CN116898010A - Preparation method of starch-based gel fat substitute and application of starch-based gel fat substitute in low-salt low-fat sausage - Google Patents

Abstract

The invention relates to the field of food processing, in particular to a preparation method of a starch-based gel fat substitute and application of the starch-based gel fat substitute in low-salt low-fat sausage. The starch-based gel fat substitute is obtained by mixing modified starch dispersion liquid and vegetable oil, homogenizing to form emulsion, mixing with natural starch, heating, cooling and molding. The directional regulation and control of the structure is realized by regulating the content of components such as vegetable oil, and the release of salt ions and the edible perception effect are regulated. The gel replaces animal fat to produce low-salt low-fat sausage, so that the texture and sensory quality of the sausage are maintained while the fat content in the sausage is reduced, and the structural adjustability of the starch-based gel can realize rapid release of sodium ions in the sausage and improve salty taste perception sensitivity, and the salt addition amount in food is reduced while salty taste is maintained.

Description

Preparation method of starch-based gel fat substitute and its use in low-salt and low-fat sausage Applications in

Technical field

The invention relates to the technical field of food processing, and specifically relates to a preparation method of a starch-based gel fat substitute and its application in low-salt and low-fat sausages.

technical background

As a traditional Chinese delicacy, sausage is deeply loved by people. In order to maintain the flavor and taste, a large amount of salt (the main component is sodium chloride) and animal fat are often added during the production process. However, high salt and high fat intake is the main risk of inducing chronic diseases. Dietary factors. Excessive fat intake will lead to obesity, which is closely related to cardiovascular diseases; while excessive sodium ion intake is closely related to chronic diseases such as hypertension and stroke. However, directly reducing the amount of fat and salt added or using substitute salt products will result in a lack of final texture, flavor and sensory properties of the food, and a significant decline in consumer acceptance. With the improvement of people's healthy dietary concepts and the release of related plans, How to prepare low-salt and low-fat traditional foods with good flavor and quality has become an urgent problem to be solved.

Emulsion gel is the main structural unit of many processed foods (such as sausages). It uses polysaccharides or proteins as the main structure and contains emulsified and dispersed vegetable oil droplets. It can better simulate the properties of plastic fat, so it can be used as a fat substitute. Improves food nutrition and functional properties, has less impact on food sensory flavor, and has high consumer acceptance. In addition, the emulsion gel has excellent structural adjustability, and as a low-calorie fat substitute, it can meet the application requirements of fat substitutes for products in different fields. Chinese patent (CN 112970934 A) invented a method of preparing vegetable protein meat using konjac compound gel as a substitute for fat. Chinese patent (CN 112931680 A) invented a method for preparing plant protein meat using inulin composite gel as a substitute for fat.

The main component of table salt is sodium chloride, of which sodium ions are the main source of salty taste perception. However, before swallowing, only about 5% of the sodium ions in the food are released in the mouth, which will contribute to the production of salty taste. The remaining sodium ions are ingested by the human body and pose health risks. How to maximize the release of sodium ions in food during oral chewing has become the key to research. During the oral processing of food, in addition to physical changes such as food structure and texture, the enzymatic interaction between enzymes and starch in saliva is the main mechanism that destroys the structure and promotes system instability. However, there is currently no relevant technology that takes advantage of the special decomposition advantages of starch gel in the oral cavity to achieve the purpose of reducing salt.

The present invention uses starch as raw material to prepare emulsion gel, and adds a certain amount of salt to it. When chewed in the mouth, the specific decomposition of the starch raw material accelerates the mass transfer and convection speed of sodium ions and accelerates ion release. In addition, the gel-like texture prolongs the chewing cycle and increases the cumulative amount of sodium ion release, thereby increasing the effective perceived concentration of salty taste. The presence of the oil phase in the emulsion gel accelerates the instability of the system and increases the sodium ion concentration in the water phase. At the same time, by adjusting the interfacial properties of the oil droplets in the emulsion gel, it is conducive to building a gradient distribution of sodium ion structure, which is also beneficial to salty taste perception. In addition, starch emulsion gel can be used as a low-calorie fat substitute in sausages to give the food excellent fat texture and taste.

