Method for determining the content of polydextrose in a diabetic complete nutritional formula

Abstract

The application relates to the technical field of medical food detection, and discloses a method for determining the content of polydextrose in a full-nutrition formula food for diabetes, which comprises the following steps: S1: after a sample is weighed, adding a trichloroacetic acid solution to precipitate proteins; S2: after centrifugation of the sample solution, part of the supernatant is taken, distilled water is used for constant volume, a filter membrane is used, and a sample solution is obtained; S3: an ion chromatograph, elution liquid: A: ultrapure water; B: 250 mM sodium hydroxide solution; C: 1 M sodium acetate-50 mM sodium hydroxide mixed solution; and potential waveform: four-potential waveform. The application has the characteristics of good reproducibility, high sensitivity, simple operation, low detection cost and the like. The enzyme hydrolysis step in the conventional standard method is cancelled, the enzyme hydrolysis time is saved, and the detection cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical and food testing technology, specifically a method for determining the content of polydextrose in a complete nutritional formula food for diabetes. Background Technology

[0002] Polydextrose is a water-soluble dietary fiber with the molecular formula (C6H10O5)n. Through ion exchange and colloid formation, it reduces the absorption of toxic and carcinogenic substances in the human body, regulates cholesterol levels, reduces the activity of β-glucuronidase in the intestine, and eliminates factors that induce arteriosclerosis. Polydextrose has special physiological metabolic functions in the human digestive system. It is not easily digested and absorbed by the human body, but it can be utilized by beneficial bacteria in the intestines, promoting intestinal peristalsis and thus preventing constipation. Simultaneously, it can reduce the absorption and deposition of fat in the intestines, helping to control weight and blood lipid levels. As a food component with health-promoting functions, polydextrose has wide applications in the food industry. It can be used as a thickener, stabilizer, emulsifier, and other food additives to improve the taste and texture of food. Polydextrose can also be used as a low-calorie sweetener to meet people's demand for healthy foods. Furthermore, polydextrose is also used as an important raw material or excipient in the fields of medicine and health products. In summary, polydextrose has the effects of being low in calories, regulating gastrointestinal function, promoting the absorption of nutrients, regulating the balance of intestinal flora, lowering blood sugar, and promoting the absorption of minerals.

[0003] Special Medical Purpose Diabetic Complete Nutritional Formula Foods are specially formulated foods for diabetic patients, providing nutritional supplementation and support to help control blood sugar, improve clinical outcomes, enhance quality of life, and reduce hospitalization costs. Given the functional properties of polydextrose, it is suitable for addition to diabetic complete nutritional formula foods. However, research on polydextrose content detection methods has revealed that standard methods are susceptible to interference from other substances (especially cassava dextrin), leading to inflated results. Therefore, developing a new detection method to eliminate background interference and accurately determine the polydextrose content in diabetic complete nutritional formula foods is crucial.

[0004] Therefore, this invention proposes a method for determining the polydextrose content in diabetic complete nutritional formula foods. Summary of the Invention

[0005] This invention provides a method for determining polydextrose in a special medical purpose diabetic complete nutritional formula food. This method has the characteristics of good reproducibility, high sensitivity, simple operation, and low testing cost, and effectively eliminates the interference of starch sugar substances such as cassava dextrin.

[0006] This application provides a method for determining the polydextrose content in a complete nutritional formula food for diabetes. The method employs ion chromatography detection technology, adding trichloroacetic acid to the sample to remove protein and fat, using polydextrose raw material as a reference standard, and detecting it with an ion chromatograph equipped with an integrating amperometric detector. The characteristic chromatographic peaks of polydextrose are used for qualitative and quantitative determination of the polydextrose content in the complete nutritional formula food for diabetes.

[0007] In this invention, the concentration of trichloroacetic acid added is 20%, and the amount added is 10 mL.

[0008] The trichloroacetic acid solution is prepared by accurately weighing 20g of trichloroacetic acid, dissolving it in water and diluting it to 100mL, then mixing well.

[0009] In this invention, the specific procedure for precipitating proteins is to add trichloroacetic acid, vortex for 30 seconds, and then let stand at room temperature for 30 minutes, vortexing once every 10 minutes during this period.

[0010] The centrifuge speed was 8000-10000 rpm for 20 minutes.

[0011] The chromatographic column used in this invention is CarboPac™ PA200 (3×250mm), and the guard column is CarboPac™ PA200 (3×50mm).

