Gel food containing a complex food colloid and a method for preparing the same

Abstract

The application relates to the technical field of food processing, and particularly discloses a gel food containing a compound food colloid and a preparation method thereof. The gel food containing the compound food colloid comprises the following raw materials in parts by weight: 25-35 parts of kappa carrageenan, 20-30 parts of enzymatic konjak gum, 12-20 parts of gellan gum, 8-15 parts of high-acyl gellan gum, 0.3-0.8 parts of a potassium ion source (calculated according to K), and 0.1-0.4 parts of a calcium ion source (calculated according to Ca). + 2+ The application uses four kinds of colloid, namely kappa carrageenan, enzymatic konjak gum, gellan gum and high-acyl gellan gum, to compound the konjak gum, so that the konjak gum molecular chain length is moderate and can be uniformly filled in the gel network to form effective physical entanglement; in combination with pH buffering and calcium ion complexing regulation of trisodium citrate, the gel structure stability under an acidic condition after high-temperature sterilization can be maintained, and the decrease of the gel strength and water holding capacity can be effectively inhibited.​

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of food processing, more particularly, it relates to a gel food containing a compound food colloid and a preparation method thereof. BACKGROUND

[0002] The compound food colloid technology is one of the core technical means in the field of gel food processing. The compound system of kappa carrageenan and konjac gum is one of the most widely used thermal irreversible gel systems. The two can form a three-dimensional gel network through intermolecular hydrogen bonding in the presence of potassium ions, and the obtained gel has good elasticity and water holding capacity, and has been widely used in the industrial production of gel foods such as meat products, jelly, and biomimetic food.

[0003] Most of the existing gel foods use the way of introducing gellan gum or kolloidgum into the compound system of kappa carrageenan and konjac gum for ternary compounding to improve the gel performance. However, the direct compounding of gellan gum and konjac gum shows antagonistic effect, which is not conducive to the formation of gel; neither kolloidgum alone nor calcium ions alone can effectively reduce the deterioration of the mechanical properties of the mixed gel of kappa carrageenan and konjac gum after heat treatment. SUMMARY

[0004] In order to solve the problem that the existing gel food cannot effectively reduce the deterioration of the mechanical properties of the mixed gel of kappa carrageenan and konjac gum after heat treatment, the present application provides a gel food containing a compound food colloid and a preparation method thereof.

[0005] The present application provides a gel food containing a compound food colloid and a preparation method thereof, which adopts the following technical scheme: In a first aspect, the present application provides a gel food containing a compound food colloid, which adopts the following technical scheme: A gel food containing a compound food colloid, comprising the following raw materials by weight: 25-35 parts of kappa carrageenan, 20-30 parts of enzymatic konjac gum, 12-20 parts of gellan gum, 8-15 parts of high-acyl kolloidgum, 0.3-0.8 parts of potassium ion source, 0.1-0.4 parts of calcium ion source, 0.1-0.3 parts of trisodium citrate, and the weight average molecular weight of the enzymatic konjac gum is 100-500 thousand Da. + 2+

[0006] ​​By employing the above technical solution, and using a compound of four colloids—κ-carrageenan, enzymatically hydrolyzed konjac gum, kelden gum, and high-acyl gellan gum—κ-carrageenan forms a double-helix network as the gel backbone under the action of potassium ions. The molecular chains of enzymatically hydrolyzed konjac gum interweave within the backbone, providing elasticity and water retention. Kelden gum forms a thermally irreversible triple-helix network under heating conditions, enhancing the gel's thermal stability. High-acyl gellan gum forms an ionic cross-linking network under the action of calcium ions, improving the gel's acid stability. The four colloids form an interwoven complex under the dual induction of potassium and calcium ions. A gel network is constructed; simultaneously, the weight-average molecular weight of enzymatically hydrolyzed konjac gum is controlled within the range of 100,000 to 500,000 Da, ensuring that the konjac gum molecular chain length is moderate and can uniformly fill the gel network to form effective physical entanglement; combined with the pH buffering and calcium ion complexation regulation effects of trisodium citrate, the gel structure remains stable even after high-temperature sterilization under acidic conditions, and the decrease in gel strength and water holding capacity is effectively inhibited. This solves the problem that existing gel foods cannot effectively reduce the deterioration of mechanical properties of κ-carrageenan and konjac gum mixed gels after heat treatment.

[0007] Preferably, the enzymatically hydrolyzed konjac gum is prepared by the following method: Konjac gum was dissolved in deionized water to prepare a solution with a mass fraction of 2% to 5%, the pH was adjusted to 5 to 6, β-mannanase was added, and enzymatic hydrolysis was carried out at 45 to 55°C for 60 to 120 minutes. After enzymatic hydrolysis is complete, the hydrolysate is cooled to 4–10°C and the pH is adjusted to 3–3.5 to terminate the enzymatic hydrolysis reaction. The treated enzymatic hydrolysate was filtered in series using ceramic membranes with molecular weight cutoffs of 100,000 Da and 500,000 Da, and the fractions with a weight average molecular weight of 100,000 to 500,000 Da were collected.

[0008] By adopting the above technical solution, after the enzymatic hydrolysis is completed, the β-mannanase is simultaneously inhibited by low temperature and low pH through cooling and pH adjustment, thus terminating the enzymatic hydrolysis reaction. This avoids further thermal degradation of konjac gum during the heating inactivation process, allowing the molecular weight distribution of the enzymatic hydrolysis product to be precisely fixed at the end of the hydrolysis. Combined with tandem filtration using ceramic membranes with molecular weight cutoffs of 100,000 Da and 500,000 Da, the konjac gum molecular chain length is ensured to be moderate, enabling the formation of a uniform filling structure in the gel network. This results in an enzymatic hydrolyzed konjac gum component with a concentrated molecular weight distribution and fully exposed active sites, making the intermolecular crosslinking between colloids in the subsequent quaternary compound system more complete and uniform.

