Process for the preparation of a tomato sauce

Abstract

This invention relates to a preparation process for tomato sauce, belonging to the field of food processing technology. Addressing the problems of low cell wall degradation efficiency and severe damage to heat-sensitive components in existing technologies, this invention provides a preparation process: adjusting the pH of tomato pulp to 4.40-4.55; adding pectinase followed by cellulase at 40-50℃ for stepwise enzymatic hydrolysis; rapidly heating to 80-90℃ at a rate of 4.8-5.2℃ / min and maintaining this temperature for 100-120 seconds to inactivate the enzymes; adjusting the pH to 4.25-4.35; vacuum concentrating until the soluble solids content reaches 25-30%; and then homogenizing, filling, and sterilizing to obtain the finished product. This invention, through the synergistic effect of stepwise enzymatic hydrolysis and precise enzyme inactivation, significantly improves cell wall degradation efficiency and the retention rate of heat-sensitive components, while inhibiting the generation of cooked flavor, making it suitable for the industrial production of tomato sauce.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a process for preparing tomato sauce. Background Technology

[0002] Tomato sauce is a compound condiment made primarily from tomatoes, commonly used in home cooking, baked goods, and Western fast food. Currently, the processing of tomato sauce on the market typically includes steps such as crushing, concentrating, flavoring, and sterilization. Product quality mainly depends on the retention rate of lycopene and vitamin C, viscosity stability, and flavor purity.

[0003] Tomato cell walls are mainly composed of pectin, cellulose, and hemicellulose, which encapsulate the cell's pigments, flavor compounds, and nutrients. To achieve good fineness and flowability, current processing methods often employ high-temperature heating or high-shear mechanical crushing. However, high-temperature heating leads to lycopene isomerization and vitamin C thermal degradation, while also producing a cooked taste, affecting the product's color and flavor. While high-shear mechanical crushing can refine the tissue, it has low enzymatic efficiency in cell wall decomposition and consumes a lot of energy.

[0004] Enzymatic hydrolysis, due to its mild reaction conditions, has been used for cell wall degradation in fruit and vegetable processing. Studies have shown that enzymatic hydrolysis of tomato raw materials using pectinase or cellulase can effectively improve the extraction rate of lycopene. However, current technologies typically employ a single enzyme preparation or the simultaneous addition of two enzymes, without considering the different reaction conditions required by the two enzymes and the substrate decomposition sequence, resulting in low efficiency of synergistic cell wall degradation.

[0005] In the enzyme inactivation process following enzymatic hydrolysis, a high temperature of 85-95℃ is typically maintained for several minutes to kill enzyme activity. However, prolonged high-temperature treatment can reduce the content of heat-sensitive components, while incomplete enzyme inactivation results in enzyme residue, which continues to decompose pectin during subsequent storage, causing a decrease in product viscosity. Currently, there are no reports on the precise control of the heating rate and holding time for enzyme inactivation in tomato sauce processing.

[0006] Therefore, how to achieve efficient cell wall degradation while maximally preserving the heat-sensitive components and natural flavor of tomatoes is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, this invention provides a tomato sauce and its preparation process. This process involves stepwise enzymatic hydrolysis by first adding pectinase and then cellulase, combined with precise enzyme inactivation through rapid heating at 4.8~5.2℃ / min to 80~90℃ and holding at that temperature for 100~120 seconds. This achieves efficient cell wall degradation while significantly improving the retention rate of lycopene and vitamin C, and suppressing the development of a cooked flavor.

[0008] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a tomato sauce, the raw materials of which, by weight, include: 60-75 parts tomato pulp, 10-20 parts sugar, 0.3-1.0 parts organic acid, 1.5-2.5 parts thickener, 0.2-0.5 parts stabilizer, 0.4-1.1 parts flavoring agent, 0.05-0.10 parts preservative, and water to make up to 100 parts.

[0009] The tomato puree is made from fresh tomatoes through washing, crushing, pulping, and passing through a 40-mesh sieve, and its soluble solids content is 5-8%.

[0010] Preferably, the tomato pulp has a lycopene content ≥40mg / 100g. As the main raw material of this invention, tomato pulp provides lycopene, vitamin C, and natural flavor substances; a higher lycopene content helps to obtain a full-colored and nutritious final product in subsequent enzymatic hydrolysis and concentration processes.

[0011] The sugar is used to adjust the sweet-to-acid ratio of the product, balance the natural acidity of tomatoes, and enhance the product's gloss.

