A soybean sauce raw oil processing method for reducing loss of amino acid nitrogen and precisely regulating color

Abstract

This invention discloses a method for processing crude oil for soy sauce that reduces amino acid nitrogen loss and precisely controls color, comprising the following steps: heating and sterilization: heating and sterilizing the crude oil and then instantly cooling it to 50-60°C to obtain semi-finished product A; heat sinking: pumping the semi-finished product A into a sealed heat sinking tank for heat sinking; then extracting oil from the middle of the heat sinking tank to obtain semi-finished product B; filtration and blending: filtering the semi-finished product B and then blending it to obtain semi-finished product C; controlled thermal reaction: heating and sterilizing the semi-finished product C and then instantly cooling it to 65-90°C, pumping it into a stainless steel tank containing a steam coil for a slow Maillard reaction at a sustained temperature, which is a controlled thermal reaction; if the crude oil being processed is light in color, liquid caramel coloring is added to the semi-finished product C during the controlled thermal reaction process to increase the bright red color and make its color meet the process design requirements; bottling: after the controlled thermal reaction is completed, bottling is performed to obtain the finished soy sauce.

Description

Technical Field

[0001] This invention belongs to the technical field of condiment processing, and specifically relates to a method for processing crude soy sauce that reduces the loss of amino acid nitrogen and precisely controls the color. Background Technology

[0002] In existing soy sauce production processes, the crude oil obtained through fermentation and pressing needs to undergo a series of processes to become finished soy sauce. The crude oil processing typically includes the following steps: crude oil → primary blending (coarse blending) → heating and sterilization → heat settling → filtration → secondary blending (fine blending) → finished product. Specifically, existing processing often involves adding monosodium glutamate (MSG), sugar, and other materials to the crude oil for primary blending, usually to obtain oil embryos with an amino acid nitrogen content of 1.50g / 100ml or higher. The oil embryos are then subjected to heating and sterilization and heat settling to facilitate the Maillard reaction and enhance flavor. The heating and sterilization and heat settling operations are as follows: the oil embryos are heated to 110~125℃ for sterilization, then cooled to a tapping temperature of 70~100℃ by water cooling, and pumped into an open heat settling tank to stand for 4~5 days to allow for the Maillard reaction and the precipitation of large particles.

[0003] The existing Cantonese-style high-salt, low-temperature fermentation process involves fermentation at natural temperatures, meaning no temperature control is applied during crude oil fermentation. Therefore, with seasonal temperature variations, fermentation conditions are affected, leading to significant variations in the color of the fermented crude oil. Crude oil produced in some seasons is darker (L* value 70-80), while crude oil produced in other seasons is lighter (L* value 90-100), making it difficult to adjust the color of the finished product. This results in the difficulty of consistently controlling the color of the finished soy sauce within a certain range. The industry generally aims to control the color of the finished soy sauce between 40 and 50, but in reality, due to the influence of seasonal temperature on the crude oil color, the L* value of the finished soy sauce color fluctuates between 35 and 60.

[0004] The darker color of the crude oil produced is mainly due to the higher temperature during fermentation. For example, in summer, the suitable temperature allows beneficial microorganisms to multiply, leading to thorough fermentation and decomposition of the material into amino acids, reducing sugars, polypeptides, esters, and other substances. This, combined with strong microbial respiration and enzymatic browning reactions, results in a darker color and higher content of reducing sugars and amino acids in the fermented crude oil. This high concentration of amino acids and reducing sugars in the crude oil causes a vigorous Maillard reaction during heat sterilization and heat deposition, resulting in significant loss of amino acid nitrogen and a further deepening of the color, leading to a substantial decrease in the L* value. In other words, processing dark-colored crude oil using existing processes presents the following problems: 1) If the crude oil is already dark, the finished soy sauce may be darker than the process design specifications, appearing black or even bitter, affecting the flavor and making it unsuitable for direct sale; 2) The vigorous Maillard reaction leads to high amino acid loss, reducing production efficiency.

[0005] The lighter-colored crude oil produced is mainly due to lower fermentation temperatures. For example, if feed is added in winter, the lower temperatures are unsuitable for the growth of beneficial microorganisms, resulting in insufficient fermentation and decomposition of the materials. This weakens the enzymatic browning reaction, leading to a lighter-colored crude oil that differs significantly from the desired color of the finished soy sauce and has a bland flavor, indicating lower levels of reducing sugars and amino acid nitrogen. For lighter-colored crude oil, technicians will determine the amount of white sugar added in each blending based on production experience. Adding white sugar and monosodium glutamate (MSG) to the crude oil enhances the Maillard reaction during the heat sterilization and heat settling processes, thereby deepening the crude oil color. However, when white sugar is added to crude oil for high-temperature reaction, due to its high moisture content, it mainly undergoes a high-temperature Maillard reaction with amino acid nitrogen, inhibiting the caramelization reaction and resulting in minimal color change. Therefore, on the one hand, existing technologies deepen the color of crude oil by enhancing the Maillard reaction, leading to high costs due to the loss of amino acid nitrogen. On the other hand, to process lighter-colored crude oil into a finished product with the required color, a large amount of white sugar is usually added in the initial blending, resulting in high sugar consumption and high soy sauce production costs. Furthermore, the color deepening produced by the Maillard reaction between white sugar and amino acids at a certain temperature has its limits; once a certain point is reached, the reaction will not continue. This means that the final color may still not meet the process design specifications after the reaction, making the finished soy sauce unsuitable for direct sale.

