Method for quickly identifying salt precipitation risk of Maotai-flavor liquor

Abstract

The application discloses a method for quickly identifying salt precipitation risk of Maotai-flavor liquor. The method takes a typical salt precipitate, magnesium palmitate, in Maotai-flavor liquor as a marker to predict the salt precipitation risk of Maotai-flavor liquor in advance. After the Maotai-flavor liquor is purified through pressure reduction filtration, a deposition layer can be formed on the organic filter membrane. The scattering of the deposition layer is analyzed through a double light path spectrophotometer, and then compared with a standard sample, so that the salt precipitation risk of the Maotai-flavor liquor during aging can be quickly predicted.

Description

Technical Field

[0001] This invention belongs to the field of liquor testing technology, and in particular relates to a rapid quantitative analysis method for the risk of salt precipitation in sauce-flavored liquor. Background Technology

[0002] Maotai-flavor baijiu, made from sorghum, wheat, water, and other raw materials, is produced through traditional solid-state fermentation, distillation, aging, and blending. It is one of the main aroma types of Chinese baijiu. The national standard "Maotai-flavor Baijiu" (GB / T 26760-2011) stipulates that "high-quality Maotai-flavor baijiu should have a colorless or slightly yellow transparent appearance, free of suspended matter and sediment," clearly defining the sensory quality requirements for Maotai-flavor baijiu. Within the industry, sedimentation in Maotai-flavor baijiu has always been a quality concern. Specifically: firstly, sedimentation affects the sensory quality of the product, and the collection process is cumbersome and difficult to quantify; secondly, the observation of sedimentation is highly subjective, with varying standards for acceptable sediment levels among individuals; and thirdly, the optimal drinking period for Maotai-flavor baijiu products is generally quite long, necessitating the determination of risk indicators to ensure product quality.

[0003] Currently, the causes of sedimentation in baijiu (Chinese liquor) are mainly categorized into precipitation of higher fatty acids, dissolution of silicates, and precipitation of metal salts. Precipitation of higher fatty acids often manifests as flocculent insoluble matter when the storage temperature is below 10℃. Since this insoluble matter dissolves normally upon rewarming, it is generally considered a normal physical phenomenon. Dissolution of silicates often manifests as turbidity caused by glass packaging. Due to improvements in glass bottle materials and optimization of bottle washing processes, this problem has been effectively controlled. Regarding the precipitation of metal salts in baijiu, CN102876554A discloses a method for removing sediment from wolfberry wine using cation exchange, which removes sediment by reducing the concentration of calcium ions. However, considering the rich variety of cations in the baijiu, complete removal is difficult, and smaller cations (such as magnesium ions) have poor removal effects.

[0004] Therefore, predicting the precipitation of sauce-flavored liquor by analyzing the distribution of acid ions and the solubility ranking of precipitates after salt formation is a more feasible method, and the prediction of metal salt precipitation risk is also of great practical significance for further improving the quality of sauce-flavored liquor products. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing technologies and provides a method for rapid identification of salt precipitation risks in Maotai-flavor liquor. The method uses magnesium palmitate, a typical salt precipitation substance in Maotai-flavor liquor, as a marker. After the liquor undergoes vacuum filtration purification, a deposition layer forms on an organic filter membrane. The scattering of the deposition layer is then analyzed using a dual-path spectrophotometer, and compared with a standard sample to predict the risk of salt precipitation during the aging process of Maotai-flavor liquor.

[0006] This invention provides the following technical solution: A method for rapid identification of salt precipitation risk in soy sauce-flavored baijiu includes the following steps: (1) Low-temperature pretreatment of sauce-flavored liquor: Select several batches of sauce-flavored liquor samples of the same type but different batches. Store the standard sauce-flavored liquor samples at 4-10℃ for 48-72 hours. After restoring to room temperature, take the upper layer of liquor samples for later use. Sauce-flavored liquor samples used for analysis do not undergo low-temperature pretreatment. (2) Preparation of magnesium palmitate standard curve: Magnesium palmitate reference standard was added to the same batch of standard sauce-flavored liquor samples that had undergone low-temperature pretreatment to prepare sauce-flavored liquor samples with different concentrations of magnesium palmitate. (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared sauce-flavored liquor samples and each batch of analytical sauce-flavored liquor samples at a ratio of 10 mg / L-30 mg / L, and stirred thoroughly. (4) Vacuum filtration: Each batch of samples after adding vitamin E was subjected to vacuum filtration, and the deposits on the organic membrane were collected. (5) Sediment purification treatment: The protein deposits remaining on the organic membrane are dissolved by protease, and then the membrane is washed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After shaking and standing to separate the layers, the lower precipitate is retained. The vacuum filtration operation of step (4) is repeated on the lower precipitate and washed with ethanol solution of the same strength to obtain a pure precipitate filter membrane. (6) Transmission analysis of sediment film: The sediment filter film formed by each batch of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (Haze, %) and total transmittance value (T, %). (7) Precipitation evaluation: When the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji less than 0.0001 mg / L, the analyzed sauce-flavored liquor sample is considered to have approximately no precipitation risk; when the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji greater than or equal to 0.0001 mg / L and less than 0.1 mg / L, the analyzed sauce-flavored liquor sample is considered to have a significant precipitation risk; when the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji greater than or equal to 0.1 mg / L and less than 1 mg / L, the analyzed sauce-flavored liquor sample is considered to have precipitation.

