High-stability cream single cream and preparation method thereof

Abstract

The invention discloses high-stability cream light cream and a preparation method thereof.The preparation method comprises the steps that under the acidic condition, sodium caseinate and xanthan gum are dispersed in water in advance, and the sodium caseinate and the xanthan gum are compounded to form a stabilizer, so that the prepared cream light cream finished product can form a stable oil-in-water composition. Compared with the prior art, the cream single cream disclosed by the invention is better in stability and better in mouth feel, and better meets the requirements of users.

Description

Technical Field

[0001] The invention belongs to the technical field of dairy product processing, and particularly relates to high-stability milk fat cream and a preparation method thereof. Background Art

[0002] Cream is a dairy product made from cow's milk, obtained through centrifugation, with a milk fat content of 35% or greater. As cream technology matures, it is widely used in baking, desserts, coffee beverages, and other fields. Its core function relies on the natural emulsification of milk fat globules and the stabilizing effect of exogenous additives to achieve whipping, shaping, a smooth texture, and an extended shelf life.

[0003] The traditional process for preparing milk fat cream usually includes steps such as raw milk separation, sterilization, homogenization, and cooling. However, due to defects in the formula and process, it still has the problem of insufficient stability, which is mainly manifested in easy collapse and oil-water separation at high temperatures. The main reason is that traditional cream relies on the natural emulsification of milk fat globules (particle size 1-10μm), but the protein layer on the surface of the fat globules (such as casein micelles) is easy to rupture under high temperature (>25℃) or mechanical shear, causing fat to aggregate and float, triggering oil-water separation. For example, after commercially available cream is placed in an environment of 30℃ for 2 hours, the fat floating rate can reach more than 5%.

[0004] To compensate for the stability defects, traditional formulas require the addition of excessive stabilizers, such as carrageenan ≥ 2% or xanthan gum ≥ 1.5%. However, high concentrations of colloids easily form rigid gels, making the cream sticky and losing its lightness, resulting in an obvious gelatinous texture. Summary of the Invention

[0005] The object of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a highly stable cream and a method for preparing the same. The inventors have discovered through long-term and in-depth research that sodium caseinate and xanthan gum can form a stable physically bonded complex in an acidic environment. The cream prepared on this basis has high stability and is not prone to collapse. Moreover, due to the reduced ratio of stabilizer added, the natural flavor of the cream can be better maintained.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing high-stability cream comprises the following steps:

[0008] A. Disperse sodium caseinate and xanthan gum in water and adjust the pH to 4-6 to form a stabilizer by compounding sodium caseinate and xanthan gum;

[0009] B. providing an aqueous phase raw material containing the stabilizer;

[0010] C. providing an oil phase raw material comprising an emulsifier and milk fat;

[0011] D. Continuously adding the oil phase raw material to the water phase raw material, accompanied by a dispersion operation, until an oil-in-water composition is formed.

[0012] In the present invention, the mechanism of action of sodium caseinate and xanthan gum forming a stabilizer is:

[0013] a) Synergistic effect of electrostatic repulsion and adsorption: Under pH conditions of 4-6, casein molecules are negatively charged, while xanthan gum is an anionic polysaccharide containing carboxylic acid groups and is negatively charged under acidic conditions. Therefore, under acidic conditions, xanthan gum and sodium caseinate are conducive to the formation of synergistic effect of electrostatic repulsion and adsorption, thereby forming a stable interface.

[0014] b) Hydrogen bonding: The hydroxyl group (-OH) of xanthan gum and the amino group (-NH2), carboxyl group (-COOH) or hydroxyl group of casein form a hydrogen bonding network, thereby enhancing the intermolecular binding force.

[0015] c) Hydrophobic interaction: Hydrophobic interactions may occur between the hydrophobic regions of sodium caseinate (such as non-polar amino acids in the peptide chain) and the hydrophobic groups of xanthan gum (such as mannose residues in the side chain), promoting complexation.

[0016] d) Steric hindrance and synergistic adsorption: Xanthan gum forms a polymer adsorption layer on the surface of ammonium caseinate, which prevents the droplets from coalescing through steric hindrance.

