Starch-based fat substitute for sauce and preparation method of starch-based fat substitute

Abstract

The invention discloses a starch-based fat substitute for sauce and a preparation method, and belongs to the technical field of food processing. The starch-based fat substitute is obtained through enzyme-chemical synergistic modification, control of the acetyl content and the crosslinking degree of ADSP and fine regulation and control of the molecular structure of starch particles by using enzyme so as to improve the rheological property of gelatinized starch, and compared with a traditional commercial custard sauce with the fat content of 16-31%, the starch-based fat substitute has the advantages that the content of fat in the custard sauce is greatly improved, and the content of fat in the custard sauce is greatly reduced. According to the custard sauce disclosed by the invention, rapeseed oil is replaced by the starch-based fat substitute, the fat content of the prepared custard sauce is reduced to 7% or below by utilizing the good thickening and smoothing properties of the starch-based fat substitute, and the custard sauce is enhanced in flowability and softer and smoother in texture, and has good application and market prospects.

Description

Technical Field

[0001] This invention relates to a starch-based fat substitute for sauces and its preparation method, belonging to the field of food processing technology. Background Technology

[0002] Custard is a common food sauce used in Western desserts. It can be used as a filling in cream puffs, cakes, macarons, and other desserts, as a decoration for dessert piping, or as a dipping sauce for bread and toast. Originally, custard was made from egg yolks, milk, sugar, and starch. Later, industrial production used a mixture of milk, sugar, vegetable oil, emulsifiers, and starch, heated to create a semi-fluid, sweet-tasting sauce that is widely popular. Custard has a typical oil-in-water structure. To successfully form a stable emulsion and maintain its smooth texture in industrial production, a large amount of oil is often added; commercially available custard typically contains 15%-30% fat. With the increasing risk of obesity, high cholesterol, and arteriosclerosis due to excessive fat intake, people are seeking low-fat foods. Since simply reducing the fat content of sauces can lead to a loss of flavor and an imbalance in the sauce's internal structure, various fat substitutes have emerged to reduce fat content while maintaining the sauce's texture. Fat substitutes can be classified into the following categories based on the type of raw material: fat-based, such as sucrose polyester and medium-chain triglycerides; protein-based, such as whey protein and soy protein; polysaccharide-based, such as pectin and xanthan gum; and starch-based, such as tapioca starch, corn starch and their modified products.

[0003] Starch is a widely available and inexpensive raw material. Cassava starch paste has high viscosity and transparency, and acetylated distarch phosphate (ADSP), modified by acetylation and cross-linking, overcomes the problems of retrogradation and poor stability of virgin cassava starch. It is widely used in sauces, where it can replace some of the functional properties of fat and thicken the sauce. However, there are still issues such as the inability to maintain the smoothness and gloss of sauces when added in low amounts, and the introduction of starch flavor when added in high amounts.

[0004] Currently, fat substitutes can also be obtained by enzymatic hydrolysis of starch. For example, patent CN118318997A discloses the addition of α-amylase to potato starch solution in conjunction with dynamic ultra-high pressure microfluidic technology to obtain micro-nano-scale potato starch enzymatically hydrolyzed fat mimics. However, this invention performs enzymatic hydrolysis in a gelatinized system, which leads to high viscosity and instability at high concentrations. In contrast, enzymatic modification can be performed in a particulate system under high concentration conditions, and the resulting starch powder retains its multi-scale structure, including granules and crystals. Therefore, it retains its swelling and gelatinization properties and prevents retrogradation, making it a modification method with good industrial potential. Summary of the Invention

[0005] To address the aforementioned issues, this invention aims to provide an enzyme-chemical modified starch-based fat substitute for sauces and its preparation method. This invention aims to control the acetyl content and cross-linking degree of ADSP through enzyme-chemical synergistic modification, and to finely regulate the starch molecular structure using enzymes to improve the rheological properties of starch after gelatinization. This allows it to be used as a fat substitute in sauce systems to reduce oil usage while maintaining a stable structure and smooth texture. This results in reduced oil usage in custard sauces, a uniform and smooth texture, uniform color, suitable consistency, and ease of application, demonstrating strong potential for industrial application.