[0012] Rinsing solutions: A: Ultrapure water; B: 250mM sodium hydroxide solution; C: 1M sodium acetate-50mM sodium hydroxide mixed solution;

[0013] The elution procedure is as follows:

[0014] Table 1 shows the elution procedure:

[0015]

[0016]

[0017] Electrochemical detector; flow rate: 0.4 mL / min; injection volume: 10 μL; column temperature: 30 °C.

[0018] In this invention, polydextrose raw material is used as a reference standard, and the characteristic chromatographic peaks of polydextrose are used for qualitative and quantitative analysis.

[0019] Compared with the prior art, the beneficial effects of the technical solution of this application are as follows:

[0020] Compared to the standard method GB 5009.245-2016, the most significant feature of this invention is the effective elimination of interference from starch sugars such as cassava dextrin. When using conventional standard methods to detect polydextrin in special medical purpose diabetic complete nutritional formula foods containing cassava dextrin, the detection results are often 2-3 times higher than the theoretical addition amount, and polydextrin is also detected in the cassava dextrin raw material. Therefore, conventional standard methods are not applicable to the detection of polydextrin in special medical purpose diabetic complete nutritional formula foods containing cassava dextrin. This invention uses polydextrin raw material as a reference standard, selects a CarboPac™ PA200 (3×250mm) chromatographic column for separation, and utilizes the characteristic chromatographic peaks of polydextrin for qualitative and quantitative analysis, effectively eliminating the interference from starch sugars such as cassava dextrin.

[0021] Compared to standard methods, this invention offers advantages such as good reproducibility, high sensitivity, simple operation, and low testing cost. It eliminates the enzymatic digestion step found in conventional standard methods, saving digestion time and reducing detection costs. Trichloroacetic acid is used to precipitate proteins, and the supernatant is collected after centrifugation for analysis. The pretreatment is simple and easy to operate, meeting the requirements for detecting polydextrose in diabetic complete nutritional formula foods for special medical purposes. Attached Figure Description

[0022] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0023] Figure 1 This is a standard curve of polydextrose.

[0024] Figure 2 This is an ion chromatogram of a polydextrose standard solution.

[0025] Figure 3 Ion chromatogram of polydextrose in a complete nutritional formula food for diabetes for special medical purposes.

[0026] Figure 4 Ion chromatograms of polydextrose determined using a CarboPac™ PA1 (4×250 mm) column. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0028] Example 1:

[0029] S1: Take 10 mL of a special medical purpose diabetic complete nutritional formula food (emulsion) and add 10 mL of 20% trichloroacetic acid.

[0030] S2: Vortex for 30 seconds, then let stand at room temperature for 30 minutes, vortexing once every 10 minutes during this period. Centrifuge at 8000-10000 rpm / min for 20 minutes, take 5 mL of the supernatant, dilute to 25 mL with distilled water, and filter through a 0.22 μm filter membrane;

[0031] S3: Column: CarboPac™ PA200 (3×250mm), Guard column: CarboPac™ PA200 (3×50mm);

[0032] Mobile phase A: 18.2 MΩ deionized water; B: 250 mM NaOH; C: 1 M NaOAc & 50 mM NaOH. Flow rate: 0.4 mL / min; Column temperature: 30 °C; Injection volume: 10 μL; Detector: Ampere detector; Potential waveform: Four-potential waveform. Elution program is shown in Table 1.

[0033] Linearity and Range:

[0034] Using polydextrose as a reference, a series of standard working solutions with concentrations of 0.2 mg / mL, 0.4 mg / mL, 0.8 mg / mL, 1.2 mg / mL, and 1.6 mg / mL were prepared.

[0035] Inject the standard series of working solutions into the ion chromatograph and measure the peak area of ​​the characteristic peaks. Plot a standard curve with the concentration of the standard working solution (polydextrose concentration) on the x-axis and the peak area of ​​the characteristic peak on the y-axis. (See figure). Figure 1 .

[0036] As shown in the figure, the linear equation for polydextrose is y = 154.87x - 0.1466, with a correlation coefficient of 0.9994. The results indicate a good linear relationship within the range of 0.2 mg / mL to 1.6 mg / mL.

[0037] Repeatability:

[0038] Using the S1, S2, and S3 methods, a special medical purpose diabetic complete nutritional formula food (emulsion) was processed in parallel 6 times, and the test results are shown in Table 2.