[0007] Preferably, the concentrations of magnesium palmitate reference standards in the magnesium palmitate-prepared sauce-flavored liquor samples in step (2) are 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L, respectively, and the preparation volume of each group is 1-3 L.

[0008] Preferably, in step (3), a magnetic stirring device is used for thorough stirring. The parameters of the magnetic stirring device are: rotor length 40-60mm, speed range 200-600rpm, and temperature control is set to room temperature.

[0009] Preferably, in step (4), a water ring type vacuum filtration device is used for filtration, requiring a vacuum degree of 0.085-0.098 MPa and a single-head pumping capacity of 6-10 L / min.

[0010] Preferably, the organic membrane in step (4) is a microfiltration membrane with a pore size of 0.22-0.80 μm; more preferably, the microfiltration membrane material is selected from 90-130 μm thick nylon 66 (polyhexamethylene adipamide), 110-120 μm thick polypropylene (PP) and 5-50 μm thick polytetrafluoroethylene (PTFE).

[0011] Preferably, the amount of protease used in step (5) is 0.2-0.6g, and the treatment time is 1-3 hours. More preferably, an acidic protease with a pH of 3.0-5.0 or a neutral protease with a pH of 6.0-7.5 is used. More preferably, an acidic protease with a pH of 3.0-5.0 is used.

[0012] Preferably, step (6) is as follows: (1) Light source setting: use the default D65 light source and d / 0° transmission mode; (2) Black and white correction: the white correction method is to use the corresponding blank organic film as the reference for 100% transmission, and the black correction method is to use a light shield to ensure a 0% transmission baseline; (3) Multi-point measurement: place the precipitated film flat in the transmission clamp, avoiding wrinkles or bubbles, and align the position with the center of the light path; measure at least 5 times and take the average value. After each measurement, rotate the film 60° around the center of the light path to obtain better representativeness through multiple measurements. After the measurement is completed, calculate the haze value (H, %) and the total transmittance value (T, %).

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) Traditionally, the industry relies on manual visual assessment of precipitation, which lacks a unified quantitative standard. The assessment results vary from person to person and cannot be standardized. This invention establishes a standard curve of magnesium palmitate concentration-haze / total transmittance, and divides the quantitative judgment thresholds into three levels: no precipitation risk, obvious precipitation risk, and precipitation already present. It uses objective values ​​from a dual-path spectrometer to replace subjective visual inspection, realizing the digital and standardized hierarchical identification of precipitation risk, which is convenient for enterprises to carry out batch quality control, product labeling and risk management.

[0014] (2) The precipitation of high fatty acid flocculents in sauce-flavored liquor at low temperature will interfere with the observation and detection of salt precipitation. This invention sets up a standard liquor sample low-temperature pretreatment step to distinguish between reversible lipid turbidity and irreversible metal salt precipitation; at the same time, vitamin E is added to the system to inhibit the low-temperature precipitation of fatty acids in the liquor, thereby eliminating the interference of lipid precipitation on the extraction and spectral detection of salt deposits from the source, avoiding misjudgment, and solving the defects of traditional visual observation and ion detection that cannot distinguish between the two types of precipitation.

[0015] (3) Existing wine ion detection methods cannot separate protein and lipid impurities, and these impurities interfere with the detection values. This invention uses multiple purification steps, including protease digestion of protein impurities attached to the filter membrane, ethanol layer purification, and secondary vacuum filtration, to remove non-salt impurities and retain only magnesium palmitate characteristic deposits for spectral analysis. This significantly reduces matrix interference and greatly improves the stability and repeatability of haze and transmittance detection data.

[0016] (4) This invention does not require complex large-scale ion detection equipment. It can be completed by conventional equipment such as vacuum filtration, enzymatic purification, and spectrophotometry. It does not require long-term ion chromatography analysis. It can process multiple batches of wine samples simultaneously, quickly complete the sedimentation risk screening of different production batches and different aging cycles of sauce-flavored wine, adapt to the large-scale quality control needs of winery raw wine and finished wine, and shorten the product risk detection cycle. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of this invention is for describing specific implementation schemes and not for limiting the scope of protection of this invention.

[0018] When a range of values ​​is given, it should be understood that, unless otherwise stated in this invention, the two endpoints of each range and any value between the two endpoints may be selected.

[0019] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly used in the field to which this invention pertains. The terminology used to describe this invention is intended only to describe a particular implementation and is not intended to limit the scope of the teachings. This invention can be implemented using any prior art methods, apparatus, and materials similar to or equivalent to those described, used, or made in the embodiments of this invention.

[0020] The term “and / or” as used herein should be understood to mean any one of the options or any combination of two or more of the options.