[0006] This invention provides a method for preparing a starch-based fat substitute, comprising the following steps:

[0007] Starch and water were mixed to form a starch slurry, which was first cross-linked and then acetylated. After washing away the salt ions, the mixture was dried to obtain modified starch acetylated distarch phosphate. The obtained modified starch acetylated distarch phosphate was mixed with phosphate buffer to form a starch slurry, which was then enzymatically modified at a temperature below the gelatinization temperature. After the reaction was completed, the mixture was dried to obtain a starch-based fat substitute.

[0008] In one embodiment of the present invention, the starch includes, but is not limited to, tapioca starch, corn starch, and glutinous corn starch.

[0009] In one embodiment of the present invention, the starch milk concentration is 1%-40%, w / v, g / mL.

[0010] In one embodiment of the present invention, the crosslinking agent used in the crosslinking modification is sodium trimetaphosphate, and the addition amount is 1%-3% (starch dry basis w / w); the crosslinking modification time is 1-4h, the temperature is 30-50℃, and the pH is 9.0-12.0; the degree of starch crosslinking is limited to 20%-40%.

[0011] In one embodiment of the present invention, the acetyl content is limited to 1.8%-2.2%; the acetylation modification conditions are temperature ≤33℃, pH 7.5-9.5, and reaction time 30-120min; the acetylation modification reagent is acetic anhydride, the amount added is 3%-6%, and starch dry basis w / w.

[0012] In one embodiment of the present invention, the degree of hydrolysis of the enzymatically hydrolyzed starch is limited to <12%, the enzyme used for modification is α-amylase or maltose α-amylase, the amount added is 10-50 U / g starch, the modification time is 2-8 h, and the temperature is 30-70℃.

[0013] In one embodiment of the present invention, the drying method includes freeze drying, atmospheric pressure drying, spray drying, drum drying, or microwave drying.

[0014] The present invention provides starch-based fat substitutes prepared by the above method.

[0015] This invention provides the application of the starch-based fat substitutes described above in the food industry.

[0016] This invention provides the application of the starch-based fat substitutes described above in sauces.

[0017] In one embodiment of the present invention, the starch-based fat substitute described above is added to the sauce to replace fat and increase the smooth and delicate texture of the sauce.

[0018] The present invention also provides a custard sauce prepared from the starch-based fat substitute described above, wherein the custard sauce is made from the following raw materials in the following percentages by weight: 4%-7% starch-based fat substitute described above, 10%-20% white sugar, 5%-7% vegetable oil, 10%-20% skim milk, 2%-4% sodium caseinate, and water to make up the balance.

[0019] In one embodiment of the present invention, the custard sauce contains 5.5% by mass of starch-based fat substitute.

[0020] In one embodiment of the present invention, the custard sauce has a homogeneity of 0.2-4.5 g / sec and a fluidity of 5-20 g / sec.

[0021] This invention provides a method for preparing the above-mentioned custard sauce, comprising the following steps:

[0022] (1) Mix white sugar, starch-based fat substitute and water evenly to obtain excipient 1;

[0023] (2) Mix sodium caseinate, skim milk, and vegetable oil evenly, and then mix with water to obtain excipient 2;

[0024] (3) Mix auxiliary materials 1 and auxiliary materials 2, stir thoroughly to homogenize and heat in a water bath to 95°C, remove and cool to room temperature to obtain the finished sauce.

[0025] Beneficial effects

[0026] (1) The enzyme-chemical composite modified starch-based fat substitute provided by the present invention has suitable acetyl content, cross-linking degree and enzyme hydrolysis degree, and has excellent resistance to retrogradation and shear resistance.

