Preparation method of rumex hanus soy sauce

Abstract

The preparation method of the rumex hanus soy sauce comprises the following steps: grinding fresh rumex hanus leaves into thick liquid, performing high-temperature steam pretreatment, drying and crushing to obtain rumex hanus powder; mixing the azolla filliculoidas powder with wheat flour, and inoculating aspergillus oryzae for culturing to obtain azolla filliculoidas koji; uniformly mixing the rumex hanus koji and a salt solution, performing enzymolysis fermentation to obtain mature soy sauce mash, and then spraying oil to obtain rumex hanus soy sauce; wherein the temperature of the high-temperature steam pretreatment is 110-130 DEG C, and the pressure of the high-temperature steam pretreatment is 0.05-0.25 MPa. The rumex hanus is used for replacing a traditional protein raw material soybean to prepare the soy sauce, the rumex hanus raw material is subjected to specific process pretreatment and then is combined with a specific method for starter propagation and fermentation, the utilization rate of raw material protein is high, the fermentation time is shortened, and the quality of the rumex hanus soy sauce is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to a preparation method of a seasoning sauce, in particular to a preparation method of a leafy grass sauce. BACKGROUND

[0002] Soy sauce is an indispensable seasoning in people's daily life. Soy sauce is rich in nutrients, containing various amino acids, organic compounds, vitamins and minerals, and rich in physiological active substances such as melanoidins, furan compounds, isoflavones and polypeptides, so that soy sauce not only has a seasoning effect but also has good functional properties.

[0003] At present, soybeans are mainly used as raw materials for soy sauce production. In the traditional fermentation process of soy sauce, soybeans account for about 50% of the total raw materials, and the demand for soybeans is high.

[0005] The new crop food resource leafy grass has a short growth cycle, strong environmental adaptability, and can be planted in marginal land such as saline-alkali land, with high yield. Once planted, it can be harvested for many years, with an annual yield of more than 300 t / hm 2 , which has shown the potential to partially replace soybeans due to its high protein content (36% to 48.7%) and high nutritional properties. Leafy grass can reduce dependence on imported soybeans.

[0006] Using leafy grass as raw material to prepare soy sauce can not only make full use of leafy grass resources, but also enrich the variety of soy sauce, improve the nutritional value of soy sauce, and improve the economic value and application value of leafy grass soy sauce.

[0007] CN202311553910.8 discloses a method for producing soy sauce with high ethyl palmitate content, which uses soybean meal and roasted wheat as the main raw materials, and adds a small amount of leafy grass as an auxiliary material. After the steps of koji preparation, koji room multi-strain koji making, mash making, and fermentation, soy sauce with high ethyl palmitate content is obtained. However, in this method, the traditional common protein soybean meal is still used as the main raw material, and the leafy grass is only used as an auxiliary material, but not completely replaced by the traditional protein raw material, and the amount is very limited.

[0008] CN113455642B discloses a method for preparing peanut sauce with steam exploded peanut shell, which uses peanut kernels as the main protein raw material and steam exploded peanut shell extraction residues to replace part of the flour (mass ratio 6:2:2 to 6:3:1). However, in this method, peanut kernels are still the traditional protein source, and peanut shells are only used as an auxiliary material to replace part of the flour. The plant by-product cannot completely replace soybean meal, and the process chain is relatively long, the microencapsulation cost is relatively high, and further evaluation is still needed for industrialization promotion. SUMMARY

[0009] The technical problem solved by the present application is to provide a preparation method of leafy vegetable soy sauce, which uses leafy vegetables instead of traditional protein raw materials such as soybeans to prepare soy sauce, has high utilization rate of raw material protein, shortens fermentation time, and ensures the quality of soy sauce.