[0017] From the above analysis, it can be seen that the sodium caseinate and xanthan gum of the present application are connected by non-chemical bonds such as electrostatic interaction or hydrogen bonding, which are not limited to these, and have better stability than the simple mixing of sodium caseinate and xanthan gum.

[0018] Furthermore, in step A, the weight percentage of sodium caseinate is greater than the weight percentage of xanthan gum. Preferably, the mass ratio of sodium caseinate to xanthan gum is 1.2-4:1. Exemplarily, it is 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1 or 4:1.

[0019] Furthermore, in step A, a pH adjuster such as lactic acid, citric acid, potassium citrate, lactic acid or malic acid may be selectively added to adjust the pH to a desired range.

[0020] Optionally, 0.02-0.04 wt% of edible salt may be added in step A. This can adjust the ionic strength, shield electrostatic repulsion, and promote hydrophobic interaction and hydrogen bond formation between sodium caseinate and xanthan gum. Furthermore, it can lower the freezing point and expansion coefficient of the aqueous phase, thereby improving emulsion stability.

[0021] Furthermore, the order of step B and step C of the present invention can be adjusted according to actual needs.

[0022] Specifically, the aqueous phase raw material may further contain other thickeners commonly used in the art, including but not limited to one or more of gellan gum, carrageenan, gelatin, locust bean gum, konjac gum, guar gum, pectin, sodium alginate, microcrystalline cellulose and carboxymethyl cellulose.

[0023] Preferably, the feeding amount of the sodium caseinate is 0.5%-2wt% based on the total weight of the aqueous phase raw material and the oil phase raw material.

[0024] Furthermore, the feeding amount of sodium caseinate of the present invention is more suitably 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt% or 2wt% based on the total weight of the aqueous phase raw material and the oil phase raw material.

[0025] Preferably, the amount of xanthan gum added is 0.1%-1wt% based on the total weight of the aqueous phase raw material and the oil phase raw material.

[0026] Furthermore, the amount of xanthan gum added is preferably 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% or 1wt% based on the total weight of the aqueous phase raw material and the oil phase raw material.

[0027] Preferably, the amount of the emulsifier added is 0.5%-2wt% based on the total weight of the aqueous phase raw material and the oil phase raw material.

[0028] Furthermore, the amount of emulsifier added is more suitably 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt% or 2wt% based on the total weight of the aqueous phase raw material and the oil phase raw material.

[0029] Preferably, the feeding amount of the milk fat is 30-40 wt% based on the total weight of the water phase raw material and the oil phase raw material.

[0030] Furthermore, the amount of milk fat added is more suitably 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt% or 40wt% based on the total weight of the water phase raw material and the oil phase raw material.

[0031] Preferably, the emulsifier is one or more of mono- and diglycerol fatty acid esters, phospholipids, glyceryl monostearate, sucrose fatty acid esters, and Tween 80. The phospholipids include at least one of lecithin and soybean lecithin.

[0032] Preferably, in step A, the specific step of compounding sodium caseinate and xanthan gum to form a stabilizer is to homogenize the mixture of sodium caseinate and xanthan gum at 15-20 MPa for 5-15 minutes, or to ultrasonically treat the mixture at 20-30 kHz for 5-15 minutes.

[0033] Preferably, step A is carried out under heating conditions, and the heating conditions are 40-60°C.

[0034] Preferably, in step C, the specific preparation steps of the oil phase raw material are: heating the milk fat to 40-55° C., adding the emulsifier while stirring, and performing high-speed shearing after the milk fat is completely dissolved.

[0035] Furthermore, the specific step of continuously adding the oil phase raw material to the water phase raw material in step D is to slowly add the preheated oil phase into the water phase in the form of a thin stream under constant stirring, and control the addition rate to 5-10% / minute of the volume of the water phase to avoid local excessive concentration leading to phase inversion.

[0036] Preferably, the constant stirring speed is 800-1200 rpm.

[0037] Preferably, the mass ratio of the water phase raw material to the oil phase raw material is 1.2-3:1.

[0038] Furthermore, the mass ratio of the aqueous phase raw material and the oil phase raw material is suitably 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1 or 3:1.

[0039] Preferably, the dispersion operation in step D is a two-stage dispersion, with the first stage pressure being 18-22 MPa and the temperature being 60-70°C; and the second stage pressure being 4-8 MPa and the temperature being 50-60°C.

