be selected, such as function transformation, Norm function and other normalization methods, which are not limited herein.

[0065] In an implementation manner of the embodiments of the present invention, the preset intensity threshold is set to 0.9.

[0066] Preferably, in some possible implementation manners of the embodiments of the present invention, for the method for obtaining the components corresponding to the overlapping peaks, please refer to Figure 2 , which shows a flowchart of a method for obtaining the components corresponding to the overlapping peaks provided by an embodiment of the present invention. The method includes:

[0067] Step S310: For each overlapping peak, perform deconvolution processing on the parent ion peak of the overlapping peak to obtain a single-charge ion peak, and obtain the molecular mass corresponding to each single-charge ion peak, the molecular mass of each component constituting the sample, and the standard mass-to-charge ratio of the fragment.

[0068] Since the parent ion is the direct evidence of the molecular weight and elemental composition, and the mass-to-charge ratio of the ion peak in a single charge state directly reflects the molecular mass of the component, and it is easy to introduce errors when inferring the molecular mass in other charge states. Therefore, through charge state deconvolution processing, the parent ion peak of the overlapping peak is restored to a molecular ion peak in a single charge state, denoted as a single-charge ion peak, which directly corresponds to the neutral molecular mass, avoiding the interference of multiple charge states on mass calculation.

[0069] It should be noted that it is well-known to those skilled in the art to perform deconvolution processing using algorithms such as peak deconvolution algorithm, deconvolution method or Bayesian deconvolution method, and to calculate the molecular mass corresponding to each single-charged ion peak. Therefore, it will not be elaborated here. The emulsifier components that make up the sample of the compound emulsifier to be tested are known, and the molecular mass of each component can be directly queried through software such as KingDraw software and ChemDraw software. For the emulsifier components that are known compounds, the mass-to-charge ratios of the parent ions and characteristic fragment ions of the emulsifier components can be directly queried from databases such as high-resolution mass spectrometry databases or metabolite databases; for the emulsifier components that cannot be queried, high performance liquid chromatography-mass spectrometry (HPLC-MS) technology is used to analyze a single emulsifier component to directly obtain the mass-to-charge ratios of its parent ion and characteristic fragment ions. The mass-to-charge ratios of the characteristic fragment ions of each component that makes up the sample are used as the fragment standard mass-to-charge ratios of the corresponding components.

[0070] Step S320: Calculate the differences between the molecular masses corresponding to each single-charged ion peak of the overlapping peaks and the molecular masses of all components that make up the sample, and select the smallest difference as the target mass difference corresponding to the single-charged ion peak, and use the component corresponding to the target mass difference as the target component of the single-charged ion peak.

[0071] It should be noted that since the molecular masses of different components are unique, the corresponding target component can be deduced from the molecular mass corresponding to the single-charged ion peak. The difference between the molecular mass corresponding to the single-charged ion peak and the molecular mass of each component can measure the similarity between the single-charged ion peak and the molecular mass of each component. The smaller the difference, the greater the similarity, and the more likely the single-charged ion peak is the parent ion peak corresponding to each component. Therefore, the component corresponding to the target mass difference is used as the target component of the single-charged ion peak.

[0072] Step S330: According to the differences between the fragment standard mass-to-charge ratios of the target components of the single-charged ion peaks of the overlapping peaks and the mass-to-charge ratios corresponding to the ion peaks in their mass spectra, and the target mass difference, obtain the component matching degrees between each single-charged ion peak of the overlapping peaks and their target components; select the target components corresponding to the component matching degrees greater than the preset matching threshold from the component matching degrees between all single-charged ion peaks of the overlapping peaks and their target components as the components corresponding to the overlapping peaks.

[0073] Preferably, in some possible implementation manners of the embodiments of the present invention, the method for obtaining the component matching degree includes: calculating the differences between the mass-to-charge ratios of each fragment standard of the target component of each single-charge ion peak of the overlapping peak and the mass-to-charge ratios of the remaining ion peaks except the parent ion peak in its mass spectrum respectively, and selecting the ion peak corresponding to the minimum difference as the fragment ion peak of the target component; taking the sum of the differences corresponding to all the fragment ion peaks of the target component of each single-charge ion peak of the overlapping peak as the ion difference degree between each single-charge ion peak of the overlapping peak and its target component; performing a negative correlation and normalization process on the product of the target mass difference and the ion difference degree to obtain the component matching degree between each single-charge ion peak of the overlapping peak and its target component.