[0010] The technical solution adopted by the present application to solve the technical problem is as follows: a preparation method of leafy vegetable soy sauce, comprising the following steps:

[0011] S1, fresh leafy vegetable is ground into pulp, then high-temperature steam pretreatment, drying, crushing, and leafy vegetable powder is obtained;

[0012] S2, the leafy vegetable powder is mixed with wheat flour, inoculated with Aspergillus oryzae for culture, and leafy vegetable koji is obtained;

[0013] S3, the leafy vegetable koji and the salt solution are uniformly mixed, enzyme hydrolysis fermentation is carried out to obtain mature mash, then oil is poured to obtain leafy vegetable soy sauce;

[0014] In step S1, the high-temperature steam pretreatment temperature is 110-130℃, and the pressure is 0.05-0.25MPa.

[0015] In some embodiments, in step S2, the mass ratio of the leafy vegetable powder to the wheat flour is (1-9):1.

[0016] In some embodiments, in step S2, the culture temperature is 30-35℃, and the culture time is 24-60h.

[0017] In some embodiments, in step S3, the concentration of the salt solution is 16-20%.

[0018] In some embodiments, in step S3, the fermentation time is 24-48d.

[0019] In some embodiments, in step S3, the fermentation temperature is 40-45℃.

[0020] In some embodiments, in step S1, the leafy vegetable is soaked with 1-3 times water for 1-2h.

[0021] In some embodiments, the process of pouring oil is: after fermentation, the mature mash is obtained, hot distilled water is added for soaking, precipitation, centrifugation, and the supernatant is taken to obtain leafy vegetable soy sauce.

[0022] In some embodiments, the temperature of the hot distilled water is 80-95℃.

[0023] In some embodiments, the soaking time of the mature mash in the hot distilled water is 6-12h.

[0024] Compared with the prior art, the present application has the following advantages:

[0025] The present application takes leaf-eating grass as the main raw material, first treats the leaf-eating grass with high-pressure steam to reduce the anti-nutritional factors such as oxalic acid in the leaf-eating grass and improve the utilization rate of protein, and at the same time, improve the content of amino acid nitrogen in the prepared soy sauce (the content of amino acid nitrogen in the soy sauce can reach 0.71 g / 100 ml), and improve the antioxidant effect of the soy sauce (DPPH· free radical clearance rate is more than 90%, ·OH clearance rate is more than 80%, O2 - clearance rate is more than 63.5%).

[0026] The present application uses a low-salt solid-state fermentation method to prepare leaf-eating grass soy sauce, shortens the fermentation time, and ensures the quality of the leaf-eating grass soy sauce.

[0027] The present application completely replaces traditional protein soybeans with leaf-eating grass as the main raw material for soy sauce preparation, not only expands the application scenarios of leaf-eating grass, but also provides new development ideas for the soy sauce market. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The present application is a leaf-eating grass soy sauce process flow chart;

[0029] Figure 2 The present application is a leaf-eating grass powder appearance photo obtained by pretreating leaf-eating grass under different conditions;

[0030] Figure 3 The present application is a leaf-eating grass pretreated under different conditions, and the vertical chart of the change of enzyme activity of Aspergillus oryzae is compared; wherein, A is the influence of leaf-eating grass pretreated under different conditions on acid protease activity; B is the influence of leaf-eating grass pretreated under different conditions on alkaline protease activity; C is the influence of leaf-eating grass pretreated under different conditions on neutral protease activity; D is the influence of leaf-eating grass pretreated under different conditions on saccharifying enzyme activity;

[0031] Figure 4 The present application is a bar chart for comparing the influence of different salt water concentrations on the amino acid nitrogen and sensory evaluation of leaf-eating grass soy sauce;

[0032] Figure 5 The present application is a bar chart for comparing the influence of different fermentation temperatures on the amino acid nitrogen and sensory evaluation of leaf-eating grass soy sauce;

[0033] Figure 6 The present application is a bar chart for comparing the influence of different material liquid ratios on the amino acid nitrogen and sensory evaluation of leaf-eating grass soy sauce;

[0034] Figure 7 The present application is a comparison chart of the influence of different fermentation times on the finished product and color of leaf-eating grass soy sauce;