[0006] The applicant proposed a soy sauce processing method using low-temperature heat sinking in Chinese patent publication number CN120188887A. This method weakens the Maillard reaction through a low-temperature heat sink at 30-40℃, thus solving the problem of significant loss of amino acid nitrogen in crude oil during processing. Specifically, because the low-temperature heat sink weakens the Maillard reaction, it can alleviate the problem of excessively dark color in dark-colored crude oil after processing. However, this method is clearly unsuitable for light-colored crude oil; even with the addition of white sugar, it is difficult to achieve the desired color in the finished product. Furthermore, because this method uses an oil extraction temperature of 30-40℃, a high degree of automation is required in the factory to control the cleanliness of the space in order to ensure that the microbiological indicators of the crude oil meet the standards. In other words, for small enterprises with low levels of automation, the microbial environment cannot be effectively controlled, posing a risk of products failing microbiological inspections. Summary of the Invention

[0007] The purpose of this invention is to provide a method for processing crude oil for soy sauce that reduces the loss of amino acid nitrogen and precisely controls the color.

[0008] To achieve the above objectives, the present invention adopts the following technical solution.

[0009] A method for processing crude soy sauce that reduces amino acid nitrogen loss and precisely controls color, characterized by comprising the following steps:

[0010] (1) Heating and sterilization: The crude oil is heated and sterilized and then cooled to 50~60℃ to obtain semi-finished product A;

[0011] (2) Heat sinking: The semi-finished product A is pumped into a closed heat sinking tank for heat sinking, and the large particles of impurities inside are settled to the bottom; then oil is extracted from the middle of the heat sinking tank to obtain semi-finished product B;

[0012] (3) Filtration and blending: The semi-finished product B is filtered and then blended according to the process requirements to obtain the semi-finished product C;

[0013] (4) Controlled thermal reaction: The semi-finished product C is heated and sterilized, then instantly cooled to 65~90℃, pumped into a stainless steel tank containing a steam coil and stirred. The steam coil is used to carry out a slow Maillard reaction at a constant temperature, that is, to carry out a controlled thermal reaction to produce a rich flavor. During the above reaction process, the color change data of the semi-finished product C is detected by an online monitoring colorimeter to accurately control the color.

[0014] If the crude oil being processed is a lighter-colored crude oil, liquid caramel coloring is added to the semi-finished product C during the controlled thermal reaction process to increase its bright red color and make its color meet the process design requirements; the liquid caramel coloring is a bright red (brownish-red) liquid obtained by boiling white sugar and water together.

[0015] (5) Filling: After the controlled thermal reaction is completed, semi-finished product D is obtained. After cooling it to below 40°C, it is filled to obtain the finished soy sauce.

[0016] The time for the aforementioned controllable thermal reaction is adjusted based on the color of the soy sauce in the stainless steel tank and the loss of amino acid nitrogen.

[0017] The crude oil used in this invention is crude oil obtained by pressing after undergoing Cantonese-style high-salt dilute-state fermentation. Specifically, the lighter-colored crude oil refers to crude oil with an L* value of 90-100, where L* value refers to brightness.

[0018] This invention lowers the heat sink oil extraction temperature to 50-60°C and employs a closed heat sink method, reducing the contact between the semi-finished product and oxygen, and preventing vigorous Maillard reactions. This addresses the problem of a significant decrease in amino acid nitrogen content, maximizing the preservation of the flavor of crude oil fermentation, and preventing darker crude oil from becoming excessively darker and bitter after heat sinking. Furthermore, this invention eliminates the blending step before heating and sterilization, weakening Maillard reactions during heating and sterilization and reducing the loss of amino acid nitrogen. In addition, due to the reduced Maillard reaction, this invention produces less precipitate during the heat sink stage, resulting in a clear overall semi-finished product B system with a turbidity 45-60% lower than existing processes before filtration. Filtration can be completed in a single step, and the turbidity after filtration is <10 ppm.

[0019] This invention reduces the impact of microorganisms in the space by using a closed heat sink method, and simultaneously adopts a heat sink temperature of 50~60℃, which is not conducive to the growth of microorganisms, to ensure that the microbial indicators of crude oil are qualified during the heat sink process. Therefore, this invention has lower requirements for the degree of automation of the plant.

[0020] This invention, through a controllable thermal reaction, not only ensures the stable color of the finished soy sauce throughout the year but also produces a rich caramel aroma. Combined with its own soy sauce aroma and ester aroma, it creates a richer and more unique soy sauce flavor, enhancing the technological barrier for enterprises. During the controllable thermal reaction process, this invention utilizes an online colorimeter to detect color change data and precisely control the color. For lighter-colored crude oil, this invention simultaneously adds liquid caramel coloring during the controllable thermal reaction to deepen the soy sauce color. Furthermore, the amount of white sugar used for color enhancement with liquid caramel coloring is far less than that required by existing technologies that directly add white sugar to participate in the Maillard reaction, resulting in lower overall raw material costs. In addition, due to the lower material temperature during the controllable thermal reaction, the Maillard reaction is slow. Even when liquid caramel coloring and / or white sugar are added to the soy sauce, the Maillard reaction is minimal. Therefore, the loss of amino acid nitrogen in this process is basically controlled within the range of 0.01~0.03g / 100ml, while producing aromatic and caramel-like substances.

[0021] In summary, this invention can reduce the loss of amino acid nitrogen in crude oil during processing, and achieve precise color adjustment through controllable thermal reaction, ensuring that the color of the finished soy sauce meets the requirements, while also improving the flavor of the finished soy sauce and reducing the cost of sugar raw materials.

[0022] Preferably, the heat sinking time is 1 to 3 days.