[0074] It should be noted that the fragment standard mass-to-charge ratio of a component is the mass-to-charge ratio of its characteristic fragment ion. By the difference between it and the mass-to-charge ratios of the remaining ion peaks except the parent ion peak in the mass spectrum of the overlapping peak, the characteristic fragment ion of the target component of the single-charge ion peak of the overlapping peak is determined. Comparing the mass-to-charge ratio, i.e., the position of the fragment standard mass-to-charge ratio, of the characteristic fragment ion of the target group with the ion peaks near the corresponding position in the mass spectrum of the overlapping peak, the possibility of the existence of the characteristic fragment ion of the target component in the mass spectrum of the overlapping peak is measured. The smaller the ion difference degree, the greater the possibility of the existence of the characteristic fragment ion of the target component in the mass spectrum of the overlapping peak. If both the target mass difference and the ion difference degree are smaller, the single-charge ion peak of the overlapping peak is more matched with the parent ion and characteristic fragment ions of its target component, then the component matching degree is greater, and further the possibility that the component corresponding to the overlapping peak contains the target component of its single-charge ion peak is greater. In the embodiments of the present invention, the opposite of the product of the ion difference degree between each single-charge ion peak of the overlapping peak and its target component and the target mass difference of each single-charge ion peak is used as the exponent of the exponential function with the natural constant as the base to achieve the negative correlation and normalization process of the product.

[0075] It should be noted that all the differences that appear in the process of obtaining the component corresponding to the overlapping peak represent the absolute values of the differences.

[0076] Preferably, in some possible implementation manners of the embodiments of the present invention, the method for obtaining the content ratio of each component includes: determining whether each chromatographic peak in the liquid chromatography diagram is an overlapping peak; if so, selecting the parent ion peak corresponding to each component from the mass spectrometry diagram of each chromatographic peak, and recording the parent ion peak and the fragment ion peak corresponding to each component of the chromatographic peak as the analysis ion peaks; taking the ratio of the sum of the ion intensities of the analysis ion peaks corresponding to each component of each chromatographic peak to the sum of the ion intensities of all the analysis ion peaks in the mass spectrometry diagram corresponding to the chromatographic peak as the overlapping ratio of each component corresponding to each chromatographic peak; taking the ratio of the signal intensity of each chromatographic peak to the sum of the signal intensities of all the chromatographic peaks in the liquid chromatography diagram as the chromatographic ratio; taking the product of the overlapping ratio and the chromatographic ratio as the content ratio of each component corresponding to each chromatographic peak; if not, taking the chromatographic ratio as the content ratio of the component corresponding to each chromatographic peak.

[0077] It should be noted that the overlapping ratio quantifies the contribution ratio of each component corresponding to the chromatographic peak in the chromatographic peak, which can reduce the interference of background signals or co-eluting substances; the chromatographic ratio reflects the contribution ratio of all components corresponding to the chromatographic peak in the overall sample, avoiding systematic errors caused by differences in mass spectrometry responses; the content ratio of each component corresponding to the chromatographic peak is calculated by combining the two, making the quantification closer to the true value. Since the remaining chromatographic peaks in the liquid chromatography diagram except the overlapping peaks only represent one component, the chromatographic ratio can directly measure the content ratio of one component corresponding to these chromatographic peaks in the overall sample.

[0078] It should be noted that in the embodiments of the present invention, the ion intensity of the ion peak and the signal intensity of the chromatographic peak both refer to the peak height of the corresponding peak, and can also refer to the peak area. The parent ion peaks of the overlapping peak include the parent ion peaks corresponding to multiple components thereof. It is necessary to divide the parent ion peaks of the overlapping peak into the parent ion peaks corresponding to each component. The specific method is: recording the mass-to-charge ratio of the parent ion peak of each component of the sample as the parent standard mass-to-charge ratio corresponding to the component, calculating the absolute value of the difference between the mass-to-charge ratio of all the parent ion peaks of the overlapping peak and the parent standard mass-to-charge ratio corresponding to each component, and taking the parent ion peak corresponding to the minimum absolute value of the difference as the parent ion peak corresponding to each component of the overlapping peak.

[0079] So far, the present invention is completed.

[0080] Embodiment 2:

[0081] The present invention provides a component content detection system for food compound emulsifiers. Please refer to Figure 3 , which shows the system structure diagram of a component content detection system for food compound emulsifiers provided by an embodiment of the present invention. The system includes:

[0082] A data acquisition module 510, which is used to obtain chromatographic peaks in the liquid chromatogram of the sample of the compound emulsifier to be tested, as well as the mass spectrum and retention time of each chromatographic peak. The sample is composed of different components;

[0083] An overlapping peak screening module 520, which is used to screen overlapping peaks from the liquid chromatogram according to the symmetry, morphological smoothness and retention time of the chromatographic peaks;

[0084] A qualitative analysis module 530, which is used to select the parent ion peak of each overlapping peak according to the sharpness and mass-to-charge ratio of the ion peaks in the mass spectrum of each overlapping peak; according to the difference between the molecular mass corresponding to the parent ion peak of each overlapping peak and the molecular masses of the components composing the sample, as well as the mass-to-charge ratio corresponding to the ion peaks in the mass spectrum of the overlapping peak, select the corresponding component of each overlapping peak from the components composing the sample; determine the components corresponding to the chromatographic peaks other than the overlapping peaks in the liquid chromatogram based on the retention time;

[0085] A quantitative analysis module 540, which is used to obtain the content ratio of each component composing the sample according to the signal intensity of each chromatographic peak and the signal intensity of the ion peaks corresponding to each component.