[0035] Figure 8Comparison chart of solid particle size and viscosity in leafy vegetable soy sauce with different fermentation time;

[0036] Figure 9 Comparison bar chart of DPPH radical scavenging rate of leafy vegetable soy sauce and commercial soy sauce of the application;

[0037] Figure 10 Comparison bar chart of OH radical scavenging rate of leafy vegetable soy sauce and commercial soy sauce of the application;

[0038] Figure 11 Comparison bar chart of O2 radical scavenging rate of leafy vegetable soy sauce and commercial soy sauce of the application - Comparison bar chart of O2 radical scavenging rate of leafy vegetable soy sauce and commercial soy sauce of the application

[0039] Figure 12 Electronic tongue radar chart and PCA chart of leafy vegetable soy sauce and commercial soy sauce of the application;

[0040] Figure 13 QDA radar chart of leafy vegetable soy sauce and commercial soy sauce of the application. DETAILED DESCRIPTION

[0041] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description. In other instances, well-known methods have not been described in detail in order to avoid unnecessarily obscuring the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0043] Example 1: Effect of different high-temperature steam pretreatment of leafy vegetables on the quality of soy sauce

[0044] As shown in Figure 1 A method for preparing leafy vegetable soy sauce, comprising the following steps:

[0045] S1, grinding leafy vegetables, then placing them in a high-temperature steam sterilization pot for high-temperature steam pretreatment for 10 min, after the pretreatment, drying them in a constant temperature drying box at 50℃ for 12 h, then crushing them, passing them through a 60-mesh sieve, taking the undersize material, and obtaining leafy vegetable powder;

[0046] S2, 6:4 of leaf-eating grass powder and wheat flour were weighed by dry weight mass ratio, leaf-eating grass powder was added to water by dry weight 1:1.25, and water was soaked for 30 min in advance, then wheat flour was added and mixed uniformly, after cooking and cooling, 0.5wt% of aspergillus oryzae was inoculated to 32℃ for koji preparation for 48h, and leaf-eating grass koji was obtained;

[0047] S3, 10g of leaf-eating grass koji was weighed, mixed with 18wt% of salt water (NaCl aqueous solution) at a solid-liquid ratio of 1:1.5, fermented at a temperature of 42℃ for 24d to obtain matured soy sauce; distilled water at 85℃ was added to the matured soy sauce to soak for 8h for precipitation, centrifuged, and the supernatant was obtained to obtain the product soy sauce;

[0048] Among them, the temperature and pressure of high-temperature steam pretreatment were set to 110℃, 0.05MPa, 115℃, 0.1MPa, 120℃, 0.15MPa, 125℃, 0.20MPa and 130℃, 0.25MPa respectively.

[0049] The leaf-eating grass powder obtained by crushing the leaf-eating grass without high-temperature steam pretreatment was used as the control group.

[0050] The protein content of the leaf-eating grass powder obtained in step S1 was determined according to GB5009.5-2016, the total sugar content was determined by anthrone sulfuric acid method, the reducing sugar content was determined by DNS method, and the soluble protein content was determined by coomassie brilliant blue.

[0051] The determination results are shown in Table 1 and Figure 2 .

[0052] Table 1 Composition of leaf-eating grass powder obtained by pretreatment under different process conditions Unit: g / 100g

[0053]

[0054] As shown in Table 1, the contents of protein, soluble protein, total sugar, reducing sugar and soluble solids of the leaf-eating grass powder obtained by high-temperature steam pretreatment were significantly higher than those of the leaf-eating grass powder without high-temperature steam pretreatment, and the effect was best when the treatment temperature was 120℃.