[0027] (2) The gel formed by the gelatinization of the starch-based fat substitute provided by the present invention has a suitable viscosity and replaces part of the fat, thereby reducing the amount of oil used. At the same time, when applied to custard sauce, it can give it excellent shape retention ability and a smoother and more uniform taste.

[0028] (3) This invention prepares a modified starch that can replace fat by cross-linking modification, acetylation modification, and enzyme composite modification of starch. When added to custard, it can maintain the smooth texture lost due to the reduction in fat content. By enzymatically modifying granular starch below the gelatinization temperature, the swelling and gelatinization characteristics of granular starch can be retained. At the same time, starch can be processed under high concentration conditions, avoiding the high viscosity and instability problems caused by high concentration processing of the gelatinization system, saving processing energy, and preventing retrogradation. In terms of eating quality, custard with the fat substitute of this invention has a delicate and smooth texture, maintaining the texture lost due to the reduction in fat content, and achieving a balance between processing performance and eating quality.

[0029] (4) The fat content of the custard sauce prepared by this invention is reduced to 7% or less, which is far lower than that of commercial custard sauce (16% to 31% fat content), and the texture is soft and smooth. Attached Figure Description

[0030] Figure 1 This is a gelatinization viscosity diagram of Comparative Examples 1 and 2, which is Example 1 of the present invention.

[0031] Figure 2 These are rheological results diagrams for Embodiment 1 and Comparative Example 1 of the present invention;

[0032] Figure 3 This is a graph showing the results of the textural firmness in Example 1 of the present invention;

[0033] Figure 4 This is a microscopic morphological feature diagram of Embodiment 1 of the present invention. Detailed Implementation

[0034] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0035] Amylase activity was determined using the DNS method. 1.0 g of amylase was diluted appropriately with 20 mL of PB buffer (50 mM, pH 6.0) before determining enzyme activity. 100 μL of the diluted solution was mixed with 900 μL of soluble starch paste (1%, w / w). At 0, 2, 4, 6, 8, and 10 min, 100 μL of the reaction solution was mixed with 400 μL of PB and 500 μL of DNS reagent, boiled for 5 min, cooled on ice for 5 min, and the OD value was measured at 540 nm. Enzyme activity was calculated using the following formula:

[0036]

[0037] 1U is defined as the amount of enzyme required to hydrolyze soluble starch to produce 1 mg of reducing sugar per minute under conditions of pH 6.0 and 50°C.

[0038] The enzyme used in the embodiments provided by this invention is TAKA α-amylase purchased from Sigma-Aldrich, with an enzyme activity of 439.0 U / mL.

[0039] The methods involved in the following embodiments and comparative examples are as follows:

[0040] 1. Method for determining enzyme hydrolysis rate (DH%)

[0041] Collect the filtrate after enzymatic hydrolysis of starch, and determine the hydrolysis rate by measuring the total sugar content in the filtrate. Mix 0.4 mL of the sample solution dilution with 0.2 mL of 6% phenol solution, then quickly add 1 mL of concentrated sulfuric acid. Let stand for 10 min, vortex for 30 s, and then place in an enzyme reactor. React at 100℃ and 300 rpm for 20 min, and measure the absorbance at 490 nm using a microplate reader. After measuring the absorbance, compare with the standard curve to obtain the glucose concentration C of the filtrate. Calculate the hydrolysis rate DH% using the following formula.

[0042]

[0043] C is the mass concentration of glucose in the filtrate; m1 is the mass of the filtrate; m is the mass of dry starch; 0.9 is the mass conversion coefficient of reducing sugar to glucan.

[0044] 2. Determination of acetyl content (AC%) and degree of crosslinking (CL%)

[0045] The acetyl content of the prepared acetylated distarch phosphate was determined using the method described in the national standard GB 29925—2013, Food Additives—Acetate Starch. The degree of crosslinking of the acetylated distarch phosphate was determined using a method for detecting the degree of crosslinking of crosslinked starch, as described in patent CN 108414459 A.

