Method for inhibiting umami nucleotide decay

Abstract

The present application belongs to the technical field of food processing, and particularly relates to a method for inhibiting the attenuation of umami nucleotides. The method first immerses pretreated pork tenderloin slices in a 1-3 mmol / L zinc chloride solution for 2-5 minutes, and then transfers the pork tenderloin slices to an ice temperature environment with a temperature setting of -1.2 DEG C for storage. The present application can avoid the attenuation of umami during storage by immersing pork tenderloin in a zinc chloride solution for 2-5 minutes, and then combining ice temperature storage, can effectively inhibit the attenuation of umami nucleotides IMP (inosinic acid) and GMP (guanylic acid), improve the overall flavor of pork, make the taste of pork more rich, reduce the fishy smell of pork, and at the same time can maintain the storage stability of pork, and bring rich taste experience to consumers. The pork can still maintain stable taste flavor and quality characteristics during storage and circulation.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and specifically relates to a method for inhibiting the decay of umami nucleotides. Background Technology

[0002] Umami is a new taste distinct from the five basic tastes of sour, sweet, bitter, salty, and spicy; it cannot be produced by combining any other tastes. Umami is the most prominent taste characteristic of pork, and part of its umami flavor comes from umami nucleotides. Umami nucleotides are a class of compounds composed of ribose or deoxyribose, purine bases, and phosphate groups. However, they only have an umami-enhancing effect if a phosphate group is attached to the 5' carbon atom and the base is a purine group rather than a pyrimidine group, and a carbonyl group or a hydroxyl group is attached to the 6' carbon atom of the purine ring.

[0003] The umami flavor of pork is mainly dominated by umami nucleotides such as inosinic acid (IMP) and guanylic acid (GMP), with inosinic acid being the most abundant. It is a key umami substance generated through ATP degradation in post-slaughter meat, and its flavor intensity is far higher than other umami nucleotides. It is the most important umami nucleotide contributing to the umami flavor of pork, with a content reaching up to 1500 mg / kg. -1 The content of these compounds reaches its peak during the mature stage, making the most significant contribution to umami flavor.

[0004] The umami nucleotides in pork decrease significantly with increasing storage time after slaughter, leading to off-flavors such as sourness and fishiness, thus affecting the flavor and quality of the pork. Although ice-temperature storage can inhibit the decline of umami nucleotides compared to refrigeration, the content of umami nucleotides will still decrease with increasing storage time during ice-temperature storage.

[0005] Therefore, in order to inhibit the decay of umami nucleotides during pork storage, a method for inhibiting the decay of umami nucleotides is urgently needed. Summary of the Invention

[0006] To address the problems in the background art, the present invention provides a method for inhibiting the decay of umami nucleotides.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a method for inhibiting the attenuation of umami nucleotides, characterized in that the method comprises:

[0008] The pre-treated pork was soaked in a zinc chloride solution and then stored in an ice-temperature environment.

[0009] Preferably, the pork mentioned above refers to pork tenderloin, but it can also be other muscle tissues of pork carcasses.

[0010] 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.

[0011] Preferably, the concentration of the zinc chloride solution is 1–3 mmol / L.

[0012] Preferably, the pork is soaked for 2 to 5 minutes, and then removed and drained.

[0013] Preferably, the ice-temperature storage temperature is -1.2℃.

[0014] Preferably, high performance liquid chromatography is used to determine the content of umami nucleotides in pork during ice-temperature storage.

[0015] Preferred 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 ℃, and the detection wavelength is 250 nm.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] This invention, by soaking pork in a zinc chloride solution of a certain concentration, can inhibit the decay of umami nucleotides in pork, effectively suppressing the decay of umami nucleotides, reducing the occurrence of off-flavors such as sourness and fishiness, enhancing the overall flavor of pork, making its taste richer, reducing meaty odor, maintaining the stability of pork during storage, and providing consumers with a rich taste experience. It ensures that pork maintains stable taste, flavor, and quality characteristics during storage and distribution. Attached Figure Description

[0018] Figure 1 Freezing curve of pork tenderloin

[0019] Figure 2 Changes in inosinic acid content in pork under ice-temperature storage conditions

[0020] Figure 3 Changes in guanylic acid content in pork under ice-temperature storage conditions Detailed Implementation

[0021] 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.

[0022] This invention provides a method for inhibiting the decay of umami nucleotides. The method involves soaking pretreated pork in a zinc chloride solution and then storing it in an ice-temperature environment, which can inhibit the decay of umami nucleotides in pork.