The present invention uses starch-based gel fat substitutes for the preparation of low-salt and low-fat sausages, thereby achieving the simultaneous reduction of salt without affecting the quality and flavor of the sausages (such as product appearance characteristics, texture characteristics and sodium ion sensing characteristics). The amount of addition and the amount of animal fat added have great application potential and are of great significance for improving the dietary structure of residents and the development of the low-salt and low-fat food industry.

Contents of the invention

In view of the shortcomings of the above background technology, the present invention provides a method for preparing a starch-based gel fat substitute, and applies it to sausages to achieve salt- and fat-reduction sausages. The sausage product of the present invention has the characteristics of low fat and salt content and excellent sensory quality, and can achieve fat reduction without reducing saltiness.

The above objects of the present invention are achieved through the following technical solutions:

The first object of the present invention is to provide a method for preparing a starch-based gel fat substitute.

The components of the starch-based gel fat substitute provided by the invention include starch, vegetable oil, salt and water.

The starch-based gel fat substitute includes the following preparation steps:

(1) Disperse the modified starch in deionized water at room temperature, then add vegetable oil to form a uniform and stable emulsion through shearing and homogenization;

(2) Disperse salt, natural starch and the emulsion of step (1) in deionized water, perform heat treatment while stirring and mixing evenly. After the starch is fully gelatinized, place it in a room temperature environment to cool, to obtain the starch-based gel. fat substitutes;

Further, the modified starch added to the emulsion in step (1) includes one or more of octenyl succinic acid esterified starch, sodium octenyl starch succinate, etc.

Further, the mass concentration of the modified starch added to the emulsion in step (1) is ≥4%.

Further, the vegetable oil in step (1) includes one or more of peanut oil, corn oil, olive oil, sunflower oil, etc.

Further, the mass concentration of vegetable oil in the emulsion described in step (1) is 10-60%.

Further, the shearing time in step (1) is ≥30s, and the homogenization pressure is ≥30MPa.

Further, the natural starch in step (2) includes one or more of potato starch, corn starch, wheat starch and tapioca starch.

Further, the mass concentration of the natural starch in step (2) is ≥10%.

Further, the mass concentration of the salt in step (2) is 0.5-1.5%.

The second object of the present invention is to provide a method for preparing low-salt and low-fat sausage containing the starch emulsion gel, which includes the following preparation steps:

(1) Raw material preparation: Cut the pig hind leg meat into small pieces, weigh the pork, salt, thirteen spices, sugar, chili powder, cooking wine, etc., mix them evenly and marinate to obtain marinated lean meat.

2) Sausage making: Thoroughly mix the starch emulsion, salt, natural starch and the cured meat in step (1), so that the salty starch emulsion is wrapped on the surface of the lean meat, quickly enema and dry it, bake it and then vacuum package it.

Further, the weight parts of the raw materials described in step (1) are: 65 to 75 parts of pork hind leg meat, 0.9 to 1.1 parts of salt, 0.2 to 0.3 parts of thirteen spices, 0.5 to 0.6 parts of sugar, and 1 to 1.2 parts of chili powder. 5 to 7 servings of cooking wine.

Further, the weights of the raw materials in step (2) are: 10-20 parts of starch emulsion, 0.25-0.35 parts of salt, 5-10 parts of natural starch, and 75-80 parts of cured meat.

Further, the processing method described in step (2) requires the salt-containing mixture to be wrapped on the surface of the cured meat.

Further, the drying conditions described in step (2) are temperature 50-78°C and time 10-20h.

Further, the baking temperature in step (2) is >78°C to ensure the formation of starch-based gel.

