A method of citrate inhibiting HxR, Hx

Abstract

The present application belongs to the technical field of food processing, and particularly relates to a method for inhibiting HxR and Hx by using citric acid. The method comprises the following steps: firstly, soaking pretreated pork in a citric acid solution for 2-5 minutes, and then transferring the pork to an ice temperature environment for storage. By soaking the pork in the citric acid solution for 2-5 minutes and then combining with ice temperature storage, the present application can avoid the phenomenon of increasing HxR (inosine) and Hx (hypoxanthine) during the storage process, effectively inhibit the increase of HxR and Hx during the storage process, inhibit the decrease of umami substances, maintain the umami quality, reduce the generation of bitterness in pork, reduce the generation of xanthine and uric acid, reduce the flavor deterioration, color deterioration and texture deterioration of pork during the storage process. The generation of bitter substances Hx is reduced, which is beneficial to maintaining the sensory quality, nutritional value and safety of pork, and prolonging the shelf life of pork during the storage and circulation period.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically relating to a method for inhibiting HxR and Hx with citric acid. Background Technology

[0002] Inosine (HxR) is an important intermediate product in nucleotide metabolism, widely present in organisms, and particularly important in meat storage, where it is closely related to umami and freshness. Hypoxanthine (Hx) is a purine base with a bitter taste. With increasing storage time, the content of HxR and Hx in pork increases. HxR is a precursor to Hx and will further degrade into Hx, producing bitterness that masks the original umami and sweetness of pork, leading to an overall flavor imbalance and deterioration. Simultaneously, Hx is a precursor to xanthine and uric acid. Under certain conditions, Hx decomposes into xanthine and uric acid, promoting bitterness, masking the original umami of pork, and reducing consumer acceptance. Increased Hx content also accelerates myoglobin oxidation, leading to browning of the meat. Hx accumulation is related to ATP degradation; depletion of ATP in muscle reduces water-holding capacity, resulting in juice loss and loose meat texture.

[0003] Inhibiting the formation of HxR and Hx can delay the degradation of umami substances, maintain flavor advantages, enhance the synergistic effect of umami substances, reduce the accumulation of purine compounds in pork, and prevent health problems such as elevated uric acid levels caused by consuming meat and meat products with high purine compound accumulation. Inhibiting the formation of HxR and Hx can improve the sensory quality and nutritional value of pork, maintain textural and color stability, and extend shelf life while reducing the risk of spoilage.

[0004] Therefore, in order to inhibit the increase of bitter substances in pork during storage, a method for inhibiting HxR and Hx with citric acid is provided. Summary of the Invention

[0005] To address the problems in the background art, the present invention provides a method for inhibiting HxR and Hx with citric acid.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a method for inhibiting HxR and Hx with citric acid, characterized in that the method comprises:

[0007] The pre-treated pork was soaked in a citric acid solution and then stored in an ice-cold environment.

[0008] Preferably, the pork mentioned above refers to any muscle tissue of pork ketone bodies.

[0009] Preferably, the pretreatment steps for pork are as follows: remove the tendons and membranes from the pork and clean it thoroughly. Cut the pork into slices that are 3cm wide, 4cm long, and 3mm thick.

[0010] Preferably, the concentration of the citric acid solution is 0.05%, 0.1%, or 0.25%.

[0011] Preferably, the pork is soaked for 2 to 5 minutes, and then removed and drained.

[0012] Preferably, storage is carried out according to the ice temperature of different parts of the pork.

[0013] Preferably, high performance liquid chromatography is used to determine the content of HxR and Hx in pork during ice-temperature storage.

[0014] This invention, by soaking pork in a citric acid solution of a certain concentration, can inhibit the increase of bitter substances in pork during ice-temperature storage. By inhibiting the formation of HxR, and thus Hx, it can reduce the bitterness of pork, enhance the synergistic effect of umami substances, and reduce the accumulation of purine compounds in pork. This prevents consumers from experiencing health problems such as elevated uric acid levels due to consuming meat and meat products with high purine compound accumulation. Inhibiting the formation of HxR and Hx can improve the sensory quality, nutritional value, and safety of pork, while also extending its shelf life. Attached Figure Description

[0015] Figure 1 Changes in HxR content in pork under ice-temperature storage conditions

[0016] Figure 2 Changes in Hx content in pork under ice-temperature storage conditions Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the following detailed description of the invention is provided in conjunction with embodiments. Those skilled in the art will understand that the following embodiments are merely exemplary and not intended to limit the scope of the invention. Furthermore, in the following description, unless specific conditions are specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0018] This invention provides a method for inhibiting HxR and Hx with citric acid. Pretreated pork is soaked in a citric acid solution and then stored in an ice-temperature environment, which can inhibit the increase of HxR and Hx content in pork during ice-temperature storage.