[0009] Preferably, the coleslaw is a pre-hydrated coleslaw, which is prepared by the following method: Disperse guar gum in deionized water to prepare a suspension with a mass fraction of 1% to 3%, and hydrate it by stirring at 40 to 45°C for 60 to 90 minutes. Cool the suspension to 25-30°C, add 0.05-0.1 parts of the total amount of trisodium citrate, and stir until homogeneous.

[0010] By adopting the above technical solution, when guar gum is hydrated at 40 to 45°C, the molecular chains are fully extended but have not yet formed a triple helix structure. At this time, the hydroxyl groups on the molecular chains are fully exposed to the active state to be cross-linked. After pre-hydration treatment, it is mixed with enzymatically hydrolyzed konjac gum. When the temperature is subsequently raised to 90 to 95°C, it can directly transform from the extended state to a triple helix structure, reducing the possibility of physical entanglement competition with konjac gum molecular chains and effectively alleviating the antagonistic effect between guar gum and konjac gum. The addition of trisodium citrate forms a weak complex with calcium ions in the subsequent process, which acts as a calcium ion buffer and is conducive to the time-sequential release regulation of calcium ions in the stepwise cross-linking process.

[0011] Preferably, the calcium ion source is a sodium alginate and chitosan composite microcapsule encapsulating calcium lactate.

[0012] By adopting the above technical solution, calcium ions are encapsulated in microcapsules and remain intact without being released during the low-temperature stage of stepwise cross-linking, thus avoiding the interference of calcium ions in the formation of the κ-carrageenan double helix network due to premature participation in cross-linking. When the temperature is raised to above 65°C, the microcapsule wall material swells and ruptures to release calcium ions, enabling the ionic cross-linking network of the high-acyl gellan gum and the κ-carrageenan double helix network to form synchronously and interpenetrate with each other, thereby achieving the orderly construction of the gel network and improving the structural stability of the gel after high-temperature sterilization.

[0013] Preferably, the composite microcapsules are prepared by the following method: Calcium lactate is dissolved in deionized water to prepare a calcium lactate solution with a mass fraction of 5% to 10%. Sodium alginate was dissolved in deionized water to prepare a sodium alginate solution with a mass fraction of 1% to 2%. Chitosan was dissolved in a 1% acetic acid solution to prepare a chitosan solution with a mass fraction of 0.5% to 1%. Calcium lactate solution and sodium alginate solution are mixed at a volume ratio of 1:2 to 3, and sprayed into chitosan solution using a high-voltage electrostatic spraying device. The spraying voltage is 5 to 15 kV, the propulsion speed is 5 to 20 mL / h, the nozzle orifice diameter is 0.2 to 0.5 mm, and the receiving distance is 10 to 20 cm. Collect the microcapsules, wash them, and freeze-dry them at -40 to -50°C for 24 to 48 hours.

[0014] By adopting the above technical solution, calcium lactate solution and sodium alginate solution are mixed and sprayed into chitosan solution through a high-voltage electrostatic spraying device. Sodium alginate and chitosan undergo electrostatic complexation on the droplet surface to form a polyelectrolyte complex wall material, encapsulating calcium lactate inside to form microcapsules. The coordinated control of spray voltage, propulsion speed, nozzle aperture and receiving distance ensures uniform microcapsule particle size distribution and intact wall material structure. Chitosan, using acetic acid solution as a solvent, can be fully dissolved under acidic conditions and maintain the extended state of molecular chains, which is conducive to sufficient electrostatic complexation with sodium alginate. Freeze-drying removes the moisture inside the microcapsules without damaging the wall material structure, allowing the microcapsules to remain intact during subsequent compounding. When the temperature rises above 65°C, the wall material swells and ruptures, releasing calcium ions, realizing the sequential release of calcium ions in the stepwise cross-linking process.

[0015] Preferably, the potassium ion source is potassium chloride.

[0016] By adopting the above technical solution, potassium chloride can fully dissociate potassium ions during the hydration process, continuously inducing κ-carrageenan to form a double helix network in the first and second steps of the stepwise crosslinking, thus ensuring the full crosslinking of the rigid gel skeleton.

[0017] Secondly, this application provides a method for preparing a gel food containing a compounded food colloid, using the following technical solution: A method for preparing a gel food containing a compound food colloid, comprising the following steps: S1. According to the weight parts, mix κ-carrageenan, enzymatically hydrolyzed konjac gum, guar gum, high acyl gellan gum and the remaining trisodium citrate with water, and hydrate at 60-70℃ to obtain a compound colloidal solution. S2. Add potassium ion source and calcium ion source to the compound colloidal solution, and perform stepwise cross-linking and gelation by sequentially holding at a first temperature, a second temperature and a third temperature. S3. After stepwise cross-linking and gelation, the mixture is cooled and molded to complete the preparation.

[0018] By adopting the above technical solution, the molecular chains of each colloidal component are fully extended under hydration conditions of 60 to 70°C, laying the molecular foundation for subsequent crosslinking. Stepwise crosslinking gelation is achieved by sequentially holding the gel at the first, second, and third temperatures, allowing different colloids to complete their respective crosslinking events in different temperature ranges. This realizes an orderly gelation process from the pre-formation of a flexible network, the synchronous construction of dual networks, to the locking of a thermally irreversible network, ultimately forming a rigid-flexible interpenetrating composite gel network, which maintains the complete network structure after high-temperature sterilization.

