Method for measuring addition amount of minced white gourd in white gourd sauce through tartronic acid

Abstract

The invention relates to a method for determining the addition amount of minced white gourd in white gourd sauce through tartronic acid, and belongs to the technical field of food detection. The method comprises the following steps: S1, preparing tartronic acid standard solutions with different concentrations, carrying out liquid phase determination to obtain a linear relation between the tartronic acid concentration and a liquid phase peak area, and making a standard curve; and S2, taking the white gourd sauce and the white gourd paste, adding water, stirring, dissolving, carrying out ultrasonic dispersion, squeezing out water through a filter bag, centrifuging, taking supernate, carrying out membrane filtration to prepare a sample, carrying out liquid phase detection, respectively determining the content of tartronic acid in the white gourd sauce and the content of tartronic acid in the white gourd paste, and obtaining the addition amount of the white gourd paste according to the standard curve. The tartronic acid is a stable characteristic index in the wax gourd sauce processing process, the method for representing the wax gourd content in the wax gourd sauce by measuring the content of the tartronic acid is an efficient and accurate method, the repeatability is good, and safety and reliability are achieved. The content determination method provided by the invention can save cost and reduce energy consumption, and is suitable for wide popularization and application.

Description

Technical Field

[0001] The invention belongs to the technical field of food detection and relates to a method for determining the amount of wax gourd puree added in wax gourd sauce by using tartronic acid. Background Art

[0002] Winter melon is very rich in nutrients, with high content of protein, carbohydrates, inorganic salts, vitamins, etc., especially vitamin C. At present, its use in my country is mainly as a vegetable and as a raw material for food industries such as mooncake fillings and malt sugar.

[0003] Related research shows that the succinic acid found in winter melon can inhibit the conversion of starch and sugars into fat in the body, preventing fat accumulation. It also has a strong diuretic effect, thereby eliminating excess water, reducing weight, lowering blood lipids, and enhancing weight loss. Currently, winter melon sauces on the market vary greatly in quality, with low winter melon content and low levels of active ingredients. To determine the winter melon content in winter melon sauce, this application describes a method for determining the amount of winter melon puree added to winter melon sauce using succinic acid. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for determining the amount of wax gourd puree added in wax gourd sauce. The method detects the content of wax gourd puree in wax gourd sauce by measuring succinic acid, a characteristic substance in wax gourd. The method has the advantages of being safe, reliable, simple and easy to operate, solves the problems in existing detection technologies, and provides ideas for quality detection of wax gourd sauce on the market.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A method for determining the amount of wax gourd puree added to wax gourd sauce by using tartronic acid, comprising the following steps: S1. Prepare standard solutions of malonic acid at different concentrations, determine by liquid chromatography, establish a linear relationship between malonic acid concentration and liquid peak area, and prepare a standard curve; S2. The winter melon paste sample was mixed with water in a weight ratio of 1:5, stirred and dispersed, and then ultrasonically treated for 30 minutes. The liquid was squeezed through a 500-mesh filter bag to separate the liquid, centrifuged, and the supernatant was filtered through a 0.22 μm membrane to obtain the test solution; S3. The wax gourd puree sample was mixed with water in a weight ratio of 1:2, and the test solution was prepared in the same manner as in step S2; S4. Determination of the content of succinic acid in the test solution of wax gourd paste and wax gourd puree by liquid chromatography; S5. Calculate the succinic acid content based on the standard curve. Combined with the succinic acid content in wax gourd puree (0.24-0.27 g / 100 g), determine the amount of wax gourd puree to be added to the wax gourd sauce.

[0006] As a preferred technical solution of the present invention, the concentrations of the tartronic acid standard solution in step S1 include 1.25 mg / mL, 1.00 mg / mL, 0.75 mg / mL, 0.50 mg / mL and 0.25 mg / mL.

[0007] As a preferred technical solution of the present invention, the standard curve equation is: Y = 2225350X - 3090.9, Where Y is the liquid phase peak area of malonic acid, X is the concentration of malonic acid (mg / mL), and the correlation coefficient R²=0.99995.

[0008] As a preferred technical solution of the present invention, the sampling amount of the winter melon sauce sample is not less than 100g.

[0009] As a preferred technical solution of the present invention, the ultrasonic treatment time is 30 minutes.

[0010] As a preferred technical solution of the present invention, the separation step includes: using a 500-mesh filter bag to squeeze and separate the liquid, and then centrifuging to obtain the supernatant.

