Microcapsule gradient cross-linked protein jelly thickening agent and jelly low-temperature production process

Abstract

The invention belongs to the technical field of food processing, and particularly relates to a microcapsule gradient cross-linked protective protein jelly thickening agent and a jelly low-temperature production process, and the thickening agent comprises the following components in percentage by mass: 20-25% of carrageenan, 10-20% of starch, 10-20% of starch, 10-20% of starch, 10-20% of starch, and the balance of water. The mass ratio of the carrageenan to the konjac gum is (1: 0.8)-(1: 1.2); 10%-15% of calcium alginate microencapsulated colloid, wherein the microencapsulated colloid wraps the whey protein or the soybean protein isolate; wherein the calcium alginate microencapsulated colloid can also be used for wrapping probiotics or fat-soluble vitamins and the like. Through a micro-capsule gradient cross-linking technology and low-temperature process innovation, the comprehensive performance of a jelly product is remarkably improved, thermosensitive active ingredients are wrapped by adopting a calcium alginate microencapsulation technology, oxidative degradation is inhibited in combination with a natural antioxidant, the activity of functional ingredients such as protein and probiotics is effectively protected under the conditions of low-temperature processing and ultrahigh-pressure sterilization, and the jelly has the beneficial effects of being free of toxic and side effects and the like. And the problem of component inactivation caused by a traditional high-temperature process is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a microcapsule gradient cross-linked protein jelly thickener and a low-temperature jelly production process. Background Art

[0002] As a popular food, jelly's texture stability, nutrient retention, and functional expansion have always been the focus of the industry. Traditional jelly thickening systems mostly rely on a single colloid (such as carrageenan) or a simple colloid combination (carrageenan-konjac gum combination), which has the following significant drawbacks: Severe damage to heat-sensitive ingredients: Conventional high-temperature sterilization processes easily lead to denaturation and inactivation of heat-sensitive ingredients such as whey protein and probiotics. The protein retention rate is generally less than 70% (e.g., application number CN201710592987.4), and the high-temperature sol process accelerates the degradation of functional ingredients. Insufficient synergy in the thickening system: While existing compounded colloids (e.g., application number CN202010463984.2) enhance gel strength by combining carrageenan and konjac gum, they lack an ion gradient control mechanism. The gel network is susceptible to pH fluctuations, resulting in uneven product texture (gel strength can fluctuate by as much as ±15%) and prone to syneresis during storage at low temperatures. Poor adaptability to low-temperature processing: Conventional thickeners (such as gelatin) do not dissolve fully when sol-gelled at low temperatures (<50°C), and are prone to colloidal agglomeration (particle size >200μm). Existing low-temperature sterilization technologies (such as pasteurization) cannot effectively kill heat-resistant spores, resulting in a shortened shelf life of the product. Summary of the Invention

[0003] (1) Technical issues to be resolved In order to overcome the defects of jelly thickeners in the prior art, such as serious destruction of heat-sensitive components, insufficient synergy of the thickening system and poor adaptability to low-temperature processing, the present invention provides a microcapsule gradient cross-linked protein-protected jelly thickener and a jelly low-temperature production process, which can achieve efficient protection and precise controlled release of functional ingredients while improving texture stability.

[0004] (2) Technical solution The present invention is achieved through the following technical solution: The present invention proposes a microcapsule gradient cross-linked protein jelly thickener, which comprises the following components by mass percentage: Carrageenan 20%-25%; Konjac gum 15%-20%, and the mass ratio of carrageenan to konjac gum is 1:0.8-1:1.2; 10%-15% calcium alginate microencapsulated colloid, wherein the microencapsulated colloid encapsulates whey protein or soy protein isolate; wherein the calcium alginate microencapsulated colloid may also encapsulate probiotics or fat-soluble vitamins; Hydroxypropyl methylcellulose 8%-10%; Natural antioxidants 1%-2%; Synergist combination 10%-20%.

[0005] Preferably, the preparation method of the calcium alginate microencapsulated colloid comprises: mixing a whey protein or soy protein isolate solution with a concentration of 5%-10% with sodium alginate, and dropping a solution containing 0.5%-1.5% Ca² + Ion-crosslinked microcapsules are formed in the colloidal liquid.

[0006] Preferably, the natural antioxidant is one of polyphenols and rosemary extract.

