Preparation and application of interface-enhanced blocky fat based on pea protein fibers and diglyceride

Abstract

The invention belongs to the technical field of food processing, and particularly relates to preparation and application of interface-enhanced blocky fat based on pea protein fibers and diglyceride. The blocky fat is prepared by utilizing the high melting point and molecular self-assembly characteristics of diglyceride and combining the interface stability characteristic of pea protein fibers. Firstly, pea protein is treated to form protein fibers, and the protein fibers and liquid oil added with diglyceride are homogenized and emulsified at high temperature; in the emulsification process, the protein fibers are firstly adsorbed on an oil-water interface to form a protein fiber adsorption layer. In the cooling process, the protein fiber can be used as a nucleation site due to the strong interaction of the protein fiber and the diglyceride, and diglyceride molecules are induced to be uniformly self-assembled on an emulsion interface along a spherical interface to form a crystallization layer. According to the interface-enhanced bulk fat, the yield stress, the structural recovery characteristic and the thermal stability and characteristic of the bulk fat are improved.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and specifically relates to the preparation and application of an interface-enhanced bulk fat based on pea protein fiber and diglycerides. Background Technology

[0002] The thermal stability of animal adipose tissue directly affects people's perception of its juiciness and oiliness. With increasing health awareness and growing concern for environmental sustainability, the demand for healthy animal fat substitutes is rising. Currently, most commercially available fat substitutes directly add liquid oil or polysaccharide hydrogels to mimic the smooth texture of animal fat. However, the significant difference in polarity between polysaccharides and liquid oils results in these fat substitutes having insufficient mechanical properties, lack of oiliness, and inadequate sensory flavor. At high temperatures, they also experience uncontrolled oil release and texture collapse. While traditional oleogel-based fat mimics can provide an oily texture that hydrogels lack, they still fall short of the smoothness and thermal melting behavior of animal fat. At high temperatures, the three-dimensional network structure of oleogels easily collapses, leading to rapid oil seepage, loss of gel structure, and product collapse and oil leakage. Liquefied hydrogels or oleogel fat mimics exhibit reduced shear strength and decreased chewiness, thus affecting overall texture and formability. There are still significant shortcomings in the research and simulation of the thermal stability of existing fat analogs. There is an urgent need for fat substitutes with good thermal stability to meet the requirements of high-temperature processing and flavor release.

[0003] In recent years, significant progress has been made in the research of fat substitutes constructed using plant proteins. Plant proteins have advantages such as wide availability and high nutritional value. The addition of proteins helps enhance the mechanical properties of fat mimics during thermal processing, forming block-shaped animal fat mimics with good processing performance. However, natural plant proteins have insufficient exposure of hydrophobic groups and low molecular flexibility, making it difficult to effectively adsorb at the oil-water interface, rapidly spread to form a dense film, and prone to droplet aggregation, resulting in poor emulsion stability.

[0004] Bulk fats exhibit the appearance and texture of animal fats in the manufacture of low-fat healthy sausages, hamburger patties, and plant-based artificial meats, and have broad application prospects. Currently, most research on bulk fats focuses on protein hydrogels or dual-gel systems. There are no reports yet on the construction of thermally stable bulk fats similar to pork back fat using protein fibers and structured lipids. Summary of the Invention

[0005] To address the shortcomings of existing animal fat substitutes, such as lack of plasticity, insufficient oiliness, and thermal instability, the primary objective of this invention is to provide a method for preparing an interface-enhanced animal fat mimicry based on pea protein fibers and diglycerides. By leveraging the strong interaction between protein fibers and diglycerides, a self-assembled interfacial layer of plant-based bulk fat mimicry is constructed. This technology endows the bulk fat with high gel strength, yield stress, and thermal stability, giving it a juicy texture. This provides theoretical guidance for the processing and production of low-fat, healthy bulk fats and a theoretical basis for the development of novel healthy meat products.

[0006] Another object of the present invention is to provide an interface-enhanced animal fat mimicry based on pea protein fiber and diglycerides prepared by the above method.