[0011] As a preferred technical solution of the present invention, the membrane filtration uses a 0.22 μm pore size filter membrane.

[0012] As a preferred technical solution of the present invention, the content of tartronic acid in the wax gourd sauce is in the range of 0.70-0.83 g / 100 g.

[0013] As a preferred technical solution of the present invention, the calculation formula for the amount of wax gourd puree added is: Addition amount of wax gourd puree (g / 100g wax gourd paste) = (content of succinic acid in wax gourd paste / content of succinic acid in wax gourd puree) × 100, The content of succinic acid in the wax gourd puree is 0.24-0.27g / 100g.

[0014] As a preferred technical solution of the present invention, the amount of wax gourd puree added to every 100g of wax gourd sauce is 260-345g.

[0015] As a preferred technical solution of the present invention, Beneficial effects of the present invention: (1) The present invention detects the content of wax gourd puree in wax gourd paste by detecting succinic acid, a characteristic substance in wax gourd, thereby providing a method for quality detection of wax gourd paste.

[0016] (2) Malonic acid is a stable characteristic indicator during the processing of winter melon paste. Determining the content of malonic acid to characterize the winter melon content in winter melon paste is an efficient and accurate method with good repeatability, safety and reliability. The content determination method of the present invention can save costs and reduce energy consumption, and is suitable for widespread promotion and use. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the examples, which are only for explaining the technical content of the present invention and providing necessary experimental evidence for its authenticity and effectiveness, and do not exist to limit the protection of the present invention.

[0018] Without departing from the spirit and essence of the present invention, any modification or substitution of the methods, steps or conditions of the present invention shall fall within the scope of the present invention.

[0019] Unless otherwise specified, the technical means used in the embodiments of the present invention are conventional means well known to those skilled in the art.

[0020] In an embodiment of the present invention, the winter melon sauce and winter melon puree are sourced from Xu Fuji (produced in Dongguan).

[0021] Example 1 In this example, wax gourd paste (0.81%) with a known tartronic acid content was used for content determination, and the specific method is as follows: (1) Preparation of malonic acid liquid chromatography standard curve Take the malonic acid standard and prepare standard solutions of 1.25 mg / mL, 1.00 mg / mL, 0.75 mg / mL, 0.50 mg / mL and 0.25 mg / mL. After determination by liquid chromatography, the linear relationship between concentration and liquid phase peak area is obtained and a standard curve is prepared.

[0022] The obtained standard curve is Y=2225350X-3090.9, R 2 =0.99995 (2) Quantitative analysis Winter melon paste and water were sampled at a weight ratio of 1:5, stirred and dispersed, ultrasonicated for 30 min, and water was squeezed out using a 500-mesh filter bag. The mixture was centrifuged, and the supernatant was collected and filtered through a 0.22 μm membrane to prepare the sample. Liquid chromatography was performed to obtain the corresponding chromatogram.

[0023] Four groups of winter melon sauce samples were accurately weighed and tested using the above-mentioned content determination method, and the content determination results were calculated. The specific results are shown in Table 1 below: Table 1 Determination results of succinic acid content in each group of winter melon sauce

[0024] As can be seen from Table 1, there is no significant difference in the succinic acid content in the above four groups of winter melon sauce samples and the succinic acid content is basically the same as the succinic acid content marked on the product.

[0025] Comparative Example 1 The determination of malonic acid content in winter melon paste was changed to polysaccharide content. The polysaccharide was precipitated with ethanol, dissolved in dilute sulfuric acid, and then reacted with phenol-sulfuric acid in a boiling water bath to form a yellow compound. The color intensity is proportional to the sugar content in the solution, and quantification is performed colorimetrically at a wavelength of 490 nm. The test results showed that the winter melon polysaccharide content in the winter melon puree provided by Xu Fuji was 0.035%. Overall, the winter melon polysaccharide content in winter melon puree is relatively low, making it difficult to accurately measure.

[0026] Comparative Example 2 Citric acid, malic acid and succinic acid in wax gourd sauce were simultaneously detected by HPLC. The results are shown in Table 2 below.

[0027] Comparative Example 3 The vitamin C content of fresh wax gourd puree and wax gourd sauce was determined (GB 5009.86-2016), and the same batch of samples were tested for tartronic acid. The results are shown in Table 3 below.