[0012] Preferably, the sugar is at least one of granulated sugar, high-fructose corn syrup, glucose, and fructose.

[0013] Preferably, the sugar is a mixture of granulated sugar and fructose syrup.

[0014] Preferably, the mass ratio of white sugar to fructose syrup is 8~15:2~6.

[0015] White sugar provides the main sweetness, while fructose syrup has high solubility and osmotic pressure, which can enhance the product's gloss and maintain sugar stability during vacuum concentration, preventing crystallization.

[0016] The organic acid is used to adjust the pH of the tomato pulp, providing a suitable acidic environment for the enzymatic hydrolysis reaction, and adjusting the pH back to the target range after enzyme inactivation, thus synergistically protecting the color stability of lycopene.

[0017] Preferably, the organic acid is citric acid.

[0018] Preferably, the organic acid is added in steps in the form of a 0.2-0.4% aqueous solution.

[0019] This invention uses citric acid as an organic acid, which has the following advantages: the ionization constant pKa of citric acid is 3.13, and the pH change pattern can be deduced during the stepwise acidification process, making it easy to control the pH precisely; at the same time, citric acid is an excellent metal ion chelating agent, which can chelate metal ions that catalyze oxidation reactions, thereby protecting lycopene and vitamin C.

[0020] The thickener imparts good viscosity and spreadability to the product, making the sauce smooth and delicate.

[0021] Preferably, the thickener is at least one of acetylated distarch adipate, hydroxypropyl distarch phosphate, and waxy corn starch.

[0022] Preferably, the thickener is acetylated distarch adipate.

[0023] Acetylated distarch adipate is a cross-linked esterified modified starch with excellent acid, heat, and shear resistance. It maintains viscosity stability during the rapid heating and homogenization processes of this invention, preventing degradation due to high temperature or high shear.

[0024] Preferably, the degree of substitution of the acetylated distarch adipate is between 0.05 and 0.10.

[0025] The stabilizer is used to prevent product stratification and improve suspension stability.

[0026] Preferably, the stabilizer is at least one of xanthan gum, sodium carboxymethyl cellulose, and guar gum.

[0027] Preferably, the stabilizer is xanthan gum.

[0028] Xanthan gum exhibits excellent suspension stability and shear thinning properties, and can produce a synergistic effect with acetylated distarch adipate. When the mass ratio of xanthan gum to acetylated distarch adipate is 1:5 to 1:10, the product's resistance to water separation is significantly improved.

[0029] The flavoring agent is used to enhance the complex flavor of the product and suppress any raw, grassy taste that may be present in the tomato raw material.

[0030] Preferably, the flavoring agent includes salt, onion powder, and garlic powder.

[0031] Preferably, the mass ratio of salt, onion powder and garlic powder is 1~2:0.3~0.8:0.1~0.3.

[0032] In addition to enhancing flavor, salt also has antibacterial properties and can work synergistically with potassium sorbate to extend the shelf life of products.

[0033] Preferably, the onion powder and / or garlic powder is a powder that has been microwave-dried and then pulverized, with a fineness ≥80 mesh.

[0034] The preservative is used to extend the product's shelf life and inhibit the growth of mold and yeast.

[0035] Preferably, the preservative is potassium sorbate, and the amount added is 0.05~0.10 parts; its antibacterial activity is best in an acidic environment.

[0036] Water is used as a solvent medium to adjust the soluble solids content of materials, ensuring uniform dispersion of each component and fluidity during processing.

[0037] Secondly, the present invention provides a process for preparing tomato sauce, comprising the following steps: (1) Ingredients and pH adjustment: Mix tomato pulp, water, sugar and flavoring agent evenly, and adjust the pH to 4.40~4.55 with organic acid to obtain pH adjusted material; (2) Stepwise enzymatic hydrolysis: The pH-adjusted material is placed at 40~50℃, pectinase is added first, and the reaction is allowed to stand for 15~25 minutes; then cellulase is added, and the reaction is allowed to stand for another 10~15 minutes to obtain the enzymatically hydrolyzed material; (3) Precise enzyme inactivation: The enzymatically hydrolyzed material is rapidly heated to 80-90℃ at a heating rate of 4.8-5.2℃ / min, and the temperature is maintained for 100-120 seconds to inactivate the enzyme, thus obtaining the enzyme-inactivated material; (4) pH adjustment and addition of excipients: Detect the pH of the material after enzyme inactivation. If the pH is > 4.35, adjust it to 4.25~4.35 with organic acid. Then add thickener, stabilizer and preservative, mix evenly and obtain the material after pH adjustment. (5) Vacuum concentration: The material after pH adjustment is concentrated until the soluble solids content reaches 25-30% to obtain the concentrated material; (6) Homogenization: The concentrated material is subjected to primary homogenization and secondary homogenization in sequence to obtain homogenized material; (7) Filling and sterilization: The homogenized material is filled and sterilized to obtain the finished product.