[0007] Another object of the present invention is to provide the application of the above-mentioned interface-enhanced animal fat mimicry based on pea protein fiber and diglycerides.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A method for preparing an interface-enhanced animal fat mimic based on pea protein fiber and diglycerides includes the following steps:

[0010] (1) Dissolve pea protein in water to obtain a protein solution;

[0011] (2) The protein solution described in step (1) is heated and stirred to react, then cooled and refrigerated to obtain a protein fiber solution;

[0012] (3) Dissolve carrageenan in water to obtain a carrageenan solution;

[0013] (4) Mix the protein fiber solution described in step (2) with the carrageenan solution described in step (3) to obtain an aqueous solution;

[0014] (5) Mix diglycerides with vegetable oil to obtain an oil phase solution;

[0015] (6) The aqueous solution described in step (4) and the oil solution described in step (5) are mixed, homogenized under high temperature conditions, and cooled to form a uniform block of fat.

[0016] Preferably, the pea protein in the protein solution in step (1) has a mass fraction of 2-6%;

[0017] To filter out impurities and purify pea protein, it is preferable to dissolve the protein at pH=2, stir the dissolved protein solution overnight, centrifuge it, and take the supernatant as the protein solution.

[0018] Preferably, the heating and stirring reaction mentioned in step (2) refers to heating to 80-95℃ and reacting for 12-28 hours;

[0019] Preferably, the cooling and refrigeration mentioned in step (2) refers to cooling to room temperature and then refrigerating overnight at 4°C. It is preferable to adjust the pH to 7 before cooling and refrigeration.

[0020] Preferably, the carrageenan mass fraction in the carrageenan solution in step (3) is 0.8-1.6%.

[0021] Preferably, the mass ratio of the protein fiber solution and the carrageenan solution in step (4) is 4:6-6:4, and more preferably 5:5.

[0022] Preferably, the vegetable oil mentioned in step (5) is at least one of soybean oil, corn oil, and peanut oil, and preferably soybean oil; the purity of the diglyceride mentioned in step (5) is 60-100%, and the fatty acid in the diglyceride is at least one of palmitic acid and stearic acid;

[0023] Preferably, the mass fraction of diglycerides in the oil phase solution in step (5) is 3-8%;

[0024] Preferably, the mass ratio of the aqueous phase solution to the oil phase solution in step (6) is 4:6-6:4, and more preferably 5:5;

[0025] Preferably, the homogenization under high temperature conditions mentioned in step (6) refers to homogenization at 65-85℃, with a homogenization speed of 8000-10000 rpm and a homogenization time of 1-4 min.

[0026] This invention utilizes the synergistic effect of plant protein fibers and diglycerides to achieve layered adsorption of the protein fibers and diglycerides at the interface, jointly constructing a self-assembled interfacial layer structure with a synergistic effect. Specifically, the protein fibers first adsorb onto the oil-water interface, and driven by the strong interaction between the protein fibers and diglyceride molecules, the diglyceride molecules further self-assemble to form a crystalline layer distributed at the interface. This interface-enhanced bulk fat improves the gel strength, yield stress, and thermal stability of the bulk fat. This interface-enhanced bulk fat can be applied to low-fat healthy sausages, hamburger patties, and plant-based artificial meat as an animal fat mimic, achieving excellent mechanical and structural recovery properties, improved thermal processing characteristics, and imparting a juicy texture to the product.

[0027] An interface-enhanced animal fat mimicry based on pea protein fiber and diglycerides, prepared by the above method.

[0028] The aforementioned interface-enhanced animal fat mimics based on pea protein fiber and diglycerides are used in the manufacture of low-fat healthy sausages, hamburger patties, plant-based artificial meat, and other fat-based products.

[0029] Principle of this invention:

[0030] This invention utilizes the high melting point and molecular self-assembly properties of diglycerides, combined with the interfacial stability of pea protein fibers, to prepare bulk fats. First, pea protein is treated to form protein fibers, which are then homogenized and emulsified with a liquid oil containing added diglycerides at high temperature. During emulsification, the protein fibers adsorb onto the oil-water interface, forming a protein fiber adsorption layer. During cooling, the strong interaction between the protein fibers and diglycerides allows the protein fibers to act as nucleation sites, inducing diglyceride molecules to uniformly self-assemble along a spherical interface at the emulsion interface, forming a crystalline layer. This interface-enhanced bulk fat improves the yield stress, structural recovery properties, and thermal stability of the bulk fat.