[0023] Preferably, the liquid caramel coloring is prepared by mixing white sugar and water in a mass ratio of 3:1 to 1:1, heating under pressure to 130-150°C, and then cooling to 90-100°C to obtain a bright red liquid caramel coloring. Specifically, the mixture is heated under pressure to 130-150°C and boiled for 3-10 minutes.

[0024] Preferably, during the controllable thermal reaction process, liquid caramel coloring is added according to the data from the colorimeter, and the color of the product can be flexibly adjusted by adding different shades of liquid caramel coloring. The flavor of soy sauce can also be controlled by adding a combination of liquid caramel coloring and white sugar.

[0025] Preferably, the heating and sterilization operation is to heat the material to 110~125℃ and sterilize it for 30~60 seconds.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) Precise color control: This invention utilizes controllable thermal reaction technology to regulate the change of color L* value online, which can control the L* value between 40 and 50, ensuring that the color of the product remains consistent throughout the year; furthermore, this invention uses controllable thermal reaction to combine white sugar with liquid caramel coloring (color rate of about 3000~7000ebc) to enhance the color deepening effect of soy sauce, and its color enhancement effect is 5 to 10 times that of the existing technical solutions.

[0028] (2) Preservation of the original flavor of fermentation: The present invention directly sterilizes crude oil and heats it at low temperature, which can effectively reduce the loss of crude oil flavor due to high temperature and preserve the original soy sauce and fermented soy sauce flavor of fermented products.

[0029] (3) Superior sensory flavor: The present invention sterilizes crude oil instead of the original high amino acid nitrogen product after adding monosodium glutamate, reduces heat sink temperature, weakens Maillard reaction, reduces the generation of burnt flavor, and at the same time retains the soy sauce aroma and savory flavor of fermented crude oil to the maximum extent; at the same time, through the technology of controlled thermal reaction, the slow heating reaction produces multi-layer flavor substances, enhancing the burnt and savory flavor of the finished soy sauce. According to the comprehensive evaluation of the experimental personnel, its flavor is superior to the existing soy sauce products.

[0030] (4) Lower production costs: The amino acid nitrogen content of the crude oil after sterilization and heat treatment after adding monosodium glutamate was reduced by 0.12~0.18 g / 100ml, while the amino acid nitrogen content of the crude oil after sterilization and heat treatment after the present invention was reduced by 0.02~0.05 g / 100ml. The amino acid nitrogen content of the controlled thermal reaction of the present invention was reduced by 0.01~0.03 g / 100ml. That is, the overall amino acid nitrogen loss of the crude oil processed by the present invention is ≤0.08 g / 100ml, and the amino acid nitrogen loss is reduced by at least 33%~56% compared with the prior art, which helps to save production costs. Based on the annual production of 100,000 tons of finished soy sauce, the low temperature heat treatment process is expected to save about RMB 9.75 million / year in amino acid nitrogen costs (based on an amino acid nitrogen loss of 0.01 g / 100ml per ton of oil, the cost is about RMB 9.75 / ton, and the heat treatment loss is reduced by 0.1 g / 100ml, saving about RMB 97.5 / ton, for a total reduction of RMB 9.75 million / year in amino acid nitrogen costs).

[0031] Furthermore, this invention adjusts the color of soy sauce by boiling liquid caramel with white sugar in a controlled thermal reaction stage, effectively reducing the material loss costs associated with the initial reaction of white sugar and amino acid nitrogen in existing technologies. Therefore, for light-colored crude oil, which is typically produced from March to June each year, and assuming an annual production of 100,000 tons of finished soy sauce, approximately 30,000 tons of crude oil require additional white sugar for color adjustment. Existing technologies require 3% to 4% white sugar for color adjustment, totaling approximately 900 to 1200 tons. The unit price of white sugar is estimated at 7.0 yuan per liter at market price. The cost of the previous method was approximately 6.3 million to 8.4 million yuan. This invention uses a controlled thermal reaction to cook caramel coloring, which is expected to consume 1%-2% white sugar, about 300 to 600 tons, at a cost of 2.1 million to 4.2 million yuan. That is, the cost of white sugar is reduced by about 3.2 million to 4.2 million yuan. In addition, the controlled thermal reaction of this invention will result in a loss of about 0.03g / 100ml of amino acid nitrogen, corresponding to a cost of about 877,500 yuan. Therefore, the controlled thermal reaction process reduces the overall cost by about 2.3225 million to 3.3225 million yuan per year.

[0032] (5) Lower requirements for plant automation: The closed heat sink method reduces the impact of space microorganisms, and the heat sink temperature of 50~60℃, which is not conducive to the growth of microorganisms, is adopted simultaneously to ensure that the microbial indicators of crude oil are qualified during the heat sink process. Therefore, the present invention has lower requirements for plant automation. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The crude oil used in the following embodiments is crude oil obtained by pressing after undergoing extensive high-salt dilute-state fermentation.

[0034] Example 1:

[0035] (1) Heating sterilization: Crude oil with amino acid nitrogen of 1.10g / 100ml and L* value of 95.2 is first sterilized at high temperature of 125℃. After holding the temperature for 30s, it is instantly cooled to 50℃ by water cooling to obtain semi-finished product A.

[0036] (2) Heat sinking: The sealed heat sink tank is first cleaned with CIP, and then semi-finished product A is pumped into the sealed heat sink tank for heat sinking for 3 days to settle large particles of impurities inside the crude oil to the bottom; then oil is pumped from the middle of the heat sink tank to obtain semi-finished product B.

[0037] (3) Filtration and blending: Semi-finished product B is filtered in one step, and the turbidity after filtration is <10ppm; then sterilized crude oil, monosodium glutamate, I+G, sucralose and other auxiliary materials are added to it for blending to obtain semi-finished product C.