[0028] Comparative Example 4 The potassium and calcium contents in winter melon sauce were determined by atomic absorption spectrometry (GB 5009.91-2017, GB 5009.92-2016). The results are shown in Table 4 below.

[0029] Comparative Example 5 Adulterated wax gourd paste was prepared by replacing 30% wax gourd puree with pumpkin puree (i.e., 30% pumpkin puree + 70% wax gourd puree). The content of succinic acid was tested. The results are shown in Table 5 below.

[0030] Comparative test results: Table 2 Determination results of citric acid, malic acid and tartronic acid contents in wax gourd puree and wax gourd sauce

[0031] Table 3 Determination results of vitamin C content in wax gourd puree and wax gourd sauce

[0032] Table 4 Determination results of potassium and calcium contents in wax gourd puree and wax gourd sauce

[0033] Table 5 Determination results of malonic acid content in adulterated winter melon sauce

[0034] The content of succinic acid in winter melon puree is stable at 0.24-0.27g / 100g, while the content of succinic acid in winter melon paste is stable at 0.70-0.83g / 100g. This means that 100g of finished winter melon paste requires 260-345g of stir-fried winter melon puree. The water content of winter melon puree is 91.27%, while that of winter melon paste is 28-33%. This means that the water content of winter melon puree is approximately 2.77-3.26 times that of winter melon paste. Considering the negligible water content of other ingredients, water evaporates during the winter melon paste production process, which is equivalent to the concentration of succinic acid. Winter melon paste is currently in the promotion stage, and appropriate product testing methods will help ensure its quality. Furthermore, this method offers low cost, simple preparation, mild reaction conditions, ease of use, rational design, and high safety, and has broad application prospects in the food industry.

[0035] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for determining the amount of wax gourd puree added to wax gourd paste by using tartronic acid, characterized in that: The following steps are involved: S1. Prepare standard solutions of malonic acid at different concentrations, determine by liquid chromatography, establish a linear relationship between malonic acid concentration and liquid peak area, and prepare a standard curve; S2. The winter melon paste sample was mixed with water in a weight ratio of 1:5, stirred and dispersed, and then ultrasonically treated for 30 minutes. The liquid was squeezed through a 500-mesh filter bag to separate the liquid, centrifuged, and the supernatant was filtered through a 0.22 μm membrane to obtain the test solution; S3. The wax gourd puree sample was mixed with water in a weight ratio of 1:2, and the test solution was prepared in the same manner as in step S2; S4. Determination of the content of succinic acid in the test solution of wax gourd paste and wax gourd puree by liquid chromatography; S5. Calculate the succinic acid content based on the standard curve. Combined with the succinic acid content in wax gourd puree (0.24-0.27 g / 100 g), determine the amount of wax gourd puree to be added to the wax gourd sauce.

2. The method according to claim 1, characterized in that The concentrations of the tartronic acid standard solution in step S1 include 1.25 mg / mL, 1.00 mg / mL, 0.75 mg / mL, 0.50 mg / mL and 0.25 mg / mL.

3. The method according to claim 1 or 2, characterized in that The standard curve equation is: Y = 2225350X - 3090.9, Where Y is the liquid phase peak area of malonic acid, X is the concentration of malonic acid (mg / mL), and the correlation coefficient R²=0.99995.

4. The method according to claim 1, wherein The sampling amount of the winter melon sauce sample is not less than 100g.

5. The method according to claim 1, wherein The ultrasonic treatment time is 30 minutes.

6. The method according to claim 1, characterized in that The separation step comprises: using a 500-mesh filter bag to squeeze and separate the liquid, and then centrifuging to obtain the supernatant.

7. The method according to claim 1, characterized in that The membrane filtration uses a 0.22 μm pore size filter membrane.

8. The method according to claim 1, characterized in that The content of tartronic acid in the wax gourd sauce is in the range of 0.70-0.83 g / 100 g.

9. The method according to claim 1 or 8, characterized in that The calculation formula for the amount of wax gourd puree added is: Addition amount of wax gourd puree (g / 100g wax gourd paste) = (content of succinic acid in wax gourd paste / content of succinic acid in wax gourd puree) × 100, The content of succinic acid in the wax gourd puree is 0.24-0.27g / 100g.

10. The method according to claim 9, characterized in that The amount of winter melon puree added to every 100g of winter melon sauce is 260-345g.

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