[0031] Compared with the prior art, the advantages and beneficial effects of this invention are as follows:

[0032] (1) This invention uses vegetable oil and diglycerides as the main lipid sources, which not only significantly reduces the saturated fatty acid content of traditional animal fats, but also reduces health risks caused by high-fat diets, such as obesity and cardiovascular disease. The protein source of this invention is pea protein, a natural and healthy raw material with high nutritional value. It has lower allergenicity compared to other proteins. At the same time, the emulsion gel is prepared without the addition of other synthetic surfactants and small molecule oil gelling agents, which has the advantages of being natural, safe, and healthy. Therefore, this block fat not only meets consumers' demand for low-calorie, healthy fats, but also provides the food industry with an environmentally friendly and sustainable fat alternative.

[0033] (2) This invention constructs an interface-crystallized reinforced bulk fat by optimizing the preparation process of plant protein fibers and the content ratio of diglycerides. The interface layer formed by the self-assembly of protein fibers and diglycerides significantly enhances the yield stress of the bulk fat, enabling it to maintain good structural integrity under external forces. This enhanced yield stress improves the product's resistance to deformation during processing, making it less prone to damage during processing.

[0034] (3) The thermal processing mechanical properties of animal fat tissue largely determine people's perception of its juiciness, oiliness, and other flavor characteristics. However, existing hydrogel and oleogel-type fat substitutes are prone to structural loss under high-temperature conditions, leading to a decline in their mechanical properties and making it difficult to reproduce the unique flavor experience of animal fat. The block fat constructed in this invention not only has good thermal reversibility but also maintains a stable gel structure under high-temperature conditions, preventing the rapid seepage of liquid oil at high temperatures and helping to improve the taste of fat products.

[0035] (4) The pea protein fiber and diglyceride interface-enhanced animal fat mimic of the present invention exhibits excellent resilience, and can largely recover its original structural morphology after the removal of external force. This ensures that the blocky structural morphology of pork back fat is highly restored after meat processing. This provides reliable technical support for the industrial production and quality improvement of meat products. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the preparation process of the present invention.

[0037] Figure 2 These are transmission electron micrographs of pea protein fibers prepared in step (2) of Examples 1-3 and pea protein fibers prepared in step (2) of Examples 1-3.

[0038] Figure 3 These are polarized microstructure images of the block fats prepared in Comparative Examples 1-3 and Examples 1-3.

[0039] Figure 4 These are rheological diagrams of block fats prepared from pea protein fibers in Comparative Examples 1-3 and Examples 1-3.

[0040] Figure 5 This is a diagram showing the interfacial expansion elastic modulus of pea protein fibers in Comparative Examples 1-3 and Examples 1-3.

[0041] Figure 6 These are temperature-rheological scans of block fats prepared from pea protein fibers in Comparative Examples 1-3 and Examples 1-3.

[0042] Figure 7 These are images of the appearance of the block-shaped fat gels prepared in Comparative Examples 4-7 and Examples 4-7.

[0043] Figure 8 These are polarized light microstructure images of the block fats prepared in Comparative Examples 4-7 and Examples 4-7. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0045] Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below. The invention will be further described in detail with reference to the accompanying drawings and embodiments, but the implementation and scope of protection of the invention are not limited thereto.

[0046] The diglycerides in this invention embodiment are prepared using existing techniques, including fatty acid and glycerol esterification (Preparation of diacylglycerol-enriched oil from free fatty acids using Lecitase Ultra-catalyzed esterification [J]. Journal of the American Oil Chemists' Society, 2011, 88, 1557-1565) or monoglyceride and fatty acid esterification (Enzymatic preparation and facile purification of medium-chain, and medium- and long-chain fatty acid diacylglycerols [J]. LWT-Food Science and Technology, 2018, 92, 227–233). The crude diglycerides obtained by these methods are purified by molecular distillation or solvent recrystallization to obtain diglycerides with a purity of 60–100%. The fatty acids in the diglycerides can be one or more of palmitic acid and stearic acid, but the preparation method of the diglycerides is not limited to the methods described above.