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

(1) The starch-based fat substitute prepared by the method of the present invention has good viscoelasticity and chewiness. In addition, the starch emulsion gel has a high swelling rate and can be fully swollen when eaten. Due to the prolonged chewing cycle, the mass transfer resistance of sodium ions is reduced and the release of sodium ions is significantly accelerated, so the gel has the advantages of high release rate and convective mass transfer rate. Compared with the animal fat-added group, the emulsion-gel substitute could significantly improve saltiness perception, achieving the effect of reducing salt but not reducing saltiness perception.

(2) The starch-based gel prepared by the present invention has a milky white appearance and viscoelastic texture, with a compact overall structure and smooth cross-section, similar to animal fat. By using it to prepare sausages instead of animal fat, sausage products with low fat content (only about 3%) can be obtained, and the sausages containing starch-based gel have similar tissue morphology and taste to sausages containing animal fat, and can simulate The creaminess and smooth mouthfeel of animal fats provide good flavor and consumer acceptability.

The sausage prepared by replacing fat with starch-based gel has both low-salt and low-fat health properties, which can satisfy consumers' demand for healthy and delicious food to a great extent.

Description of the drawings

Figure 1 is the appearance structure of the starch-based gel prepared in Example 1, Example 2, Example 3, Example 4 and Comparative Example 1;

Figure 2 is an analysis chart of the swelling rate of starch-based gels prepared in Example 1, Example 2, Example 3, Example 4 and Comparative Example 1;

Figure 3 is an analysis chart of sodium ion release of starch-based gels prepared in Example 1, Example 2, Example 3, Example 4 and Comparative Example 1;

Figure 4 is a sensory evaluation analysis chart of low-salt and low-fat sausages containing starch-based gel prepared by Application Example 1, Application Example 2, Application Example 3, Application Comparative Example 1 and Application Comparative Example 2;

Figure 5 is a principal component analysis diagram of the taste characteristics of the electronic tongue test using Examples 1-4 and Application Examples 1 and 2; (A: Comparison of taste characteristics between the starch-based gel substitute sausage product group and the emulsion gel group B: Market Comparison of taste characteristics between sold sausages and starch-based gel substitute sausage products with different fat contents C: Comparison of taste characteristics between the starch-based gel substitute sausage product group and the pork backfat fat control group).

Detailed ways

The present invention will be further described below with reference to specific embodiments and drawings, but the implementation of the present invention is not limited thereto.

Unless otherwise stated, room temperature means 25±2°C.

Example 1 (oil content is 5%)

(1) Dissolve 8g of starch octenylsuccinate in 82g of deionized water at room temperature by stirring, then add 10g of corn oil and shear at 10000rpm for 1min, and then circulate and homogenize at 50MPa for 5min. , after homogenization, place the mixed solution in an ice water bath to quickly cool down to obtain a starch emulsion, and place it in a 4°C refrigerator for storage until later use;

(2) Disperse 32g of potato starch in 68g of deionized water to obtain a potato starch dispersion;

(3) Add 100g of the emulsion and 2g of salt from step (1) to the starch dispersion in step (2), mix evenly, and then heat it to 80°C with the help of a heating magnetic stirrer. Wait until the starch is fully gelatinized and then Cool in a room temperature environment and stabilize for 24 hours to obtain a starch-based emulsion gel fat substitute.

Example 2

Adjust "82g deionized water, 10g corn oil" in step (1) of Example 1 to "72g deionized water, 20g corn oil", and keep the others consistent with Example 1 to obtain a starch-based emulsion gel fat substitute ( Oil content is 10%).

Example 3:

Adjust "82g deionized water, 10g corn oil" in step (1) of Example 1 to "62g deionized water, 30g corn oil", and keep the others consistent with Example 1 to obtain a starch-based emulsion gel fat substitute ( Oil content is 15%).