[0023] In this embodiment of the invention, the umami nucleotides are extracted from pork tenderloin. The changes in the content of umami nucleotides in pork are used to reveal the inhibitory effect of zinc chloride on the attenuation of umami nucleotides during ice-temperature storage.

[0024] There is no particular limitation on the method for determining the umami nucleotide content in pork; those skilled in the art can choose from commonly used methods. In one specific embodiment of the present invention, high-performance liquid chromatography (HPLC) is used to determine the umami nucleotide content in pork. Furthermore, the extraction method and chromatographic conditions for free nucleotides in pork used in this embodiment are merely exemplary, and those skilled in the art can select appropriate conditions based on the actual target being identified.

[0025] In one specific embodiment, a precise amount of zinc chloride solid (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 an ice-temperature storage environment at -1.2℃. Samples are taken at storage time points of 0h, 24h, 48h, 72h, 96h, 120h, and 144h to determine the dynamic changes in the umami nucleotide content of the pork.

[0026] In one specific embodiment, the extraction method of the pork free nucleotides 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.

[0027] 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.

[0028] Specifically, the standard curve regression equations for IMP and GMP are as follows:

[0029] Standard products Standard curve Correlation coefficient IMP y = 15.7453x + 18.7352 <![CDATA[R 2 =0.99996]]> GMP y = 23.5446x + 27.6025 <![CDATA[R 2 =0.99996]]>

[0030] In one specific embodiment, the formula for calculating the umami nucleotide content in pork is as follows:

[0031]

[0032] Specifically, X: the nucleotide content 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.

[0033] To make the technical solution of the present invention clearer, the present invention will be described in detail below through several specific embodiments.

[0034] Example 1

[0035] The freezing point of pork was determined using a freezing method. After removing the fascia, the pork was cut into 3cm x 3cm x 3cm cubes. The pork samples were sealed with polyethylene plastic wrap, and a portable digital thermometer probe was inserted into the center of each cube. The cubes were then wrapped with polylactic acid plastic wrap and placed in a -18℃ cryogenic bath. Temperature changes at the center of the pork were recorded starting at 4℃, with data recorded every minute. A slight temperature rebound followed by a slow decline was observed when the temperature dropped below 0℃; this inflection point was taken as the freezing point.

[0036] Example 2

[0037] Prepare a 1 mmol / L zinc chloride solution; accurately weigh 0.136 g of zinc chloride solid (ZnCl2) and dissolve it completely in 1000 mL of ultrapure water with a glass rod.

[0038] 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 a 1mmol / L zinc chloride solution for 3 minutes, then store it at -1.2℃. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in the umami nucleotide content of the pork.

[0039] 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.

[0040] 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.

[0041] Example 3

[0042] Prepare a 1.5 mmol / L zinc chloride solution; accurately weigh 0.204 g of zinc chloride solid (ZnCl2) and dissolve it completely in 1000 mL of ultrapure water with a glass rod.

[0043] 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 a 1.5mmol / L zinc chloride solution for 3 minutes, then store it in an ice-temperature environment of -1.2℃. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in the content of umami nucleotides in the pork.

[0044] 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.

[0045] 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.

[0046] Example 4

[0047] Prepare a 2 mmol / L zinc chloride solution; accurately weigh 0.272 g of zinc chloride solid (ZnCl2) and dissolve it completely in 1000 mL of ultrapure water with a glass rod.

[0048] 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 a 2mmol / L zinc chloride solution for 3 minutes, then store it at -1.2℃. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in the umami nucleotide content of the pork.

[0049] 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.

[0050] 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.

[0051] Example 5

[0052] Prepare a 2.5 mmol / L zinc chloride solution; accurately weigh 0.340 g of zinc chloride solid (ZnCl2) and dissolve it completely in 1000 mL of ultrapure water with a glass rod.

[0053] 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 a 2.5mmol / L zinc chloride solution for 3 minutes, then store it at -1.2℃. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in the content of umami nucleotides in the pork.

[0054] 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.

[0055] 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.

[0056] Experimental Example 1

[0057] To verify whether zinc chloride has an inhibitory effect on the attenuation of umami nucleotides, a control group was set up. The zinc chloride solution was replaced with ultrapure water.

[0058] 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 (0mmol / L) for 3 minutes, then store it in an ice-temperature environment of -1.2℃. Samples were taken at 0h, 24h, 48h, 72h, 96h, 120h, and 144h of storage to determine the dynamic changes in the content of umami nucleotides in the pork.