[0040] Specifically, the first stage of homogenization primarily serves to initially break up fat globules and reduce particle size distribution. The temperature range of this first stage of homogenization reduces fat globule membrane rigidity and improves homogenization efficiency. The second stage of homogenization further refines fat globule size while minimizing mechanical shear damage to the natural structure of milk fat. The temperature range of this second stage of homogenization better balances fat fluidity and the protection of heat-sensitive proteins. These two-stage homogenization processes effectively refine fat globules and prevent aggregation.

[0041] Furthermore, after the second stage of homogenization, the target fat globule size D50 is ≤ 0.8 μm. A smaller D50 indicates finer particles overall in the cream, more uniform fat globules in the cream, and higher emulsion stability.

[0042] Furthermore, in step D, 0.05-0.15 wt% of an antioxidant such as potassium sorbate, vitamin E, tocopherol succinate, tea polyphenol nanoemulsion, citric acid, ascorbyl palmitate or rosemary extract may be selectively added to enhance the antioxidant effect of the finished product and extend the shelf life.

[0043] A high-stability milk fat cream is prepared by the above preparation method.

[0044] A cake product comprises the above-mentioned cream.

[0045] Beneficial effects of the present invention:

[0046] (1) The cream formula provided by the present invention adds a complex formed by sodium caseinate and xanthan gum under acidic conditions as a stabilizer. In the complex, sodium caseinate and xanthan gum are connected by non-chemical bonds such as electrostatic action or hydrogen bonding, which is not limited to these. Compared with a simple mixture of sodium caseinate and xanthan gum, the two are more evenly distributed around each other, which is conducive to the respective stabilizing effects, thereby improving the stability of the cream.

[0047] (2) The cream of the present invention is in the form of an oil-in-water composition, which enhances the mouthfeel without affecting the stability. DETAILED DESCRIPTION

[0048] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with preferred embodiments:

[0049] The cream of the present invention can be obtained by commercial purchase or self-preparation. The cream can be prepared by the following steps:

[0050] S11: filtering, degassing, purifying and pasteurizing the qualified raw milk, wherein the pasteurization temperature is 85-95°C and the time is 15-30s;

[0051] S12: After the temperature drops to 50-60°C, the raw milk is separated into milk fat and skim milk by a centrifuge; wherein the rotation speed of the centrifuge can be appropriately adjusted according to the milk fat content, preferably in the range of 5000-10000 rpm.

[0052] Example 1

[0053] This embodiment provides a cream, which comprises, by weight, 35 parts of milk fat, 1.3 parts of sodium caseinate, 0.5 parts of xanthan gum, and 0.25 parts of glyceryl monostearate, and is obtained by the following preparation method:

[0054] A. Disperse sodium caseinate and xanthan gum in water and adjust the pH to 4.6. Homogenize the mixture at 15-20 MPa for 10 minutes under heating conditions at 55°C to form a stabilizer.

[0055] B. using the stabilizer as the aqueous phase raw material;

[0056] C. Heat the cream to 50°C to melt the cream, add glyceryl monostearate while stirring, and shear at high speed until the cream is completely dissolved to obtain the oil phase raw material;

[0057] D. Under constant stirring at 1000 rpm, continuously add the oil-phase raw material to the water-phase raw material in a thin stream, accompanied by a dispersion operation, until an oil-in-water composition is formed. The mass ratio of the water-phase raw material to the oil-phase raw material is 2:1. The dispersion operation is a two-stage dispersion operation, with the first stage pressure of 18-22 MPa and a temperature of 65°C; the second stage pressure of 4-8 MPa and a temperature of 55°C.

[0058] Example 2

[0059] The difference between this embodiment and embodiment 1 is that 0.5 parts by weight of gellan gum is further added in this embodiment. The gellan gum is mixed with the stabilizer in step B and serves as the aqueous phase raw material.

[0060] Example 3

[0061] The difference between this embodiment and embodiment 1 is that 0.25 parts by weight of sucrose fatty acid ester is further added in this embodiment. The sucrose fatty acid ester and glycerol monostearate are added to the milk fat together as emulsifiers in step C to prepare the oil phase raw material.