[0021] As used herein, the term "about" indicates a range of ±20% of the following value. In some embodiments, the term "about" indicates a range of ±10% of the following value. In some embodiments, the term "about" indicates a range of ±5% of the following value.

[0022] This invention provides a method for rapid identification of salt precipitation risk in soy sauce-flavored baijiu, comprising the following steps: First, typical salt precipitates in Maotai-flavor liquor were analyzed to determine magnesium palmitate as a key parameter for evaluating the long-term stability of Maotai-flavor liquor during aging. Second, vitamin E was added to the liquor to reduce the oxidation of higher fatty acid esters during vacuum filtration, preventing the formation of difficult-to-separate yellow oxides on the organic filter membrane, which would affect the smoothness of the deposits on the membrane and reduce the impact of wrinkles or bubbles on the transmission analysis of the deposit membrane. Third, the sediment layer was further purified using protease, and after settling in a separatory funnel, the lower precipitate was retained and re-filtered under vacuum to form a sediment layer on the organic filter membrane. Finally, the scattering of the sediment layer was analyzed using a dual-path spectrophotometer, and compared with standard samples to predict the risk of salt precipitation during the aging process of Maotai-flavor liquor.

[0023] In one specific implementation, the following steps are included: (1) Pretreatment of sauce-flavored liquor samples: Select several batches of sauce-flavored liquor samples of the same type but different batches. Among them, the standard sauce-flavored liquor samples (batch number ≥ 3) are stored at 4-10℃ for 48-72 hours, and then after returning to room temperature, the upper layer of liquor is taken for use. Each batch is used as a parallel test, and the average of at least 3 parallel tests is taken. The sauce-flavored liquor samples used for analysis are not subjected to low-temperature pretreatment (batch number ≥ 3), and each batch is used as an independent test.

[0024] In this step, the purpose of low-temperature pretreatment is to remove the original precipitates in the sauce-flavored liquor, so that the concentration of the sauce-flavored liquor sample can be more accurate when magnesium palmitate is added later.

[0025] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after the same batch was pretreated at low temperature, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, 100 mg / L. The preparation volume of each group was 1-3 L.

[0026] In this step, the magnesium palmitate curve is prepared, and magnesium palmitate is used as a typical representative of salt precipitation in soy sauce liquor. The main reason is that the salt precipitation in soy sauce liquor is mainly composed of calcium or magnesium salts formed by lactic acid, acetic acid, and palmitic acid anions. Among them, the precipitate formed by palmitate ions and cations in soy sauce liquor has the lowest solubility and is the most preferential to precipitate when all acid anions coexist, thus having an early predictive function. In addition, considering that the calcium ion concentration is usually low during the brewing and blending process of soy sauce liquor, the needle-like crystal precipitates formed by higher fatty acid salts are mainly magnesium palmitate. Therefore, the magnesium palmitate content is used as one of the key parameters for evaluating the long-term stability of soy sauce liquor during aging.

[0027] (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared soy sauce-flavored liquor samples (1-3L, 7 groups) and each batch of analytical soy sauce-flavored liquor samples (1-3L) in a magnetic stirring apparatus, at an addition ratio of 10mg / L-30mg / L. The magnetic stirring apparatus parameters were: rotor length 40-60mm, rotation speed range 200-600rpm, and room temperature control.

[0028] In this step, vitamin E (V) is added to the sauce-flavored liquor. E The main purpose is to reduce the oxidation of higher fatty acid esters during vacuum filtration, which forms difficult-to-separate yellow oxides on the organic filter membrane, affecting the smoothness of the deposits on the membrane and reducing the impact of wrinkles or bubbles on the membrane transmission analysis of the precipitate. Simultaneously, to subtract background, the volume of the liquor used for preparing the magnesium palmitate sample must be consistent with the volume of the liquor sample being analyzed, i.e., the amount of vitamin E added must be consistent.

[0029] (4) Vacuum filtration: A water-ring vacuum filtration device, in conjunction with an organic membrane material, was used to filter each batch of samples after the addition of vitamin E, and the deposits on the organic membrane were collected. The vacuum degree of the water-ring vacuum filtration device was 0.085-0.098 MPa, the single-head air extraction rate was 6-10 L / min, and the water tank volume was 15 L.

[0030] In this step, the organic membrane materials are nylon 66 (polyhexamethylene adipamide), polypropylene (PP), and polytetrafluoroethylene (PTFE), with thicknesses of 90-130μm, 110-120μm, and 5-50μm, respectively, and pore sizes of 0.22μm, 0.45μm, and 0.80μm and above, respectively, for microfiltration membranes.

[0031] Besides differences in membrane thickness and pore size, the hydrophilic and hydrophobic properties of the membranes also differ. Nylon 66 membranes are naturally hydrophilic, polypropylene membranes are moderately hydrophilic, while polytetrafluoroethylene membranes are hydrophobic. Considering the permeability and filtration efficiency of the liquor sample, the hydrophilic nylon 66 membrane is preferred.