[0038] Preferably, in step (1), the stirring speed of the mixture is 40~60 rpm and the stirring time is 5~10 minutes, so that the mixture is fully dissolved and mixed evenly.

[0039] Preferably, in step (1), the organic acid is a citric acid solution; the pH adjustment is to slowly add a citric acid solution with a concentration of 0.2~0.4% at a dropping rate of 1~2 mL / kg / min to adjust the pH to the range of 4.40~4.55.

[0040] Preferably, in step (1), the pH adjustment is performed with continuous stirring at a speed of 40-60 rpm to avoid local over-acidity; after pH adjustment, stirring is continued for 2-3 minutes, and the pH value is retested to confirm that it is within the range of 4.40-4.55. This step provides the necessary acidic environment for the subsequent enzymatic hydrolysis reaction, ensuring that pectinase and cellulase exert their maximum catalytic activity under optimal pH conditions.

[0041] In step (2), the amount of pectinase and cellulase added is calculated based on the initial weight of the tomato pulp in step (1).

[0042] Preferably, in step (2), pectinase is added to the material after pH adjustment, and the amount added is 0.03~0.05% of the total weight of tomato pulp.

[0043] Preferably, in step (2), the pectinase is added slowly while maintaining a stirring speed of 30-50 rpm to ensure uniform dispersion; after the addition is complete, stirring is stopped and the mixture is allowed to stand at 40-50°C for 15-25 minutes.

[0044] Preferably, in step (2), after the reaction is allowed to stand for 15 to 25 minutes, cellulase is added, and the amount added is 0.01 to 0.02% of the total weight of the tomato pulp.

[0045] Preferably, in step (2), the cellulase is added slowly while maintaining a stirring speed of 20-40 rpm to ensure even dispersion. Then, stirring is stopped, and the mixture is allowed to stand for 10-15 minutes at a temperature of 40-50°C.

[0046] Preferably, in step (2), the pectinase has an activity of 10,000 to 30,000 U / g, and the cellulase has an activity of 5,000 to 15,000 U / g.

[0047] In this step, pectinase breaks down the pectin components in the tomato cell wall, exposing the cellulose. The subsequently added cellulase acts more efficiently on the cellulose, achieving synergistic degradation of the cell wall and releasing lycopene, flavor compounds, and nutrients trapped within the cells. This step-by-step addition method avoids the mutual inhibition that occurs when the two enzymes are added simultaneously, significantly improving the cell wall degradation efficiency.

[0048] Preferably, in step (3), the heating rate is achieved by adjusting the opening of the steam valve.

[0049] Preferably, in step (3), the enzymatically hydrolyzed material is heated by a jacketed steam heating method to rapidly heat to 80-90°C at a heating rate of 4.8-5.2°C / min; during the heating process, it is continuously stirred at 20-40 rpm to ensure that the material is heated evenly; after the material reaches 80-90°C, it is kept at a constant temperature for 100-120 seconds to completely inactivate pectinase and cellulase.

[0050] The coordinated control of heating rate and holding time in this step is one of the key innovations of this invention. Rapid heating at 4.8~5.2℃ / min can shorten the residence time of materials at 60~80℃, reducing the damage to heat-sensitive components; the parameter combination of holding the temperature at 80~90℃ for 100~120 seconds has been optimized and verified, which can ensure complete enzyme inactivation, avoid enzyme residue leading to a decrease in product viscosity, and also avoid prolonged high-temperature heating that destroys lycopene and vitamin C, while inhibiting the generation of cooked flavor.

[0051] Preferably, in step (4), if the pH of the enzyme-inactivated material is >4.35, a 0.2-0.4% citric acid solution is added dropwise to adjust the pH, which is then precisely controlled within the range of 4.25-4.35. During the pH adjustment process, the mixture is continuously stirred at 20-40 rpm, and the dropwise addition rate is controlled at 1-2 mL / kg / min. After the pH adjustment is completed, the mixture is stirred for 1-2 minutes, and the pH is retested to confirm that it is within the range of 4.25-4.35. Then, thickener, stabilizer and preservative are added, and the mixture is stirred at 20-40 rpm for 5-10 minutes until it is evenly mixed.