[0019] In this embodiment of the invention, HxR and Hx are extracted from pork. The inhibitory effect of citric acid solution on HxR and Hx during ice-temperature storage is revealed by analyzing the changes in the content of HxR and Hx in pork.

[0020] The method for determining the content of HxR and Hx in pork is not particularly limited, and those skilled in the art can choose to use a commonly used method. In one specific embodiment of the present invention, high performance liquid chromatography is used to determine the content of HxR and Hx in pork. At the same time, the extraction method and chromatographic conditions of pork free nucleotides used in the embodiments of the present invention are only exemplary, and those skilled in the art can select appropriate conditions according to the actual object to be identified.

[0021] In one specific embodiment, a precise amount of solid citric acid (food additive grade) is accurately weighed and prepared into a solution. The pre-treated pork is then completely immersed in the solution for 2-5 minutes. After removal, the surface moisture is drained, and the pork is stored in a chilled environment. Samples are taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in HxR and Hx content in the pork.

[0022] In one specific embodiment, the extraction method of HxR and Hx from pork is as follows: Using pork as raw material, take about 30g of meat sample evenly, cut it into slices, freeze it in liquid nitrogen for 10min, and then use an ultra-micro grinder to grind it into powder. Accurately weigh 15.00g of the ground meat powder, place it in a 500mL plastic centrifuge cup, add 40mL of 5% trichloroacetic acid (TCA) solution, stir with a glass rod until evenly dispersed, and extract by standing at 4℃ for 2h. After taking it out, centrifuge at 5000r / min for 10min, transfer the supernatant to a 100mL beaker, adjust the pH to 6.5 with 3mol / L KOH solution, filter it into a 50mL volumetric flask using medium-speed qualitative filter paper, make up to volume with ultrapure water and shake well, take about 1mL and filter it through a 0.22μm filter membrane and inject it into the sample bottle to obtain the sample solution.

[0023] In one specific embodiment, the high-performance liquid chromatography (HPLC) conditions are as follows: a C18 column (4.6 mm × 250 mm × 5 μm) is used, the mobile phase is pure methanol solution and 0.05 mol / L potassium dihydrogen phosphate solution, gradient elution of the sample is performed, the flow rate is 0.8 mL / min, the column temperature is 30 °C, and the detection wavelength is 250 nm.

[0024] Specifically, the standard curve regression equations for HxR and Hx are as follows:

[0025] Standard products Standard curve Correlation coefficient HxR y = 30.1051x + 25.1548 <![CDATA[R 2 =0.99999]]> Hx y = 41.9966x + 54.2289 <![CDATA[R 2 =0.99976]]>

[0026] In one specific embodiment, the formula for calculating the HxR and Hx content in pork is as follows:

[0027]

[0028] Specifically, X: the content of Hx in the sample, mg / 100g; C: the concentration of metabolites in the sample assay solution obtained by substituting the peak area into the standard curve fitting equation, μg / ml; V: the volume of the sample extract, mL, which is 50mL in this experiment; m: the mass of the sample, g, which is 15g in this experiment.

[0029] To make the technical solution of the present invention clearer, the present invention will be described in detail below through several specific embodiments.

[0030] Example 1

[0031] First, prepare a 0.05% citric acid solution. Remove the tendons and membranes from the pork and clean it thoroughly. Cut the pork into slices 3cm wide, 4cm long, and 3mm thick. Soak the pre-treated pork in the 0.05% citric acid solution for 3 minutes, then store it in a chilled environment. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in HxR and Hx content in the pork.

[0032] Take approximately 30g of meat sample evenly, cut it into slices, and freeze it in liquid nitrogen for 10 minutes. Then, use an ultrafine grinder to grind it into powder. Accurately weigh 15.00g of the ground meat powder and place it in a 500mL plastic centrifuge cup. Add 40mL of 5% trichloroacetic acid (TCA) solution and stir with a glass rod until evenly dispersed. Incubate at 4℃ for 2 hours. After extraction, centrifuge at 5000r / min for 10 minutes. Transfer the supernatant to a 100mL beaker and adjust the pH to 6.5 with 3mol / L KOH solution. Filter the solution through medium-speed qualitative filter paper into a 50mL volumetric flask, dilute to volume with ultrapure water, and shake well. Take approximately 1mL of the solution, filter it through a 0.22μm filter membrane, and inject it into a sample vial to obtain the sample solution.