[0039] Table 2 shows the results of the repeatability experiment:

[0040]

[0041] The test results show that after six parallel treatments of the special medical purpose diabetic complete nutritional formula food (emulsion), the polydextrose content was within the range of 0.795 to 0.809 g / 100 mL, with an RSD of 0.71%, indicating good repeatability.

[0042] The ion chromatogram of the polydextrose standard solution is shown below. Figure 2 The ion chromatogram of polydextrose in diabetic complete nutritional formula for special medical purposes is shown below. Figure 3 As can be seen from the figure, the characteristic peaks of polydextrose are effectively separated from adjacent peaks, and the peak shapes are normal.

[0043] Accuracy:

[0044] Using a special medical purpose diabetic complete nutritional formula food (emulsion) as the matrix, 0.55 g / 100 mL of polydextrose standard substance was added. Six replicates were performed, and the spiked recovery rate was calculated. The test results are shown in Table 3.

[0045] Table 3 shows the accuracy experiment results:

[0046]

[0047] Therefore, the method of this invention has a small deviation, with an average spiked recovery rate of 93.9%.

[0048] Comparative Example 1:

[0049] The same detection method as in Example 1 was used, except that potassium ferrocyanide and zinc acetate were used for protein precipitation in this comparative example. The study found that using the protein precipitation method of Comparative Example 1, the ion chromatograms of the samples did not yield characteristic peaks with good separation and easy qualitative and quantitative analysis.

[0050] Comparative Example 2:

[0051] The same detection method as in Example 1 was used, except that a CarboPac™ PA1 (4×250 mm) column was used in this comparative example. The results showed that, using the column of Comparative Example 2, the ion chromatogram of the sample did not yield characteristic peaks with good separation and easy qualitative and quantitative analysis. The ion chromatogram of polydextrose determination using the CarboPac™ PA1 (4×250 mm) column is shown below. Figure 4 .

[0052] The specific embodiments described above provide a series of detailed explanations of the technical problems solved, the technical solutions, and the beneficial effects of the present invention. However, this description is merely illustrative of specific embodiments of the present invention, and all equivalent embodiments or modifications made without departing from the technical basis, principles, and spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the polydextrose content in a complete nutritional formula food for diabetes, characterized in that, The determination method includes the following steps: S1: After weighing the sample, add trichloroacetic acid solution to precipitate the protein; S2: After centrifuging the sample solution, take a portion of the supernatant, dilute it to volume with distilled water, filter it through a membrane, and obtain the injection solution; S3: Ion chromatograph; the eluent consists of A, B, and C, where A is ultrapure water, B is 250 mM sodium hydroxide solution, and C is a 1 M sodium acetate-50 mM sodium hydroxide mixed solution; the potential waveform is a four-potential waveform; gradient elution is used. In step S1, the concentration of the added trichloroacetic acid solution is 20%, and the amount added is 10 mL. In S3, the chromatographic column is a CarboPac™ PA200 with a specification of 3×250mm, and the guard column is a CarboPac™ PA200 with a specification of 3×50mm. In step S3, the elution procedure is shown in the table below: 。 2. The method for determining the polydextrose content in a diabetic complete nutritional formula food according to claim 1, characterized in that, In step S1, the specific operation of precipitating the protein is as follows: after adding trichloroacetic acid, vortex for 30 seconds, and then let it stand at room temperature for 30 minutes, vortexing once every 10 minutes during this period.

3. The method for determining the polydextrose content in a diabetic complete nutritional formula food according to claim 1, characterized in that, In step S2, the centrifuge speed is 8000-10000 rpm and the time is 20 minutes.

4. The method for determining the polydextrose content in a diabetic complete nutritional formula food according to claim 1, characterized in that, In step S2, after centrifugation, take 5 mL of the supernatant, dilute it to 25 mL with distilled water, and filter it through a 0.22 μm aqueous filter membrane.

5. The method for determining the polydextrose content in a diabetic complete nutritional formula food according to claim 1, characterized in that, Polydextrose was used as a reference standard.

6. The method for determining the polydextrose content in a diabetic complete nutritional formula food according to claim 1, characterized in that, In S3, the detector is an electrochemical detector; the flow rate is 0.4 mL / min; the injection volume is 10 μL; and the column temperature is 30 °C.

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