Example 4:

Adjust "82g deionized water, 10g corn oil" in step (1) of Example 1 to "32g deionized water, 60g corn oil", and keep the others consistent with Example 1 to obtain a starch-based emulsion gel fat substitute ( Oil content is 30%).

Comparative example 1

The vegetable oil in Example 1 was omitted, and the others were kept the same as in Example 1 to obtain a starch-based gel fat substitute.

The emulsions during the implementation of Examples 1 to 4 and Comparative Example 1 and the finally obtained starch-based gel were tested. The test methods and results are as follows:

Particle size determination

Take 100 μL of the sample in a test tube, add 10 mL of deionized water to dilute it 100 times, and use a laser particle size analyzer Zetasizer Nano-ZS90 to measure the droplet size of the emulsion. During the measurement process, set the refractive index to 1.450 and maintain equilibrium at 25°C for 2 minutes. In order to reduce the measurement error caused by multiple scattering, each sample was measured three times, and the average value was taken as the final particle size.

Table 1 Differences in particle size of emulsions prepared under different conditions

It can be seen from Table 1 above that the particle size of the emulsion increased from 189.63±2.74nm to 320.23±0.57nm as the amount of vegetable oil added increased. The particle sizes of the samples were evenly distributed and there were significant differences between different examples (P<0.05).

Mechanical property determination

Use the CT3 texture analyzer at room temperature to conduct a texture profile analysis (TPA) test on the prepared starch-based gel fat substitute. The set parameters are probe TA5, test rate 1mm/s, probe sensing force 5g, and compression height. is 10mm, and the number of cyclic compressions is 2. Use TexturePro CT fitting data to obtain analytical index data such as hardness, elasticity, viscosity, chewiness, and cohesion. Each treated sample was measured 4 times in parallel, and the average of the 4 measurements was taken.

Table 2 TPA texture properties of starch-based gel fat substitutes prepared under different conditions

As can be seen from Table 2, compared with pure starch gel (Comparative Example 1), the addition of vegetable oil is beneficial to improving the mechanical properties of the gel (such as gel strength, hardness, viscosity, elasticity, cohesion and chewiness). As the amount of vegetable oil added increased, the gel strength, hardness and elasticity of the gel showed an overall trend of first increasing and then decreasing. The maximum mechanical properties were reached when the amount of vegetable oil was added to 10%. Good mechanical properties will help extend the The chewing cycle of the gel during oral processing not only increases the degree of gel fragmentation but also increases the degree of contact between the taste buds on the tongue surface and the gel during consumption. The embodiments of the starch emulsion gel significantly reduce the fat content, achieve a low-fat effect, and meet the health needs of consumers.

Swelling measurement

Press the gel to be tested with a cylindrical mold with a diameter of 12mm. Weigh about 5g of the cylindrical gel sample into a 25mL beaker. Add 20mL of deionized water to perform a swelling experiment. Sampling time is 12h. Wait until the gel is removed. The experiment ended when the swelling equilibrium state was reached in the ionized water. Use a balance to accurately weigh the gel mass at different swelling time intervals. Before weighing, use filter paper to absorb the surface liquid. Each sample was repeated 4 times, and the swelling rate (%) of the sample was calculated according to the following formula (1).

Swelling rate of gel (%) = (mass after swelling - initial mass)/initial mass × 100% (1)

As shown in Figure 2, under the same swelling time, the swelling degree of the starch-based gel containing vegetable oil is significantly higher than that of the blank starch-based gel without vegetable oil. The swelling rate at the 12th hour more than doubled. After 72 hours, the swelling rate of the starch-based gel containing vegetable oil was more than doubled. The starch-based gel can swell and absorb water up to 35% of its own weight; under a fixed formula ratio, as the swelling time increases, the degree of swelling increases, but the example with 30% oil content reaches saturation after 48 hours. And the swelling degree of starch-based gel samples decreased slightly as the oil content increased. The decrease in swelling rate also shows that as the volume of filled oil droplets increases, the uniformity and density of the gel network is improved, which will reduce the mass transfer resistance of internal substances (ions) and help achieve the release of substances (ions) dissolution.

