A block fat simulant based on curdlan and preparation method thereof

Abstract

The present invention belongs to the field of food processing technology, and specifically relates to a block fat simulator based on curdlan gel and a preparation method thereof. The present invention achieves the design of the texture of curdlan gel by regulating the conformation of the curdlan molecular chain and its microscopic network structure only by preheating the curdlan gel, and prepares curdlan gel with similar block fat. The preparation process is simple and convenient for industrial large-scale production and application. The curdlan gel prepared by the present invention has good thermal stability, acid stability and ion stability, and can be applied to various different food processing systems. The curdlan gel prepared by the present invention has a fracture behavior similar to that of real fat, has a higher degree of fit with the texture of real fat, and can simulate the process of real fat breaking and fracturing in the human mouth.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to a block fat simulant based on curdlan and a preparation method thereof. Background Art

[0002] As one of the most important components of food, fat gives food its unique taste, flavor, and texture. At the same time, fat is also one of the important nutrients necessary for the human body, providing energy and maintaining the normal functioning of human physiological functions. However, excessive fat intake not only leads to obesity in consumers, but also induces a variety of acute and chronic diseases, threatening consumers' health. Therefore, in order to ensure consumers' healthy diet, it is particularly important to reduce the fat content in food and reduce fat intake. Simply removing fat from food often destroys the taste and flavor of the food, seriously affecting the food quality. Therefore, the search for fat mimics with similar properties to fat that can replace the fat component in food has attracted widespread attention and research.

[0003] Fat simulants can replace part or all of the fat in food, and at the same time simulate the physical and sensory properties of fat, thereby achieving the purpose of reducing the fat content in food.At present, fat simulants are mainly divided into the following categories according to the raw material matrix: (1) Protein-based fat simulants. After modification, the protein exhibits hydrophobicity similar to that of fat, and then forms microparticles through physical shearing, which can simulate the lubricating properties of fat, but its high-temperature stability is poor (Kew B, Holmes M, Liamas E, et al. Transforming sustainable plant proteins into high performance lubricating microgels [J]. Nature Communications, 2023, 14 (1): 4743.); (2) Polysaccharide-based fat simulants. Polysaccharide macromolecules can simulate the sticky and lubricating taste of fat in the mouth by forming gels with "wet and soft" properties. The raw material source is wide, and the gel stability is good, making it a more ideal fat simulant (Ruiz-Capillas C, Triki M, Herrero AM, et al. Konjac gel as pork backfat replacer in dry fermented sausages: Processing and quality characteristics [J]. Meat science, 2012, 92(2): 144-150.); (3) lipid-based fat mimics, fatty acids are modified to derive compounds with fat-like properties, which can replace oils in food, but the production cost is high and it is not easily digested and absorbed by the human body (Surber KJ, Miller M S. Dextrose-containing chocolate products with sucrose fatty acid polyester fatsubstitutes: US Patent 5,474,795[P]. 1995-12-12.); (4) complex fat mimics, usually single-matrix fat mimics are difficult to completely simulate fat properties, so multiple matrix raw materials are mixed and compounded to utilize their synergistic effect to better simulate fat properties, but the ingredients are complex and it is difficult to achieve clean label requirements (Guo Y, Zhang X, Hao W, et al. Nano-bacterial cellulose / soy protein isolate complex gel as fatsubstitutes in ice cream model[J]. Carbohydrate polymers, 2018, 198: 620-630.).

[0004] At present, relevant fat replacement patents are mainly prepared by compounding multiple raw materials with compound fat simulations. Although these patents prepare fat simulations with certain similarity to fat by different methods, the preparation process is complicated and cumbersome, not easy to large-scale factory production, and product stability is poor. Patent CN106615220A discloses a special fat simulation for meat products, and this patent document compounds curdlan, carrageenan and vegetable oil in a certain proportion, and by regulating pH and high temperature heat treatment, prepares a fat simulation with similar solid fat outward appearance and physical properties. Patent CN113973930A is based on long-chain fatty acids, and compounding konjac gum and sodium alginate gel prepares block fat simulations, and this method forms a gel network by hot mixing, alkaline cross-linked konjac gum and sodium alginate to trap lipid and fatty acid and prepare block fat simulations, while also retaining certain lipid nutrients. Patents CN109730272A and CN109730273A prepare block-shaped fat mimics by compounding carrageenan, curdlan, and konjac gum in specific proportions, followed by shearing, high-pressure homogenization, and high-temperature heat treatment to form a gel. These fat mimics have improved water and oil retention. Patent CN116076584A prepares a freeze-thaw-resistant fat mimic. This patent document prepares microparticles of oil-in-water gel by dispersing konjac gum in vegetable oil, adding soy protein isolate for emulsification, and then adding curdlan to the microparticles for heat treatment to form a double emulsion gel system.