[0055] The enzyme activity of the leaf-eating grass koji obtained in step S2 was determined, and when the enzyme activity was determined, the crude enzyme solution was diluted 10 times with the corresponding buffer, and the activities of acid protease, alkaline protease, neutral protease and saccharifying enzyme were determined by spectrophotometry. The determination results are shown in Table 2. Figure 3

[0056] As Figure 3 , different high-temperature steam treatments of leaf-eating grass had a significant impact on aspergillus oryzae. ​

[0057] The quality of the product soy sauce obtained in step S3 was determined, specifically as follows:

[0058] The pH was measured with a pH meter, and the total acid, amino acid nitrogen, total nitrogen, NaCl content, and salt-free solid content were determined according to GB / T 18186-2000 “Brewed Soy Sauce”. The total sugar content was determined by the anthrone sulfuric acid method, and the reducing sugar content was determined by the 3, 5-dinitrosalicylic acid (DNS) method.

[0059] The determination results are shown in Table 2.

[0060] Table 2 Basic physicochemical properties of soy sauce obtained by pretreatment under different process conditions Unit: g / 100g

[0061]

[0062] Example 2 Effect of different mass ratios of leafy grass powder to wheat flour on the quality of soy sauce

[0063] The preparation method of this example is the same as that of Example 1, except that in step S1, the temperature for high-pressure steam pretreatment of leafy grass is 120°C, and the pressure is 0.15 MPa; in step S2, the mass ratio of leafy grass powder to wheat flour is different, and the specific mass ratios and the enzyme activities of the leafy grass koji and the quality of the soy sauce obtained are shown in Tables 3-4, respectively.

[0064] Among them, when determining the enzyme activity, the crude enzyme solution is diluted 10 times with the corresponding buffer, and the activities of acid protease, alkaline protease, neutral protease, and saccharifying enzyme are determined by spectrophotometry, respectively.

[0065] Table 3 Effect of mass ratio of leafy grass to wheat flour on enzyme activity of leafy grass koji Unit: U / g

[0066]

[0067] Table 4 Effect of mass ratio of leafy grass to wheat flour on physicochemical properties of soy sauce Unit: g / 100g

[0068]

[0069] As shown in Tables 3 and 4, when the mass ratio of leafy grass powder to wheat flour is 6:4, the enzyme activities of the koji (acid / alkaline / neutral protease, saccharifying enzyme) and the amino acid nitrogen, total nitrogen, and salt-free solids of the soy sauce all reach the highest values, and are significantly better than other ratios, proving that this ratio is the optimal ratio.

[0070] Example 3 Effect of water amount for leafy grass powder on the quality of soy sauce

[0071] The preparation method of the embodiment is the same as that of Example 1, except that in step S1, the temperature of high-pressure steam pretreatment of the leafy grass is 120℃, and the pressure is 0.15MPa; in step S2, the water content of the leafy grass powder is different, and the specific water content, the enzyme activity of the leafy grass koji, and the quality of the soy sauce are shown in Table 5-Table 6, respectively.

[0072] Table 5 Effect of water content of leafy grass on enzyme activity of leafy grass koji Unit: U / g

[0073]

[0074] Table 6 Effect of water content of leafy grass on basic physicochemical properties of soy sauce Unit: g / 100g

[0075]

[0076] As shown in Table 5 and Table 6, when the leafy grass powder is added with water at a ratio of 1:1.25, the activities of acid, alkali, neutral protease and saccharifying enzyme of the koji material are all significantly the highest, and the amino acid nitrogen, total nitrogen and salt-free solids of the soy sauce also reach the peak, which are significantly better than other water contents, so 1:1.25 is the best water content ratio.

[0077] Example 4 Effect of koji making time on quality of soy sauce

[0078] The preparation method of the embodiment is the same as that of Example 1, except that in step S1, the temperature of high-pressure steam pretreatment of the leafy grass is 120℃, and the pressure is 0.15MPa; in step S2, the time of inoculating Aspergillus oryzae and then culturing and making koji is different, and the specific koji making time, the enzyme activity of the leafy grass koji, and the quality of the soy sauce are shown in Table 8 and Table 9, respectively.