Sodium release assay

The CT3 texture analyzer was used to conduct multiple compression tests on gel samples soaked in saliva samples at room temperature, and then the sodium ion content in the saliva was measured to evaluate the release of sodium ions during oral chewing. Compression test conditions: test rate 1mm/s, probe induction force 5g, compression height 10mm, cyclic compression times 10 times. Weigh about 5g of cylindrical gel sample into a 25mL beaker, add 20mL of simulated saliva with α-amylase (2g/L, pH=6.8) as the main component at the 0th compression, and then perform a compression test. Quantitatively take 10 μL of the mixed solution during the 1st, 5th, and 10th compression, and use a kit to measure the sodium ion content. Among them, the principle of testing the sodium ion content is that sodium ions and 6-antimony hydroxide form a uniform turbidity in the presence of a dispersant, and the sodium ion content in the sample is obtained through colorimetric calculation at 620nm.

It can be seen from Figure 3 that the sodium ion release amount of starch-based gel structures with different oil contents during the simulated oral chewing compression process is significantly different. After the start of uniaxial compression, the water-absorbed swollen gel is crushed radially by vertical compression and the slurry is discharged, transferring a large amount of dissolved sodium from the interior of the gel to the surrounding environment; during multiple compression processes, the degree of sodium ion release increases. Clear differences emerged, with the emulsion gel with 10% vegetable oil content having the greatest sodium release and the pure starch-based gel having the lowest sodium ion release. In the simulated saliva medium, the starch gel matrix undergoes compression deformation and enzymatic decomposition. Compared with pure starch gel, the uniform network structure of the oil-containing gel forms uniform pores during the swelling process, which reduces the mass transfer resistance of sodium ions and compresses Process slurry release enables convection and mass transfer of sodium, ultimately releasing it from the gel into the surrounding environment. However, it should be noted that as the oil content increases, the diffusion trend of sodium ions first increases and then decreases. This is because the addition of oil helps to increase the effective salt concentration in the water phase, thereby achieving efficient mass transfer during the swelling process. However, the addition of a large amount of oil may cause the release of oil during the swelling and extrusion process and hinder the effective transfer of sodium ions. Therefore, the present invention further proves that the partial addition of vegetable oil is beneficial to the fragmentation of the structure and the rapid release of sodium ions.

Specific application examples

Application Example 1

(1) Use pork hind leg meat as raw meat, remove excess fat and connective tissue, and cut it into small pieces of 3 to ^5cm3 ;

(2) Prepare raw materials according to weight: 70 parts of pork shank, 0.7 parts of salt, 0.2 parts of thirteen spices, 0.6 parts of sugar, 1.2 parts of chili powder, 5 parts of cooking wine, then marinate at room temperature for 60 minutes to obtain a mixture 1;

(3) Obtain starch emulsion with reference to step (1) of Example 1. That is: at room temperature, 8g of octenyl starch succinate was dissolved in 82g of deionized water by stirring, then 10g of corn oil was added and sheared at 10000rpm for 1min, and then circulated and homogenized at 50MPa for 5min. After homogenization, place the mixed solution in an ice-water bath to cool quickly and place it in a 4°C refrigerator for later use to obtain a uniform and stable emulsion;

(4) Refer to step (2) of Example 1 to prepare a starch dispersion. That is: uniformly disperse 32g of potato starch in 68g of deionized water by stirring to obtain a potato starch dispersion;

(5) Add 45 parts of the emulsion and 0.9 parts of salt in step (3) to 45 parts of the starch dispersion in step (4), mix evenly, and then add 233.1 parts of mixture 1 of step (2) to obtain mixture 2;

(6) Fill the mixture 2 obtained in step (5) with a casing with a diameter of 38-40mm on a vacuum filling machine;

(7) Pickle the sausage filled in step (6) in the oven, the pickling conditions are 50°C, 20h;

(8) Pack the cured sausage in step (7) in a PE vacuum packaging bag at a vacuum degree of -0.07 to -0.1kPa, to obtain low-salt and low-fat sausage containing starch emulsion gel fat substitute.