[0019] Preferably, in step S1, the amount of water added is such that the total solids concentration of the system is 0.5% to 1.5%.

[0020] By adopting the above technical solution, when the total solids concentration of the system is controlled within the range of 0.5% to 1.5%, each colloidal molecular chain has sufficient space to move in the solution to achieve full extension and uniform mixing. At the same time, this concentration range can ensure the effective collision frequency and cross-linking density between molecular chains in the subsequent stepwise cross-linking process, so that the formed gel network has sufficient cross-linking strength, while avoiding the network structure becoming too dense and brittle due to excessive solids concentration.

[0021] Preferably, in step S2, the stepwise crosslinking gelation includes the following steps: Cool the compound colloidal solution to a first temperature of 50-55℃, add a potassium ion source and sodium alginate and chitosan composite microcapsules loaded with calcium lactate, and stir for 10-15 minutes. Heat to a second temperature of 65-70℃, and maintain this temperature while stirring for 20-30 minutes. Continue heating to a third temperature of 90-95℃ and hold for 15-20 minutes.

[0022] By adopting the above technical solution, in the first temperature stage of 50 to 55°C, high-acyl gellan gum forms a preliminary weak cross-linked network, while κ-carrageenan remains in solution. In the second temperature stage of 65 to 70°C, microcapsules rupture and release calcium ions, high-acyl gellan gum forms a complete ionic cross-linked network, and κ-carrageenan forms a double helix network under the action of potassium ions, interpenetrating with the gellan gum network. Enzymatic hydrolysis of konjac gum molecular chains connects to the two networks through hydrogen bonds. In the third temperature stage of 90 to 95°C, kerlan gum forms a thermally irreversible triple helix network, which entangles with the carrageenan double helix network, completing the overall gel solidification. The three temperature stages are sequentially connected, transforming the gel network from disordered entanglement to an ordered interpenetrating structure, thus improving the structural stability of the gel after high-temperature sterilization.

[0023] Preferably, in step S3, the cooling and molding temperature is 4-10°C, and the time is 2-4 hours.

[0024] By adopting the above technical solution, the gel network is cooled and solidified at 4 to 10°C for 2 to 4 hours, which allows the κ-carrageenan double helix structure to be further arranged and aggregated in an orderly manner within this temperature range. The gellan gum ion crosslinking network also tends to be stable under low temperature conditions, ultimately forming a gel product with a complete structure.

[0025] In summary, this application has the following beneficial effects: 1. This application uses a compound of four colloids: κ-carrageenan, enzymatically hydrolyzed konjac gum, kerlan gum, and high-acyl gellan gum. κ-carrageenan forms a double-helix network as the gel backbone under the action of potassium ions; the molecular chains of enzymatically hydrolyzed konjac gum interweave within the backbone, providing elasticity and water retention; kerlan gum forms a thermally irreversible triple-helix network under heating conditions, enhancing the gel's thermal stability; and high-acyl gellan gum forms an ionic cross-linking network under the action of calcium ions, improving the gel's acid stability. The four colloids form an interwoven compound gel under the dual induction of potassium and calcium ions. The network; simultaneously, the weight-average molecular weight of enzymatically hydrolyzed konjac gum is controlled within the range of 100,000 to 500,000 Da, ensuring that the konjac gum molecular chain length is moderate and can uniformly fill the gel network to form effective physical entanglement; combined with the pH buffering and calcium ion complexation regulation of trisodium citrate, the gel structure remains stable even after high-temperature sterilization under acidic conditions, and the decrease in gel strength and water holding capacity is effectively inhibited. This solves the problem that existing gel foods cannot effectively reduce the deterioration of mechanical properties of κ-carrageenan and konjac gum mixed gels after heat treatment.

[0026] 2. In this application, the enzymatic hydrolysis reaction is preferably terminated by cooling combined with pH adjustment. This causes β-mannanase to be inactivated by the dual inhibition of low temperature and low pH, avoiding further thermal degradation of konjac gum during the heating inactivation process. This allows the molecular weight distribution of the enzymatic hydrolysis products to be precisely fixed at the end of the enzymatic hydrolysis. Combined with tandem filtration using ceramic membranes with specific molecular weight cutoffs, the weight-average molecular weight of the enzymatic hydrolysis products is precisely controlled within a suitable range. This ensures that the konjac gum molecular chain length is moderate, enabling the formation of a uniform filling structure in the gel network. This allows for more complete and uniform intermolecular crosslinking between the colloids in the subsequent quaternary compound system.

[0027] 3. In this application, sodium alginate and chitosan composite microcapsules encapsulating calcium lactate are preferably used as the calcium ion source. After the calcium ions are encapsulated in the form of microcapsules, they remain intact and are not released during the low-temperature stage of stepwise cross-linking, thus avoiding the interference of calcium ions on the formation of the κ-carrageenan double helix network due to premature participation in cross-linking. After heating, the microcapsule wall material swells and ruptures to release calcium ions, so that the ionic cross-linking network of the high-acyl gellan gum and the κ-carrageenan double helix network can be formed synchronously and interpenetrate with each other, realizing the orderly construction of the gel network, thereby improving the structural stability of the gel after high-temperature sterilization.