[0038] (4) Controllable thermal reaction: The semi-finished product C is sterilized at an ultra-high temperature of 125°C to kill the microbial risks introduced by the addition of monosodium glutamate, I+G and other materials, and is instantly cooled to 90°C and pumped into a stainless steel tank with a steam coil and stirred. The slow Maillard reaction is carried out at a holding temperature (90°C) through the steam coil. At the same time, liquid caramel is added to the heat-insulated product as needed to increase the bright red color and make it reach the target color (L* value) requirement. During this period, the color change data is detected by an online monitoring colorimeter to accurately control the color. The preparation method of liquid caramel is as follows: white sugar and water are mixed in a 1:1 ratio, and the caramel is boiled at 150°C for 3~10 minutes and cooled to 95°C to obtain a bright red caramel.

[0039] (5) Filling: After the controlled heat reaction is qualified, the semi-finished product D is obtained. The temperature is reduced to 40°C and directly cooled and filled to obtain the finished soy sauce. This reduces the need for reheating and sterilization, and at the same time, the loss of amino acid nitrogen is lower, and the various physicochemical indicators and flavor are more stable.

[0040] The cost, appearance, sensory properties, and physicochemical properties of the resulting soy sauce are shown in Table 1 below.

[0041] Example 2:

[0042] (1) Crude oil sterilization: Crude oil with amino acid nitrogen of 1.10g / 100ml and L* value of 80.5 is first sterilized at high temperature of 125℃. After holding the temperature for 30s, it is instantly cooled to 55℃ by water cooling to obtain semi-finished product A.

[0043] (2) Heat sinking: The sealed heat sink tank is first cleaned with CIP, and then semi-finished product A is pumped into the sealed heat sink tank for heat sinking for 2 days; large particles of impurities inside the crude oil are settled to the bottom, and then oil is pumped from the middle of the heat sink tank to obtain semi-finished product B.

[0044] (3) Filtration and blending: Semi-finished product B is filtered in one step, and the turbidity after filtration is <10ppm; then sterilized crude oil, monosodium glutamate, I+G, sucralose and other auxiliary materials are added to it for blending to obtain semi-finished product C.

[0045] (4) Controlled thermal reaction: The semi-finished product C is sterilized at ultra-high temperature of 125℃ to kill the microbial risks introduced by the addition of monosodium glutamate, I+G and other materials, and then instantly cooled to 90℃ before being pumped into a stainless steel tank containing a steam coil and stirred. A slow Maillard reaction is carried out at a sustained temperature (90℃) through the steam coil. During this process, color change data is detected by an online colorimeter to precisely control the color.

[0046] (5) Filling: After the controlled heat reaction is qualified, the semi-finished product D is obtained. The temperature is reduced to 40°C and directly cooled and filled to obtain the finished soy sauce. This reduces the need for reheating and sterilization, and at the same time, the loss of amino acid nitrogen is lower, and the various physicochemical indicators and flavor are more stable.

[0047] The cost, appearance, sensory properties, and physicochemical properties of the resulting soy sauce are shown in Table 2 below.

[0048] Example 3:

[0049] (1) Heating sterilization: Crude oil with amino acid nitrogen of 1.10g / 100ml and L* value of 92.5 is first sterilized at high temperature of 125℃. After holding the temperature for 30s, it is instantly cooled to 60℃ by water cooling to obtain semi-finished product A.

[0050] (2) Heat sinking: The sealed heat sink tank is first cleaned with CIP, and then semi-finished product A is pumped into the sealed heat sink tank for heat sinking for 2 days to settle large particles of impurities inside the crude oil to the bottom; then oil is pumped from the middle of the heat sink tank to obtain semi-finished product B.

[0051] (3) Filtration and blending: Semi-finished product B is filtered in one step, and the turbidity after filtration is <10ppm; then sterilized crude oil, monosodium glutamate, I+G, sucralose and other auxiliary materials are added to it for blending to obtain semi-finished product C.

[0052] (4) Controllable thermal reaction: The semi-finished product C is sterilized at an ultra-high temperature of 125°C to kill the microbial risks introduced by the addition of monosodium glutamate, I+G and other materials, and then instantly cooled to 75°C and pumped into a stainless steel tank containing a steam coil and stirred. The slow Maillard reaction is carried out at a sustained temperature (75°C) through the steam coil. At the same time, liquid caramel is added to the insulated product as needed to increase the bright red color and make it reach the target color (L* value) requirement. During this period, the color change data is detected by an online monitoring colorimeter to accurately control the color. The preparation method of liquid caramel is as follows: white sugar and water are mixed in a 1:1 mass ratio, pressurized and heated to 150°C to cook the caramel for 3~10 minutes, and then cooled to 95°C to obtain a bright red caramel.

[0053] (5) Filling: After the controlled heat reaction is qualified, the semi-finished product D is obtained. The temperature is reduced to 40°C and directly cooled and filled to obtain the finished soy sauce. This reduces the need for reheating and sterilization, and at the same time, the loss of amino acid nitrogen is lower, and the various physicochemical indicators and flavor are more stable.

[0054] The cost, appearance, sensory properties, and physicochemical properties of the resulting soy sauce are shown in Table 3 below.

[0055] Example 4:

[0056] (1) Heating sterilization: Crude oil with amino acid nitrogen of 1.10g / 100ml and L* value of 93.2 is first sterilized at high temperature of 125℃. After holding the temperature for 30s, it is instantly cooled to 50℃ by water cooling to obtain semi-finished product A.