[0047] The pea protein in the embodiments of the present invention has a purity greater than 90%.

[0048] In this embodiment, the interfacial dilatation modulus was measured using the following method: 10 μL of protein solution was added dropwise to vegetable oil using a 1 ml syringe. The droplet volume deformation was set to 10%, and the frequency was 0.1 Hz. Five sinusoidal oscillation cycles were measured for the droplet, lasting for 60 minutes. The interfacial dilatation modulus was calculated based on the interfacial tension results.

[0049] In Example 1, the percentage of structural recovery of the bulk fat was determined using the following method: A constant and extremely low shear stress of 0.1 Pa was maintained between 0 and 60 seconds, and the elastic modulus of the bulk fat was measured. A shear stress of 100 Pa was applied between 60 and 120 seconds to completely destroy the structure of the bulk fat. A shear stress of 0.1 Pa was then restored between 120 and 180 seconds, and the elastic modulus of the bulk fat was measured again. The percentage of the elastic modulus of the bulk fat before and after destruction was calculated as the structural recovery rate.

[0050] Compare with Example 1

[0051] (1) Dissolve 0.2g of pea protein in 9.8g of deionized water to obtain a protein solution with a mass fraction of 2%. Add hydrochloric acid to adjust the pH of the solution to 2. Stir overnight and then centrifuge at 25℃ and 10000rpm for 15min. Take the supernatant to obtain the protein solution.

[0052] (2) Heat the protein solution obtained in step (1) to 85°C and stir continuously for 0 h; after the reaction, cool the solution to room temperature and refrigerate it at 4°C overnight, then adjust the pH to 7 to obtain a protein fiber solution.

[0053] (3) Dissolve 0.08g of carrageenan in 9.92g of deionized water to prepare a carrageenan solution with a mass fraction of 0.8%, and stir overnight until completely dissolved;

[0054] (4) Mix the protein fiber solution from step (2) with the carrageenan solution from step (3) at a mass ratio of 1:1 to obtain an aqueous solution;

[0055] (5) Mix 0.5g of diglyceride stearate with 9.5g of soybean oil to prepare an oil phase with a diglyceride mass fraction of 5%;

[0056] (6) The aqueous solution from step (4) and the oil phase from step (5) are mixed at a mass ratio of 1:1, homogenized at 10,000 rpm for 3 minutes at 85°C, and cooled to room temperature in an ice-water bath to form a uniform block of fat.

[0057] Compare with Example 2

[0058] Referring to the steps and conditions of Comparative Example 1, the difference is that the continuous stirring reaction time in step (2) is 4 hours.

[0059] Compare with Example 3

[0060] Referring to the steps and conditions of Comparative Example 1, the difference is that the continuous stirring reaction time in step (2) is 8 hours.

[0061] Example 1

[0062] (1) Dissolve 0.2g of pea protein in 9.8g of deionized water to obtain a protein solution with a mass fraction of 2%. Add hydrochloric acid to adjust the pH of the solution to 2. Stir overnight and then centrifuge at 25℃ and 10000 rpm for 15min. Take the supernatant to obtain the protein solution.

[0063] (2) Heat the protein solution obtained in step (1) to 85°C and stir continuously for 12 hours; after the reaction, cool the solution to room temperature and refrigerate it at 4°C overnight, then adjust the pH to 7 to obtain a protein cellulose solution.

[0064] (3) Dissolve 0.08g of carrageenan in 9.92g of deionized water to prepare a carrageenan solution with a mass fraction of 0.8%, and stir overnight until completely dissolved;

[0065] (4) The protein fiber solution from step (2) and the carrageenan solution from step (3) are mixed at a mass ratio of 1:1 to obtain an aqueous solution;

[0066] (5) Mix 0.5g of diglyceride stearate with 9.5g of soybean oil to prepare an oil phase with a diglyceride mass fraction of 5% (w / w);

[0067] (6) The aqueous solution from step (4) and the oil phase from step (5) are mixed at a mass ratio of 1:1, homogenized at 10,000 rpm for 3 minutes at 85°C, and cooled to room temperature in an ice-water bath to form a uniform block of fat.