[0086] It should be noted that: for the device provided in the above embodiment, only the division of the above functional modules is used for illustration. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the computer device is divided into different functional modules to complete all or part of the functions described above. In addition, a component content detection system for food compound emulsifiers and an embodiment of a component content detection method for food compound emulsifiers provided in the above embodiment belong to the same inventive concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0087] Embodiment 3:

[0088] Based on the same inventive concept as the above embodiment of a component content detection method for food compound emulsifiers, a component content detection device for food compound emulsifiers provided by an embodiment of the present invention includes a processor, and when the processor executes, it implements the above-mentioned component content detection method for food compound emulsifiers. A component content detection method for food compound emulsifiers has been described in detail in the above embodiment and will not be repeated here.

[0089] Embodiment 4:

[0090] This embodiment also provides a computer-readable storage medium, in which computer program code is stored. When the computer program code runs on a computer, the computer is made to execute the above-mentioned related method steps to implement the component content detection method for food compound emulsifiers provided in the above embodiment.

[0091] Example 5:

[0092] This embodiment also provides a computer program product. When the computer program product runs on a computer, it causes the computer to execute the above-related steps to implement a method for detecting the component content of a food compound emulsifier provided in the above embodiment.

[0093] Among them, the device, computer-readable storage medium or computer program product provided in this embodiment are all used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be elaborated here.

[0094] In the embodiments provided in this application, it should be understood that the disclosed device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point, the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in electrical, mechanical or other forms.

[0095] It should be noted that the above sequence of the embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0096] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key points of each embodiment are the differences from other embodiments.

Claims

1. A method for detecting the component content of a compound food emulsifier, characterized in that, The method includes: obtaining chromatographic peaks in the liquid chromatogram of the compound emulsifier sample to be tested, as well as the mass spectrum and retention time of each chromatographic peak, wherein the sample is composed of different components; screening overlapping peaks from the liquid chromatogram according to the symmetry, morphological smoothness and retention time of the chromatographic peaks; selecting the precursor ion peak of each overlapping peak according to the sharpness and mass-to-charge ratio of the ion peaks in the mass spectrum of each overlapping peak; selecting the corresponding component of each overlapping peak from the components composing the sample according to the difference between the molecular mass corresponding to the precursor ion peak of each overlapping peak and the molecular masses of the components composing the sample, and the mass-to-charge ratio corresponding to the ion peaks in the mass spectrum of the overlapping peak; determining the components corresponding to the chromatographic peaks other than the overlapping peaks in the liquid chromatogram based on the retention time; obtaining the content proportion of each component composing the sample according to the signal intensity of each chromatographic peak and the signal intensity of the ion peaks corresponding to each component.

2. The component content detection method for a food compound emulsifier according to claim 1, characterized in that, The screening of overlapping peaks from the liquid chromatogram includes: calculating the absolute value of the difference between the time intervals from the highest point of the chromatographic peak to the two peak boundaries, which is denoted as the symmetry degree; extracting the response value sequence of all time points from the highest point of the chromatographic peak to each peak boundary, obtaining the first-order difference sequence of the response value sequence, and taking the sum of the change times of the symbols of the adjacent two elements in the first-order difference sequence corresponding to the two peak boundaries of the chromatographic peak as the morphological smoothness; obtaining the retention time of the chromatographic peak and the standard retention times of all components composing the sample, and denoting the minimum value among the differences between all the standard retention times and the retention time of the chromatographic peak as the retention time deviation degree; obtaining an overlapping determination index for the chromatographic peak according to the symmetry degree, the morphological smoothness and the retention time deviation degree; and denoting the chromatographic peaks in the liquid chromatogram with the overlapping determination index greater than a preset overlapping threshold as overlapping peaks.

3. A method for detecting the component content of a food compound emulsifier according to claim 1, characterized in that, The selection of the precursor ion peak of each overlapping peak includes: taking the ratio of the peak value to the peak width of the ion peak as the sharpness, and obtaining the peak intensity of the ion peak according to the mass-to-charge ratio corresponding to the ion peak and the sharpness; and selecting the ion peak corresponding to the peak intensity greater than a preset intensity threshold from the mass spectrum of each overlapping peak as the precursor ion peak of each overlapping peak.