[0032] (5) Sediment purification treatment: Each batch of magnesium palmitate-prepared sauce-flavored liquor samples (1-3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (1-3L) were treated with protease to dissolve the protein deposits remaining on the organic microfiltration membrane. The amount of protease used was 0.2-0.6g, and the treatment time was 1-3 hours. Then, the membrane was rinsed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After thorough shaking and standing to separate the layers, the lower precipitate was retained. Then, step (4) vacuum filtration was repeated, and ethanol solution of the same strength was used for rinsing until a relatively pure sediment was formed on the organic filter membrane.

[0033] In this step, in order to better remove the protein precipitates accumulated on the membrane after vacuum filtration, the following types of proteases can be used: acidic proteases (optimal pH 3.0-5.0) and neutral proteases (optimal pH 6.0-7.5). Considering the pH value of Maotai liquor, acidic proteases are preferred.

[0034] (6) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (Haze, %) and total transmittance value (T, %). The specific steps are as follows: (1) Light source setting: Use the default D65 light source and d / 0° (transmission) mode; (2) Black and white correction: The white correction method is to use the corresponding blank organic film as the 100% transmittance reference, and the black correction method is to use a light shield to ensure a 0% transmittance baseline; (3) Multi-point measurement: Place the sediment film flat in the transmission clamp, avoiding wrinkles or bubbles, and align the position with the center of the light path. Measure at least 5 times and take the average value. After each measurement, rotate the film about 60° around the center of the light path to obtain better representativeness through multiple measurements. After the measurement is completed, the instrument will automatically calculate the haze value (H, %) and total transmittance value (T, %).

[0035] The main roles of each detection index in the analysis of salt precipitation in soy sauce liquor are as follows: Haze value (H, %) refers to the degree of blurring caused by scattering when light passes through the film. Since a blank organic film is used as the benchmark for 100% transmission during calibration, when the organic film is flat, without wrinkles or bubbles, the change in haze value is mainly affected by the scattering of magnesium palmitate crystals in the purified deposits; Total transmittance value (T, %) refers to the proportion of total transmitted light flux to incident light, which is related to the amount of purified magnesium palmitate deposits collected on the organic film.

[0036] (7) Precipitation evaluation: When the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji less than 0.0001 mg / L, it indicates that the analyzed sauce-flavored liquor sample has approximately no risk of precipitation; when the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji less than 0.1 mg / L, it indicates that the analyzed sauce-flavored liquor sample has a significant risk of precipitation; when the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji less than 1 mg / L, it indicates that precipitation has occurred in the analyzed sauce-flavored liquor sample.

[0037] In this step, "nearly no risk of precipitation" means that under conditions of 40℃±2℃, uncontrolled humidity (sealed), and protection from light, the sample remains clear and free of precipitation after more than 90 days of observation; "significant risk of precipitation" means that under conditions of 40℃±2℃, uncontrolled humidity (sealed), and protection from light, precipitation appears in the sample within 30 days of observation.

[0038] The following embodiments are provided to aid in understanding the present invention. However, it should be understood that these embodiments are for illustrative purposes only and do not constitute any limitation. The actual scope of protection of the present invention is set forth in the claims. It should be understood that any modifications and changes can be made without departing from the spirit of the present invention. Unless otherwise specified, the raw materials used in the embodiments are all commercially available products in the art, their specifications are conventional specifications in the art, and the methods used are conventional methods in the art. The instruments and equipment used in the embodiments are conventional instruments and equipment in the art.

[0039] Example 1 This embodiment provides a method for rapid identification of salt precipitation risk in Maotai-flavor liquor, including the following steps: (1) Pretreatment of sauce-flavored liquor samples: Six batches of sauce-flavored liquor samples of the same type but different batches were selected. Among them, the standard sauce-flavored liquor samples (3 batches) were stored at 4℃ for 60 hours, and then the samples were taken from the top layer after being restored to room temperature. Each batch was used as a parallel test and the average value of the parallel tests was taken. The sauce-flavored liquor samples used for analysis were not subjected to low-temperature pretreatment (3 batches), and each batch was used as an independent test.

[0040] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after low-temperature pretreatment, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L. The volume of each group was 1 L.

[0041] (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared baijiu sample (1L, 7 groups) and each batch of analytical baijiu sample (1L) in a magnetic stirring apparatus, at an addition ratio of 15mg / L. The magnetic stirring apparatus parameters were: rotor length 50mm, rotation speed range 300rpm, and room temperature control.

[0042] (4) Vacuum filtration: A water-ring vacuum filtration device was used in conjunction with an organic membrane material to filter each batch of samples after the addition of vitamin E, and the deposits on the organic membrane were collected. The water-ring vacuum filtration device had a vacuum degree of 0.098 MPa, a single-head pumping capacity of 10 L / min, a water tank volume of 15 L, and the organic membrane material was nylon 66 (polyhexamethylene adipamide) with a thickness of 90-130 μm and a pore size of 0.45 μm.