[0062] Example 4

[0063] The difference between this embodiment and embodiment 1 is that 0.1 parts by weight of vitamin E and 0.03 parts by weight of edible salt are further added in this embodiment. In step D, the vitamin E and edible salt are added to the aqueous phase raw material after the oil phase raw material is added to the aqueous phase raw material.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that the pH value in step A in this comparative example is adjusted to 7.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 1 is that the pH value in step A of this comparative example is adjusted to 8.5.

[0068] Comparative Example 3

[0069] The difference between this comparative example and Example 1 is that xanthan gum is replaced by gellan gum in this comparative example.

[0070] Comparative Example 4

[0071] The difference between this comparative example and Example 1 is that sodium caseinate is replaced by lecithin in this comparative example.

[0072] Comparative Example 5

[0073] The difference between this comparative example and Example 1 is that in this comparative example, the weight portion of sodium caseinate is 0.5 parts, and the weight portion of xanthan gum is 1.3 parts.

[0074] Comparative Example 6

[0075] The difference between this comparative example and Example 1 is that the mass ratio of the water phase raw material to the oil phase raw material in this comparative example is 1:1.2, and in step D, the oil phase raw material is directly poured into the water phase raw material to form a water-in-oil composition.

[0076] The finished emulsion cream products obtained above were numbered respectively, wherein the finished products of Examples 1-4 corresponded to numbers 1-4, and the finished products of Comparative Examples 1-6 corresponded to numbers 5-10, respectively.

[0077] Sensory properties test

[0078] The sensory properties of the emulsion cream obtained above were evaluated in turn according to the "National Food Safety Standard - Cream, Butter and Anhydrous Butter" (GB 19646-2025). The specific operation method is as follows:

[0079]

[0080] The samples were scored according to the above requirements. The higher the score, the better the sensory performance. The full score for each item was 10 points.

[0081]

[0082]

[0083] The above scoring results indicate that the emulsion cream of Example 4 received the highest overall score, demonstrating that the emulsion creams produced by the present invention exhibit excellent overall sensory properties. The emulsion creams produced in Comparative Examples 1 and 2 contained some flocculation, possibly due to the interaction of xanthan gum with sodium caseinate via other groups (such as hydroxyl groups) under neutral or alkaline conditions, resulting in non-adsorption of the polysaccharide and initiation of flocculation. Comparative Examples 3 and 4 also contained some flocculation, possibly due to a lack of xanthan gum or sodium caseinate, which prevented the formation of a stable composite structure in the system and affected the subsequent stability of the cream. Comparative Example 6 exhibited a relatively high amount of precipitate, possibly due to the formation of a water-in-oil mixture in the cream, impacting the stability of the system.

[0084] Physical stability test

[0085] (1) Room temperature stability test: The emulsion cream products obtained above were whipped separately and then placed at room temperature (25°C) for 2 hours to observe whether they collapsed and the degree of collapse. The collapse degree was scored on a scale of 0-5, where 0 means no collapse and 5 means severe collapse. The higher the score, the more severe the collapse.

[0086] (2) The finished emulsion cream obtained above was refrigerated at 4°C for 12 hours. 10 mL of each sample was then taken out in sequence and placed into centrifuge tubes. The tubes were centrifuged at 3000 rpm for 15 minutes and then allowed to stand vertically in a constant temperature environment at 4°C for 24 hours. The upper precipitate and lower precipitate were obtained and the separation index L1 was measured. A lower L1 indicates a stronger resistance to separation of the emulsion cream. Wherein, L1 (%) = (volume of serum layer / total sample volume) × 100%.

[0087] (3) The finished emulsion cream product obtained above was refrigerated at 4°C for 12 hours, and then the fat globule diameter (D50) and particle size distribution width (PDI) of the finished emulsion cream product obtained above were respectively measured using a laser particle size analyzer. The working principle of the laser particle size analyzer is that particles of different sizes produce different diffraction angles under laser irradiation, with small particles having a large diffraction angle and large particles having a small diffraction angle. Therefore, the smaller the fat globule size, the better the stability of the emulsion cream; the closer the PDI is to 0, the better the homogeneity of the emulsion cream.