Application Example 2

Adjust "82g deionized water, 10g corn oil" in step (3) of Application Example 1 to "72g deionized water, 20g corn oil", and keep the others consistent with Application Example 1 to obtain a starch-containing emulsion gel fat substitute Low-salt and low-fat sausage.

Application Example 3

Adjust "82g deionized water, 10g corn oil" in step (3) of Application Example 1 to "62g deionized water, 30g corn oil", and keep the others consistent with Application Example 1 to obtain a starch-containing emulsion gel fat substitute Low-salt and low-fat sausage.

Application Example 4

Adjust "82g deionized water, 10g corn oil" in step (3) of Application Example 1 to "32g deionized water, 60g corn oil", and keep the others consistent with Application Example 1 to obtain a starch-containing emulsion gel fat substitute Low-salt and low-fat sausage.

Application control example 1 (pure starch gel group)

Omit the vegetable oil, and keep the other conditions consistent with Application Example 1 to obtain a low-salt and low-fat sausage containing a starch-based gel fat substitute.

Application control example 2 (pig backfat fat group)

Referring to the steps of Application Example 1, adjust step (5) as follows: mix 90 parts of pork backfat fat and 0.9 parts of salt evenly, and then add 233.1 parts of mixture 1 of step (2) to obtain mixture 2; other and application examples 1Stay consistent and get a sausage containing pork backfat fat.

The low-salt and low-fat sausages containing the starch-based gel fat substitute obtained in Comparative Examples 1 and 2 and Application Examples 1 to 4 were tested. The test methods and results are as follows:

Sensory evaluation

Sensory evaluation was conducted on the products prepared in Application Examples 1 to 4 and Application Comparative Examples 1 and 2. The sensory scoring standards and scoring results are shown in Table 3 and Figure 4 respectively.

Table 3 Sensory scoring standards for low-salt and low-fat sausages

It can be seen from Figure 4 that the color, smell and texture of the low-salt and low-fat sausages containing starch-based emulsion gel fat substitute are higher than the actual sausages containing pig backfat fat, and the consumer acceptability is 6.5 points. The above can meet consumers’ quality requirements for taste and characteristic flavor.

Analysis of taste characteristics of electronic tongue

Take 5g of the sample and add it to 45g of ultrapure water containing α-amylase (2g/L). Use a glass rod to compress it three times to simulate chewing to break the sample. Place it in a 37°C water bath and heat it for 1 minute. Filter it with filter paper and collect the filtrate. Then Centrifuge at 10000r/min for 10min, and take the supernatant for later use. The electronic tongue was used to measure and analyze the salty, fresh, sour, bitter, astringent and richness of the filtrate. The electronic tongue testing conditions are: cleaning for 5.5 minutes, test time of 30 seconds, and aftertaste test time of 30 seconds. The reference solution is 0.3mmol/L tartaric acid and 30mmol/L KCl solution.