[0043] (5) Sediment purification treatment: Each batch of magnesium palmitate-prepared sauce-flavored liquor samples (groups 1 and 7) and each batch of analytical sauce-flavored liquor samples (1L) were treated with acidic protease to dissolve the protein deposits remaining on the organic microfiltration membrane. The amount of protease used was 0.2g, and the treatment time was 1 hour. Then, the membrane was rinsed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After thorough shaking and standing to separate the layers, the lower precipitate was retained. Then, step (4) vacuum filtration was repeated, and ethanol solution of the same strength was used for rinsing until a relatively pure sediment was formed on the organic filter membrane.

[0044] (6) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (H, %) and total transmittance value (T, %).

[0045] (7) Precipitation evaluation: The haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji of the analyzed sauce-flavored liquor sample being less than 0.0001 mg / L, 0.1 mg / L, and 1 mg / L, respectively, are measured. The results are shown in Table 1.

[0046] Example 2 This embodiment provides a method for rapid identification of salt precipitation risk in Maotai-flavor liquor, including the following steps: (1) Pretreatment of sauce-flavored liquor samples: Six batches of sauce-flavored liquor samples of the same type but different batches were selected. Among them, the standard sauce-flavored liquor samples (3 batches) were stored at 4℃ for 60 hours, and then the samples were taken from the top layer after being restored to room temperature. Each batch was used as a parallel test and the average value of the parallel tests was taken. The sauce-flavored liquor samples used for analysis were not subjected to low-temperature pretreatment (3 batches), and each batch was used as an independent test.

[0047] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after low-temperature pretreatment, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L. The preparation volume of each group was 3 L.

[0048] (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) in a magnetic stirring apparatus, at an addition ratio of 15mg / L. The magnetic stirring apparatus parameters were: rotor length 50mm, rotation speed range 300rpm, and room temperature control.

[0049] (4) Vacuum filtration: A water-ring vacuum filtration device was used in conjunction with an organic membrane material to filter each batch of samples after the addition of vitamin E, and the deposits on the organic membrane were collected. The water-ring vacuum filtration device had a vacuum degree of 0.098 MPa, a single-head pumping capacity of 10 L / min, a water tank volume of 15 L, and the organic membrane material was nylon 66 (polyhexamethylene adipamide) with a thickness of 90-130 μm and a pore size of 0.45 μm.

[0050] (5) Sediment purification treatment: Each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) were treated with acidic protease to dissolve the protein deposits remaining on the organic microfiltration membrane. The amount of protease used was 0.6g, and the treatment time was 3 hours. Then, the membrane was rinsed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After thorough shaking and standing to separate the layers, the lower precipitate was retained. Then, step (4) vacuum filtration was repeated, and ethanol solution of the same strength was used for rinsing until a relatively pure sediment was formed on the organic filter membrane.

[0051] (6) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (H, %) and total transmittance value (T, %).

[0052] (7) Precipitation evaluation: The haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji of the analyzed sauce-flavored liquor sample being less than 0.0001 mg / L, 0.1 mg / L, and 1 mg / L, respectively, are measured. The results are shown in Table 1.

[0053] Example 3 This embodiment provides a method for rapid identification of salt precipitation risk in Maotai-flavor liquor, including the following steps: (1) Pretreatment of sauce-flavored liquor samples: Six batches of sauce-flavored liquor samples of the same type but different batches were selected. Among them, the standard sauce-flavored liquor samples (3 batches) were stored at 4℃ for 60 hours, and then the samples were taken from the top layer after being restored to room temperature. Each batch was used as a parallel test and the average value of the parallel tests was taken. The sauce-flavored liquor samples used for analysis were not subjected to low-temperature pretreatment (3 batches), and each batch was used as an independent test.

[0054] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after low-temperature pretreatment, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L. The preparation volume of each group was 3 L.

[0055] (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) in a magnetic stirring apparatus, at an addition ratio of 15mg / L. The magnetic stirring apparatus parameters were: rotor length 50mm, rotation speed range 300rpm, and room temperature control.

[0056] (4) Vacuum filtration: A water-ring vacuum filtration device was used in conjunction with an organic membrane material to filter each batch of samples after the addition of vitamin E, and the deposits on the organic membrane were collected. The water-ring vacuum filtration device had a vacuum degree of 0.098 MPa, a single-head pumping capacity of 10 L / min, a water tank volume of 15 L, and the organic membrane material was a polypropylene (PP) organic membrane with a thickness of 110-120 μm and a pore size of 0.45 μm.

[0057] (5) Sediment purification treatment: Each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) were treated with acidic protease to dissolve the protein deposits remaining on the organic microfiltration membrane. The amount of protease used was 0.6g, and the treatment time was 3 hours. Then, the membrane was rinsed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After thorough shaking and standing to separate the layers, the lower precipitate was retained. Then, step (4) vacuum filtration was repeated, and ethanol solution of the same strength was used for rinsing until a relatively pure sediment was formed on the organic filter membrane.

[0058] (6) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (H, %) and total transmittance value (T, %).

[0059] (7) Precipitation evaluation: The haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji of the analyzed sauce-flavored liquor sample being less than 0.0001 mg / L, 0.1 mg / L, and 1 mg / L, respectively, are measured. The results are shown in Table 1.