[0005] Curdlan gum is a non-toxic, odorless, microbially fermented polysaccharide. It is a homopolysaccharide, a linear glucan formed by D-glucose subunits linked by β-1,3-glycosidic bonds and lacking side chains. Curdlan gum has unique gelling properties. Depending on the heating temperature, it can form two distinct types of gels: a thermoreversible gel formed when a curdlan aqueous suspension is heated to approximately 55°C, and a thermoirreversible gel formed when heated above 80°C. For example, patent CN103125615A discloses this. Curdlan gum has broad application potential in the food industry due to its unique gelling properties and excellent thickening properties. In China, curdlan gum was approved as a food additive in 2006. Curdlan gum is widely used as a thickener, gelling agent, and stabilizer in products such as meat products, sausages, ham, frozen noodles, cakes, and ice cream. Furthermore, curdlan gel has a fat-like, lubricating texture, suggesting its potential as a fat substitute. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a block-shaped fat simulant based on curdlan and a preparation method thereof.

[0007] In order to achieve the above object, the solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a method for preparing a block-shaped fat mimetic based on curdlan, comprising the following steps:

[0009] Step (1), dispersing curdlan in water to obtain a uniformly dispersed curdlan suspension;

[0010] Step (2), preheating the curdlan suspension obtained in step (1) at 45-65° C. for 20-60 minutes;

[0011] Step (3), heating the preheated curdlan gel prepared in step (2) at 85-105° C. for 20-60 minutes;

[0012] Step (4), naturally cooling to room temperature to form a curdlan gel.

[0013] Preferably, step (1) includes the following steps:

[0014] Step (1.1), adding curdlan to pure water and high-speed shearing at 6000-10000 rpm for 1-10 minutes to prepare a curdlan suspension with a mass concentration of 2%-5%;

[0015] In step (1.2), a 3% to 5% by mass curdlan suspension is subjected to high-pressure homogenization at a pressure of 100 to 300 bar for three times to prepare a uniformly dispersed curdlan suspension.

[0016] Preferably, in step (1), the mass concentration of the Curdlan suspension is 3%-4%, preferably 4%.

[0017] Preferably, the temperature for the preheating treatment in step (2) is 45-60°C, preferably 45-55°C, and more preferably 50°C.

[0018] Preferably, the preheating time in step (2) is 20-50 min, preferably 20-40 min, and more preferably 30 min.

[0019] Preferably, the temperature of the heat treatment in step (3) is 85-100°C, preferably 85-95°C, and more preferably 90°C.

[0020] Preferably, the heat treatment time in step (3) is 20-50 min, preferably 20-40 min, and more preferably 30 min.

[0021] In a second aspect, the present invention further provides a curdlan-based fat block simulant prepared by the above-mentioned preparation method, wherein the raw materials of the curdlan-based fat block simulant consist of curdlan and water.

[0022] Preferably, the curdlan accounts for 2%-5% of the total mass, preferably 3%-4%, more preferably 4%.

[0023] Preferably, the curdlan-based block fat simulator can simulate the process of real fat breaking and rupturing in the human mouth.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention achieves the design of the texture of the curdlan gel by regulating the conformation of the curdlan molecular chain and its microscopic network structure only by preheating the curdlan gel, and prepares the curdlan gel with a block-like shape similar to fat. The preparation process is simple and convenient for industrial large-scale production and application.

[0026] (2) The curdlan gel prepared by the present invention has good thermal stability, acid stability and ion stability, and can be applied to various food processing systems.