[0079] Among them, the sensory evaluation standard is shown in Table 7.

[0080] Table 7 Sensory evaluation standard of leafy grass soy sauce

[0081]

[0082] Table 8 Effect of koji making time on enzyme activity of leafy grass koji Unit: U / g

[0083]

[0084] Table 9 Effect of koji making time of leafy grass on basic physicochemical properties of soy sauce Unit: g / 100g

[0085]

[0086] As shown in Table 8 and Table 9, 48h koji-making can make the four enzyme activities and the amino acid nitrogen, total nitrogen and salt-free solids of soy sauce reach the highest value, which is significantly better than other time, so 48h is the best koji-making time; extending to 64h, each index decreases.

[0087] Example 5: Effect of different salt concentrations on the quality of soy sauce

[0088] The preparation method of this example is the same as that of Example 1, except that in step S1, the temperature for high-pressure steam pretreatment of the food leaf grass is 120℃, and the pressure is 0.15MPa; in step S3, the concentration of the salt water used is different, and the specific salt water concentration and the quality of the obtained soy sauce are shown in Table 10 and Figure 4 Table 11.

[0089] Table 10: Basic physicochemical properties of soy sauce obtained from different salt water concentrations (unit: g / 100g)

[0090]

[0091] As shown in Table 10 and Figure 4 Table 11, under the concentration of 18% salt, the amino acid nitrogen, total nitrogen, salt-free solids and total acid of soy sauce all reach the highest value, and the sensory score is also the best; too low or too high concentration significantly reduces the quality, so 18% is the best salt amount.

[0092] Example 6: Effect of fermentation temperature on the quality of food leaf grass soy sauce

[0093] The preparation method of this example is the same as that of Example 1, except that in step S1, the temperature for high-pressure steam pretreatment of the food leaf grass is 120℃, and the pressure is 0.15MPa; in step S3, the fermentation temperature is different, and the specific fermentation temperature and the quality of the obtained soy sauce are shown in Table 10 and Figure 5 Table 11.

[0094] Table 11: Basic physicochemical properties of food leaf grass soy sauce obtained from different fermentation temperatures (unit: g / 100g)

[0095]

[0096]

[0097] As shown in Table 11 and Figure 5 Table 12, when the fermentation temperature is 42℃, the amino acid nitrogen, total nitrogen, salt-free solids and total acid of soy sauce all reach the highest value, which is significantly better than 36℃ and 44℃, and the sensory score is also the best, indicating that 42℃ is the most suitable temperature for low-salt solid-state fermentation of food leaf grass soy sauce.

[0098] Example 7: Effect of material-liquid ratio on the quality of food leaf grass soy sauce

[0099] The preparation method of this embodiment is the same as that of Example 1, except that in step S1, the temperature of high-pressure steam pretreatment of the food leaf grass is 120℃, and the pressure is 0.15MPa; in step S3, the feed liquid ratio of the food leaf grass koji and salt water is different, and the specific feed liquid ratio and the quality of the obtained soy sauce are shown in Table 12 and Figure 6

[0100] Table 12 Basic physicochemical properties of soy sauce obtained at different feed liquid ratios (unit: g / 100g)

[0101]

[0102] As shown in Table 12 and Figure 6 When the feed liquid ratio is 1:1.5, the amino acid nitrogen, total nitrogen, salt-free solids and total acid of the soy sauce all reach the highest value and are significantly better than other ratios, and the sensory score is also the best, indicating that this feed liquid ratio can fully dissolve the nutrients and maintain a good fermentation environment, and is the optimal ratio.

[0103] Example 8 Effect of fermentation time on the quality of food leaf grass soy sauce

[0104] The preparation method of this embodiment is the same as that of Example 1, except that in step S1, the temperature of high-pressure steam pretreatment of the food leaf grass is 120℃, and the pressure is 0.15MPa; in step S3, the fermentation time is different, and the prepared samples are marked as F0 (fermentation time is 0d), F8 (fermentation time is 8d), F16 (fermentation time is 16d), F24 (fermentation time is 24d), and F32 (fermentation time is 32d) according to the different fermentation times. The specific fermentation time and the quality of the obtained soy sauce are shown in Table 13.