[0060] Example 4 This embodiment provides a method for rapid identification of salt precipitation risk in Maotai-flavor liquor, including the following steps: (1) Pretreatment of sauce-flavored liquor samples: Six batches of sauce-flavored liquor samples of the same type but different batches were selected. Among them, the standard sauce-flavored liquor samples (3 batches) were stored at 4℃ for 60 hours, and then the samples were taken from the top layer after being restored to room temperature. Each batch was used as a parallel test and the average value of the parallel tests was taken. The sauce-flavored liquor samples used for analysis were not subjected to low-temperature pretreatment (3 batches), and each batch was used as an independent test.

[0061] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after low-temperature pretreatment, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L. The preparation volume of each group was 3 L.

[0062] (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) in a magnetic stirring apparatus, at an addition ratio of 15mg / L. The magnetic stirring apparatus parameters were: rotor length 50mm, rotation speed range 300rpm, and room temperature control.

[0063] (4) Vacuum filtration: A water-ring vacuum filtration device was used in conjunction with an organic membrane material to filter each batch of samples after the addition of vitamin E, and the deposits on the organic membrane were collected. The water-ring vacuum filtration device had a vacuum degree of 0.098 MPa, a single-head pumping capacity of 10 L / min, a water tank volume of 15 L, and the organic membrane material was polytetrafluoroethylene (PTFE) with a thickness of 5-50 μm and a pore size of 0.45 μm.

[0064] (5) Sediment purification treatment: Each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) were treated with acidic protease to dissolve the protein deposits remaining on the organic microfiltration membrane. The amount of protease used was 0.6g, and the treatment time was 3 hours. Then, the membrane was rinsed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After thorough shaking and standing to separate the layers, the lower precipitate was retained. Then, step (4) vacuum filtration was repeated, and ethanol solution of the same strength was used for rinsing until a relatively pure sediment was formed on the organic filter membrane.

[0065] (6) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (H, %) and total transmittance value (T, %).

[0066] (7) Precipitation evaluation: The haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji of the analyzed sauce-flavored liquor sample being less than 0.0001 mg / L, 0.1 mg / L, and 1 mg / L, respectively, are measured. The results are shown in Table 1.

[0067] Comparative Example 1 This comparative example provides a method for rapid identification of salt precipitation risk in Maotai-flavor liquor, including the following steps: (1) Pretreatment of sauce-flavored liquor samples: Six batches of sauce-flavored liquor samples of the same type but different batches were selected. Among them, the standard sauce-flavored liquor samples (3 batches) were stored at 4℃ for 60 hours, and then the samples were taken from the top layer after being restored to room temperature. Each batch was used as a parallel test and the average value of the parallel tests was taken. The sauce-flavored liquor samples used for analysis were not subjected to low-temperature pretreatment (3 batches), and each batch was used as an independent test.

[0068] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after low-temperature pretreatment, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L. The preparation volume of each group was 3 L.

[0069] (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) in a magnetic stirring apparatus, at an addition ratio of 15mg / L. The magnetic stirring apparatus parameters were: rotor length 50mm, rotation speed range 300rpm, and room temperature control.

[0070] (4) Vacuum filtration: A water-ring vacuum filtration device was used in conjunction with an organic membrane material to filter each batch of samples after the addition of vitamin E, and the deposits on the organic membrane were collected. The vacuum degree of the water-ring vacuum filtration device was 0.098 MPa, the single-head pumping volume was 10 L / min, the water tank volume was 15 L, and the organic membrane material was nylon 66 (polyhexamethylene adipamide) microfiltration membrane with a pore size of 0.20 μm.

[0071] (5) Sediment purification treatment: Each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) were treated with protease to dissolve the protein deposits remaining on the organic microfiltration membrane. The amount of protease used was 0.6g, and the treatment time was 3 hours. Then, the membrane was rinsed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After thorough shaking and standing to separate the layers, the lower precipitate was retained. Then, step (4) vacuum filtration was repeated, and ethanol solution of the same strength was used for rinsing until a relatively pure sediment was formed on the organic filter membrane.

[0072] (6) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (H, %) and total transmittance value (T, %).

[0073] (7) Precipitation evaluation: The haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji of the analyzed sauce-flavored liquor sample being less than 0.0001 mg / L, 0.1 mg / L, and 1 mg / L, respectively, are measured. The results are shown in Table 1.

[0074] Comparative Example 2 This comparative example provides a method for rapid identification of salt precipitation risk in Maotai-flavor liquor, including the following steps: (1) Pretreatment of sauce-flavored liquor samples: Six batches of sauce-flavored liquor samples of the same type but different batches were selected. Among them, the standard sauce-flavored liquor samples (3 batches) were stored at 4℃ for 60 hours, and then the samples were taken from the top layer after being restored to room temperature. Each batch was used as a parallel test and the average value of the parallel tests was taken. The sauce-flavored liquor samples used for analysis were not subjected to low-temperature pretreatment (3 batches), and each batch was used as an independent test.