[0052] This step eliminates pH changes caused by heating during enzyme inactivation, stabilizing the product pH within the range of 4.25-4.35. pH adjustment offers the following advantages: firstly, it inhibits the growth of residual microorganisms, extending the product's shelf life; secondly, it provides a stable acidic environment for subsequent concentration processes; thirdly, it protects the color stability of lycopene; and fourthly, it provides the optimal pH conditions for potassium sorbate to inhibit bacterial growth. Adding thickeners, stabilizers, and preservatives after enzyme inactivation avoids the impact of high temperatures on the performance of thickeners and stabilizers, while the preservatives exhibit optimal antibacterial activity in the acidic environment after pH adjustment.

[0053] Preferably, in step (5), the material after pH adjustment is transferred into a vacuum concentrator and vacuum concentrated to a vacuum degree of 0.06~0.08 MPa and a temperature of 65~75℃. The mixture is continuously stirred at a stirring speed of 20~30 rpm until the soluble solids content reaches 25~30%. During the vacuum concentration process, the soluble solids content is sampled and tested regularly to avoid over-concentration or under-concentration.

[0054] This step uses vacuum concentration to evaporate moisture at a lower temperature, further reducing the loss of heat-sensitive components. After concentration to a soluble solids content of 25-30%, the product achieves the required viscosity and spreadability.

[0055] Preferably, in step (6), the concentrated material is homogenized by a homogenizer, with the pressure of the first homogenization being 15~25 MPa and the pressure of the second homogenization being 2~6 MPa.

[0056] The homogenization process in step (6) makes the product more delicate and smooth in texture, while also improving product stability and preventing stratification or water separation during storage. This step, used in conjunction with the thickener and stabilizer described in the first aspect, further enhances the product's resistance to water separation.

[0057] Preferably, in step (7), the homogenized material is hot-filled and sealed at 80~90℃, then kept at 90~95℃ for 10~20 minutes for secondary sterilization, and cooled to below 40℃ to obtain the finished product.

[0058] In this step, hot filling creates a vacuum, which helps extend the product's shelf life; secondary sterilization further ensures the product's microbial safety, while deactivating the pungent components in the flavoring agent, transforming them into a caramelized flavor that complements the natural acidity of tomatoes.

[0059] The beneficial effects of this invention are as follows: 1. This invention employs a combination of rapid heating and low-temperature short-time enzyme inactivation parameters, effectively preventing the thermal degradation of vitamin C and lycopene. Compared with high-temperature long-time enzyme inactivation, the retention rates of vitamin C and lycopene in this invention are significantly improved.

[0060] 2. This invention employs a stepwise addition method, first pectinase and then cellulase, to achieve synergistic degradation of the cell wall. Compared to simultaneous addition of enzymes or the addition of only a single enzyme, this invention can more thoroughly disrupt the cell wall structure, releasing lycopene, flavor substances, and nutrients encapsulated within the cells, thereby significantly increasing the product viscosity and making the sauce smoother and thicker.

[0061] 3. This invention employs rapid heating to inactivate enzymes, shortening the residence time of materials at 60-80℃ and avoiding Maillard reactions and sulfide formation caused by prolonged heating, thereby effectively suppressing the generation of a cooked flavor. Compared with slow heating or high-temperature long-term enzyme inactivation, the product of this invention has a pure tomato aroma, natural flavor, no unpleasant odors, and significantly improved sensory quality.

[0062] 4. The process parameters of the present invention can achieve good technical results within a wide range, are easy to operate, and have controllable parameters, making them suitable for large-scale production. Detailed Implementation

[0063] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0064] Unless otherwise specified, the experimental methods used in the examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0065] The tomato sauces prepared in the embodiments and comparative examples of the present invention were subjected to the following tests: 1. Vitamin C content: Determined by 2,6-dichlorophenolindophenol titration according to the method specified in GB 5009.86. The vitamin C retention rate is calculated using the following formula: Vitamin C retention rate (%) = (Product vitamin C content / Raw tomato pulp vitamin C content) × 100% 2. Viscosity: According to GB / T 10247, the viscosity was measured using a rotational viscometer at 25℃ and 50 r / min. The unit is mPa·s. Each batch of samples was measured 3 times, and the average value was taken.

[0066] 3. Soluble solids content: Determined according to GB / T 14215 "General Rules for Quality of Canned Tomato Sauce"; the concentration of the tomato sauce used is the soluble solids content in the tomato sauce.