[0046] 3. Rapid Viscosity Analysis (RVA)

[0047] The gelatinization viscosity characteristics of starch were determined using a rapid viscosity analyzer (RVA 4500). The moisture content of the starch sample was calibrated to 14%, and 3g of starch was added to water to prepare a starch suspension with a mass fraction of 7% (w / w). The sample was thoroughly mixed using a paddle stirrer and then placed in the RVA instrument. The test procedure was set as follows: the sample was preheated at 50℃ for 1 min, then heated to 95℃ at a rate of 12.2℃ / min and held at that temperature for 2.5 min; subsequently, the temperature was reduced to 50℃ at a rate of 11.8℃ / min and held for 2 min. The gelatinization temperature, peak viscosity, and final viscosity of the sample were analyzed.

[0048] 4. Rheological property analysis

[0049] After the RVA gelatinized sample gel was cooled to room temperature, it was placed on the rheometer testing platform for rheological testing. The specific procedure was as follows: Thixotropy test: The static rheological properties of the starch paste were measured at a constant temperature of 25℃ with a spacing of 1 mm and a shear rate starting from 0.1 s⁻¹. -1 Increase to 100s -1 Then from 100s -1 Reduced to 0.1s -1 The change of shear stress with shear rate was measured using the power law equation (τ = Kγ). n τ - shear stress / Pa, K - consistency coefficient / Pa·S n γ-shear rate / s -1 Regression analysis was performed on the static rheological curve data of starch (n-fluid index) to obtain the consistency coefficient K, fluid index n, and multiple correlation coefficient R. 2 and the area of ​​the hysteresis loop.

[0050] 5. Morphological characteristics of starch granules

[0051] The dried sample powder was adhered to a sample stage coated with conductive adhesive using a bamboo skewer. After gold sputtering, the surface morphology of the sample was observed using an SU8100 cold field emission scanning electron microscope. The accelerating voltage was 3.0 kV, and the magnification was 3000x.

[0052] 6. Texture property analysis

[0053] The textural properties of different samples were determined using a TA-XT plus texture analyzer at 25℃. An A / BE reverse compression device was selected for the measurements. A 35mm transparent plastic disc was used, and 50g of sample was placed in a 50mm diameter standard test cup. The test parameters were as follows: Compression mode selected, probe initial height 55mm, moving speeds before, during, and after the test 1.0, 2.0, and 10.0mm / s respectively, compression distance 30mm, and trigger force threshold 5.0g. Each sample was measured in triplicate to obtain results for flowability, firmness, homogeneity, and cohesiveness.

[0054] Example 1

[0055] ① Prepare 35% (w / v) tapioca starch milk, stir and mix it in a beaker, activate it at 40℃ for 10 min, control the temperature at 38-45℃, adjust the pH to 10.0-11.0, add 2% (starch dry basis w / w) sodium trimetaphosphate, react for 2 h, cool down to below 33℃, adjust the pH to 7.0-7.5 to end the cross-linking reaction, adjust the pH to 8.0-8.5, slowly add 6% (starch dry basis w / w) acetic anhydride, react for 2 h, adjust the pH to 4.5-5.5 to terminate the reaction, wash 3 times, and dry to obtain chemically modified starch acetylated distarch phosphate, named ZA.

[0056] ② Prepare 15% (w / v) starch milk by adding acetylated distarch phosphate ester of chemically modified starch to 50mM, pH 6.0 phosphate buffer. Add 10, 20, 30, 40, and 50 U / g (dry starch basis) of α-amylase respectively, and incubate at 50℃ for 160rpm for 2h. Adjust the pH to <3.0 to stop the reaction, then adjust back to neutral, wash and dry, and pass through a 100-mesh sieve to obtain enzyme-chemically modified starch, which are the starch-based fat substitutes of this invention, named T-ZA-1, 2, 3, 4, and 5 respectively.