[0027] (3) The curdlan gel prepared by the present invention has a fracture behavior similar to that of real fat, has a higher degree of fit with the texture of real fat, and can simulate the process of real fat breaking and fracture in the human mouth. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a hardness chart of 3 wt % Curdlan gels subjected to different heat treatments according to an embodiment of the present invention;

[0029] Figure 2 This is a cryo-scanning electron micrograph (×6000) of a 3 wt % curdlan gel according to an embodiment of the present invention;

[0030] Figure 3 1. The hardness (a) and compressive stress-strain curves (b) of different curdlan gels and real fat involved in the embodiments of the present invention;

[0031] Figure 4 These are photos of the compressed state of the Curdlan gel and real fat involved in the embodiments of the present invention; in the figure, (a) is fat, (b) is 3%.CU-50, (c) is 4%.CU-50, (d) is 3%.CU*, and (e) is 4%.CU*. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the examples. The various raw materials used in the present invention are all commercially available food raw materials. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. For those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can also be made. All equivalent conversions made using the present invention's description, or direct or indirect applications in other related technical fields, are included in the scope of protection of the present invention's patent.

[0033] Example:

[0034] 1. Preparation of Curdlan preheating gel:

[0035] First, prepare a solution of Curdlan at different concentrations. Disperse the solution at 8000 rpm for 1 minute. Then, homogenize the solution three times at 200 bar to obtain a uniformly dispersed Curdlan suspension. The uniformly dispersed Curdlan suspension is then preheated at different temperatures for 30 minutes, then placed in a 90°C water bath for 30 minutes to form a gel. The solution is then cooled naturally to room temperature to form a Curdlan preheated gel.

[0036] 2. Testing of the texture characteristics of Curdlan gel and fat:

[0037] Curdlan gel and fat were cut into regular rectangular blocks (10mm×10mm×5mm) and tested for hardness, a TPA property, using a texture analyzer. The test speed was 1mm / s and the test deformation was 50%. The mechanical properties of the samples during compression were determined by compression using a texture analyzer with a compression speed of 0.25mm / s. The changes in strain and stress were recorded in real time, and stress-strain diagrams were plotted to compare the differences in the fracture behavior of different samples during compression.

[0038] 3. Microscopic morphology detection of Curdlan gel:

[0039] The differences in the microstructure of preheated and non-preheated curdlan gel were observed by cryo-scanning electron microscopy.

[0040] 4. Texture characteristics of natural gel obtained by different heat treatment methods:

[0041] like Figure 1As shown, 3 wt% curdlan gels formed by different heat treatments exhibited varying degrees of hardness. The CU* sample was directly gelled by heating in a 90°C waterbath for 30 minutes. The CU-40, CU-50, CU-60, CU-70, and CU-80 samples were preheated in a waterbath at 40°C, 50°C, 60°C, 70°C, and 80°C for 30 minutes, respectively. Following this preheating, the final gels were heated in a 90°C waterbath for 30 minutes. Preheating the curdlan gels at different temperatures had varying degrees of influence on their final gel hardness. There was no significant difference in gel hardness between the CU-40 and CU* samples, indicating that preheating at 40°C did not affect the final hardness of the curdlan gels. However, when the preheating temperature reached or exceeded 50°C, the curdlan gel hardness decreased to varying degrees. The curdlan gels preheated at 50°C had the lowest hardness and became soft and brittle, with a texture similar to that of fat chunks.

[0042] 5. Microstructure of curdlan gel after different heat treatments:

[0043] like Figure 2 As shown in Figure 2, the microstructure of the curdlan gel was analyzed using cryo-scanning electron microscopy. The study revealed that the curdlan gel formed a uniform three-dimensional network. The CU* sample exhibited a tightly connected lamellar structure, with curdlan fibers forming a denser and more compact network between the lamellar layers. This resulted in the gel exhibiting high hardness and toughness. The gel network formed by the CU-50 sample had larger voids and looser connections, resulting in a soft, brittle gel with low hardness and a lack of toughness.

[0044] 6. Mechanical properties of different curdlan gels and real fat:

[0045] The study compared the mechanical properties of two mass concentrations (3% and 4%) of preheated gel (CU-50) with those of unpreheated gel (CU*) and real fat. Figure 3 As shown in (a), after preheating at 50°C, the hardness of the curdlan gel was greatly reduced, and the hardness of the 4% CU-50 sample was not significantly different from that of real fat. In addition, the study simulated the process of gel and real fat breaking in the human mouth through compression strain experiments. Figure 3As shown in (b), 3% CU-50, 4% CU-50, and fat show no obvious fracture, while the 3% CU* and 4% CU* samples exhibit distinct fracture behavior when the compressive strain reaches 70%-80%. Compression strain experiments reveal the toughness of a sample under compression. The compression curves reveal that the unheated curdlan gel exhibits high toughness, while the gel loses its toughness after preheating at 50°C, closely resembling the texture of fat. Furthermore, the compression curve of the 4% CU-50 sample nearly overlaps with that of real fat, indicating that the sample exhibits similar fracture and fragmentation behavior to fat during compression, demonstrating that the sample can simulate real fat.