[0105] Table 13 Basic physicochemical properties of soy sauce obtained at different fermentation times (unit: g / 100g)

[0106]

[0107] As shown in Table 13, with the fermentation time from F0 to F32, most of the physicochemical indexes of the soy sauce show regular changes, which comprehensively affect the quality, flavor and nutritional value of the soy sauce. The indexes are relatively stable and have high values in the later fermentation period, indicating that the soy sauce has reached a good state in terms of nutrient accumulation and flavor substance accumulation at this time.

[0108] The OD value of the 10-fold diluted sample was measured at different wavelengths, with distilled water as a blank control. The calculation method is as follows:

[0109]

[0110] Color depth substance = 10 x OD 420 Equation (3)​

[0111] The measurement results are as follows Figure 7 As shown.

[0112] Depend on Figure 7 It can be seen that the color of the herb-based soy sauce becomes darker and darker as fermentation time progresses, with a significant increase in dark-colored substances.

[0113] The viscosity of soy sauce was determined using an Ubbelohde viscometer. Particle size distribution and average particle size were measured using a particle size analyzer. The upper and lower limits of refractive index were adjusted to 10-15, and each sample was tested in triplicate.

[0114] The measurement results are as follows Figure 8 As shown.

[0115] Depend on Figure 8 It can be seen that as fermentation time progresses, the particle size distribution of the herbaceous plant soy sauce gradually decreases, the zeta potential decreases, and the viscosity increases.

[0116] In summary, the optimal process conditions for preparing the herbaceous plant soy sauce of the present invention specifically include the following steps:

[0117] S1. Grind fresh edible grass into a pulp, then place it in a high-temperature steam sterilizer and pre-treat it with high-temperature steam at 120℃ and 0.15MPa for 10 minutes. Then, place the pre-treated edible grass raw material in a constant temperature drying oven at 50℃ for 12 hours. After drying, pulverize it, pass it through a 60-mesh sieve, and take the sieve-passing material to obtain edible grass powder.

[0118] S2. Weigh out the edible grass powder and wheat flour at a dry weight ratio of 6:4. First, add the edible grass powder to water at a dry weight ratio of 1:1.25 and moisten it for 30 minutes. Then add the wheat flour and mix evenly. Cook at 121℃ for 30 minutes and then cool. Inoculate with Aspergillus oryzae equivalent to 0.5wt% of the raw material (the mixture after cooking) for koji making. The koji making temperature is controlled at 32℃ and the koji making time is 48 hours. Turn the koji every 8 hours to prevent burning. When the koji material is loose and contains a large number of spores, the koji making is successful and the edible grass koji (koji material) is obtained.

[0119] S3. Crush the starter culture material, mix it with salt water at a mass ratio of 1:1.5, put it into a fermentation vessel, and place it in a constant temperature incubator at 42℃ for 25 days to obtain mature soy sauce mash. Add distilled water at 85℃ to the mature soy sauce mash and soak it for 8 hours to allow it to settle. Then centrifuge and take the supernatant to obtain raw soy sauce.

[0120] The quality analysis of the herbaceous plant soy sauce prepared according to this optimal embodiment is as follows:

[0121] I. Determination of the physicochemical properties of leafy green soy sauce

[0122] The content of amino acid nitrogen, soluble salt-free solids and total nitrogen in the prepared soy sauce was determined according to the method specified in GB 18186-2000.

[0123] The determination results are shown in Table 14.

[0124] Table 14 Quality analysis of the soy sauce prepared from the leaves of the grass

[0125]

[0126] As shown in Table 14, the prepared soy sauce from the leaves of the grass is a second-grade soy sauce in accordance with the national standard.