[0057] (2) Heat sinking: The sealed heat sink tank is first cleaned with CIP, and then semi-finished product A is pumped into the sealed heat sink tank for heat sinking for 3 days to settle large particles of impurities inside the crude oil to the bottom; then oil is pumped from the middle of the heat sink tank to obtain semi-finished product B.

[0058] (3) Filtration and blending: Semi-finished product B is filtered in one step, and the turbidity after filtration is <10ppm; then sterilized crude oil, monosodium glutamate, I+G, sucralose and other auxiliary materials are added to it for blending, and then semi-finished product C is added.

[0059] (4) Controllable thermal reaction: The semi-finished product C is sterilized at an ultra-high temperature of 125°C to kill the microbial risks introduced by the addition of monosodium glutamate, I+G and other materials, and is instantly cooled to 80°C and pumped into a stainless steel tank with a steam coil and stirred. The slow Maillard reaction is carried out at a holding temperature (80°C) through the steam coil. At the same time, white sugar and liquid caramel are added to the heat-insulated product as needed to increase the bright red color and make it reach the target color (L* value) requirement. During this period, the color change data is detected by an online monitoring colorimeter to accurately control the color. The preparation method of liquid caramel is as follows: white sugar and water are mixed in a ratio of 2:1, the caramel is boiled at 150°C under pressure, and then cooled to 95°C to obtain a bright red caramel.

[0060] (5) Filling: After the controlled heat reaction is qualified, the semi-finished product D is obtained. The temperature is reduced to 40°C and directly cooled and filled to obtain the finished soy sauce. This reduces the need for reheating and sterilization, and at the same time, the loss of amino acid nitrogen is lower, and the various physicochemical indicators and flavor are more stable.

[0061] The cost, appearance, sensory properties, and physicochemical properties of the resulting soy sauce are shown in Table 3 below.

[0062] Comparative Example 1:

[0063] (1) First blending: Add sodium glutamate, white sugar and other materials to crude oil with an amino acid nitrogen content of 1.10 g / 100 ml and an L* value of 94.2 to obtain oil embryo with an amino acid nitrogen content of 1.60 g / 100 ml;

[0064] (2) Heating and sterilization: The oil embryo is sterilized at a high temperature of 125°C and held at the temperature for 30 seconds. Then it is instantly cooled to 100°C by water cooling to obtain semi-finished product A.

[0065] (3) Heat sink: The semi-finished product A is pumped into an open heat sink tank and left to stand for 5 days to carry out the Maillard reaction and precipitate out the precipitate and large particulate impurities to settle to the bottom, but some impurities are in a suspended state; then the oil is extracted from the middle of the heat sink tank to obtain the semi-finished product B.

[0066] (4) Filtration and secondary blending: Semi-finished product B is filtered twice; then it is supplemented with auxiliary materials such as monosodium glutamate, I+G, and sucralose for secondary blending to obtain semi-finished product C.

[0067] (5) Filling: Sterilize the semi-finished product C at a high temperature of 125°C, cool it down to 40°C and then fill it to obtain the finished soy sauce.

[0068] Comparative Example 2:

[0069] (1) First blending: Add sodium glutamate, white sugar, I+G and other materials to crude oil with amino acid nitrogen content of 1.10 g / 100 ml and L* value of 78.9 to obtain oil embryo with amino acid nitrogen content of 1.60 g / 100 ml;

[0070] (2) Heating and sterilization: The oil embryo is sterilized at a high temperature of 125°C and held at the temperature for 30 seconds. Then it is instantly cooled to 100°C by water cooling to obtain semi-finished product A.

[0071] (3) Heat sink: The semi-finished product A is pumped into an open heat sink tank and left to stand for 5 days to carry out the Maillard reaction and precipitate out the precipitate and large particulate impurities to settle to the bottom, but some impurities are in a suspended state; then the oil is extracted from the middle of the heat sink tank to obtain the semi-finished product B.

[0072] (4) Filtration and secondary blending: Semi-finished product B is filtered twice; then it is supplemented with auxiliary materials such as monosodium glutamate, I+G, and sucralose for secondary blending to obtain semi-finished product C.

[0073] (5) Filling: Sterilize the semi-finished product C at a high temperature of 125°C, cool it down to 40°C and then fill it to obtain the finished soy sauce.

[0074] Comparative Example 3:

[0075] (1) Heating sterilization: Crude oil with amino acid nitrogen of 1.10g / 100ml and L* value of 94.9 is first sterilized at high temperature of 125℃. After holding the temperature for 30s, it is instantly cooled to 50℃ by water cooling to obtain semi-finished product A.

[0076] (2) Heat sinking: The sealed heat sink tank is first cleaned with CIP, and then semi-finished product A is pumped into the sealed heat sink tank for heat sinking for 3 days to settle large particles of impurities inside the crude oil to the bottom; then oil is pumped from the middle of the heat sink tank to obtain semi-finished product B.

[0077] (3) Filtration and blending: Semi-finished product B is filtered in one step, and the turbidity after filtration is <10ppm; then sterilized crude oil, monosodium glutamate, I+G, sucralose and other auxiliary materials are added to it for blending to obtain semi-finished product C.

[0078] (4) Filling: The semi-finished product C is sterilized at an ultra-high temperature of 125°C and then cooled to 40°C for filling.

[0079] The cost, appearance, sensory properties, and physicochemical properties of the resulting soy sauce are shown in Table 1 below.

[0080] Comparative Example 4:

[0081] (1) Heating sterilization: Crude oil with amino acid nitrogen of 1.10g / 100ml and L* value of 93.8 is first sterilized at high temperature of 125℃. After holding the temperature for 30s, it is instantly cooled to 60℃ by water cooling to obtain semi-finished product A.