[0028] 4. The method of this application completes the pre-formation of high acyl gellan gum network, the synchronous construction of κ-carrageenan double helix network and gellan gum network at different temperature stages in sequence, and the locking of the thermoirreversible gel network, so that the gel network is transformed from disordered entanglement to ordered interpenetrating structure, and finally forms a rigid-flexible interpenetrating composite gel network, which effectively improves the structural stability and water retention performance of gel after high temperature sterilization. Attached Figure Description

[0029] Figure 1 This is a flowchart of a method for preparing a gel food containing compound food colloids provided in this application; Figure 2 This is a graph showing the results of the gel strength test provided in this application; Figure 3 This is a diagram showing the test results of water-holding capacity provided in this application; Figure 4 This is a graph showing the test results of gel strength determination under acidic conditions provided in this application; Figure 5 This is a graph showing the results of the gel transparency test provided in this application. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0031] Technical Concept: While the κ-carrageenan and konjac gum blend can form a thermally irreversible gel network, its gel strength and water-holding capacity significantly decrease after high-temperature sterilization under acidic conditions. This is mainly because κ-carrageenan is prone to acid degradation in acidic environments, causing its double helix structure to fail to recover effectively after unwinding at high temperatures. Simultaneously, konjac gum undergoes molecular chain contraction and degradation under acidic conditions, weakening its hydrogen bond cross-linking with carrageenan. Furthermore, the increased thermal motion of water molecules within the gel network during high-temperature sterilization, coupled with a lack of sufficient thermal stability, makes the network structure prone to irreversible relaxation, leading to decreased gel strength and water loss.

[0032] Based on this, this application discovered that four colloids—κ-carrageenan, enzymatically hydrolyzed konjac gum, kerogen gum, and high-acyl gellan gum—can form an interpenetrating complex gel network under the dual induction of potassium and calcium ions. The double helix network of κ-carrageenan serves as a rigid framework, the short-chain molecules of enzymatically hydrolyzed konjac gum provide elasticity and water retention, the thermally irreversible triple helix network of kerogen gum acts as a high-temperature locked structure, and the ionic crosslinking network of high-acyl gellan gum provides acid stability. Furthermore, by controlling the molecular weight of the enzymatically hydrolyzed konjac gum within a suitable range and employing a stepwise crosslinking process to sequentially crosslink each colloid at different temperature stages, an ordered interpenetrating double network structure is ultimately formed, effectively inhibiting structural deterioration of the gel after high-temperature sterilization under acidic conditions.

[0033] Unless otherwise specified, all experimental methods used below are conventional methods. All materials, reagents, methods, and instruments used, unless otherwise specified, are conventional materials, reagents, methods, and instruments in this field, which can be obtained commercially or prepared according to literature methods by those skilled in the art.

[0034] Preparation Example 1: Preparation of enzymatically hydrolyzed konjac gum 100g of konjac gum was dissolved in deionized water to prepare a 3.5% (w / w) solution. The pH was adjusted to 5.5 with citric acid, and 6.5 U / g of β-mannanase was added. The solution was enzymatically hydrolyzed in a 50°C water bath for 90 minutes with a stirring speed of 200 rpm. After hydrolysis, the hydrolysate was cooled to 7°C in an ice-water bath, and the pH was adjusted to 3.25 with citric acid. The hydrolysis was terminated by stirring for 8 minutes. The treated hydrolysate was then filtered in series using ceramic membranes with molecular weight cutoffs of 100,000 Da and 500,000 Da. The transmembrane pressure was 0.2 MPa, the temperature was 30°C, and the cross-flow velocity was 3 m / s. The fraction that permeated through the 100,000 Da membrane and was retained by the 500,000 Da membrane was collected; this fraction, with a weight-average molecular weight of 300,000 Da, is the hydrolyzed konjac gum fraction.

[0035] Preparation Example 2: Preparation of sodium alginate and chitosan composite microcapsules loaded with calcium lactate Dissolve 100g of calcium lactate in deionized water to prepare a 7.5% calcium lactate solution. This is done by weighing 100g of calcium lactate, adding water to 1333mL, and stirring until completely dissolved.

[0036] Dissolve 15g of sodium alginate in deionized water to prepare a 1.5% sodium alginate solution. Specifically, weigh 15g of sodium alginate and add water to 1000mL. Stir at 500rpm in a 50℃ water bath until completely dissolved. Filter through a 0.45μm microporous membrane and allow the filtrate to stand at 25℃ for 1.5 hours to remove bubbles.

[0037] Dissolve 7.5g of chitosan in 1000mL of 1% acetic acid solution and stir at 500rpm at 25℃ until completely dissolved to prepare a 0.75% chitosan solution. Filter the solution through a 0.45μm microporous membrane and allow the filtrate to stand at 25℃ for 1.5 hours to remove bubbles.

[0038] Calcium lactate solution and sodium alginate solution were mixed at a volume ratio of 1:2.5 and stirred until homogeneous to obtain a core-wall material mixture. The mixture was then sprayed into a chitosan solution using a high-voltage electrostatic spraying device. The spraying voltage was 10 kV, the propulsion speed was 12.5 mL / h, the nozzle orifice diameter was 0.35 mm, and the receiving distance was 15 cm. The mixture formed microcapsules in the chitosan solution through electrostatic complexation between sodium alginate and chitosan.

[0039] The microcapsules were collected, washed three times with deionized water, and freeze-dried at -45°C for 36 hours to obtain sodium alginate and chitosan composite microcapsules loaded with calcium lactate.

[0040] To better understand the above technical solutions, the technical solutions of the present invention will be clearly and completely described below in conjunction with embodiments.

[0041] Please see the appendix Figure 1The following is a further description with reference to the embodiments: Example 1: A gel food containing compound food colloids, comprising the following raw materials in parts by weight: 30 parts κ-carrageenan, 25 parts enzymatically hydrolyzed konjac gum, 16 parts guar gum, 11.5 parts high-acyl gellan gum, and a potassium ion source (K... + 0.55 parts total, calcium ion source in the form of Ca 2+ 0.25 parts of total content, 0.2 parts of trisodium citrate. The weight-average molecular weight of the enzymatically hydrolyzed konjac gum is 300,000 Da.

