Deep eutectic solvent degumming agent based on choline chloride and lactic acid and application of deep eutectic solvent degumming agent

Abstract

The invention belongs to the technical field of food processing, and particularly relates to a deep-eutectic solvent degumming agent based on choline chloride and lactic acid and application of the deep-eutectic solvent degumming agent. The invention provides a deep-eutectic solvent degumming agent and a pretreatment method for beef tallow degumming. The deep-eutectic solvent degumming agent comprises a hydrogen bond acceptor and a hydrogen bond donor, the hydrogen bond acceptor is choline chloride, and the hydrogen bond donor is lactic acid. The pretreatment method for degumming beef tallow comprises the following steps: mixing untreated raw beef tallow with a deep eutectic solvent degumming agent, heating and stirring, and carrying out solid-liquid separation to obtain treated degummed beef tallow; compared with the prior art, the deep eutectic solvent degumming agent is adopted to perform degumming pretreatment on the raw beef tallow, and the method is simple in process, easy in raw material synthesis, low in synthesis cost, non-toxic, biodegradable, pollution-free and high in degumming efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of food processing, and particularly relates to a deep eutectic solvent degumming agent based on choline chloride and lactic acid and application thereof. BACKGROUND

[0002] Beef tallow is a core raw material for making hot pot base, catering seasoning and food industry. Its quality directly determines the flavor and stability of the end product. Crude beef tallow contains phospholipids and mucilage and other hydrophilic and hydrophobic impurities, collectively referred to as "gums". The presence of these gums will cause beef tallow to produce foam, turbidity when heated, and affect its color, flavor and storage stability. Therefore, "degumming" as the first step of beef tallow refining is the key process to improve its quality and value.

[0003] At present, the degumming of beef tallow in industry still heavily relies on traditional methods, which mainly exist the following technical paths and inherent defects:

[0004] I. Chemical degumming method: This method usually uses inorganic or organic acids such as phosphoric acid, citric acid for "acid refining", or uses sodium hydroxide solution for "alkali refining". Its principle is to separate impurities by taking advantage of the difference in stability of gums and oil under acid / alkali conditions. However, this method has insurmountable drawbacks: (1) It produces a large amount of wastewater containing phosphorus and high chemical oxygen demand (COD), which causes serious pressure on the environment, and the subsequent wastewater treatment cost is high; (2) Strong acid or alkali environment easily causes saponification and hydrolysis of oil, not only leading to loss of neutral oil and reducing refining yield, but also damaging the rich flavor of beef tallow itself and affecting product quality.

[0005] II. Physical hydration degumming method: This method adds hot water to hot oil to make hydrophilic gums such as phospholipids swell and coagulate, and then separates them by centrifugation. Although this method is relatively mild, it has the following disadvantages: (1) It is only effective for hydrated phospholipids, and has poor removal effect on non-hydrated phospholipids and other hydrophobic impurities commonly found in beef tallow, resulting in incomplete degumming; (2) The process control window is narrow, insufficient water addition will result in poor degumming effect, and excessive water addition will easily cause oil phase emulsification, leading to separation difficulty and oil yield reduction; (3) It also produces process wastewater that needs to be treated.

[0006] In response to increasingly stringent environmental requirements, the industry has begun to explore and apply physical adsorption method, i.e. using porous adsorbents such as silica and diatomite to adsorb and remove gums. Although this method avoids the generation of wastewater from the source, it exposes new technical defects in practice: (1) The adsorbent will irreversibly and non-selectively strongly adsorb a large amount of neutral oil while adsorbing the gums, resulting in a significant reduction in refining yield and direct economic loss; (2) Its strong adsorption will also strip valuable characteristic flavor substances from beef tallow, causing the product flavor to become bland, which severely restricts its application in high-end beef tallow products.