[0067] 4. pH value: Measured using a pH meter at 25℃, in accordance with GB / T 10786. After calibration with standard buffer solutions (pH 4.00 and pH 6.86), insert the electrode into the sample and read the pH value after the reading stabilizes. Measure each batch of samples three times and take the average value.

[0068] 5. Lycopene content: Determined spectrophotometrically according to the method specified in NY / T 1651. Lycopene retention rate is calculated using the following formula: Lycopene retention rate (%) = (Lycopene content in the product / Lycopene content in the raw tomato pulp) × 100% 6. Sensory evaluation: The sensory attributes of the samples were described using a sensory profile in accordance with GB / T 39625 "Guidelines for Establishing Sensory Profiles in Sensory Analysis Methodology"; as shown in Table 1: Table 1 Sensory Evaluation

[0069] Ten evaluators scored each sample based on four dimensions: aroma, color, appearance, and taste, using a scale of 1-5 (1 being the worst and 5 the best). After evaluating each sample, evaluators rinsed their mouths with water and rested for two minutes to remove any lingering taste. The final score for each sample was the arithmetic mean of the scores from all ten evaluators. The overall sensory score was calculated using the following formula: Overall score (out of 10) = (Aroma score + Color score + Appearance score + Taste score) ÷ 4 × 2 Example 1 This embodiment provides a tomato sauce, which, by weight, consists of the following ingredients: 65 parts tomato pulp, 12 parts white sugar, 3 parts fructose syrup, 0.5 parts citric acid, 2.0 parts acetylated distarch adipate, 0.25 parts xanthan gum, 1.5 parts salt, 0.5 parts onion powder, 0.2 parts garlic powder, 0.08 parts potassium sorbate, and water to make up to 100 parts.

[0070] The preparation process is as follows: (1) Ingredients and pH adjustment: Add tomato puree, water, white sugar, fructose syrup, salt, onion powder, and garlic powder to the mixing container, and stir at 50 rpm for 8 minutes to mix evenly; slowly Add 0.3% citric acid solution dropwise at a rate of 1.5 mL / kg / min to adjust the pH to 4.50, stirring continuously at 50 rpm during the adjustment process; after adjustment, continue stirring for 2 minutes, and retest the pH value to confirm that it is within the range of 4.50±0.05.

[0071] (2) Stepwise enzymatic hydrolysis: The pH-adjusted material is heated to 45°C, pectinase (enzyme activity 20000U / g) is added at a rate of 0.04% of the total weight of tomato pulp, and the mixture is dispersed by stirring at 40 rpm and then stirring is stopped. The mixture is allowed to stand for 15 minutes. Then cellulase (enzyme activity 10000U / g) is added at a rate of 0.015% of the total weight of tomato pulp, and the mixture is dispersed by stirring at 30 rpm and then stirring is stopped. The mixture is allowed to stand for 10 minutes.

[0072] (3) Precise enzyme inactivation: The enzymatically hydrolyzed material is heated by jacketed steam heating at a rate of 5.0℃ / min to 84.5℃. During the heating process, the material is continuously stirred at 30 rpm. After reaching 84.5℃, the temperature is kept constant for 110 seconds to completely inactivate the enzyme.

[0073] (4) pH adjustment and addition of excipients: The pH of the material after enzyme inactivation was 4.38. 0.3% citric acid solution was added dropwise to adjust the pH to 4.30. During the adjustment process, the mixture was stirred continuously at 30 rpm and the dropwise addition rate was 1.5 mL / kg / min. After the adjustment was completed, the mixture was stirred for 1 minute and the pH value was retested to confirm that it was within the range of 4.30±0.03. Then, acetylated distarch adipate, xanthan gum and potassium sorbate were added and stirred at 30 rpm for 8 minutes to mix evenly.

[0074] (5) Vacuum concentration: Transfer the material into a vacuum concentration kettle, control the vacuum degree to 0.07 MPa and the temperature to 70℃, and continuously stir at 25 rpm until the soluble solids content reaches 28%. Take samples for testing periodically during the concentration process.

[0075] (6) Homogenization: The concentrated material is homogenized by a homogenizer. The pressure of the first homogenizer is 20 MPa and the pressure of the second homogenizer is 4 MPa.

[0076] (7) Filling and sterilization: The homogenized material is hot-filled and sealed at 88°C, and then sterilized again at 92°C for 18 minutes. After cooling to below 40°C, the finished product is obtained.