[0033] The sample solution was analyzed using a high-performance liquid chromatography (HPLC) instrument. The HPLC conditions were as follows: a C18 column (4.6 mm × 250 mm × 5 μm), a mobile phase of pure methanol solution and 0.05 mol / L potassium dihydrogen phosphate solution, gradient elution of the sample, flow rate: 0.8 mL / min, column temperature: 30 ℃, and detection wavelength: 250 nm.

[0034] Example 2

[0035] First, prepare a 0.1% citric acid solution. Remove the tendons and membranes from the pork and clean it thoroughly. Cut the pork into slices 3cm wide, 4cm long, and 3mm thick. Soak the pre-treated pork in the 0.1% citric acid solution for 3 minutes, then store it in a chilled environment. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in HxR and Hx content in the pork.

[0036] Take approximately 30g of meat sample evenly, cut it into slices, and freeze it in liquid nitrogen for 10 minutes. Then, use an ultrafine grinder to grind it into powder. Accurately weigh 15.00g of the ground meat powder and place it in a 500mL plastic centrifuge cup. Add 40mL of 5% trichloroacetic acid (TCA) solution and stir with a glass rod until evenly dispersed. Incubate at 4℃ for 2 hours. After extraction, centrifuge at 5000r / min for 10 minutes. Transfer the supernatant to a 100mL beaker and adjust the pH to 6.5 with 3mol / L KOH solution. Filter the solution through medium-speed qualitative filter paper into a 50mL volumetric flask, dilute to volume with ultrapure water, and shake well. Take approximately 1mL of the solution, filter it through a 0.22μm filter membrane, and inject it into a sample vial to obtain the sample solution.

[0037] The sample solution was analyzed using a high-performance liquid chromatography (HPLC) instrument. The HPLC conditions were as follows: a C18 column (4.6 mm × 250 mm × 5 μm), a mobile phase of pure methanol solution and 0.05 mol / L potassium dihydrogen phosphate solution, gradient elution of the sample, flow rate: 0.8 mL / min, column temperature: 30 ℃, and detection wavelength: 250 nm.

[0038] Example 3

[0039] First, prepare a 0.25% citric acid solution. Remove the tendons and membranes from the pork and clean it thoroughly. Cut the pork into slices 3cm wide, 4cm long, and 3mm thick. Soak the pre-treated pork in the 0.25% citric acid solution for 3 minutes, then store it in an ice-temperature environment. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in HxR and Hx content in the pork.

[0040] Take approximately 30g of meat sample evenly, cut it into slices, and freeze it in liquid nitrogen for 10 minutes. Then, use an ultrafine grinder to grind it into powder. Accurately weigh 15.00g of the ground meat powder and place it in a 500mL plastic centrifuge cup. Add 40mL of 5% trichloroacetic acid (TCA) solution and stir with a glass rod until evenly dispersed. Incubate at 4℃ for 2 hours. After extraction, centrifuge at 5000r / min for 10 minutes. Transfer the supernatant to a 100mL beaker and adjust the pH to 6.5 with 3mol / L KOH solution. Filter the solution through medium-speed qualitative filter paper into a 50mL volumetric flask, dilute to volume with ultrapure water, and shake well. Take approximately 1mL of the solution, filter it through a 0.22μm filter membrane, and inject it into a sample vial to obtain the sample solution.

[0041] The sample solution was analyzed using a high-performance liquid chromatography (HPLC) instrument. The HPLC conditions were as follows: a C18 column (4.6 mm × 250 mm × 5 μm), a mobile phase of pure methanol solution and 0.05 mol / L potassium dihydrogen phosphate solution, gradient elution of the sample, flow rate: 0.8 mL / min, column temperature: 30 ℃, and detection wavelength: 250 nm.

[0042] Experimental Example 1

[0043] To verify whether citric acid solution has an inhibitory effect on HxR and Hx, a control group was set up. The citric acid solution was replaced with ultrapure water.

[0044] Remove the fascia from the pork and clean it thoroughly. Cut the pork into slices 3cm wide, 4cm long, and 3mm thick. Soak the pre-treated pork in ultrapure water for 3 minutes, then store it in an ice-temperature environment. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in Hx content in the pork.