[0042] The enzymatic hydrolysate of konjac gum was prepared by the following method: Konjac gum was dissolved in deionized water to prepare a 3.5% (w / w) solution, the pH was adjusted to 5.5, 6.5 U / g β-mannanase was added, and the solution was enzymatically hydrolyzed at 50°C for 90 minutes. After the enzymatic hydrolysis was completed, the hydrolysate was cooled to 7°C and the pH was adjusted to 3.25 to terminate the enzymatic hydrolysis reaction. The treated hydrolysate was filtered in series using ceramic membranes with molecular weight cutoffs of 100,000 Da and 500,000 Da, and the fraction with a weight average molecular weight of 300,000 Da was collected.

[0043] The gellan gum is a pre-hydrated gellan gum prepared by the following method: gellan gum is dispersed in deionized water to prepare a suspension with a mass fraction of 2%, and hydrated by stirring at 42.5°C for 75 minutes; the suspension is cooled to 27.5°C, 0.075 parts of trisodium citrate are added, and the mixture is stirred evenly.

[0044] The calcium ion source was a sodium alginate and chitosan composite microcapsule loaded with calcium lactate, prepared by the following method: calcium lactate was dissolved in deionized water to prepare a 7.5% (w / w) calcium lactate solution; sodium alginate was dissolved in deionized water to prepare a 1.5% (w / w) sodium alginate solution; chitosan was dissolved in a 1% (w / w) acetic acid solution to prepare a 0.75% (w / w) chitosan solution; the calcium lactate solution and sodium alginate solution were mixed at a volume ratio of 1:2.5, and sprayed into the chitosan solution using a high-voltage electrostatic spraying device with a spray voltage of 10kV, a propulsion speed of 12.5mL / h, a nozzle orifice diameter of 0.35mm, and a receiving distance of 15cm; the microcapsules were collected, washed, and freeze-dried at -45℃ for 36 hours.

[0045] The potassium ion source is potassium chloride.

[0046] A method for preparing a gel food containing a compound food colloid includes the following steps: 30 parts by weight of κ-carrageenan, 25 parts by weight of enzymatically hydrolyzed konjac gum with a weight-average molecular weight of 300,000 Da, 16 parts by weight of guar gum, 11.5 parts by weight of high-acyl gellan gum, and 0.125 parts by weight of trisodium citrate are mixed with water, the amount of water added being such that the total solids concentration of the system is 1%, and the mixture is hydrated at 65°C to obtain a compound colloidal solution; potassium chloride is added to the compound colloidal solution, wherein potassium ions are expressed as K+. +The amount was calculated to be 0.55 parts, and sodium alginate and chitosan composite microcapsules containing calcium lactate were added, wherein the calcium ions were in the form of Ca. 2+ Counting as 0.25 parts, the compound colloidal solution was cooled to 52.5℃ and stirred for 12.5 minutes, then heated to 67.5℃ and stirred for 25 minutes. The temperature was then increased to 92.5℃ and held for 17.5 minutes to carry out stepwise cross-linking and gelation. After stepwise cross-linking and gelation, the solution was cooled at 7℃ for 3 hours to complete the preparation.

[0047] Example 2: This example differs from Example 1 above in that: In gelled foods, κ-carrageenan comprised 35 parts, enzymatically hydrolyzed konjac gum 30 parts, guar gum 20 parts, high-acyl gellan gum 15 parts, and potassium ion source K + Counted as 0.8 parts, calcium ion source as Ca 2+ The weight-average molecular weight of the enzymatically hydrolyzed konjac gum was 500,000 Da, with 0.4 parts of trisodium citrate and 0.3 parts of sodium citrate.

[0048] In the preparation method of enzymatic hydrolysis of konjac gum, the mass fraction of konjac gum solution is 5%, the pH is 6, the amount of β-mannanase added is 10 U / g konjac gum, the enzymatic hydrolysis temperature is 55℃, and the enzymatic hydrolysis time is 120 minutes. After the enzymatic hydrolysis is completed, the enzymatic hydrolysate is cooled to 10℃ and the pH is adjusted to 3.5 to terminate the enzymatic hydrolysis reaction.

[0049] In the prehydration treatment of guar gum, the mass fraction of the suspension is 3%, the hydration temperature is 45℃, and the hydration time is 90 minutes; the suspension is cooled to 30℃, and 0.1 parts of trisodium citrate are added.

[0050] In the preparation of microcapsules, the mass fraction of calcium lactate solution was 10%, the mass fraction of sodium alginate solution was 2%, the mass fraction of chitosan solution was 1%, the volume ratio of calcium lactate solution to sodium alginate solution was 1:3, the spray voltage was 15kV, the propulsion speed was 20mL / h, the nozzle orifice diameter was 0.5mm, the receiving distance was 20cm, the freeze-drying temperature was -40℃, and the freeze-drying time was 48 hours.

[0051] In the preparation method, 35 parts of κ-carrageenan, 30 parts of enzymatically hydrolyzed konjac gum with a weight-average molecular weight of 500,000 Da, 20 parts of guar gum, 15 parts of high-acyl gellan gum, and 0.2 parts of trisodium citrate are mixed with water to make the total solids concentration of the system 1.5%, and hydrated at 70℃; potassium chloride is added to the compound colloidal solution, wherein potassium ions are in the form of K+. + The amount was calculated to be 0.8 parts, and sodium alginate and chitosan composite microcapsules containing calcium lactate were added, wherein the calcium ions were in the form of Ca. 2+Count 0.4 parts, cool the compound colloidal solution to 55℃, stir for 15 minutes, heat to 70℃, keep warm and stir for 30 minutes, continue to heat to 95℃, keep warm for 20 minutes; the cooling temperature for molding is 10℃, and the time is 4 hours.