[0075] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after low-temperature pretreatment, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L. The preparation volume of each group was 3 L.

[0076] (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) in a magnetic stirring apparatus, at an addition ratio of 15mg / L. The magnetic stirring apparatus parameters were: rotor length 50mm, rotation speed range 300rpm, and room temperature control.

[0077] (4) Vacuum filtration: A water-ring vacuum filtration device was used in conjunction with an organic membrane material to filter each batch of samples after the addition of vitamin E, and the deposits on the organic membrane were collected. The vacuum degree of the water-ring vacuum filtration device was 0.098 MPa, the single-head pumping volume was 10 L / min, the water tank volume was 15 L, and the organic membrane material was nylon 66 (polyhexamethylene adipamide) microfiltration membrane with a pore size of 0.80 μm.

[0078] (5) Sediment purification treatment: Each batch of magnesium palmitate-prepared sauce-flavored liquor samples (3L, 7 groups) and each batch of analytical sauce-flavored liquor samples (3L) were treated with protease to dissolve the protein deposits remaining on the organic microfiltration membrane. The amount of protease used was 0.6g, and the treatment time was 3 hours. Then, the membrane was rinsed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After thorough shaking and standing to separate the layers, the lower precipitate was retained. Then, step (4) vacuum filtration was repeated, and ethanol solution of the same strength was used for rinsing until a relatively pure sediment was formed on the organic filter membrane.

[0079] (6) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (H, %) and total transmittance value (T, %).

[0080] (7) Precipitation evaluation: The haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji of the analyzed sauce-flavored liquor sample being less than 0.0001 mg / L, 0.1 mg / L, and 1 mg / L, respectively, are measured. The results are shown in Table 1.

[0081] Comparative Example 3 This comparative example provides a method for rapid identification of salt precipitation risk in Maotai-flavor liquor, including the following steps: (1) Pretreatment of sauce-flavored liquor samples: Six batches of sauce-flavored liquor samples of the same type but different batches were selected. Among them, the standard sauce-flavored liquor samples (3 batches) were stored at 4℃ for 60 hours, and then the samples were taken from the top layer after being restored to room temperature. Each batch was used as a parallel test and the average value of the parallel tests was taken. The sauce-flavored liquor samples used for analysis were not subjected to low-temperature pretreatment (3 batches), and each batch was used as an independent test.

[0082] (2) Preparation of magnesium palmitate standard curve: In the standard sauce-flavored liquor sample, after low-temperature pretreatment, magnesium palmitate reference standard was used to prepare corresponding samples in the following proportions: 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L. The preparation volume of each group was 3 L.

[0083] (3) Vacuum filtration: A water-ring vacuum filtration device was used in conjunction with an organic membrane material to filter each batch of samples and collect the deposits on the organic membrane. The water-ring vacuum filtration device had a vacuum degree of 0.098 MPa, a single-head pumping capacity of 10 L / min, a water tank volume of 15 L, and the organic membrane material was nylon 66 (polyhexamethylene adipamide) microfiltration membrane with a pore size of 0.45 μm.

[0084] (4) Transmission analysis of sediment film: The sediment filter film formed by the above batches of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (H, %) and total transmittance value (T, %).

[0085] (5) Precipitation evaluation: The haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji of the analyzed sauce-flavored liquor sample being less than 0.0001 mg / L, 0.1 mg / L, and 1 mg / L, respectively, are measured. The results are shown in Table 1.

[0086] Table 1

[0087] Examples 1 and 2 investigated the effect of filtration volume on the wine. In Example 1, each group of wine samples was 1 liter, and in Example 2, each group was 3 liters. For homogeneous wine samples, the amount of magnesium palmitate, the target precipitate, was approximately equal per liter. The larger the filtration volume, the more magnesium palmitate was collected on the filter membrane. In Example 1, the amount of magnesium palmitate collected was too small to be characterized, and the data was not statistically significant; therefore, the time to the first precipitation was not analyzed. In Example 2, the collection volume was appropriate, meeting the requirements for characterizing haze and total transmittance, and could be used to analyze the time to the first precipitation; that is, the wine sample used for characterization was at least 3 liters.

[0088] Examples 2-4 investigated the effect of membrane type. When the pore size of different membranes was uniformly 0.45 μm, the membrane thicknesses of Examples 2 and 3 were 90-130 μm and 110-120 μm, respectively, which could form an ideal magnesium palmitate filter cake layer, allowing for characterization and analysis, and their performance was similar. In Example 4, the membrane thickness was 5-50 μm, and since a magnesium palmitate filter cake layer could not be formed, characterization was not possible. Comparing Examples 1-2, the effect of membrane pore size was examined. Since the filter membrane performance of Examples 2 and 3 is similar, the nylon 66 filter membrane from Example 2 was selected as the example for subsequent comparative studies to examine the effect of different membrane pore sizes. When a magnesium palmitate filter cake layer could be successfully formed, the smaller the membrane pore size, the higher the haze value; the larger the pore size, the lower the haze value. Total transmittance was negatively correlated with haze value. This indicates that compared to filter membranes with pore sizes of 0.45 μm and 0.80 μm, the 0.22 μm filter membrane is more sensitive and can more quickly identify the ease of sedimentation in the wine by the total time of the first sedimentation.