[0007] In summary, those skilled in the art have long faced a critical technical choice: while chemical or hydration methods can achieve a certain degumming effect, they incur high environmental costs and quality losses; while physical adsorption methods solve the wastewater problem, they come at the cost of reduced yield and flavor. Therefore, developing a new green degumming technology that can eliminate wastewater at the source while maintaining high degumming efficiency and high product yield has become a core challenge urgently needing to be addressed in this field, and this is the starting point for this invention. Summary of the Invention

[0008] To solve the above-mentioned technical problems, the technical solution of the present invention specifically includes the following three core parts:

[0009] 1. Preparation of eutectic solvent degumming agent

[0010] The eutectic solvent degumming agent of the present invention consists of hydrogen bond acceptors and hydrogen bond donors.

[0011] Hydrogen bond acceptor: choline chloride. It is inexpensive, non-toxic, stable, and readily available.

[0012] Hydrogen bond donor: lactic acid. It is a food-grade additive, safe and harmless, and can form a eutectic solvent with excellent degumming properties with choline chloride.

[0013] Preparation method: Weigh choline chloride and lactic acid into a container at a molar ratio of 1:1 to 1:3, and add 10% to 30% of the total mass of deionized water to the mixture to reduce the solvent viscosity. Place the mixture in a water bath at 60 to 120°C and stir continuously until the system becomes a homogeneous, clear, and transparent liquid, which usually takes 30 minutes to 1 hour. Then, cool the resulting eutectic solvent to room temperature for later use. This preparation process is simple and requires no complex equipment.

[0014] 2. Tallow degumming method based on eutectic solvent

[0015] The method for degumming butter according to the present invention comprises the following specific steps:

[0016] (1) Raw material preparation: Melt beef fat into oil, then filter it through a 0.4mm filter screen to remove coarse residue and obtain crude beef tallow. Take a certain amount of crude beef tallow, and if it is solid, heat it until it is completely melted and kept in a liquid state to facilitate mixing and reaction.

[0017] (2) Mixing and reaction: Mix the crude tallow with the prepared eutectic solvent degumming agent in a specified ratio. The key process parameters are controlled as follows:

[0018] Solvent addition amount: The mass of the eutectic solvent degumming agent is 0.1% to 5% of the mass of crude tallow. This is a crucial innovation, as such a low dosage is key to achieving high economic efficiency. The preferred range is 0.6% to 2%.

[0019] Reaction temperature: Heat the mixture to 60-120℃. Within this temperature range, the viscosity of the oil decreases, the solvent flowability increases, and the mass transfer efficiency improves, which is conducive to the rapid degumming reaction. The preferred range is 60-80℃.

[0020] Reaction time: At the stated temperature, the mixture is stirred continuously at 200-600 rpm for 0.5-3 hours. Sufficient contact and interaction time between the colloid and solvent are ensured. A preferred range is 0.5-2 hours.

[0021] Separation and post-processing: After the reaction is complete, the reaction mixture is subjected to solid-liquid separation. Centrifugation can be used (e.g., at 3000 rpm).

[0022] The separation is achieved by centrifuging at ~6000 rpm for 10 ~ 15 minutes. After separation, the upper clear liquid phase is the degummed butter, and the lower layer or filter residue is a solid phase containing gum and a small amount of solvent.

[0023] 3. Explanation of the relationship between the mechanism and advantages of the technical solution

[0024] The technical solution of the present invention systematically solves the problems in the prior art through the above-mentioned specific solvent combination and process:

[0025] Solving the wastewater problem: Although a small amount of water is pre-added during solvent preparation, there is no need to continuously add large amounts of process water in the core degumming reaction stage and subsequent treatment, as is the case with traditional methods. Therefore, this invention does not generate highly polluting washing wastewater or hydration wastewater that requires discharge and treatment, achieving wastewater source reduction and pollution control.