[0082] (2) Heat sinking: The sealed heat sink tank is first cleaned with CIP, and then semi-finished product A is pumped into the sealed heat sink tank for heat sinking for 2 days to settle large particles of impurities inside the crude oil to the bottom; then oil is pumped from the middle of the heat sink tank to obtain semi-finished product B.

[0083] (3) Filtration and blending: Semi-finished product B is filtered in one step, and the turbidity after filtration is <10ppm; then sterilized crude oil, monosodium glutamate, I+G, sucralose and other auxiliary materials are added to it for blending to obtain semi-finished product C.

[0084] (4) Color control: The semi-finished product C is sterilized at 125°C to kill the microbial risks introduced by the addition of monosodium glutamate, I+G and other materials, and then cooled to 40°C. Then, liquid caramel is added to the insulated product as needed to increase the bright red color and make it meet the target color (L* value) requirements. During this period, the color change data is detected by an online colorimeter to accurately control the color. The preparation method of liquid caramel is as follows: white sugar and water are mixed in a 1:1 mass ratio, and the caramel is boiled at 150°C for 3-10 minutes under pressure and then cooled to 95°C to obtain a bright red caramel.

[0085] (5) Filling: The semi-finished product D obtained by color control is directly cooled and filled, which reduces the need for reheating and sterilization, and at the same time, the loss of amino acid nitrogen is lower, and the various physicochemical indicators and flavor are more stable.

[0086] The resulting finished soy sauce, compared to its previous state, exhibits improvements in cost, appearance, sensory properties, and physicochemical indicators.

[0087] Table 1

[0088] index Example 1 Comparative Example 1 Comparative Example 3 Physicochemical properties of crude oil or oil preform before heat sterilization Total acid 1.80g / 100ml, L* value 95.2, amino acids 1.10g / 100ml. Total acid: 1.45g / 100ml, L* value 94.2, amino acids 1.60g / 100ml. Total acid 1.80g / 100ml, L* value 94.9, amino acids 1.10g / 100ml. Heating and sterilization parameters The heating temperature is 125℃, and the oil output temperature is 50℃. The oil output temperature is reduced to achieve sterilization while preserving the soy sauce and fermented bean flavor of the crude oil to the greatest extent and reducing the loss of flavor substances. The heating temperature is 125℃, and the oil output temperature is 100℃, which produces a caramel and soy sauce flavor. The heating temperature is 125℃, and the oil exit temperature is 50℃. Lowering the oil exit temperature achieves sterilization while preserving the original soy sauce and fermented bean flavors to the greatest extent and reducing the loss of flavor substances. Heat sink environment The use of a sealed heat sink reduces airborne microbial contamination. The clean environment helps to lower the heat sink temperature, thereby reducing the Maillard reaction. At the same time, the sealed tank allows for slower heat dissipation, which facilitates better pasteurization in the later stages. The L* value of semi-finished product B is 69.2. The open-top heat sink tank allows for rapid heat dissipation and direct contact with air, making it susceptible to microbial contamination and potentially leading to excessive levels of microorganisms. Consequently, the oil output temperature is high, the evaporation rate is large, and the loss of amino acids due to the Maillard reaction is significant, resulting in a potential burnt odor. The L* value of semi-finished product B is 55.2. The use of a sealed heat sink reduces airborne microbial contamination. The clean environment helps to lower the heat sink temperature, thereby reducing the Maillard reaction. At the same time, the sealed tank allows for slower heat dissipation, which facilitates better pasteurization in the later stages. The L* value of the semi-finished product B is 68.7. amino acid reduction after heat deposition The decrease was 0.05g / 100ml; the decrease was 0.13g / 100ml less than that of Comparative Example 1. The decrease was 0.18g / 100ml. The decrease was 0.06g / 100ml; the decrease was 0.12g / 100ml less than that of Comparative Example 1. Physicochemical properties of semi-finished product C after blending Total acid: 1.89g / 100ml, amino acids: 1.41g / 100ml, L* value: 63.3. Total acid: 1.85g / 100ml, amino acids: 1.41g / 100ml, L* value: 53.5. Total acid: 1.89g / 100ml, amino acids: 1.41g / 100ml, L* value: 65.1. Controllable thermal reaction parameters and physicochemical properties of semi-finished product D Hold at 90℃ for 30 minutes while adding liquid caramel coloring; the amount of white sugar used is 1.2%; total acid: 1.89g / 100ml, amino acids: 1.40g / 100ml, L* value: 40.3; / / Overall evaluation of finished products Score: 9.5 out of 10. Color: Reddish-brown, L* value is approximately 13.2 deeper than Comparative Example 1. Appearance: Clear, free of impurities, turbidity after filtration is 0.3ppm. Flavor: Rich in soy sauce and fermented bean aroma, very fragrant, and has a superior flavor compared to existing products. Score: 8.7 out of 10. Color: Slightly light in color, bright red. Appearance: Slightly cloudy, turbidity 83.1 ppm, high amino acid concentration before filtration, difficult to filter; Flavor: Soy sauce aroma, moderate saltiness, with a caramel aroma, good flavor. Score: 8.3 out of 10. Color: Light, clear, and yellowish. Appearance: Clear, free of impurities, turbidity after filtration: 0.8 ppm. Flavor: Rich in soy sauce and fermented bean aroma, with a pleasant fragrance and good flavor. Solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC / MS) for the detection and analysis of finished soy sauce products There are 77 volatile substances, including 14 alcohols, 11 acids, 9 esters, 9 phenols, 1 ether, 7 aldehydes, 3 ketones, 11 heterocyclic compounds, and 12 other volatile components. There are 73 volatile substances, including 12 alcohols, 11 acids, 9 esters, 8 phenols, 1 ether, 7 aldehydes, 3 ketones, 10 heterocyclic compounds, and 12 other volatile components. There are 75 volatile substances, including 14 alcohols, 11 acids, 9 esters, 8 phenols, 1 ether, 7 aldehydes, 3 ketones, 10 heterocyclic compounds, and 12 other volatile components.