[0052] Example 3: This example differs from Example 1 above in that: In gelled foods, κ-carrageenan comprised 25 parts, enzymatically hydrolyzed konjac gum 20 parts, guarana gum 12 parts, high-acyl gellan gum 8 parts, and potassium ion source K + Counted as 0.3 parts, calcium ion source as Ca 2+ The weight-average molecular weight of the enzymatically hydrolyzed konjac gum is 100,000 Da, and the trisodium citrate is 0.1 parts.

[0053] In the preparation method of enzymatic hydrolysis of konjac gum, the mass fraction of konjac gum solution is 2%, the pH is 5, the amount of β-mannanase added is 3 U / g konjac gum, the enzymatic hydrolysis temperature is 45℃, and the enzymatic hydrolysis time is 60 minutes. After the enzymatic hydrolysis is completed, the enzymatic hydrolysate is cooled to 4℃ and the pH is adjusted to 3 to terminate the enzymatic hydrolysis reaction.

[0054] In the prehydration treatment of guar gum, the mass fraction of the suspension is 1%, the hydration temperature is 40℃, and the hydration time is 60 minutes; the suspension is cooled to 25℃, and 0.05 parts of trisodium citrate are added.

[0055] In the preparation of microcapsules, the mass fraction of calcium lactate solution was 5%, the mass fraction of sodium alginate solution was 1%, the mass fraction of chitosan solution was 0.5%, the volume ratio of calcium lactate solution to sodium alginate solution was 1:2, the spray voltage was 5kV, the propulsion speed was 5mL / h, the nozzle orifice diameter was 0.2mm, the receiving distance was 10cm, the freeze-drying temperature was -50℃, and the freeze-drying time was 24 hours.

[0056] In the preparation method, 25 parts of κ-carrageenan, 20 parts of enzymatically hydrolyzed konjac gum with a weight-average molecular weight of 100,000 Da, 12 parts of guar gum, 8 parts of high-acyl gellan gum, and 0.05 parts of trisodium citrate are mixed with water. The amount of water added is such that the total solids concentration of the system is 0.5%, and the mixture is hydrated at 60℃. Potassium chloride is added to the compound colloidal solution, wherein potassium ions are added in the form of K+. + Calculated as 0.3 parts, and added sodium alginate and chitosan composite microcapsules loaded with calcium lactate, wherein calcium ions are in the form of Ca 2+ Calculate 0.1 parts, cool the compound colloidal solution to 50℃, stir for 10 minutes, raise the temperature to 65℃, keep it at this temperature and stir for 20 minutes, continue to raise the temperature to 90℃, and keep it at this temperature for 15 minutes; the cooling and solidification temperature is 4℃, and the time is 2 hours. Comparative Example 1: This comparative example differs from Example 1 above in that: Enzymatically hydrolyzed konjac gum was replaced with unhydrolyzed natural konjac gum, which has a weight-average molecular weight of 800,000 Da.

[0057] Comparative Example 2: This comparative example differs from Example 1 above in that: The weight-average molecular weight of the enzymatically hydrolyzed konjac gum is 30,000 Da. In the preparation method of enzymatically hydrolyzed konjac gum, the enzymatic hydrolysis time is 180 minutes, and the component with a weight-average molecular weight of 30,000 Da is collected.

[0058] Comparative Example 3: This comparative example differs from Example 1 above in that: The calcium ion source is calcium lactate powder, rather than sodium alginate and chitosan composite microcapsules containing calcium lactate; calcium ions are added in the form of calcium lactate powder along with potassium chloride in the step of cooling to 52.5°C.

[0059] Comparative Example 4: This comparative example differs from Example 1 above in that: The preparation method did not employ stepwise cross-linking gelation. Specifically, 30 parts of κ-carrageenan, 25 parts of enzymatically hydrolyzed konjac gum, 16 parts of guar gum, 11.5 parts of high-acyl gellan gum, and 0.125 parts of trisodium citrate were mixed with water to achieve a total solids concentration of 1%. The mixture was hydrated at 65°C to obtain a compound colloidal solution. Potassium chloride was then added to the compound colloidal solution, with potassium ions present as K+. + The amount was calculated to be 0.55 parts, and sodium alginate and chitosan composite microcapsules containing calcium lactate were added, wherein the calcium ions were in the form of Ca. 2+ Counting as 0.25 parts, the compound colloidal solution was directly heated to 92.5℃ and kept at that temperature for 55 minutes to carry out one-step cross-linking and gelation.

[0060] Comparative Example 5: This comparative example differs from Example 1 above in that: Without the addition of guar gum, the amount of κ-carrageenan was increased to 46 parts.

[0061] Performance testing: The gel foods containing compound food colloids prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to the following performance tests.