[0007] Preferably, the synergist combination is a mixture of sodium citrate and potassium chloride in a mass ratio of 3:2-5:3, wherein potassium chloride and carrageenan synergistically enhance gel strength, and sodium citrate is added in an amount of 6%-10% of the total mass to adjust the system pH to 6.5-7.0.

[0008] Preferably, the particle size of the calcium alginate microencapsulated colloid is 50-100 μm.

[0009] The present invention also provides a low-temperature production process for jelly, which is based on the above-mentioned thickener and comprises: Low temperature staged sol: dry mix the thickener and white sugar, then stir and dissolve in 40-50℃ purified water; Gradient cooling molding: In the first stage, the temperature was lowered to 30-35°C at a rate of 2-5°C / min to achieve initial cross-linking of the carrageenan-konjac gum network; In the second stage, the temperature was lowered to 4-10°C at a rate of 0.5-1°C / min to promote the synergistic stabilization of calcium alginate microcapsules and hydroxypropyl methylcellulose; Non-thermal sterilization: Use 300-500MPa ultra-high pressure sterilization for 3-10min.

[0010] (3) Beneficial effects Compared with the prior art, the present invention has the following beneficial effects: The present invention significantly improves the comprehensive performance of jelly products through microcapsule gradient cross-linking technology and low-temperature process innovation. It uses calcium alginate microencapsulation technology to encapsulate heat-sensitive active ingredients, combines natural antioxidants to inhibit oxidative degradation, effectively protects the activity of functional ingredients such as proteins and probiotics under low-temperature processing and ultra-high pressure sterilization conditions, avoids the problem of ingredient inactivation caused by traditional high-temperature processes, optimizes the design of the compound thickening system, and forms a uniform and stable gel network through the synergistic effect of carrageenan, konjac gum and hydroxypropyl methylcellulose in combination with ion regulation enhancers, thereby significantly improving the texture strength and water holding capacity of the jelly. To solve the defects of gel easy dehydration and shrinkage and uneven texture in traditional processes, the gradient cooling molding process regulates the gel cross-linking process in stages, which not only avoids colloid agglomeration during low-temperature sol, but also strengthens the binding stability of microcapsules and gel matrix through slow cooling, ensuring the precise controlled release of functional ingredients during the shelf life. In addition, this technology can be expanded to the targeted delivery of various functional ingredients such as probiotics and fat-soluble vitamins, breaking through the release control bottleneck of traditional microencapsulation technology. At the same time, there is no need to rely on chemical preservatives, providing an efficient and adaptable industrial solution for the development of high-protein, low-sugar, functional jelly products. DETAILED DESCRIPTION