[0068] Example 2

[0069] Referring to the steps and conditions of Comparative Example 1, the difference is that the continuous stirring reaction time in step (2) is 20h.

[0070] Example 3

[0071] Referring to the steps and conditions of Comparative Example 1, the difference is that the continuous stirring reaction time in step (2) is 28h.

[0072] Transmission electron microscopy (TEM) images of the pea protein fibers prepared in step (2) of Examples 1-3 and those prepared in step (2) of Examples 1-3 are shown below. Figure 2 As shown. In Comparative Examples 1-3, the pea protein fibers exhibited spherical aggregates. In Examples 1-3, the protein fibers were characterized by a nanometer diameter. The microstructures of the blocky fats prepared in Comparative Examples 1-3 and Examples 1-3 are shown below. Figure 3 As shown, in Control Examples 1-3, the crystals in the blocky fat were distributed within the bulk phase of the oil droplets; while in Examples 1-3, the blocky fat showed crystals at the droplet interface. The interaction between the protein fibers as "emulsifiers" and the crystal molecules induced the self-assembly of the diglyceride interface, constructing an interfacial crystalline layer.

[0073] The rheological diagrams of the pea protein fiber-stabilized bulk fat prepared in step (2) of Examples 1-3 and the pea protein fiber-stabilized bulk fat prepared in step (2) of Examples 1-3 are shown below. Figure 4As shown in Table 1, the elastic modulus and yield stress are as follows. The elastic modulus and yield stress of the block fat prepared in Examples 1-3 are both greater than those of the block fat prepared in Control Examples 1-3. As shown in Table 1, the elastic modulus of the block fat prepared from natural pea protein (i.e., Control Example 1) is only 450.80 Pa, and the yield stress is 8.48 Pa. The elastic modulus of the block fat prepared from protein fibers in Example 3 is 1197.50 Pa, and the yield stress increases to 48.63 Pa. This indicates that replacing natural pea protein with protein fibers in Example 3 increases the yield stress of the block fat by 6 times. Gradually extending the fiberization time can increase the elastic modulus and yield stress of the block fat.

[0074] Table 1: Statistical table of elastic modulus and yield stress of block fat in Comparative Examples 1-3 and Examples 1-3

[0075]

[0076] The interfacial expansion modulus of pea protein fibers in Comparative Examples 1-3 and Examples 1-3 at the oil-water interface is as follows: Figure 5 As shown. Compared to globular proteins, protein fibers with a high aspect ratio are more prone to entanglement, forming an elastic membrane at the oil droplet interface. The interfacial layer formed by the protein fibers acts as a template for heterogeneous nucleation of lipid crystals or plays a seeding role, promoting the self-assembly of diglyceride molecules at the interface. The uniform distribution of diglyceride crystals at the interface forms a crystal network ( Figure 3 This structure effectively disperses external stress. The interfacial layer formed by the assembly of protein fibers and diglycerides significantly enhances the elastic yield stress of bulk fat.

[0077] Temperature scanning rheology of bulk fats prepared in Comparative Examples 1-3 and Examples 1-3 is as follows: Figure 6 After the bulk fats in Examples 1-3 were heated to 40-50℃, their loss modulus (G”) was higher than their storage modulus (G’). This indicates that under high-temperature conditions, the bulk structure of the bulk fats in Examples 1-3 was disrupted, and the bulk fats underwent a transformation from a gel state to a liquid state. However, during the heating process from 4-80℃, the G’ of the protein fiber bulk fats in Examples 1-3 was consistently greater than G”, indicating that the bulk fats remained in a gel state. Upon cooling, both the control and example fats recovered their original structures. However, the elastic modulus of Examples 1-3 was significantly higher than that of the control group, indicating superior thermal reversibility and structural stability.