4. The component content detection method for a food compound emulsifier according to claim 1, characterized in that, The selection of the corresponding component of each overlapping peak from the components composing the sample includes: for each overlapping peak, performing deconvolution processing on the precursor ion peak of the overlapping peak to obtain a single-charged ion peak, and obtaining the molecular mass corresponding to each single-charged ion peak, the molecular masses of each component composing the sample, and the fragment standard mass-to-charge ratio; calculating the differences between the molecular masses corresponding to each single-charged ion peak of the overlapping peak and the molecular masses of all components composing the sample, selecting the minimum difference as the target mass difference corresponding to the single-charged ion peak, and taking the component corresponding to the target mass difference as the target component corresponding to the single-charged ion peak; According to the difference between the fragment standard mass-to-charge ratio of the target component of the single-charge ion peak of the overlapping peak and the mass-to-charge ratio corresponding to the ion peak in its mass spectrum, and the target mass difference, obtain the component matching degree between each single-charge ion peak of the overlapping peak and its target component; select the target component corresponding to the component matching degree greater than the preset matching threshold from the component matching degrees between all single-charge ion peaks of the overlapping peak and their target components as the corresponding component of the overlapping peak.

5. The component content detection method for a food compound emulsifier according to claim 4, wherein, The method for obtaining the component matching degree includes: Calculate the difference between each fragment standard mass-to-charge ratio of the target component of each single-charge ion peak of the overlapping peak and the mass-to-charge ratio corresponding to the remaining ion peaks except the parent ion peak in its mass spectrum, and select the ion peak corresponding to the minimum difference as the fragment ion peak of the target component; Take the sum of the differences corresponding to all fragment ion peaks of the target component of each single-charge ion peak of the overlapping peak as the ion difference degree between each single-charge ion peak of the overlapping peak and its target component; Perform negative correlation and normalization processing on the product of the target mass difference and the ion difference degree to obtain the component matching degree between each single-charge ion peak of the overlapping peak and its target component.

6. The component content detection method for a food compound emulsifier according to claim 5, characterized in that, The method for obtaining the content proportion of each component constituting the sample includes: Judge whether each chromatographic peak in the liquid chromatogram is an overlapping peak. If so, select the parent ion peak of each corresponding component from the mass spectrum of each chromatographic peak, record the parent ion peak and the fragment ion peak of each corresponding component of the chromatographic peak as the analysis ion peak, and take the ratio of the sum of the ion intensities of the analysis ion peaks corresponding to each component of each chromatographic peak to the sum of the ion intensities of all analysis ion peaks in the mass spectrum of the corresponding chromatographic peak as the overlapping proportion of each chromatographic peak corresponding to each component; take the ratio of the signal intensity of each chromatographic peak to the sum of the signal intensities of all chromatographic peaks in the liquid chromatogram as the chromatographic proportion; the product of the overlapping proportion and the chromatographic proportion is used as the content proportion of each chromatographic peak corresponding to each component; If not, take the chromatographic proportion as the content proportion of each chromatographic peak corresponding to the component.

7. A method for detecting the component content of a compound food emulsifier according to claim 3, characterized in that, The method for obtaining the peak intensity includes: Calculate the difference between the mass-to-charge ratio corresponding to each ion peak in each mass spectrum and the minimum value of the mass-to-charge ratios corresponding to all ion peaks, and perform normalization processing on the product of the difference and the sharpness to obtain the peak intensity of each ion peak in each mass spectrum.

8. A method for detecting the component content of a food compound emulsifier according to claim 1, characterized in that, Each chromatographic peak other than the overlapping peak in the liquid chromatogram corresponds to one component.

9. A component content detection system for food compound emulsifiers, characterized in that, The system includes: A data acquisition module for obtaining the chromatographic peaks in the liquid chromatogram of the to-be-detected compound emulsifier sample, as well as the mass spectrum and retention time of each chromatographic peak, where the sample is composed of different components; An overlapping peak screening module for screening overlapping peaks from the liquid chromatogram according to the symmetry, morphological smoothness and retention time of the chromatographic peaks; A qualitative analysis module, which is used to select the parent ion peak of each overlapping peak according to the sharpness and mass-to-charge ratio of the ion peaks in the mass spectrum of each overlapping peak; according to the difference between the molecular mass corresponding to the parent ion peak of each overlapping peak and the molecular masses of the components constituting the sample, and the mass-to-charge ratio corresponding to the ion peaks in the mass spectrum of the overlapping peak, select the corresponding component of each overlapping peak from the components constituting the sample; determine the components corresponding to the chromatographic peaks other than the overlapping peaks in the liquid chromatogram based on the retention time. A quantitative analysis module, which is used to obtain the content proportion of each component constituting the sample according to the signal intensity of each chromatographic peak and the signal intensity of the ion peaks corresponding to each component.

10. A component content detection device for food compound emulsifiers, characterized in that, The device includes a processor, and when the processor executes, it implements the steps of a method for detecting the component content of a food compound emulsifier according to any one of claims 1 to 8.

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