[0089] Table 2

[0090] index Example 2 Comparative Example 2 Physicochemical properties of crude oil or oil preform before heat sterilization Total acid 1.80g / 100ml, L* value 80.5, amino acids 1.10g / 100ml. Total acid: 1.45g / 100ml, L* value 78.9, amino acids: 1.60g / 100ml; Heating and sterilization parameters The heating temperature is 125℃, and the oil output temperature is 55℃. The lower output temperature achieves sterilization while preserving the soy sauce and fermented bean flavor of the crude oil to the greatest extent and reducing the loss of flavor substances. The heating temperature is 125℃ and the oil output temperature is 100℃, which produces a caramel and soy sauce flavor. Heat sink environment The use of a closed heat sink reduces airborne microbial contamination. The clean environment helps to lower the heat sink temperature, thereby reducing the Maillard reaction. At the same time, the closed tank allows for slower heat dissipation, which facilitates better pasteurization in the later stages. The L* value of semi-finished product B is 56.3. Open-top heat sink; rapid heat dissipation, short sterilization time, direct contact with air, easy contact with microorganisms leading to excessive microbial levels, resulting in higher oil output temperature, larger evaporation rate, greater loss of amino acids due to Maillard reaction, and potential for burnt odor; L* value of semi-finished product B is 35.3. Heat-sinking amino acid reduction The decrease was 0.06g / 100ml; the decrease in comparison example 2 was 0.11g / 100ml. The decrease was 0.17g / 100ml; Physicochemical properties of semi-finished product C after blending Total acid: 1.89g / 100ml, amino acids: 1.41g / 100ml, L* value: 49.2. Total acid: 1.85g / 100ml, amino acids: 1.41g / 100ml, L* value: 32.5. Controllable thermal reaction parameters and physicochemical properties of semi-finished product D Hold at 90℃ for 15 min; total acid: 1.86 g / 100 ml, amino acids: 1.40 g / 100 ml, L* value: 44.3. / Overall evaluation of finished soy sauce products Score: 9.7 out of 10. Color: Reddish amber, reddish brown, good adhesion to the glass; Appearance: Clear, turbidity 1.3ppm; Flavor: Rich soy sauce and fermented bean aroma, very fragrant, excellent flavor, superior to existing products. Score: 7.5 out of 10. Color: Dark, blackish-brown, and dull. Appearance: Slightly cloudy. Filtration: 75ppm. High amino acid concentration before filtration, making it difficult to filter. Flavor: Soy sauce aroma, slightly salty and bitter. Solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC / MS) for the detection and analysis of finished soy sauce products There are 76 volatile substances, including 13 alcohols, 11 acids, 10 esters, 9 phenols, 1 ether, 7 aldehydes, 3 ketones, 10 heterocyclic compounds, and 12 other volatile components. There are 73 volatile substances, including 12 alcohols, 11 acids, 9 esters, 8 phenols, 1 ether, 7 aldehydes, 3 ketones, 10 heterocyclic compounds, and 12 other volatile components.