[0026] Solving the problems of yield and efficient degumming: This method is based on the "dissolve-extraction" mechanism. On the one hand, this mechanism has a strong dissolving ability for phospholipids and other gums, thus achieving extremely high degumming efficiency, manifested in a significant reduction in residual gum content and phospholipid content. On the other hand, this mechanism is completely different from the strong and irreversible adsorption of neutral oils in physical adsorption methods. As shown in Table 1, while achieving a better degumming effect, the refining yield of this invention is significantly higher than that of physical adsorption methods, fundamentally avoiding oil loss caused by adsorbents, and significantly improving economic efficiency.

[0027] Solving energy consumption issues: Highly efficient degumming can be achieved with extremely low solvent usage (0.1%-5%), significantly reducing raw material costs. Simultaneously, since no subsequent "washing" and "drying" stages are required, the steam energy consumption of the entire process is significantly reduced.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) Green and environmentally friendly, with no discharge of process wastewater: Although a small amount of water is added in the solvent preparation stage to form a homogeneous system and reduce the viscosity of the solvent, no additional water is required during the entire degumming reaction and subsequent separation process. Therefore, compared with traditional methods, this invention eliminates the generation and discharge of phosphorus-containing, high-COD process wastewater from the source, solving the biggest environmental pain point of traditional degumming. The small amount of water used is retained in the solvent system or in the final small amount of solid waste, and does not need to be treated as wastewater.

[0030] (2) The degumming efficiency is significantly better than existing green technologies: This invention is the first to discover that the eutectic solvent formed by choline chloride and lactic acid has a specific ability to dissolve and extract phospholipids and other gums in tallow. As shown in the following examples, under the same usage, the degumming efficiency of this invention is significantly higher than that of the physical adsorption method, and its residual gum rate and phospholipid content are greatly reduced.

[0031] (3) Improved degumming efficiency and product yield: As shown in the following examples, under the same usage, the degumming efficiency of the present invention (measured by residual gum rate and phospholipid content) is significantly higher than that of the physical adsorption method. At the same time, due to its unique "dissolve-extract" mechanism, the loss of oil co-adsorption in the physical adsorption method is avoided, and the refining yield of the present invention is significantly improved, achieving a balance between efficiency and economic benefits.

[0032] (4) Simple process and low energy consumption: The method only involves mixing, reaction and separation, without the need for precise control of water addition, which fundamentally avoids the risk of emulsification, and significantly reduces steam energy consumption because no subsequent drying section is required. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] Example 1: Preparation of Eutectic Solvent

[0035] Choline chloride and lactic acid were mixed in a molar ratio of 1:1 and placed in a beaker. 20% of the total mass of deionized water was added to the mixture to reduce the solvent viscosity. The mixture was heated and stirred in a 60°C water bath until a homogeneous, clear, and transparent liquid was formed. The mixture was then cooled to room temperature to obtain a eutectic solvent degumming agent for later use.

[0036] Example 2: Preparation of Eutectic Solvent

[0037] Choline chloride and lactic acid were mixed in a molar ratio of 1:2 and placed in a beaker. 20% of the total mass of deionized water was added to the mixture to reduce the solvent viscosity. The mixture was heated and stirred in a 60°C water bath until a homogeneous, clear, and transparent liquid was formed. The mixture was then cooled to room temperature to obtain a eutectic solvent degumming agent for later use.

[0038] Example 3: Preparation of Eutectic Solvent

[0039] Choline chloride and lactic acid were mixed in a molar ratio of 1:3 and placed in a beaker. 20% of the total mass of deionized water was added to the mixture to reduce the solvent viscosity. The mixture was heated and stirred in a 60°C water bath until a homogeneous, clear, and transparent liquid was formed. The mixture was then cooled to room temperature to obtain a eutectic solvent degumming agent for later use.

[0040] Example 4: Method for degumming butter

[0041] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude oil. 50.00 g of crude beef tallow (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.30 g (0.6% of the beef tallow's mass) of the eutectic solvent degumming agent prepared in Example 1 was added. The reaction was carried out at 600 rpm for 0.5 hours under a water bath temperature of 60°C.