[0127] II. Antioxidation determination of the soy sauce prepared from the leaves of the grass

[0128] The prepared soy sauce from the leaves of the grass was compared with the commonly available second-grade soy sauce on the market to test the antioxidation of the soy sauce.

[0129] (1) DPPH· radical scavenging capacity

[0130] 2 mL of the sample solution was taken in a 10 mL test tube, 2 mL of 0.02 mmol / L DPPH-absolute ethanol solution was added, and after mixing, the solution was reacted in the dark for 30 min, and the absorbance A1 was determined at 517 nm. The absorbance A2 was determined by using absolute ethanol instead of DPPH, and the absorbance A0 was determined by using absolute ethanol instead of the sample solution.

[0131] The formula for the DPPH· scavenging rate is:

[0132]

[0133] The determination results are shown in Table 15. Figure 9

[0134] (2) Determination of ·OH scavenging rate

[0135] 1 mL of the sample solution was taken in a 10 mL test tube, 1 mL of 9 mmol / L ferrous sulfate solution and 1 mL of 9 mmol / L salicylic acid-ethanol solution were added, and after mixing, 1 mL of 8.8 mmol / L hydrogen peroxide solution was added, and after mixing, the solution was reacted in a 37°C constant-temperature water bath for 30 min, and the absorbance A1 was determined at 510 nm. The absorbance A2 was determined by using distilled water instead of the hydrogen peroxide solution, and the absorbance A0 was determined by using distilled water instead of the sample solution. The calculation formula for the ·OH scavenging rate is:

[0136]

[0137] The determination results are shown in Table 15. Figure 10

[0138] (3) O2​​- • Determination of scavenging capacity

[0139] Determination by autoxidation of pyrogallol. 3 mL of 50 mmol / L Tirs-HCl buffer solution (pH = 8.2) was added to a 10 mL test tube, which was preheated in a 25 °C water bath for 20 min. 1 mL of sample solution and 0.6 mL of 30 mmol / L pyrogallol solution were added, mixed well, and preheated at 25 °C for 5 min. The reaction was terminated by adding 0.5 mL of 1 mol / L HCl solution, and the absorbance A1 was measured at 420 nm. The absorbance A0 was measured with 1 mL of distilled water instead of the sample solution as a blank control, and the absorbance A2 was measured with 0.6 mL of distilled water instead of the pyrogallol solution. O2 - • Calculation formula of scavenging rate:

[0140]

[0141] The determination results are shown in Table 1. Figure 11

[0142] III. Electronic tongue determination of leaf-eating grass soy sauce

[0143] The taste of different leaf-eating grass soy sauce samples was characterized using a TS-5000Z taste analysis system (INSENT Co. Ltd., Tokyo, Japan). AAE (umami and richness), CA0 (sourness), AE1 (astringency), C00 (bitterness), GL1 (sweetness), and CT0 (saltiness) were selected as a total of 6 sensors for testing. During detection, 25.00 mL of leaf-eating grass soy sauce sample (diluted 30 times with deionized water) was placed in a beaker for electronic tongue analysis. The test was carried out at room temperature, and the sensor was pretreated in a reference solution (potassium chloride solution containing tartaric acid) before analysis. Each sample analysis was repeated 3 times.

[0144] The results are shown in Table 2. Figure 12

[0145] Figure 12 The three-dimensional sensory evaluation diagram of A intuitively presents the sensory differences between commercially available soy sauce and leaf-eating grass soy sauce and other samples from six dimensions of acidity, sweetness, bitterness, freshness, body, and saltiness. Different scores of these dimensions reflect the uniqueness of leaf-eating grass soy sauce in flavor, while Figure 12 The principal component analysis diagram of B reveals the similarity and difference of different soy sauce sample groups in composition by showing the distribution of SH1, SH2, SH3, and SYC four sample groups with PC1 (explaining 56.26% of the variance) and PC2 (explaining 23.62% of the variance) as axes, reflecting that leaf-eating grass soy sauce may be different from commercially available soy sauce in the composition of main components due to unique raw materials or process.