[0046] 7. The state of different Curdlan gels and real fat after compression:

[0047] like Figure 4 As shown in the figure, the preheated Curdlan gel (b, c) is relatively soft and has no toughness. After compression, it breaks into a paste, which is similar to the state of real fat (a) after compression and crushing. On the other hand, the unpreheated Curdlan gel (d, e) has high toughness. After compression and crushing, most of it remains in a blocky state, which is significantly different from the state of real fat after compression and crushing.

[0048] Comparative Example:

[0049] Patent document CN103125615A discloses a method for preparing an animal fat substitute with curdlan as a matrix, wherein curdlan, water and vegetable oil are used as main raw materials, and other auxiliary materials (starch, protein or colloid) are added, and the mixture is micronized and emulsified in oil and water by high-speed shearing, and then undergoes the following two processes respectively: (1) the resulting dispersion is heated to 55-65°C, kept at a constant temperature for 30 minutes, and cooled to room temperature to form a thermoreversible low-position gel, which is in a semi-solid animal fat state with good plasticity and is similar to an animal fat thick emulsified substance; (2) the resulting dispersion is heated to 80-100°C, kept at a constant temperature for 30 minutes, and cooled to room temperature to form a thermoreversible high-position gel, which is in a solid animal fat state and is fat-like, similar to a fat white and tender substance.

[0050] Compared with the technical solution of patent document CN103125615A, the present invention has the following differences and innovations:

[0051] (1) Differences in raw material components: The patent document requires the addition of auxiliary materials to control the texture properties of curdlan gel in order to achieve a texture similar to fat, while the present invention only requires one raw material, curdlan gel, to prepare a fat mimetic that is highly similar to block fat;

[0052] (2) Different heat treatment steps: The patent document heat-treats the curdlan raw material once (heating the dispersion containing curdlan to 55-65°C and heating the dispersion containing curdlan to 80-100°C, respectively, to obtain two different states of curdlan gel). The present invention heat-treats the curdlan gel twice at different temperatures to form a highly stable fat mimetic.

[0053] (3) The difference in the properties of the obtained gels: The low-position gel prepared in the patent document is a thermoreversible gel and does not have high-temperature thermal stability. The high-position gel prepared is a thermoirreversible gel, but has high toughness and does not have the texture of fat being soft and melt-in-the-mouth. The present invention preheats the curdlan and then gels it at high temperature, forming a fat simulant that has low toughness, is soft and lubricated, and has high-temperature thermal stability.

[0054] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a block fat simulant based on curdlan, characterized in that: The steps include: Step (1), dispersing curdlan in water to obtain a uniformly dispersed curdlan suspension; the mass concentration of the curdlan suspension is 4%; Step (2), preheating the curdlan suspension obtained in step (1) at 50° C. for 30 minutes; Step (3), heating the preheated curdlan gel prepared in step (2) at 85-105° C. for 20-60 minutes; Step (4), naturally cooling to room temperature to form a curdlan gel.

2. The preparation method according to claim 1, characterized in that Step (1) includes the following steps: Step (1.1), adding curdlan to pure water and high-speed shearing at 6000-10000 rpm for 1-10 minutes to prepare a curdlan suspension; In step (1.2), the curdlan suspension is subjected to high-pressure homogenization at a pressure of 100-300 bar for three times to prepare a uniformly dispersed curdlan suspension.

3. The preparation method according to claim 1, characterized in that The temperature of the heat treatment in step (3) is 90°C.

4. The preparation method according to claim 1, characterized in that The heat treatment time in step (3) is 30 min.

5. A block-shaped fat simulant based on curdlan prepared by the preparation method according to any one of claims 1 to 4, characterized in that: The raw materials of the curdlan-based block fat mimetic consist of curdlan and water.

6. The use of the block-shaped fat simulant based on curdlan according to claim 5, characterized in that: The curdlan-based block fat simulator can simulate the process of real fat breaking and rupturing in the human mouth.

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