[0057] Comparative Example 1

[0058] Prepare a 35% (w / v) tapioca starch milk, stir and mix it in a beaker, activate it at 40℃ for 10 min, control the temperature at 38-45℃, adjust the pH to 10.0-11.0, add 2% (starch dry basis w / w) sodium trimetaphosphate, react for 2 h, cool to below 33℃, adjust the pH to 7.0-7.5 to stop the cross-linking reaction, adjust the pH to 8.0-8.5, slowly add 6% (starch dry basis w / w) acetic anhydride, react for 2 h, adjust the pH to 4.5-5.5 to stop the reaction, wash 3 times, and dry to obtain chemically modified starch acetylated distarch phosphate.

[0059] A 15% (w / v) starch slurry was prepared by adding chemically modified starch acetylated distarch phosphate to 50 mM, pH 6.0 phosphate buffer. The mixture was reacted in a 50°C water bath at 160 rpm for 2 h. The reaction was stopped by adjusting the pH to < 3.0. The mixture was then returned to neutral, washed, and dried to obtain a starch-based fat substitute, named T-ZA-0.

[0060] Comparative Example 2

[0061] 15% (w / v) starch milk was prepared by adding 50 mM, pH 6.0 phosphate buffer to raw cassava starch. α-amylase was added at concentrations of 10, 20, 30, 40, and 50 U / g (dry starch basis), respectively. The mixture was reacted in a 50°C water bath at 160 rpm for 2 hours. The reaction was stopped when the pH was adjusted to < 3.0. The mixture was then brought back to neutral, washed, dried, and passed through a 100-mesh sieve to obtain enzyme-modified starch, which was named T-1, 2, 3, 4, and 5, respectively.

[0062] Example 2

[0063] The sample from Example 1 was used as a fat substitute to prepare custard sauce. 20g (w / w) of white sugar, 5.5g (w / w) of the sample, and water were mixed evenly to prepare auxiliary ingredient 1. 2.5g (w / w) of sodium caseinate, 20g (w / w) of skim milk, and 7g (w / w) of rapeseed oil were stirred evenly and mixed with water to prepare auxiliary ingredient 2. Auxiliary ingredients 1 and 2 were mixed, thoroughly stirred to homogenize, and heated in a water bath to 95°C. After cooling to room temperature, the finished sauce was obtained. The sauces prepared according to T-ZA-1, 2, 3, 4, and 5 of Example 1 were named Samples 1-5, respectively.

[0064] The sauce with added ZA was named Control Sample 1, and the sauce with added T-ZA-0 was named Control Sample 2.

[0065] The starch prepared in Example 1 was characterized as follows:

[0066] 1. Acetyl group content and cross-linking degree are significantly positively correlated with the anti-retrogradation, acid and alkali resistance, and shear resistance of acetylated distarch phosphate. Table 1 shows the hydrolysis rate, acetyl group content, and cross-linking degree of Examples 1 and 2. With increasing hydrolysis rate, enzyme treatment did not significantly affect the AC% and CL% of acetylated distarch phosphate.

[0067] Table 1. Starch chemical group information for Example 1

[0068]

[0069] 2. The gelatinized viscosity of the sample starch is as follows: Figure 1 As shown, acetylation and cross-linking combined modification lowered the gelatinization temperature of virgin cassava starch and significantly increased both peak and tail viscosity. Enzyme treatment reduced both the peak and tail viscosity of ZA, indicating a reduction in viscosity generated during processing and a decrease in adhesion after processing.

[0070] 3. The rheological results of the sample starch after gelatinization are as follows: Figure 2 As shown in Table 2, the internal structure of starch gel is disrupted as the shear rate increases, leading to a rapid increase in shear stress. When the shear rate decreases, the gel structure is difficult to fully recover, forming a unique hysteresis loop on the rheological curve. The size of the hysteresis loop indicates the strength of the starch paste's thixotropy, reflecting its ability to form and recover the gel structure under shear force. The larger the hysteresis loop area, the stronger the starch's thixotropy and the worse its ability to form and recover the gel structure. Figure 2 The results in Table 2 show that after enzyme action, the hysteresis loop area decreased, starch paste thixotropy increased, and shear resistance was further enhanced.