[0077] According to the test results, the product of Example 1 had a vitamin C retention rate of 88.6%, a soluble solids content of 28.2%, a pH value of 4.30, and a lycopene retention rate of 91.8%.

[0078] Comparison before and after processing: The viscosity of the tomato pulp before processing was 1635 mPa·s, and after processing it increased to 18500 mPa·s.

[0079] The sensory evaluation results were as follows: color 4.8 points, aroma 4.6 points, appearance 4.7 points, taste 4.5 points, and overall sensory score 9.2 points. After being left to stand for 24 hours, the appearance remained good and there was no steamed or boiled taste.

[0080] Example 2 The only difference between this embodiment and Embodiment 1 is that the process parameters use lower limit values, as detailed below: The raw material composition is the same as that in Example 1, by weight.

[0081] In step (1): the pH is adjusted to 4.40 using organic acids.

[0082] In step (2): the amount of pectinase added is 0.03% of the total weight of tomato pulp, and the reaction is allowed to stand for 15 minutes; the amount of cellulase added is 0.01% of the total weight of tomato pulp, and the reaction is allowed to stand for 10 minutes.

[0083] In step (3): the heating rate is 4.8℃ / min, the enzyme inactivation temperature is 80℃, and the temperature is maintained for 100 seconds.

[0084] In step (4): pH is adjusted back to 4.25 using organic acids.

[0085] In step (5): Concentrate until the soluble solids content reaches 25.2%.

[0086] The remaining steps are the same as in Example 1.

[0087] According to the test results, the product of Example 2 had a vitamin C retention rate of 84.2%, a soluble solids content of 25.2%, a pH value of 4.25, a lycopene retention rate of 87.5%, and a viscosity of 16800 mPa·s.

[0088] The sensory evaluation results are as follows: color 4.5 points, aroma 4.3 points, appearance 4.4 points, taste 4.2 points, and overall sensory score 8.5 points. After being left to stand for 24 hours, the appearance remained good and there was no steamed or boiled taste.

[0089] Example 3 The only difference between this embodiment and Embodiment 1 is that the process parameters use upper limits, as detailed below: The raw material composition is the same as that in Example 1, by weight.

[0090] In step (1): the pH is adjusted to 4.55 using an organic acid.

[0091] In step (2): the amount of pectinase added is 0.05% of the total weight of tomato pulp, and the reaction is allowed to stand for 25 minutes; the amount of cellulase added is 0.02% of the total weight of tomato pulp, and the reaction is allowed to stand for 15 minutes.

[0092] In step (3): the heating rate is 5.2℃ / min, the enzyme inactivation temperature is 90℃, and the temperature is maintained for 120 seconds.

[0093] In step (4): pH is adjusted back to 4.34 using organic acids.

[0094] In step (5): Concentrate until the soluble solids content reaches 29.7%.

[0095] The remaining steps are the same as in Example 1.

[0096] According to the test results, the product of Example 3 had a vitamin C retention rate of 86.8%, a soluble solids content of 29.7%, a pH value of 4.34, a lycopene retention rate of 90.2%, and a viscosity of 18200 mPa·s.

[0097] The sensory evaluation results were as follows: color 4.7, aroma 4.5, appearance 4.6, taste 4.4, and overall sensory score 8.9. After being left to stand for 24 hours, the appearance remained good and there was no steamed or boiled taste.

[0098] Example 4 The only difference between this embodiment and Example 1 is the substitution of components: the mixture of granulated sugar and fructose syrup is replaced with an equal amount of granulated sugar, while the remaining raw material composition and process parameters are the same as in Example 1.

[0099] The ingredients, by weight, are: 65 parts tomato puree, 15 parts white sugar, 0.5 parts citric acid, 2.0 parts acetylated distarch adipate, 0.25 parts xanthan gum, 1.5 parts salt, 0.5 parts onion powder, 0.2 parts garlic powder, 0.08 parts potassium sorbate, and water to make up to 100 parts.

[0100] According to the test results, the product of Example 4 had a vitamin C retention rate of 87.2%, a soluble solids content of 28.0%, a pH value of 4.30, a lycopene retention rate of 91.0%, and a viscosity of 18100 mPa·s.

[0101] The sensory evaluation results were as follows: color 4.6 points, aroma 4.5 points, appearance 4.6 points, taste 4.4 points, and overall sensory score 8.8 points. After being left to stand for 24 hours, the appearance remained good and there was no steamed or boiled taste.