[0011] In this technical solution: In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0012] The present invention provides a microcapsule gradient cross-linked protein jelly thickener, which comprises the following components by mass percentage: Carrageenan 20%-25%; Konjac gum 15%-20%, and the mass ratio of carrageenan to konjac gum is 1:0.8-1:1.2; 10%-15% calcium alginate microencapsulated colloid, wherein the microencapsulated colloid encapsulates whey protein or soy protein isolate, and has a particle size of 50-100 μm; wherein the calcium alginate microencapsulated colloid may also encapsulate probiotics or fat-soluble vitamins; Hydroxypropyl methylcellulose (HPMC) 8%-10%; Natural antioxidant 1%-2%, selected from one of polyphenols and rosemary extract; A synergist combination of 10%-20%, consisting of sodium citrate and potassium chloride in a mass ratio of 3:2-5:3, wherein sodium citrate accounts for 6%-10% of the mass of the synergist combination and is used to adjust the system pH to 6.5-7.0; The preparation method of the calcium alginate microencapsulated colloid comprises: mixing a whey protein or soy protein isolate solution with a concentration of 5%-10% with sodium alginate, and dripping the mixture into a colloidal solution containing 0.5%-1.5% Ca²⁺ to form ion-crosslinked microcapsules; A low-temperature jelly production process is implemented based on the above-mentioned thickener, and the low-temperature jelly production process comprises: Low temperature staged sol: dry mix the thickener and white sugar, then stir and dissolve in 40-50℃ purified water; Gradient cooling molding: In the first stage, the temperature was lowered to 30-35°C at a rate of 2-5°C / min to achieve initial cross-linking of the carrageenan-konjac gum network; In the second stage, the temperature was lowered to 4-10°C at a rate of 0.5-1°C / min to promote the synergistic stabilization of calcium alginate microcapsules and hydroxypropyl methylcellulose; Non-thermal sterilization: use 300-500MPa ultra-high pressure sterilization for 3-10min; The present invention uses calcium alginate microencapsulated colloid (10%-20%) to encapsulate whey protein or soy protein isolate, forming a dense capsule wall (particle size 50-100μm) through ionic crosslinking. Combined with natural antioxidants (polyphenols / rosemary extract, 1%-3%), it inhibits oxidative degradation. During subsequent ultra-high pressure sterilization (300-500MPa, 3-10min) and low-temperature sol (40-50°C), the protein retention rate is ≥90%, significantly superior to traditional high-temperature processes (<70%). The present invention optimizes the ratio of the composite thickener (carrageenan 20%-30%, konjac gum 15%-25%, HPMC 8%-12%), and through the synergistic effect of the carrageenan-konjac gum mass ratio (1:0.8-1:1.2) and the synergistic agent combination (sodium citrate-potassium chloride, mass ratio 3:2-5:3), adjusts the system pH to 6.5-7.0. At the same time, potassium chloride is used to strengthen the double helix structure of the carrageenan, so that the gel strength is stabilized to ≥450g / cm² (fluctuation range <±5%), effectively solving the syneresis and uneven texture problems of traditional processes. The present invention adopts a gradient cooling molding process, namely, the first stage (cooling at 2-5°C / min to 30-35°C): promoting the rapid cross-linking of the carrageenan-konjac gum network to avoid colloid agglomeration (particle size <50 μm) caused by low-temperature sol; the second stage (cooling at 0.5-1°C / min to 4-10°C): inducing the formation of hydrogen bonds between HPMC and calcium alginate microcapsules by slow cooling, thereby enhancing the water retention of the gel and the stability of the microcapsules, and ensuring that the microcapsule release rate is ≤5% during the shelf life; The present invention can also expand the embedding of probiotics (viable bacteria count ≥ 1×10 9CFU / g) or fat-soluble vitamins (encapsulation rate ≥85%), and achieve controlled release in an intestinal targeted environment (pH>7.0), breaking through the technical bottleneck of traditional microcapsules (shelf life release rate>30%).

[0013] Example 1: Whey protein functional jelly: formula: Carrageenan 22%; Konjac gum 18% (carrageenan: konjac gum = 1:0.82); Calcium alginate microencapsulated whey protein 12% (microcapsule particle size 60-80μm) Hydroxypropyl methylcellulose HPMC 9%; Tea polyphenols 1.5%; Synergist combination 17% (sodium citrate: potassium chloride = 3:2, of which sodium citrate accounts for 8% of the synergist); Process: Sol: Dry mix the thickener and white sugar (15% of the total formula), and stir and dissolve in 45℃ purified water for 30 minutes; Gradient cooling molding: In the first stage, the temperature was lowered to 32°C at 3°C / min and allowed to stand for 10 min to form a preliminary gel network; In the second stage, the temperature was lowered to 8°C at 0.8°C / min and maintained for 2 hours to enhance microcapsule binding; Ultra-high pressure sterilization: 400MPa for 5min.

[0014] Test results: Whey protein retention rate: 93.2% (Kjeldahl method, compared to about 68.5% of traditional high-temperature process); Gel strength: 468g / cm² (fluctuation ±3.5%, TA.XT Plus texture analyzer); The release rate of microcapsules after 6 months of shelf life is 4.1% (release rate in simulated digestive fluid, HPLC detection).

[0015] Example 2: Soy protein isolate high-fiber jelly: formula: Carrageenan 24%; Konjac gum 20% (mass ratio 1:0.83); Calcium alginate microencapsulated soy protein 14% (particle size 70-90 μm); HPMC 8%; Rosemary extract 1.8%; Synergist combination 12% (sodium citrate: potassium chloride = 5:3, sodium citrate accounts for 9% of the synergist); Process: Sol: dissolved in pure water at 48°C, shear rate 2000 rpm; Gradient cooling: The first stage: 4℃ / min→35℃, keep warm for 15min; The second stage is 0.6℃ / min→6℃, lasting 3 hours; Sterilization: 450MPa high pressure treatment for 8min; Test results: Protein retention rate: 91.5% (Kjeldahl method); Gel strength: 455g / cm² (fluctuation ±4.1%, Kjeldahl method); Microcapsule release rate (6 months): 3.8% (release rate in simulated digestive fluid, HPLC detection).