[0071] Table 2. Starch gel hysteresis loop area in Example 1

[0072]

[0073] 4. The results of the textural firmness of the sample after starch gelatinization are as follows: Figure 3 As shown, enzyme treatment reduces firmness, making the starch paste softer and increasing palatability in the mouth.

[0074] 5. Electron microscopy results are as follows: Figure 4 As shown, enzyme modification preserves the complete granular structure of starch, allowing it to enter the interior through the relatively loose gaps on the surface of the starch granules to modify the molecular structure. This results in starch with unique properties that can be used as a fat substitute in sauces, improving both processing and edible quality.

[0075] 6. Characterize the custard sauce prepared in Example 2:

[0076] The textural results of the prepared custard are shown in Table 3. The texture analyzer can identify the mechanical properties of food in the oral cavity to obtain the texture of the food. Among them, the lower the flowability value, the stronger the flowability of the sample; the higher the firmness value, the softer the sample; homogeneity represents the smoothness of the sample, and the lower the value, the better the internal uniformity of the sample; cohesiveness represents the strength of intermolecular binding, and the higher the value, the stronger the cohesiveness. The results in Table 3 show that the custard prepared with the addition of the starch-based fat substitute of the present invention has a softer and more delicate texture with only 7% fat added.

[0077] Table 3. Texture characteristics of Custard sauce in Example 2

[0078]

[0079] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing a starch-based fat substitute, characterized in that, The steps include: Starch and water were mixed to form a starch slurry, which was first cross-linked and then acetylated. After washing and drying, modified starch acetylated distarch phosphate was obtained. The obtained modified starch acetylated distarch phosphate was mixed with phosphate buffer to form a starch slurry. Enzymatic modification was carried out at a temperature below the gelatinization temperature. After the reaction was completed, the product was washed and dried to obtain a starch-based fat substitute.

2. The method according to claim 1, characterized in that, The starch is one or more of tapioca starch, corn starch, and glutinous corn starch.

3. The method according to claim 1, characterized in that, The starch milk concentration is 1%-40%, w / v, g / mL.

4. The method according to claim 1, characterized in that, The crosslinking agent used in the crosslinking modification is sodium trimetaphosphate, with an addition amount of 1%-3% (dry starch basis, w / w); the crosslinking modification time is 1-4 h, the temperature is 30-50 °C, and the pH is 9.0-12.0; the degree of starch crosslinking is 20%-40%.

5. The method according to claim 1, characterized in that, The acetyl content is 1.8%-2.2%; the acetylation modification conditions are temperature ≤33℃, pH 7.5-9.5, and reaction time 30-120min; the acetylation modification reagent is acetic anhydride, with an addition amount of 3%-6%, starch dry basis, w / w.

6. The method according to claim 1, characterized in that, The degree of hydrolysis of starch by enzymatic hydrolysis is <12%. The enzyme used for modification is α-amylase or maltose α-amylase, with an addition amount of 10-50 U / g starch. The modification time is 2-8 h, and the temperature is 30-70℃.

7. The starch-based fat substitute prepared by any one of claims 1-6.

8. The application of the starch-based fat substitute according to claim 7 in the food industry.

9. A custard sauce, characterized in that, The custard sauce is made from the following ingredients in the following percentages by weight: 4%-7% starch-based fat substitute as described in claim 7, 10%-20% white sugar, 5%-7% vegetable oil, 10%-20% skim milk, 2%-4% sodium caseinate, and water to make up the balance.

10. The method for preparing custard sauce according to claim 9, characterized in that, Includes the following steps: (1) Mix white sugar, starch-based fat substitute and water evenly to obtain excipient 1; (2) Mix sodium caseinate, skim milk, and vegetable oil evenly, and then mix with water to obtain excipient 2; (3) Mix auxiliary materials 1 and auxiliary materials 2, stir thoroughly to homogenize and heat in a water bath to 95°C, remove and cool to obtain the finished sauce.

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