[0042] After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to separate the clear upper layer of degummed butter.

[0043] Example 5: Method for degumming butter

[0044] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude oil. 50.00 g of crude beef tallow (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.30 g (0.6% of the beef tallow's mass) of the eutectic solvent degumming agent prepared in Example 2 was added. The reaction was carried out at 600 rpm for 0.5 hours under a 60°C water bath.

[0045] After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to separate the clear upper layer of degummed butter.

[0046] Example 6: Method for degumming butter

[0047] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude oil. 50.00 g of crude beef tallow (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.30 g (0.6% of the beef tallow's mass) of the eutectic solvent degumming agent prepared in Example 3 was added. The reaction was carried out at 600 rpm for 0.5 hours under a water bath temperature of 60°C.

[0048] After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to separate the clear upper layer of degummed butter.

[0049] Comparative Example 1: Physical Adsorption Method

[0050] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude oil. 50.00 g of crude beef tallow from the same source as in Example 4 (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.30 g (0.6% of the tallow's mass) of commercially available diatomaceous earth adsorbent was added. The mixture was stirred at 600 rpm for 0.5 hours in a 60°C water bath. After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to obtain the clear, degummed upper layer of tallow.

[0051] Comparative Example 2: Physical Adsorption Method

[0052] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude tallow. 50.00 g of crude tallow from the same source as in Example 4 (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.30 g (0.6% of the tallow's mass) of commercially available silica adsorbent was added. The mixture was stirred at 600 rpm for 0.5 hours in a 60°C water bath. After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to obtain the clear, degummed tallow layer on top.

[0053] Comparative Example 3: Physical Adsorption Method

[0054] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude oil. 50.00 g of crude beef tallow from the same source as in Example 4 (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.06 g (0.6% of the beef tallow's mass) of commercially available silica-diatomaceous earth in a 1:1 mass ratio was added as an adsorbent. The mixture was stirred at 600 rpm for 0.5 hours in an oil bath at 60°C. After the reaction, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to obtain the clear, degummed beef tallow layer.

[0055] Comparative Example 4: Physical Adsorption Method

[0056] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude oil. 50.00 g of crude beef tallow from the same source as in Example 4 (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.06 g (0.6% of the beef tallow's mass) of choline chloride was added as an adsorbent. The reaction was carried out at 600 rpm for 0.5 hours under a 60°C water bath. After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to obtain the clear, degummed beef tallow layer.

[0057] Comparative Example 5: Physical Adsorption Method

[0058] Beef tallow was melted into oil, and then pre-filtered through a 0.4 mm filter to remove coarse residue, yielding crude oil. 50.00 g of crude beef tallow from the same source as in Example 4 (with a phospholipid content of 61.59 mg / g and an acid value of 1.8 mg KOH / g) was placed in a 250 mL reaction flask. 0.06 g (0.6% of the tallow's mass) of lactic acid was added as an adsorbent. The reaction was carried out at 600 rpm for 0.5 hours under a 60°C water bath. After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 3000 rpm for 10 minutes to separate the clear, degummed tallow from the supernatant.

[0059] Tests and Results

[0060] The degummed butter obtained in Examples 4-6 and Comparative Examples 1-5 was subjected to performance testing, and the results are shown in Table 1 below.