[0078] Compare with Example 4

[0079] (1) Dissolve 0.04 g of carrageenan in 9.96 g of deionized water to obtain a carrageenan solution with a mass fraction of 0.4%;

[0080] (2) 0.3g of palmitic acid diglyceride was mixed with 9.7g of soybean oil to obtain an oil phase with a diglyceride mass fraction of 3%;

[0081] (3) The carrageenan solution described in step (1) and the oil phase described in step (2) are homogenized at 85°C and 10,000 rpm for 3 min, and then cooled to room temperature in an ice-water bath.

[0082] Compare with Example 5

[0083] (1) Dissolve 0.2g of pea protein in 9.8g of deionized water to obtain a protein solution with a mass fraction of 2%. After stirring overnight, centrifuge at 25℃ and 10000rpm for 15min and take the supernatant to obtain the protein solution as the aqueous phase solution.

[0084] (2) Dissolve 0.08g of carrageenan in 9.92g of deionized water to obtain a carrageenan solution with a mass fraction of 0.8%;

[0085] (3) The protein fiber solution from step (2) and the carrageenan solution from step (3) are mixed at a mass ratio of 1:1 to obtain an aqueous solution;

[0086] (4) Mix 0.3g of palmitic acid diglyceride with 9.7g of soybean oil to prepare an oil phase with a diglyceride mass fraction of 3% (w / w);

[0087] (5) Mix the aqueous solution from step (3) with the oil phase from step (2) at a mass ratio of 1:1, homogenize at 10,000 rpm for 3 minutes at 65°C, and cool to room temperature in an ice-water bath.

[0088] Compare with Example 6

[0089] (1) Dissolve 0.2g of pea protein in 9.8g of deionized water to obtain a protein solution with a mass fraction of 2%. Add hydrochloric acid to adjust the pH of the solution to 2. Stir overnight and then centrifuge at 25℃ and 10000rpm for 15min. Take the supernatant to obtain the protein solution.

[0090] (2) Heat the protein solution obtained in step (1) to 85°C and stir continuously for 28 hours; after the reaction, cool the solution to room temperature and refrigerate it at 4°C overnight, then adjust the pH to 7 to obtain a protein cellulose solution.

[0091] (3) Dissolve 0.08g of carrageenan in 9.92g of deionized water to prepare a carrageenan solution with a mass fraction of 0.8%, and stir overnight until completely dissolved;

[0092] (4) Mix the protein fiber solution from step (2) with the carrageenan solution from step (3) at a mass ratio of 1:1 to obtain an aqueous solution;

[0093] (5) Take 10g of soybean oil as the oil phase;

[0094] (6) Mix the aqueous solution from step (4) with the oil phase from step (5) at a mass ratio of 1:1, homogenize at 10,000 rpm for 3 min at 75°C, and cool to room temperature in an ice-water bath.

[0095] Compare with Example 7

[0096] (1) Dissolve 0.1g of pea protein in 9.9g of deionized water to obtain a protein solution with a mass fraction of 1% (w / w). Add hydrochloric acid to adjust the pH of the solution to 2, stir overnight, and then centrifuge at 25℃ and 10000rpm for 15min. Take the supernatant to obtain the protein solution.

[0097] (2) Heat the protein solution obtained in step (1) to 85°C and stir continuously for 28 hours; after the reaction, cool the solution to room temperature and refrigerate it at 4°C overnight, then adjust the pH to 7 to obtain a protein cellulose solution as an aqueous phase solution.

[0098] (3) Mix 0.3g of palmitic acid diglyceride with 9.7g of soybean oil to prepare an oil phase with a diglyceride mass fraction of 3%;

[0099] (6) Mix the aqueous solution from step (2) and the oil solution from step (3) at a mass ratio of 1:1, homogenize at 10,000 rpm for 3 min at 85°C, and cool to room temperature in an ice-water bath.

[0100] Example 4

[0101] (1) Dissolve 0.2g of pea protein in 9.8g of deionized water to obtain a protein solution with a mass fraction of 2%. Add hydrochloric acid to adjust the pH of the solution to 2. Stir overnight and then centrifuge at 25℃ and 10000rpm for 15min. Take the supernatant to obtain the protein solution.