[0062] Gel strength determination: The gel food samples prepared in Examples 1-3 and Comparative Examples 1-5 were subjected to gel strength determination using a texture analyzer at room temperature. The probe model was P / 0.5, the test speed was 1 mm / s, the compression distance was 10 mm, and the gel strength values ​​were recorded. After sealing and packaging the above samples, they were placed in an autoclave at 121℃ for 30 minutes. After being removed and cooled to room temperature, the gel strength after high-temperature sterilization was measured using the same method as above. The gel strength retention rate was calculated as follows: gel strength retention rate = gel strength after high-temperature sterilization / gel strength before high-temperature sterilization × 100%. Water-holding capacity test: Take about 5g of gel food samples prepared in Examples 1-3 and Comparative Examples 1-5 and place them in a centrifuge tube. Centrifuge at 10000r / min for 30 minutes at 4℃. After centrifugation, take out the gel sample, blot the surface water with filter paper, weigh it, and calculate the water-holding capacity. Water-holding capacity = weight of gel after centrifugation / weight of gel before centrifugation × 100%; After sealing and packaging the above samples, they were placed in an autoclave at 121°C for 30 minutes. After being removed and cooled to room temperature, the water holding capacity after high-temperature sterilization was measured using the same method as above. Gel strength determination under acidic conditions: The gel food samples prepared in Examples 1-3 and Comparative Examples 1-5 were respectively immersed in a citric acid-sodium citrate buffer solution with a pH of 3.5, and left to stand at 25°C for 24 hours. After being taken out, the gel strength was determined by a texture analyzer under the same conditions as above. Gel transparency measurement: The gel food samples prepared in Examples 1-3 and Comparative Examples 1-5 were cut into thin slices with a thickness of 1 cm. The transmittance was measured at a wavelength of 600 nm using a UV-Vis spectrophotometer, with deionized white as a control. The experimental results are shown in Table 1.

[0063] Table 1

[0064] In conjunction with Example 1 and Comparative Example 1, and in conjunction with Table 1, Figure 2 , Figure 3 It can be seen that the molecular weight regulation of enzymatically hydrolyzed konjac gum can maintain the high-temperature stability of the gel. After enzymatic hydrolysis, the molecular chain of konjac gum is moderately shortened, exposing more hydroxyl active sites, which is conducive to forming a denser hydrogen bond cross-linking network with κ-carrageenan. However, the molecular weight of unhydrolyzed natural konjac gum is too large and the molecular chain is too long. During the high-temperature sterilization process, the thermal motion of the molecular chain intensifies, which leads to the relaxation of the gel network structure and a significant decrease in gel strength retention and water holding capacity.

[0065] In conjunction with Example 1 and Comparative Example 2, and in conjunction with Table 1 and Figure 2 , Figure 4 It can be seen that the weight-average molecular weight of enzymatically hydrolyzed konjac gum needs to be controlled to maintain an intact gel network structure. When the molecular weight is below 100,000 Da, the konjac gum molecular chains are too short to form effective physical entanglements and hydrogen bond cross-linking points in the gel network, resulting in an incomplete gel network structure. The gel strength, the strength retention rate after high-temperature sterilization, and the gel strength under acidic conditions are all significantly reduced. Controlling the molecular weight within the range of 100,000 to 500,000 Da can balance cross-linking efficiency and network integrity.

[0066] In conjunction with Example 1 and Comparative Example 3, and in conjunction with Table 1 and Figure 2 , Figure 3It can be seen that the form of calcium ion addition has a significant impact on the ordered construction of the gel network. When calcium ions are added directly in the form of calcium lactate powder, they participate in the cross-linking reaction too early at the low temperature stage, resulting in the gellan gum network being pre-cross-linked before the formation of the carrageenan double helix network. The two networks cannot achieve synchronous construction and uniform interpenetration, and the gel network structure is prone to local damage after high-temperature sterilization. When calcium ions are encapsulated in the form of microcapsules, they remain intact and do not release at the low temperature stage. They are released and participate in cross-linking only when the temperature is raised to above 65°C, thus achieving synchronous formation and uniform interpenetration of the gellan gum network and the carrageenan network.

[0067] In conjunction with Example 1 and Comparative Example 4, and in conjunction with Table 1 and Figure 2 , Figure 3 It can be seen that stepwise crosslinking can construct an ordered double network structure. In the one-step crosslinking process, guar gum, carrageenan, and gellan gum crosslink randomly at the same temperature, which cannot form an ordered rigid-flexible double network interpenetrating structure, and the gel network uniformity is poor. The stepwise crosslinking process completes the pre-formation of the gellan gum network, the synchronous construction of the double network, and the thermal irreversible network locking at three temperature stages of 50 to 55℃, 65 to 70℃, and 90 to 95℃, respectively, forming an ordered, dense, and uniform interpenetrating network structure, thereby significantly improving the stability of the gel structure after high-temperature sterilization.

[0068] In conjunction with Example 1 and Comparative Example 5, and in conjunction with Table 1 and Figure 2 It can be seen that gellan gum is an important guarantee for the stability of gel structure under high temperature conditions. Gelatan gum forms a thermally irreversible triple helix network at 90 to 95℃. This network is intertwined with the carrageenan double helix network, which plays a locking role in the overall gel network. In the absence of gellan gum, the carrageenan double helix network unwinds and rearranges during high-temperature sterilization, resulting in irreversible damage to the gel network structure and a significant decrease in gel strength.