[0061] Table 1: Comparison of degumming effect, acid value, and oil yield (additive dosage is 0.6%)

[0062] Item Degumming agent Phospholipid content (mg / g) Degumming rate Acid value (mg / g) Oil yield Comparative Example 1 Diatomaceous earth 22.61 63.30% 2.5 98.00% Comparative Example 2 Silicon dioxide 34.75 56.42% 2.5 98.70% Comparative Example 3 Diatomaceous earth + silicon dioxide 31.91 48.20% 2.4 98.30% Comparative Example 4 Choline chloride 31.15 49.43% 2.15 96.96% Comparative Example 5 Lactic acid 21.15 65.67% 4.6 97.90% Example 4 Choline chloride : lactic acid (1 : 1) 19.12 68% 2.6 98.40% Example 5 Choline chloride : lactic acid (1 : 2) 11.68 81.03% 2.4 98.84% Example 6 Choline chloride : lactic acid (1 : 3) 39.87 35.27% 3.6 98.34% Blank treatment Crude oil 61.59 1.8

[0063] Results analysis:

[0064] As shown in Table 1, under the same conditions where the usage is 0.6%:

[0065] Degumming efficiency comparison: The degumming rate of the method of the present invention (Example 5) was increased to 81.03%, and the phospholipid content was reduced to 11.68 mg / g. The degumming effect was significantly better than the physical adsorption method of Comparative Example 3 (degumming rate 48.20%, phospholipid content 30.91 mg / g).

[0066] This demonstrates that, with the same amount of additives, the degumming efficiency of this invention has a significant advantage.

[0067] The process is gentle, and the product quality potential is high: Unlike traditional acid refining methods that use strong inorganic acids, this invention uses lactic acid as a gentle hydrogen bond donor. The resulting increase in acid value is limited and controllable, avoiding the severe hydrolysis and flavor degradation of oils caused by a strong acid environment, thus laying a solid foundation for the production of high-quality oils.

[0068] Economic Comparison: More importantly, the refining yield of the method of this invention is as high as 98.84%, significantly higher than the 98.30% of the physical adsorption method. This is directly due to the irrecoverable losses caused by the strong adsorption of neutral oils by physical adsorbents. This invention avoids this drawback, converting more raw oils into finished products, resulting in significant economic value.

[0069] Acid value explanation: The acid value increases slightly after treatment according to this invention. This is due to the introduction of lactic acid and is a characteristic of the process. Traditional physical degumming methods also cause an increase in acid value. The acid value change of this invention is easily corrected in the subsequent standard deacidification process and does not affect the core advantages of this degumming step.

[0070] Conclusion: This invention provides an advanced solution that, compared with existing green physical adsorption methods, achieves both higher degumming efficiency and higher product yield with the same amount of additives, resulting in significant overall technical and economic benefits.

[0071] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A low-eutectic solvent degumming agent for efficient and green degumming of oils and fats, characterized in that, The eutectic solvent degumming agent consists of hydrogen bond acceptors and hydrogen bond donors.

2. The eutectic solvent degumming agent according to claim 1, characterized in that, The hydrogen bond acceptor is choline chloride; the hydrogen bond donor is lactic acid.

3. The eutectic solvent degumming agent according to claim 1, characterized in that, The molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1 to 1:

3.

4. The eutectic solvent degumming agent according to claim 1, characterized in that, The eutectic solvent degumming agent contains 10% to 30% by mass of deionized water.

5. The eutectic solvent degumming agent according to any one of claims 1-4, characterized in that, The fat is tallow.

6. A method for preparing degummed butter, characterized in that, The preparation method includes the following steps: mixing crude tallow with the eutectic solvent degumming agent as described in any one of claims 1-5, stirring and reacting, and performing solid-liquid separation after the reaction to obtain the degummed tallow.

7. The method according to claim 6, characterized in that, The mass of the eutectic solvent degumming agent is 0.1% to 5% of the mass of the crude tallow; the reaction temperature is 60℃ to 120℃; and the reaction time is 0.5 to 3 hours.

8. The method according to claim 7, characterized in that, The mass of the eutectic solvent degumming agent is 0.6% to 2% of the mass of the crude tallow; the reaction temperature is 60-80℃; and the reaction time is 0.5 to 2 hours.

9. The application of the eutectic solvent degumming agent as described in any one of claims 1-4 in the degumming of oils and fats.

10. The application according to claim 9, characterized in that, Its features are, The fat is tallow.