[0059] 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.

[0060] 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.

[0061] Experimental results are as follows Figures 1-3 As shown.

[0062] Figure 1 The figure shows the freezing curve of pork tenderloin. As can be seen, after the pork temperature drops, it rebounds, remains at -1.2℃ for a period, and then slowly decreases again. At this point, ice crystals form within the meat sample. Although there is heat exchange, the temperature remains relatively stable. Therefore, -1.2℃ is taken as the freezing point temperature of pork tenderloin. Due to differences in tissue structure, composition, and functional uses of different parts of pork, their freezing temperatures vary. If other parts of pork are to be used in the experiment, their freezing temperatures must be re-measured.

[0063] Figure 2This study investigated the changes in inosinic acid (IA) content in pork under ice-temperature storage conditions. IIA is the most abundant umami nucleotide in pork, with a significantly higher flavor intensity than other umami nucleotides, making it the most important umami nucleotide contributing to the umami flavor of pork. As shown in the figure, with increasing storage time, the IIA content in pork without added zinc chloride (ultrapure water) generally decreased, from 168.99 mg / 100g to 100.30 mg / 100g. Zinc chloride solutions of 1 mmol / L, 1.5 mmol / L, 2 mmol / L, and 2.5 mmol / L all caused the IIA content in pork to initially increase and then decrease. Even after 144 hours of storage, the IIA content in all four groups of pork was still higher than the initial content (168.99 mg / 100g), at 187.57 mg / 100g, 191.21 mg / 100g, 198.21 mg / 100g, and 177.41 mg / 100g, respectively. As can be clearly seen from the figure, zinc chloride can significantly inhibit the decline of inosinic acid and increase the content of inosinic acid during storage, thereby enhancing the overall flavor of pork and making it more flavorful and delicious.

[0064] Figure 3 This study investigated the changes in guanylic acid (GAN) content in pork under ice-temperature storage conditions. Although the GAN content in pork is not as high as that of inosinic acid, GAN can significantly enhance the umami intensity and complexity of pork through a synergistic effect with inosinic acid. As shown in the figure, the GAN content in pork without added zinc chloride (ultrapure water) decreased with increasing storage time. Zinc chloride solutions at concentrations of 1 mmol / L, 1.5 mmol / L, 2 mmol / L, and 2.5 mmol / L all inhibited the decline of GAN, slowing down the umami degradation during pork storage. Inhibiting the decline of GAN effectively maintains the natural umami intensity of pork, prolongs flavor persistence, and improves processing and storage stability.

[0065] according to Figure 2-3 The results show that this invention can significantly inhibit the attenuation of umami nucleotides (inosine monophosphate and guanylic acid), significantly improve and maintain the umami quality of pork, and maximize the retention of the natural umami substances in pork.

[0066] Finally, it should be noted that although the description of the present invention is quite detailed and the embodiments described have been described, it is not intended to be limited to any of these details or embodiments. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, combinations, simplifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for inhibiting the attenuation of umami nucleotides, characterized in that: The pre-treated pork was soaked in a zinc chloride solution and then stored in an ice-temperature environment.

2. The method for inhibiting the attenuation of umami nucleotides according to claim 1, wherein the pork used is pork tenderloin.

3. The method for inhibiting the attenuation of umami nucleotides according to claim 1, wherein the pork pretreatment steps 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.

4. The method for inhibiting the attenuation of umami nucleotides according to claim 1, characterized in that, The concentration of zinc chloride solution is 1–3 mmol / L.

5. The method for inhibiting the attenuation of umami nucleotides according to claim 1, characterized in that, Soak the pork for 2-5 minutes, then remove and drain.

6. The method for inhibiting the attenuation of umami nucleotides according to claim 1, characterized in that, The ice-temperature storage temperature is -1.2℃.

7. The method for inhibiting the attenuation of umami nucleotides according to claim 1, characterized in that, High performance liquid chromatography (HPLC) was used to determine the content of umami nucleotides in pork during ice-temperature storage.

8. The method according to claim 6, characterized in that, The high performance liquid chromatography (HPLC) conditions were as follows: a C18 column (4.6 mm × 250 mm × 5 μm) was used, the mobile phase was pure methanol and 0.05 mol / L potassium dihydrogen phosphate solution, gradient elution of the sample was performed, the flow rate was 0.8 mL / min, the column temperature was 30 ℃, and the detection wavelength was 250 nm.

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