[0069] In conjunction with Examples 1 to 3 and Comparative Examples 1 to 5, and in conjunction with Table 1 and Figures 2 to 5It can be seen that the quaternary compound of κ-carrageenan, enzymatically hydrolyzed konjac gum, gellan gum, and high-acyl gellan gum, combined with dual crosslinking of potassium and calcium ions and synergistic regulation by trisodium citrate, resulted in gel foods with stable gel strength, excellent structural stability after high-temperature sterilization, good gel strength retention under acidic conditions, and high transparency. When the weight-average molecular weight of the enzymatically hydrolyzed konjac gum is controlled between 100,000 and 500,000 Da, the molecular chain length is moderate, balancing crosslinking efficiency and network integrity, allowing the gel network to maintain its intact structure after high-temperature sterilization. Calcium ions, encapsulated in sodium alginate and chitosan composite microcapsules, remain intact and do not release at low temperatures, but are released when the temperature rises above 65°C and participate in network construction simultaneously with gellan gum, avoiding excessive calcium ion release. Early crosslinking interferes with the formation of the carrageenan double helix network, achieving ordered interpenetration between the gellan gum network and the carrageenan double helix network; trisodium citrate releases complexed calcium ions under acidic conditions to compensate for the loss of crosslinking density, maintaining the structural integrity of the gel in an acidic environment; the three temperature stages of stepwise crosslinking sequentially complete the pre-formation of the gellan gum network, the synchronous construction of the double network, and the thermally irreversible network locking of the gellan gum, transforming the gel network from disordered crosslinking to an ordered interpenetrating structure; the gellan gum forms a thermally irreversible triple helix network, which intertwines with the carrageenan double helix network, playing a locking role in the overall structure of the gel during high-temperature sterilization, thus achieving the comprehensive effect of stable structure, good performance under acidic conditions, and high transparency in gel foods containing compound food colloids after high-temperature sterilization.

[0070] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A gel food containing compound food colloids, characterized in that, The raw materials include the following parts by weight: 25-35 parts κ-carrageenan, 20-30 parts enzymatically hydrolyzed konjac gum, 12-20 parts guar gum, 8-15 parts high-acyl gellan gum, and a potassium ion source, with K... + 0.3–0.8 parts of calcium ion source, with Ca 2+ The total amount is 0.1 to 0.4 parts, trisodium citrate is 0.1 to 0.3 parts, and the weight average molecular weight of the enzymatically hydrolyzed konjac gum is 100,000 to 500,000 Da.

2. A gel food containing compounded food colloids according to claim 1, characterized in that: The enzymatically hydrolyzed konjac gum is prepared by the following method: Konjac gum was dissolved in deionized water to prepare a solution with a mass fraction of 2% to 5%, the pH was adjusted to 5 to 6, β-mannanase was added, and enzymatic hydrolysis was carried out at 45 to 55°C for 60 to 120 minutes. After enzymatic hydrolysis is complete, the hydrolysate is cooled to 4–10°C and the pH is adjusted to 3–3.5 to terminate the enzymatic hydrolysis reaction. The treated enzymatic hydrolysate was filtered in series using ceramic membranes with molecular weight cutoffs of 100,000 Da and 500,000 Da, and the fractions with a weight average molecular weight of 100,000 to 500,000 Da were collected.

3. A gel food containing compounded food colloids according to claim 1, characterized in that: The kellan gum is a pre-hydrated kellan gum, which is prepared by the following method: Disperse guar gum in deionized water to prepare a suspension with a mass fraction of 1% to 3%, and hydrate it by stirring at 40 to 45°C for 60 to 90 minutes. Cool the suspension to 25-30°C, add 0.05-0.1 parts of the total amount of trisodium citrate, and stir until homogeneous.

4. A gel food containing compounded food colloids according to claim 1, characterized in that: The calcium ion source is a composite microcapsule of sodium alginate and chitosan encapsulating calcium lactate.

5. A gel food containing compounded food colloids according to claim 4, characterized in that: The composite microcapsules were prepared by the following method: Calcium lactate is dissolved in deionized water to prepare a calcium lactate solution with a mass fraction of 5% to 10%. Sodium alginate was dissolved in deionized water to prepare a sodium alginate solution with a mass fraction of 1% to 2%. Chitosan was dissolved in a 1% acetic acid solution to prepare a chitosan solution with a mass fraction of 0.5% to 1%. Calcium lactate solution and sodium alginate solution are mixed at a volume ratio of 1:2 to 3, and sprayed into chitosan solution using a high-voltage electrostatic spraying device. The spraying voltage is 5 to 15 kV, the propulsion speed is 5 to 20 mL / h, the nozzle orifice diameter is 0.2 to 0.5 mm, and the receiving distance is 10 to 20 cm. Collect the microcapsules, wash them, and freeze-dry them at -40 to -50°C for 24 to 48 hours.

6. A gel food containing compounded food colloids according to claim 1, characterized in that: The potassium ion source is potassium chloride.

7. A method for preparing a gel food containing compound food colloids, characterized in that, Includes the following steps: S1. According to the weight parts, mix κ-carrageenan, enzymatically hydrolyzed konjac gum, guar gum, high acyl gellan gum and the remaining trisodium citrate with water, and hydrate at 60-70℃ to obtain a compound colloidal solution. S2. Add potassium ion source and calcium ion source to the compound colloidal solution, and perform stepwise cross-linking and gelation by sequentially holding at a first temperature, a second temperature and a third temperature. S3. After stepwise cross-linking and gelation, the mixture is cooled and molded to complete the preparation.

8. The method for preparing a gel food containing compound food colloids according to claim 7, characterized in that, In step S1, the amount of water added is such that the total solids concentration of the system is 0.5% to 1.5%.

9. A method for preparing a gel food containing compound food colloids according to claim 7, characterized in that, In step S2, the stepwise crosslinking gelation includes the following steps: Cool the compound colloidal solution to a first temperature of 50-55℃, add a potassium ion source and sodium alginate and chitosan composite microcapsules loaded with calcium lactate, and stir for 10-15 minutes. Heat to a second temperature of 65-70℃, and maintain this temperature while stirring for 20-30 minutes. Continue heating to a third temperature of 90-95℃ and hold for 15-20 minutes.

10. A method for preparing a gel food containing a compound food colloid according to claim 7, characterized in that, In step S3, the cooling and molding temperature is 4-10°C, and the time is 2-4 hours.

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