[0091] Table 3

[0092] index Example 3 Example 4 Comparative Example 4 Physicochemical properties of crude oil or oil preform before heat sterilization Total acid 1.79g / 100ml, L* value 92.5, amino acids 1.10g / 100ml. Total acid 1.83g / 100ml, L* value 93.2, amino acids 1.10g / 100ml. Total acid 1.85g / 100ml, L* value 93.8, amino acids 1.10g / 100ml. Heating and sterilization parameters The heating temperature is 125℃, and the oil output temperature is 60℃. The lower output temperature achieves sterilization while preserving the soy sauce and fermented bean flavor of the crude oil to the greatest extent and reducing the loss of flavor substances. The heating temperature is 125℃, and the oil output temperature is 50℃. The oil output temperature is reduced to achieve sterilization while preserving the soy sauce and fermented bean flavor of the crude oil to the greatest extent and reducing the loss of flavor substances. The heating temperature is 125℃, and the oil output temperature is 60℃. The lower output temperature achieves sterilization while preserving the soy sauce and fermented bean flavor of the crude oil to the greatest extent and reducing the loss of flavor substances. Heat sink environment The use of a sealed heat sink reduces airborne microbial contamination. The clean environment helps to lower the heat sink temperature, thereby reducing the Maillard reaction. At the same time, the sealed tank allows for slower heat dissipation, which facilitates better subsequent pasteurization. The L* value of semi-finished product B is 62.5. The use of a sealed heat sink reduces airborne microbial contamination. The clean environment helps to lower the heat sink temperature, thereby reducing the Maillard reaction. At the same time, the sealed tank allows for slower heat dissipation, which facilitates better subsequent pasteurization. The L* value of semi-finished product B is 67.5. The use of a closed heat sink reduces airborne microbial contamination. The clean environment helps to lower the heat sink temperature, thereby reducing the Maillard reaction. At the same time, the closed tank allows for slower heat dissipation, which facilitates better subsequent pasteurization. The L* value of semi-finished product B is 61.9. Heat-sinking amino acid reduction The decrease was 0.06g / 100ml; the decrease was 0.12g / 100ml less than that of Comparative Example 1. The decrease was 0.05g / 100ml; the decrease was 0.13g / 100ml less than that of Comparative Example 1. The decrease was 0.06g / 100ml; the decrease was 0.12g / 100ml less than that of Comparative Example 1. Physicochemical properties of semi-finished product C after blending Total acid: 1.89g / 100ml, amino acids: 1.41g / 100ml, L* value: 59.2; Total acid: 1.89g / 100ml, amino acids: 1.41g / 100ml, L* value: 65.8; Total acid: 1.89g / 100ml, amino acids: 1.41g / 100ml, L* value: 60.1; Controllable thermal reaction parameters and physicochemical properties of semi-finished product D Hold at 75℃ for 40 minutes; add liquid caramel coloring, equivalent to 1.2% white sugar, total acid: 1.89g / 100ml, amino acids: 1.40g / 100ml, L* value: 42.8. Hold at 80℃ for 30 minutes; add liquid caramel coloring, which is equivalent to 1.2% white sugar, with an additional 1.3% white sugar added, for a total of 2.5% white sugar added; total acid: 1.93g / 100ml, amino acids: 1.40g / 100ml, L* value: 43.5. Adding liquid caramel coloring, equivalent to approximately 1.7% white sugar, results in a total acid content of 1.90g / 100ml, amino acid content of 1.40g / 100ml, and an L* value of 48.3. Overall evaluation of finished soy sauce products Score: 9.7 out of 10. Color: Reddish-brown, thick and clinging to the glass; Appearance: Clear after filtration, turbidity 2.3ppm; Flavor: Rich in soy sauce and fermented bean aroma, very fragrant and flavorful, superior to existing products. Score: 9.5 out of 10. Color: Reddish-brown. Appearance: Clear after filtration, turbidity 3.5ppm; Flavor: Rich aroma of soy sauce, caramel, fermented black bean, and sweetness, with a very pleasant and superior flavor compared to existing products. Score: 8.8 out of 10. Color: Reddish-brown, slightly lighter; Appearance: Clear after filtration, turbidity 2.2ppm; Flavor: Rich in soy sauce and fermented bean aroma, fresh and sweet, superior to existing products. Solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC / MS) for the detection and analysis of finished soy sauce products There are 77 volatile substances, including 14 alcohols, 11 acids, 9 esters, 9 phenols, 1 ether, 7 aldehydes, 3 ketones, 11 heterocyclic compounds, and 12 other volatile components. There are 77 volatile substances, including 14 alcohols, 11 acids, 9 esters, 9 phenols, 1 ether, 7 aldehydes, 3 ketones, 11 heterocyclic compounds, and 12 other volatile components. There are 75 volatile substances, including 13 alcohols, 11 acids, 10 esters, 8 phenols, 1 ether, 7 aldehydes, 3 ketones, 10 heterocyclic compounds, and 12 other volatile components.

[0093] Note: The comprehensive evaluation of soy sauce finished products in Tables 1-3 above includes three modules: color, appearance, and flavor. The evaluation is based on GB / T18186, with each module scored out of 10. The scores are then weighted and summed based on color (30%), appearance (30%), and sensory evaluation (40%) to obtain the comprehensive evaluation score.

Claims

1. A method for processing crude soy sauce that reduces amino acid nitrogen loss and precisely controls color, characterized in that, Includes the following steps: (1) Heating and sterilization: The crude oil is heated and sterilized and then cooled to 50~60℃ to obtain semi-finished product A; (2) Heat sinking: The semi-finished product A is pumped into a closed heat sinking tank for heat sinking, and the large particles of impurities inside are settled to the bottom; then oil is extracted from the middle of the heat sinking tank to obtain semi-finished product B. (3) Filtration and blending: The semi-finished product B is filtered and then blended to obtain the semi-finished product C; (4) Controlled thermal reaction: The semi-finished product C is heated and sterilized, then instantly cooled to 65~90℃, pumped into a stainless steel tank containing a steam coil and stirred. The steam coil is used to carry out a slow Maillard reaction at a constant temperature, that is, to carry out a controlled thermal reaction to produce a rich flavor. During the above reaction process, the color change data of the semi-finished product C is detected by an online monitoring colorimeter to accurately control the color. If the crude oil being processed is a light-colored crude oil, liquid caramel coloring is added to the semi-finished product C during the controlled thermal reaction process to increase its bright red color and make its color meet the process design requirements; the liquid caramel coloring is a bright red liquid obtained by boiling white sugar and water together. (5) Filling: After the controlled thermal reaction is completed, semi-finished product D is obtained. After cooling it to below 40°C, it is filled to obtain the finished soy sauce.

2. The method for processing crude soy sauce according to claim 1, characterized in that, The method for preparing the liquid caramel coloring is as follows: granulated sugar and water are mixed in a mass ratio of 3:1 to 1:1, and the mixture is boiled at 130 to 150°C for 3 to 10 minutes under pressure, and then cooled to 90 to 100°C to obtain a bright red liquid caramel coloring.

3. The method for processing crude soy sauce according to claim 2, characterized in that, The heat sinking time is 1 to 3 days.

4. The method for processing crude soy sauce according to claim 3, characterized in that, During the controlled thermal reaction process, liquid caramel coloring is added according to the data from the colorimeter, and the color of soy sauce is flexibly adjusted by adding different combinations of liquid caramel coloring with varying shades, and / or the flavor of soy sauce is controlled by adding a combination of liquid caramel coloring and white sugar.

5. The method for processing crude soy sauce according to claim 4, characterized in that, The heating and sterilization operation is as follows: heat the material to 110~125℃ and sterilize for 30~60 seconds.