[0089] Comparative Example 3, V was examined E The effect of dosage and enzyme treatment. If vitamin V is missing... E The two steps of adding the amount of magnesium palmitate and enzyme treatment cannot form a magnesium palmitate filter cake layer.

[0090] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A method for rapid identification of salt precipitation risk in soy sauce-flavored Baijiu, characterized in that, Includes the following steps: (1) Low-temperature pretreatment of sauce-flavored liquor: Select several batches of sauce-flavored liquor samples of the same type but different batches. Store the standard sauce-flavored liquor samples at 4-10℃ for 48-72 hours. After restoring to room temperature, take the upper layer of liquor samples for later use. Sauce-flavored liquor samples used for analysis do not undergo low-temperature pretreatment. (2) Preparation of magnesium palmitate standard curve: Magnesium palmitate reference standard was added to the same batch of standard sauce-flavored liquor samples that had undergone low-temperature pretreatment to prepare sauce-flavored liquor samples with different concentrations of magnesium palmitate. (3) Add vitamin E (V E At room temperature, vitamin E was added to each batch of magnesium palmitate-prepared sauce-flavored liquor samples and each batch of analytical sauce-flavored liquor samples at a ratio of 10 mg / L-30 mg / L, and stirred thoroughly. (4) Vacuum filtration: Each batch of samples after adding vitamin E was subjected to vacuum filtration, and the deposits on the organic membrane were collected. (5) Sediment purification treatment: The protein deposits remaining on the organic membrane are dissolved by protease, and then the membrane is washed with ethanol solution of the same strength to separate the deposits on the filter membrane and collect them into a separatory funnel. After shaking and standing to separate the layers, the lower precipitate is retained. The vacuum filtration operation of step (4) is repeated on the lower precipitate and washed with ethanol solution of the same strength to obtain a pure precipitate filter membrane. (6) Transmission analysis of sediment film: The sediment filter film formed by each batch of samples was analyzed using a dual-path spectrophotometer (ColorQuest XE) to measure the overall haze value (Haze, %) and total transmittance value (T, %). (7) Precipitation evaluation: When the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji less than 0.0001 mg / L, the analyzed sauce-flavored liquor sample is considered to have approximately no precipitation risk; when the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji greater than or equal to 0.0001 mg / L and less than 0.1 mg / L, the analyzed sauce-flavored liquor sample is considered to have a significant precipitation risk; when the analyzed sauce-flavored liquor sample is at the level of the haze value (H, %) or total transmittance value (T, %) corresponding to the magnesium palmitate content in the standard koji greater than or equal to 0.1 mg / L and less than 1 mg / L, the analyzed sauce-flavored liquor sample is considered to have precipitation.

2. The method according to claim 1, characterized in that, The concentrations of magnesium palmitate reference standards in the samples of soy sauce liquor prepared in step (2) were 0 mg / L, 0.001 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L, respectively, and the preparation volume of each group was 1-3 L.

3. The method according to claim 1, characterized in that, In step (3), a magnetic stirring device is used for thorough stirring. The parameters of the magnetic stirring device are: rotor length 40-60mm, speed range 200-600rpm, and temperature control is set to room temperature.

4. The method according to claim 1, characterized in that, In step (4), a water ring type vacuum filtration device is used for filtration, requiring a vacuum degree of 0.085-0.098 MPa and a single-head pumping capacity of 6-10 L / min.

5. The method according to claim 1, characterized in that, The organic membrane mentioned in step (4) is a microfiltration membrane with a pore size of 0.22-0.80 μm.

6. The method according to claim 5, characterized in that, The microfiltration membrane material is selected from 90-130μm thick nylon 66, 110-120μm thick polypropylene and 5-50μm thick polytetrafluoroethylene.

7. The method according to claim 1, characterized in that, In step (5), the amount of protease used is 0.2-0.6g, and the treatment time is 1-3 hours.

8. The method according to claim 7, characterized in that, Use an acidic protease with a pH of 3.0-5.0 or a neutral protease with a pH of 6.0-7.

5.

9. The method according to claim 8, characterized in that, An acidic protease with a pH of 3.0-5.0 was used.

10. The method according to claim 1, characterized in that, Step (6) The specific steps are as follows: (1) Light source setting: Use the default D65 light source and d / 0° transmission mode; (2) Black and white correction: The white correction method is to use the corresponding blank organic film as the reference for 100% transmission, and the black correction method is to use a light shield to ensure 0% transmission baseline; (3) Multi-point measurement: Place the precipitated film flat in the transmission clamp, avoiding wrinkles or bubbles, and align the position with the center of the optical path; take at least 5 measurements and take the average value. After each measurement, rotate the film 60° around the center of the optical path to obtain better representativeness through multiple measurements. After the measurement is completed, the haze value (H, %) and the total transmittance value (T, %) are calculated.

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