[0102] Comparative Example 1 The only difference between this comparative example and Example 1 is step (2): pectinase and cellulase are added simultaneously, with the addition amounts being 0.04% and 0.015% of the total weight of the tomato pulp, respectively, and the total standing reaction time is 25 minutes. The remaining steps are the same as in Example 1.

[0103] The raw material composition is the same as that in Example 1, by weight.

[0104] According to the test results, the vitamin C retention rate of Comparative Example 1 product was 72.8%, the soluble solids content was 28.0%, the pH value was 4.30, the lycopene retention rate was 78.5%, and the viscosity was 15200 mPa·s.

[0105] The sensory evaluation results are as follows: color 4.0, aroma 3.8, appearance 3.9, taste 3.7, overall sensory score 7.5, no steaming or cooking taste.

[0106] Comparative Example 2 The only difference between this comparative example and Example 1 is step (2): only pectinase is added, the amount of which is 0.055% of the total weight of the tomato pulp, and the reaction is allowed to stand for 25 minutes. Cellulase is not added. The remaining steps are the same as in Example 1.

[0107] The raw material composition is the same as that in Example 1, by weight.

[0108] According to the test results, the vitamin C retention rate of Comparative Example 2 product was 68.9%, the soluble solids content was 27.9%, the pH value was 4.31, the lycopene retention rate was 75.4%, and the viscosity was 12800 mPa·s.

[0109] The sensory evaluation results are as follows: color 3.7 points, aroma 3.5 points, appearance 3.5 points, taste 3.4 points, overall sensory score 6.8 points, no steaming or boiling taste.

[0110] Comparative Example 3 The only difference between this comparative example and Example 1 is step (3): the heating rate is controlled at 1~2℃ / min, and the other steps are the same as in Example 1.

[0111] The raw material composition is the same as that in Example 1, by weight.

[0112] According to the test results, the vitamin C retention rate of Comparative Example 3 product was 65.4%, the soluble solids content was 28.1%, the pH value was 4.30, the lycopene retention rate was 70.7%, and the viscosity was 16800 mPa·s.

[0113] The sensory evaluation results are as follows: color 3.8 points, aroma 3.6 points, appearance 4.0 points, taste 3.7 points, overall sensory score 7.2 points, with a slight steamed or boiled taste.

[0114] Comparative Example 4 The only difference between this comparative example and Example 1 is step (3): the enzyme inactivation conditions are changed to 95°C for 5 minutes, and the remaining steps are the same as in Example 1.

[0115] The raw material composition is the same as that in Example 1, by weight.

[0116] According to the test results, the vitamin C retention rate of Comparative Example 4 product was 42.3%, the soluble solids content was 28.0%, the pH value was 4.30, the lycopene retention rate was 58.8%, and the viscosity was 14200 mPa·s.

[0117] The sensory evaluation results are as follows: color 3.2 points, aroma 3.0 points, appearance 3.5 points, taste 3.0 points, overall sensory score 6.0 points, with a distinct steamed or boiled flavor.

[0118] The test data for Examples 1-4 and Comparative Examples 1-4 are shown in Table 2: Table 2 Summary of Results

[0119] As can be seen from the data in Table 2: 1. The viscosity and sensory scores of Comparative Examples 1 and 2 were significantly lower than those of Example 1, indicating that the simultaneous addition of pectinase and cellulase or the addition of pectinase alone could not achieve the synergistic degradation effect of the two enzymes added in steps. The cell wall degradation efficiency and product quality were significantly inferior to those of the present invention.

[0120] 2. The vitamin C retention rate and lycopene retention rate of Comparative Examples 3 and 4 were significantly lower than those of Example 1, and a cooked taste appeared. This indicates that slow heating or high-temperature long-term enzyme inactivation will cause significant damage to heat-sensitive components and produce a cooked taste, which is not as effective as the combination of rapid heating and low-temperature short-time enzyme inactivation parameters of the present invention.

[0121] 3. All indicators of Comparative Examples 1-4 are significantly lower than those of Examples 2 and 3, indicating that the process parameters of the present invention can still achieve good results within a wide range, while the comparative examples have significantly reduced effects due to deviation from the process parameters of the present invention.

[0122] 4. Compared with Example 1, which uses a mixture of white sugar and fructose syrup, Example 4, which uses only white sugar, shows that all performance indicators are basically the same, but the color score is slightly lower. This indicates that the combination of white sugar and fructose syrup has a synergistic effect on the product's gloss, but a good overall effect can still be achieved after sugar substitution.