[0016] Example 3: Probiotic active jelly: formula: Carrageenan 20%; Konjac gum 16% (mass ratio 1:0.8); Calcium alginate microencapsulated probiotics (Lactobacillus plantarum) 15% (viable count 1.2×10 9 CFU / g); HPMC 10%; Tea polyphenols 2%; Synergist combination 17% (sodium citrate: potassium chloride = 4:3, sodium citrate accounts for 7% of the synergist); Process: Low temperature sol: dissolve at 42℃ to avoid inactivation of probiotics; Gradient cooling: The first stage: 2℃ / min→30℃; The second stage is 0.5℃ / min→4℃, refrigeration for 12 hours; Sterilization: 350MPa ultra-high pressure treatment for 10min; Test results: Probiotic survival rate: 89.7% (traditional process <50%, plate count method, shelf life ≥1×10 9 CFU / g); Gel strength: 442g / cm² (syneresis ≤ 1.5% (centrifugation method, 3000rpm / 10min)); Release rate during shelf life: 4.9% (92% release rate at simulated intestinal pH 7.5).

[0017] Comparative example: traditional high-temperature jelly Formula (refer to CN202010463984.2 for part of the formula): Carrageenan 25% Konjac gum 20% Whey protein (unencapsulated) 10% Potassium sorbate 0.2% Process: High temperature sol: dissolve by stirring at 75℃; High temperature sterilization: 85℃ for 20min; Rapidly cool to 25℃ and form; Test results: Protein retention rate: 68.3% (severe high temperature denaturation); Gel strength: 380g / cm² (fluctuation ±18%); Syneresis after 7 days of storage: 12.5%; Microencapsulated Release Rate (No Microencapsulation): N / A.

[0018] Comparison table of the above three embodiments and comparative examples

[0019] By comparing the data of the examples with the comparative examples, the present invention is significantly superior to the traditional technology in terms of heat-sensitive component protection, texture stability and processing adaptability.

[0020] Finally, it should be noted that the above is merely a specific example of the present invention. Obviously, the present invention is not limited to the above example and is subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A microcapsule gradient cross-linked protein jelly thickener, characterized by: The thickener comprises the following components by mass percentage: Carrageenan 20%-25%; Konjac gum 15%-20%, and the mass ratio of carrageenan to konjac gum is 1:0.8-1:1.2; 10%-15% of calcium alginate microencapsulated colloid, wherein the microencapsulated colloid encapsulates whey protein or soy protein isolate; Hydroxypropyl methylcellulose 8%-10%; Natural antioxidants 1%-2%; Synergist combination 10%-20%.

2. The microcapsule gradient cross-linked protein jelly thickener according to claim 1, characterized in that: The preparation method of the calcium alginate microencapsulated colloid comprises: mixing a whey protein or soy protein isolate solution with a concentration of 5%-10% with sodium alginate, and dropping a solution containing 0.5%-1.5% Ca² + Ion-crosslinked microcapsules are formed in the colloidal liquid.

3. The microcapsule gradient cross-linked protein jelly thickener according to claim 1, characterized in that: The natural antioxidant is one of polyphenols and rosemary extract.

4. The microcapsule gradient cross-linked protein jelly thickener according to claim 1, characterized in that: The synergist combination is a mixture of sodium citrate and potassium chloride in a mass ratio of 3:2-5:3, wherein potassium chloride and carrageenan synergistically enhance gel strength, and the amount of sodium citrate added is 6%-10% of the total mass to adjust the system pH to 6.5-7.

0.

5. The microcapsule gradient cross-linked protein jelly thickener according to claim 1, characterized in that: The particle size of the calcium alginate microencapsulated colloid is 50-100 μm.

6. The microcapsule gradient cross-linked protein jelly thickener according to claim 1, characterized in that: The calcium alginate microencapsulated colloid can also encapsulate probiotics or fat-soluble vitamins.

7. A low-temperature production process for jelly based on the microcapsule gradient cross-linked protein jelly thickener according to any one of claims 1 to 6, characterized in that: The low-temperature production process of jelly comprises: Low temperature staged sol: dry mix the thickener and white sugar, then stir and dissolve in 40-50℃ purified water; Gradient cooling molding: In the first stage, the temperature was lowered to 30-35°C at a rate of 2-5°C / min to achieve initial cross-linking of the carrageenan-konjac gum network; In the second stage, the temperature was lowered to 4-10°C at a rate of 0.5-1°C / min to promote the synergistic stabilization of calcium alginate microcapsules and hydroxypropyl methylcellulose; Non-thermal sterilization: Use 300-500MPa ultra-high pressure sterilization for 3-10 minutes.

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