[0146] ​​IV. QDA evaluation of the leafy vegetable soy sauce

[0147] The effect of fermentation time on the taste and aroma of the leafy vegetable soy sauce was analyzed by quantitative descriptive analysis (QDA). The sensory evaluation panel consisted of 9 people (5 women and 4 men), and the evaluation was performed in a sensory evaluation room at room temperature of 25°C. Before the formal sensory evaluation, the panel members were trained to taste commercially available soy sauce, and the sensory description words (color, transparency, salty taste, umami taste, sweet taste, sour taste, bitter taste, and richness) and the definition of each word were determined according to the agreed method. The specific definitions are shown in Table 1. After the training, the sensory evaluation personnel could accurately evaluate the intensity of the given attributes, and the sensory evaluation of the soy sauce was performed by scoring from 0 (extremely weak) to 7 (extremely strong). The overall score of the soy sauce was scored according to the preference of the 9 sensory evaluation personnel for various soy sauces, and then the average value of the overall score of various soy sauces was calculated. The leafy vegetable soy sauce at different fermentation times was filtered and sterilized, and then subjected to sensory evaluation.

[0148] The results are shown in Figure 13 .

[0149] Table 15 Sensory description words and definitions of the leafy vegetable soy sauce

[0150]

[0151] Each of the technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not contradict each other, they should be considered as the scope of the present disclosure.

[0152] The above-described embodiments only express several implementation manners of the present disclosure, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the present disclosure. It should be noted that, for those skilled in the art, without departing from the concept of the present disclosure, a number of modifications and improvements can be made, which are all within the protection scope of the present disclosure.

Claims

1. A method for preparing a leafy herb sauce, characterized by, The method comprises the following steps: S1. grinding fresh leafy grass, then carrying out high-temperature steam pretreatment, drying, and crushing to obtain leafy grass powder; S2. mixing the leafy grass powder with wheat flour, inoculating Aspergillus oryzae for culture to obtain leafy grass koji; S3. uniformly mixing the leafy grass koji with a salt solution, carrying out enzymatic fermentation to obtain mature mash, then adding oil to obtain leafy grass soy sauce; In step S1, the high-temperature steam pretreatment is carried out at a temperature of 110-130 DEG C and a pressure of 0.05-0.25 MPa.

2. The method of claim 1, wherein the leafy vegetable soy sauce is prepared by the steps of: In step S2, the mass ratio of the leafy grass powder to the wheat flour is (2-3):(3-2). ​ 3. The method for preparing leafy green soy sauce according to claim 1 or 2, characterized in that, In step S2, the culture temperature is 30-35 DEG C, and the culture time is 24-60 h.

4. The method of claim 1 or 2, wherein the leafy vegetable soy sauce is prepared by adding 0.1 to 0.5% of the leafy vegetable extract to 100 parts of the soy sauce. In step S3, the concentration of the salt solution is 16-20%.

5. The method for preparing leafy green soy sauce according to claim 1 or 2, characterized in that, In step S3, the fermentation time is 24-48 d.

6. The method for preparing leafy green soy sauce according to claim 1 or 2, characterized in that, In step S3, the fermentation temperature is 40-45 DEG C.

7. The method for preparing leafy green soy sauce according to claim 1 or 2, characterized in that, In step S1, the leafy grass is soaked with 1-3 times water for 1-2 h.

8. The method for preparing leafy green soy sauce according to claim 1 or 2, characterized in that, The process of adding oil is as follows: the mature mash obtained after fermentation is soaked with hot distilled water, precipitated, and centrifuged to obtain leafy grass soy sauce.

9. The method of claim 8, wherein the soy sauce is prepared by the steps of: The temperature of the hot distilled water is 80-95 DEG C. ​ 10. Leafy grass soy sauce prepared by the method of any one of claims 1-9.

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