[0102] (2) Heat the protein solution obtained in step (1) to 85°C and stir continuously for 28 hours; after the reaction, cool the solution to room temperature and refrigerate it at 4°C overnight, then adjust the pH to 7 to obtain a protein cellulose solution.

[0103] (3) Dissolve 0.08g of carrageenan in 9.92g of deionized water to prepare a carrageenan solution with a mass fraction of 0.8%, and stir overnight until completely dissolved;

[0104] (4) Mix the protein fiber solution from step (2) with the carrageenan solution from step (3) at a mass ratio of 1:1 to obtain an aqueous solution;

[0105] (5) Mix 0.3g of palmitic acid diglyceride with 9.7g of soybean oil to prepare an oil phase with a diglyceride mass fraction of 3%;

[0106] (6) The aqueous solution from step (4) and the oil solution from step (5) are mixed at a mass ratio of 1:1, homogenized at 8000 rpm for 4 min at 65°C, and cooled to room temperature in an ice-water bath to form a uniform block of fat.

[0107] Example 5

[0108] Referring to the steps and conditions of Example 4, the difference is that in step (1), 0.6g of pea protein is added and dissolved in 9.4g of deionized water to obtain a protein solution with a mass fraction of 6%.

[0109] Example 6

[0110] Referring to the steps and conditions of Example 4, the difference is that in step (5), 0.5g of palmitic acid diglyceride is mixed with 9.5g of soybean oil to obtain an oil phase with a diglyceride mass fraction of 5% (w / w).

[0111] Example 7

[0112] Referring to the steps and conditions of Example 4, the difference lies in step (3), where 0.16 g of carrageenan is dissolved in 9.84 g of deionized water to obtain a 1.6% (w / w) carrageenan solution, which is stirred overnight. After mixing with protein fibers, the final aqueous phase contains 0.8% carrageenan by mass.

[0113] Figure 7 Appearance images of the blocky fats prepared in Comparative Examples 4-7 and Examples 4-7. Figure 7 As can be seen, Comparative Examples 4, 5, and 7 failed to form a blocky fat structure, while Examples 4-7 all formed a blocky fat structure. When no protein was added to the aqueous phase (Comparative Example 4) or only pea protein was added to the aqueous phase (Comparative Example 5), only an emulsion could be formed, and blocky fat could not be formed.

[0114] Figure 8The images show polarized light microstructures of the bulk fats prepared in Comparative Examples 4-7 and Examples 4-7. The microstructures reveal the aggregation behavior of diglyceride crystals. This aggregation behavior resulted in Comparative Examples 4 and 5 forming only liquid fats with elastic moduli less than 100 Pa and no structural recovery ability, as shown in Table 2. Adding protein fibers promoted the formation of bulk fats (Comparative Example 6). The microstructure of Comparative Example 6 shows that the protein fibers effectively emulsified the vegetable oil, and the droplet-filling structure promoted the formation of bulk fats. However, the elastic modulus of the bulk fats without added diglycerides was low, only 211.65 Pa. Increasing the concentration of diglycerides increased the elastic modulus of the bulk fats to 1197.50 Pa (Example 6). Increasing the concentration of pea protein to 6% and converting it into protein fibers significantly increased the elastic modulus of the bulk fats to 1916.89 Pa (Example 5). This indicates that protein fibers promote the uniform distribution of oil phase crystals at the interface, forming a thicker interfacial crystal layer. The thicker interfacial crystal layer effectively disperses external stress and inhibits the destruction of the fatty block structure.

[0115] A comparison of Comparative Example 5 and Example 4 shows that, with the same content of diglycerides and carrageenan, pea protein fiber promotes the formation and stability of pea fat blocks more effectively than pea protein. 1% pea protein failed to form fat blocks (Comparative Example 5), exhibiting an elastic modulus of only 26.3 Pa and no structural resilience. In contrast, 1% pea protein fiber formed stable fat blocks, increasing the elastic modulus by 16 times (434.15 Pa) while imparting a structural resilience of 58.06% (Example 4).