[0123] Comparative Examples 1-4 showed significantly lower levels of vitamin C retention, lycopene retention, viscosity, and sensory scores compared to the embodiments of the present invention, demonstrating that the present invention achieved unexpected technical effects through the synergistic effect of stepwise enzymatic hydrolysis, precise enzyme inactivation, and stepwise pH adjustment.

[0124] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A process for preparing tomato sauce, characterized in that, Includes the following steps: (1) Ingredients and pH adjustment: Mix tomato pulp, water, sugar and flavoring agent evenly, and adjust the pH to 4.40~4.55 with organic acid to obtain pH-adjusted material; (2) Stepwise enzymatic hydrolysis: The pH-adjusted material is placed at 40~50℃, pectinase is added first, and the reaction is allowed to stand for 15~25 minutes; then cellulase is added, and the reaction is allowed to stand for another 10~15 minutes to obtain the enzymatically hydrolyzed material; (3) Precise enzyme inactivation: The enzymatically hydrolyzed material is rapidly heated to 80-90℃ at a heating rate of 4.8-5.2℃ / min, and kept at a constant temperature for 100-120 seconds to inactivate the enzyme, thus obtaining the enzyme-inactivated material; (4) pH adjustment and addition of excipients: Detect the pH of the material after enzyme inactivation. If the pH is > 4.35, adjust it to 4.25~4.35 with organic acid. Then add thickener, stabilizer and preservative, mix evenly and obtain the material after pH adjustment. (5) Vacuum concentration: The material after pH adjustment is concentrated until the soluble solids content reaches 25-30% to obtain the concentrated material; (6) Homogenization: The concentrated material is subjected to primary homogenization and secondary homogenization in sequence to obtain homogenized material; (7) Filling and sterilization: The homogenized material is filled and sterilized to obtain the finished product.

2. The preparation process according to claim 1, characterized in that, By weight, the tomato paste comprises 60-75 parts, sugar comprises 10-20 parts, organic acid comprises 0.3-1.0 parts, thickener comprises 1.5-2.5 parts, stabilizer comprises 0.2-0.5 parts, flavoring agent comprises 0.4-1.1 parts, preservative comprises 0.05-0.10 parts, and water is made up to 100 parts.

3. The preparation process according to claim 1, characterized in that, The tomato paste has a soluble solids content of 5-8% and a lycopene content of ≥40mg / 100g; the flavoring agent includes salt, onion powder and garlic powder, with a mass ratio of 1-2:0.3-0.8:0.1-0.

3.

4. The preparation process according to claim 1, characterized in that, The organic acid mentioned in step (1) is citric acid, which is added dropwise in the form of a 0.2~0.4% aqueous solution to adjust the pH; the sugar is a mixture of granulated sugar and fructose syrup in a mass ratio of 8~15:2~6.

5. The preparation process according to claim 1, characterized in that, The amount of pectinase added in step (2) is 0.03~0.05% of the total weight of tomato pulp, and the enzyme activity is 10000~30000U / g; the amount of cellulase added is 0.01~0.02% of the total weight of tomato pulp, and the enzyme activity is 5000~15000U / g.

6. The preparation process according to claim 1, characterized in that, The organic acid mentioned in step (4) is a citric acid solution with a concentration of 0.2~0.4%. During the back-up process, the mixture is continuously stirred at 20~40 rpm, and the dropping speed is controlled at 1~2 mL / kg / min. After the pH has adjusted, add the thickener, stabilizer and preservative, and continue stirring at 20-40 rpm for 5-10 minutes.

7. The preparation process according to claim 1, characterized in that, The thickener comprises acetylated distarch adipate with a degree of substitution of 0.05 to 0.10; the stabilizer comprises xanthan gum with a mass ratio of xanthan gum to acetylated distarch adipate of 1:5 to 1:10; and the preservative is potassium sorbate.

8. The preparation process according to claim 1, characterized in that, In step (5), the vacuum concentration is performed at a vacuum level of 0.06~0.08 MPa and a temperature of 65~75℃. During the vacuum concentration process, the mixture is continuously stirred at 20~30 revolutions per minute.

9. The preparation process according to claim 1, characterized in that, In step (6), the pressure for the first homogenization is 15~25 MPa, and the pressure for the second homogenization is 2~6 MPa.

10. The preparation process according to claim 1, characterized in that, In step (7), the filling temperature is 80~90℃, and the sterilization treatment is 90~95℃ for 10~20 minutes.

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