[0045] Take approximately 30g of meat sample evenly, cut it into slices, and freeze it in liquid nitrogen for 10 minutes. Then, use an ultrafine grinder to grind it into powder. Accurately weigh 15.00g of the ground meat powder and place it in a 500mL plastic centrifuge cup. Add 40mL of 5% trichloroacetic acid (TCA) solution and stir with a glass rod until evenly dispersed. Incubate at 4℃ for 2 hours. After extraction, centrifuge at 5000r / min for 10 minutes. Transfer the supernatant to a 100mL beaker and adjust the pH to 6.5 with 3mol / L KOH solution. Filter the solution through medium-speed qualitative filter paper into a 50mL volumetric flask, dilute to volume with ultrapure water, and shake well. Take approximately 1mL of the solution, filter it through a 0.22μm filter membrane, and inject it into a sample vial to obtain the sample solution.

[0046] The sample solution was analyzed using a high-performance liquid chromatography (HPLC) instrument. The HPLC conditions were as follows: a C18 column (4.6 mm × 250 mm × 5 μm), a mobile phase of pure methanol solution and 0.05 mol / L potassium dihydrogen phosphate solution, gradient elution of the sample, flow rate: 0.8 mL / min, column temperature: 30 ℃, and detection wavelength: 250 nm.

[0047] Experimental results are as follows Figures 1-2 As shown.

[0048] Figure 1The graph shows the changes in HxR content in pork under ice-temperature storage conditions. As can be seen, citric acid can inhibit the increase of HxR within a certain range, with the 0.05% citric acid solution showing the best inhibitory effect. Throughout the storage period, the HxR content in the 0.05% citric acid solution treatment group was consistently lower than that in the 0% experimental group, significantly inhibiting the increase of HxR in pork during ice-temperature storage. The inhibitory effect of the 0.25% citric acid solution treatment group was higher than that of the 0.1% citric acid solution treatment group. Within the range of 0–50 h, the 0.1% citric acid solution treatment group showed an inhibitory effect on HxR, but after 50 h of storage, the HxR content was significantly higher than that in the 0% experimental group. Within the range of 0–82 h, the 0.25% citric acid solution treatment group showed an inhibitory effect on HxR, but after 80 h of storage, the HxR content was significantly higher than that in the 0% experimental group. As shown in the figure, 0.1% and 0.25% citric acid solutions can inhibit HxR within a certain time range, while 0.05% citric acid solution has the best inhibitory effect on HxR and has an inhibitory effect on HxR throughout the 144h storage period.

[0049] Figure 2 The graph shows the changes in Hx content in pork under ice-temperature storage conditions. As can be seen from the graph, the Hx content in pork consistently increases with increasing storage time. 0.05%, 0.1%, and 0.25% citric acid solutions all significantly inhibited the Hx content in pork during ice-temperature storage. The 0.25% citric acid solution showed a stronger inhibitory effect than the 0.05% solution, and the 0.05% solution showed a stronger inhibitory effect than the 0.1% solution.

[0050] according to Figure 1 , Figure 2 The results show that a 0.05% citric acid solution inhibited both Hx and HxR during storage. A 0.1% citric acid solution inhibited HxR within the range of 0–50 h and also inhibited Hx throughout the entire storage period. A 0.25% citric acid solution inhibited HxR within the range of 0–82 h and also inhibited Hx throughout the entire storage period.

[0051] This invention utilizes citric acid solutions at concentrations of 0.05%, 0.1%, and 0.25% to inhibit the increase of HxR and Hx during ice-temperature storage within a certain storage time range. This reduces the bitterness of pork, enhances the synergistic effect of umami substances, and reduces the accumulation of purine compounds in pork, preventing health problems such as elevated uric acid levels caused by consuming meat and meat products with high purine compound accumulation. Inhibiting the formation of HxR and Hx improves the sensory quality and nutritional value of pork, maintains textural and color stability, and extends shelf life while reducing the risk of spoilage.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for inhibiting HxR and Hx with citric acid, characterized in that: The pre-treated pork was soaked in a citric acid solution and then stored in an ice-cold environment.

2. According to claim 1, the method for inhibiting HxR and Hx with citric acid, the pretreatment steps for pork are as follows: removing the fascia from the pork and cleaning it thoroughly. Cutting the pork into slices 3cm wide, 4cm long, and 3mm thick.

3. The method for inhibiting HxR and Hx with citric acid according to claim 1, characterized in that, The citric acid solutions had concentrations of 0.05%, 0.1%, and 0.25%.

4. The method for inhibiting HxR and Hx with citric acid according to claim 1, characterized in that, Soak the pork for 2-5 minutes, then remove and drain.

5. The method for inhibiting HxR and Hx with citric acid according to claim 1, characterized in that, Storing should be done according to the ice temperature required for different parts of the pork.

6. The method for inhibiting HxR and Hx with citric acid according to claim 1, characterized in that, High performance liquid chromatography was used to determine the contents of HxR and Hx in pork during ice-temperature storage.

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