[0116] Comparing Comparative Example 6 and Example 6, the elastic modulus of the pea protein fiber containing 1% but without diglycerides was only 211.65 Pa, and the protein fiber-stabilized droplet structure had a structural recovery rate of 57.75% (Comparative Example 6). Increasing the diglyceride concentration to 5% (Example 6) increased the elastic modulus of the bulk fat to 1197.50 Pa and the structural recovery rate to 62.19%. The results indicate that the interfacial layer formed by the assembly of protein fibers and diglycerides has a synergistic reinforcing effect, which can simultaneously improve the gel structure recovery rate of bulk fat.

[0117] Comparing Examples 4 and 7 with Comparative Example 7, in Comparative Example 7 without carrageenan, emulsion droplets aggregated. In Example 4, the introduction of carrageenan as a highly efficient gelling agent effectively prevented droplet aggregation, forming a relatively stable continuous aqueous phase structure. Increasing the carrageenan content in the aqueous solution from 0.4% (Example 4) to 0.8% (Example 7) improved the elastic modulus of the bulk fat, but had no significant effect on its structural resilience. This indicates that carrageenan, as a highly efficient hydrogelling agent, can enhance the elastic modulus of the gel, but has limited effect on the structural resilience of bulk fat.

[0118] Table 2: Statistical table of elastic modulus and structural recovery percentage of block fat in Comparative Examples 4-7 and Examples 4-7

[0119]

[0120] In Table 2, “ / ” indicates that the emulsion has strong fluidity and does not form a blocky fat structure, making it impossible to measure its elastic modulus or structural recovery rate.

[0121] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides, characterized in that... Includes the following steps: (1) Dissolve pea protein in water to obtain a protein solution; (2) The protein solution described in step (1) is heated and stirred to react, then cooled and refrigerated to obtain a protein fiber solution; (3) Dissolve carrageenan in water to obtain a carrageenan solution; (4) Mix the protein fiber solution described in step (2) with the carrageenan solution described in step (3) to obtain an aqueous solution; (5) Mix diglycerides with vegetable oil to obtain an oil phase solution; (6) The aqueous solution described in step (4) and the oil solution described in step (5) are mixed, homogenized under high temperature conditions, and cooled to form a uniform block of fat.

2. The method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides according to claim 1, characterized in that: The pea protein in the protein solution described in step (1) has a mass fraction of 2-6%.

3. The method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides according to claim 1, characterized in that: The heating and stirring reaction mentioned in step (2) refers to heating to 80-95℃ and reacting for 12-28 hours.

4. The method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides according to claim 1, characterized in that: The carrageenan mass fraction in the carrageenan solution in step (3) is 0.8-1.6%.

5. The method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides according to claim 1, characterized in that: The mass ratio of the protein fiber solution and carrageenan solution in step (4) is 4:6-6:

4.

6. The method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides according to claim 1, characterized in that: The vegetable oil mentioned in step (5) is at least one of soybean oil, corn oil, and peanut oil; The diglyceride mentioned in step (5) has a purity of 60-100%, and the fatty acid in the diglyceride is at least one of palmitic acid and stearic acid.

7. The method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides according to claim 1, characterized in that: The mass fraction of diglycerides in the oil phase solution described in step (5) is 3-8%.

8. The method for preparing interface-enhanced bulk fat based on pea protein fiber and diglycerides according to claim 1, characterized in that: The mass ratio of the aqueous phase solution and the oil phase solution in step (6) is 4:6-6:4; The homogenization under high temperature conditions mentioned in step (6) refers to homogenization at 65-85℃, with a homogenization speed of 8000-10000 rpm and a homogenization time of 1-4 min.

9. An interface-enhanced bulk fat based on pea protein fiber and diglycerides prepared by the method according to any one of claims 1-8.

10. The application of the interface-enhanced block fat based on pea protein fiber and diglycerides as described in claim 9 in the manufacture of low-fat healthy sausages, hamburger patties, and plant-based artificial meat.

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