[0088] The experimental results of the above test on the physical stability of the emulsion cream are as follows:

[0089] serial number Degree of collapse L1(％) D50(μm) PDI 1 1 4.85 7.5 0.3 2 1 4.54 7.1 0.2 3 1 4.79 6.7 0.2 4 1 4.29 6.3 0.2 5 2 6.76 8.9 0.4 6 2 6.51 8.6 0.4 7 2 6.13 9.1 0.5 8 2 6.57 9.2 0.5 9 2 5.72 8.3 0.4 10 2 8.31 9.8 0.6

[0090] From the above experimental results, it can be seen that the stability of the emulsion cream of the embodiment group is better than that of the comparative example group.

[0091] Specifically, in terms of the degree of collapse, the cream of the embodiment group is preliminarily treated with xanthan gum and sodium caseinate to form a stable composite structure under acidic conditions, and thus has a better anti-collapse effect.

[0092] In terms of anti-segregation ability, the Example groups all added sodium caseinate and xanthan gum as stabilizers, effectively improving the anti-segregation ability of the emulsion cream. After pH adjustment in Comparative Examples 1 and 2, the performance of the stabilizer formed by sodium caseinate and xanthan gum decreased. The creams in Comparative Examples 3 and 4 also showed reduced stability due to the lack of a pre-formed composite structure of sodium caseinate and xanthan gum. In Comparative Example 5, the weight ratio of sodium caseinate to xanthan gum was changed, resulting in reduced cream stability. This is likely due to the low sodium caseinate concentration, which did not form sufficient surface adsorption sites, and the high xanthan gum concentration, which led to competitive adsorption and thus affected the cream's stability. The cream formed in Comparative Example 6 was a water-in-oil composition, and its stability was far inferior to that of the oil-in-water composition.

[0093] In terms of fat globule diameter (D50) and particle size distribution width (PDI) tests, the emulsification effect of the emulsion cream obtained in this embodiment is better than that of the cream of the comparative example, and the fat globule diameter (D50) and particle size distribution width (PDI) tests both meet the requirements of the national standard GB 19646-2025.

[0094] In summary, the emulsion cream prepared by the present invention has good stability.

[0095] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing high-stability cream, characterized in that: The following steps are involved: A. Disperse sodium caseinate and xanthan gum in water and adjust the pH to 4-6 to form a stabilizer by compounding sodium caseinate and xanthan gum; B. providing an aqueous phase raw material containing the stabilizer; C. providing an oil phase raw material comprising an emulsifier and milk fat; D. Continuously adding the oil phase raw material to the water phase raw material, accompanied by a dispersion operation, until an oil-in-water composition is formed.

2. The preparation method according to claim 1, characterized in that The feeding amount of the sodium caseinate is 0.5%-2wt% based on the total weight of the aqueous phase raw material and the oil phase raw material.

3. The preparation method according to claim 1, characterized in that The amount of xanthan gum added is 0.1%-1wt% based on the total weight of the water phase raw material and the oil phase raw material.

4. The preparation method according to claim 1, characterized in that The amount of the emulsifier added is 0.5%-2wt% based on the total weight of the water phase raw material and the oil phase raw material.

5. The preparation method according to claim 1, characterized in that The feeding amount of the milk fat is 30-40 wt % based on the total weight of the water phase raw material and the oil phase raw material.

6. The preparation method according to claim 1, characterized in that The emulsifier is one or more of mono- and di-glycerol fatty acid esters, phospholipids, glyceryl monostearate, sucrose fatty acid esters and Tween 80.

7. The preparation method according to claim 1, characterized in that In step A, the specific step of compounding sodium caseinate and xanthan gum to form a stabilizer is to homogenize the mixture of sodium caseinate and xanthan gum under 15-20 MPa for 5-15 minutes, or to ultrasonically treat the mixture under 20-30 kHz for 5-15 minutes.

8. The preparation method according to claim 1, characterized in that Step A is carried out under heating conditions, and the heating conditions are 40-60°C; The mass ratio of the aqueous phase raw material to the oil phase raw material is 1.2-3:1; The dispersion operation in step D is a two-stage dispersion, with the first stage pressure being 18-22 MPa and the temperature being 60-70° C.; the second stage pressure being 4-8 MPa and the temperature being 50-60° C.

9. A high-stability cream, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

10. A cake product, characterized in that: Containing the cream as claimed in claim 9.

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