It can be seen from Figure 5 that the saltiness perception intensity from high to low is: starch gel replacing sausage group > emulsion gel group, emulsion gel replacing sausage group > animal back fat; the trend of saltiness intensity after the product is air-dried is: starch gel Substitute > Emulsion Gel G10 > Emulsion Gel G5 > Emulsion Gel G15, commercially available sausage. During the chewing process, the emulsion gel-based fat substitute has a higher degree of overall structural swelling compared with protein and other structural components in meat products, which is beneficial to the release and mass transfer of salt; and the product of the application example by adding lean meat components The salt coating on the surface achieves uneven distribution of salt, and enhances the salty perception of the product by increasing the salty contrast, instant stimulation and intermittent stimulation. The salty taste attribute of the product is related to the rheological properties of the food bolus formed by mixing with saliva. Samples with a certain viscosity and elasticity have higher tactile perception and are conducive to promoting the salty taste perception effect, such as G10. In addition, the addition of oil phase components can increase the effective salt concentration, increase the sensitivity of taste buds to salty taste during chewing, adjust the texture characteristics of food to control the diffusion and release of salt during chewing, and ultimately achieve an effective salty taste control effect; However, excessive oil release coats the surface of taste buds, hindering the transmission of sodium ions and inhibiting salty taste perception. Therefore, the appropriate addition of oil can help enhance the salty taste perception effect. Taking the above factors into consideration, under the same salt addition conditions, the sausage prepared with an emulsion gel (G10, corresponding to a 3% oil addition in the sausage) fat substitute with a vegetable oil addition of 10% has a higher salty taste. And lower in fat.

The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above solutions. All simple modifications and combinations based on the technical concept of the present invention should be included in the protection scope of the present invention.

Claims (12)

1. A method for preparing a starch-based gel fat substitute, which is characterized in that it includes the following steps: (1) Disperse the modified starch in deionized water at room temperature, then add vegetable oil and form a uniform and stable emulsion through shearing and homogenization; (2) Disperse salt, natural starch and the emulsion of step (1) in deionized water, perform heat treatment while stirring and mixing evenly. After the starch is fully gelatinized, place it in a room temperature environment to cool and form, thereby obtaining the starch-based gel fat. substitution. 2. The preparation method of starch-based gel fat substitute according to claim 1, characterized in that the vegetable oil in step (1) includes one or more of peanut oil, corn oil, olive oil, sunflower oil, etc. kind. 3. The preparation method of starch-based gel fat substitute according to claim 1, characterized in that the shearing time in step (1) is ≥ 30 s, and the homogenization pressure is ≥ 30 MPa. 4. The preparation method of starch-based gel fat substitute according to claim 1, characterized in that the modified starch added in the emulsion of step (1) includes octenyl succinate esterified starch, One or more of sodium starch octenylsuccinate, etc. 5. The preparation method of starch-based gel fat substitute according to claim 1, characterized in that the mass concentration of modified starch added to the emulsion in step (1) is ≥ 4%. 6. The preparation method of starch-based gel fat substitute according to claim 1, characterized in that the natural starch in step (2) includes one or more of potato starch, corn starch, wheat starch and tapioca starch. kind. 7. The preparation method of starch-based gel fat substitute according to claim 1, characterized in that the mass concentration of natural starch in step (2) is ≥10%. 8. Starch-based gel fat substitute prepared according to the preparation method according to any one of claims 1-7. 9. Application of the starch-based gel fat substitute in low-salt and low-fat sausages according to claim 8. 10. The application according to claim 9, wherein the preparation method of low-salt and low-fat sausage includes the following steps: (1) Raw material preparation: Cut the pig hind leg meat into small pieces, weigh 65 to 75 parts of pork, 0.65 to 0.75 parts of salt, 0.2 to 0.3 parts of thirteen spices, 0.5 to 0.6 parts of sugar, and 1 to 1.2 parts of chili powder. , 5 to 7 portions of cooking wine, and marinate to obtain marinated lean meat. (2) Sausage making: Mix 10-20 parts of starch emulsion, 0.25-0.35 parts of salt, 5-10 parts of natural starch and 75-80 parts of cured meat, so that the salt-containing starch emulsion is wrapped on the surface of the lean meat and quickly enema It is dried, baked and then vacuum packed. 11. The processing method according to claim 10, characterized in that the wrapping method in step (2) is to fully wrap the salt-containing mixture on the surface of the cured meat to ensure uneven distribution of salt. 12. The processing method according to claim 10, characterized in that the baking temperature in step (2) is ≥78°C to ensure starch-based gel formation.