Colloidal composition with thixotropic properties and use thereof

Abstract

The present application provides a gel composition with thixotropic property. Compared with the prior art, the present application combines gelatin with different gel strength and controls the total amount of addition, thereby obtaining a gel composition with thixotropic property, which, when applied in dairy product processing, can impart good texture, sensory performance and stability to the dairy product, and has a firm texture at low temperature and good flowability after being subjected to external force when close to human body temperature.

Description

Technical Field

[0001] This invention belongs to the field of food technology, and in particular relates to a colloidal composition with thixotropic properties and its applications. Background Technology

[0002] Dairy products and other foods are favored by consumers for their rich nutrition, unique flavor and taste. However, this also requires that the impact of production, transportation, sales and storage be fully considered when designing food products. Otherwise, their composition and texture may change, which will affect the quality of the products.

[0003] Currently, in order to solve the above problems, complex formulas and processes are needed to control product quality during food production. For example, common set yogurt, due to its post-fermentation characteristics, requires the addition of a large amount of stabilizers and emulsifiers to maintain the product's taste and stability.

[0004] Furthermore, when fruit jam with chunks is added online to set-type yogurt, the fruit chunks cannot be evenly distributed throughout the product, affecting the consumer experience. In contrast, while stirred yogurt can have fruit jam with chunks added online, its texture is difficult to achieve the smooth, bouncy feel characteristic of set-type products. Therefore, there is a technical bottleneck in set-type dairy products where texture, consistency, and uniformity of fruit chunks cannot be simultaneously achieved. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a colloidal composition with thixotropic properties and its application, which, when applied to dairy processing, can impart good texture, sensory performance and stability to dairy products.

[0006] The present invention provides a colloidal composition with thixotropic properties, comprising a first gelatin and a second gelatin; the gel strength of the first gelatin is less than 200 Bloom g; the gel strength of the second gelatin is greater than or equal to 200 Bloom g; and the total gel strength of the first gelatin and the second gelatin is 1200 to 1900 Bloom g.

[0007] Preferably, the gel strength of the first gelatin is 100-150 Bloom·g; and the gel strength of the second gelatin is 200-240 Bloom·g.

[0008] Preferably, the mass ratio of the first gelatin to the second gelatin is 0.5 to 2.5:1.

[0009] The present invention also provides a method for preparing the above-mentioned colloidal composition with thixotropic properties, comprising the following steps:

[0010] S1) The first gelatin and the second gelatin are heated and mixed in the solution to form a colloidal solution;

[0011] S2) The colloidal solution is subjected to rapid cooling and refrigeration to obtain a colloidal composition with thixotropic properties.

[0012] Preferably, the heating and mixing temperature in step S1) is 60℃~75℃; the heating and mixing time is 20~40min.

[0013] Preferably, the rapid cooling process specifically involves reducing the temperature of the colloidal solution from above 40°C to 20°C to 30°C within 2 to 4 hours.

[0014] Preferably, the temperature for post-cold ripening is 2℃ to 10℃; and the post-cold ripening time is at least 8 hours.

[0015] The present invention also provides a dairy product comprising the above-described colloidal composition having thixotropic properties.

[0016] Preferably, the dairy product is a fermented dairy product or a dairy pudding.

[0017] Preferably, the dairy product further includes particulate matter; the mass of the particulate matter is 5% to 20% of the mass of the dairy product.

[0018] This invention provides a thixotropic colloidal composition comprising a first gelatin and a second gelatin; the first gelatin has a gel strength of less than 200 Bloom·g; the second gelatin has a gel strength greater than or equal to 200 Bloom·g; and the total gel strength of the first and second gelatin is 1200–1900 Bloom·g. Compared with the prior art, this invention combines gelatin with different gel strengths and controls the total amount added to obtain a thixotropic colloidal composition, which, when applied to dairy processing, can impart good texture, sensory properties, and stability to dairy products.

[0019] This invention also provides a method for preparing a colloidal composition with thixotropic properties, comprising the following steps: S1) heating and mixing a first gelatin and a second gelatin in a solution to form a colloidal solution; S2) subjecting the colloidal solution to rapid cooling and post-cold curing to obtain a colloidal composition with thixotropic properties. Compared with the prior art, this invention combines gelatin with different gel strengths and combines rapid cooling and post-cold curing to give the colloidal composition good thixotropic properties and structural characteristics. Applying this composition and its preparation method to dairy product processing can impart good texture, sensory performance, and stability to dairy products.

[0020] Furthermore, this invention combines hot filling and a two-stage cooling process. When the colloidal composition is at 30℃ to 45℃, it begins to form a gel network, exhibiting weak gel properties. This ensures that foreign particles do not all float or sink, and also withstands external forces such as shear, maintaining gelation and giving the colloidal composition good processing performance. When the colloidal composition is cooled to 20℃ to 30℃, it is in a critical period of liquid-to-solid phase transformation, which further enhances gel performance, giving the colloidal composition good textural strength and reducing the precipitation of whey and other liquids. The staged cooling at 20℃ to 30℃ and 2℃ to 10℃ further endows the colloidal composition with good thixotropic properties and structural characteristics. Applying this composition and its preparation method to dairy product processing can impart good texture, sensory characteristics, and stability to dairy products. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] The present invention provides a colloid; the colloid comprises a first gelatin and a second gelatin; the first gelatin has a gel strength value of less than 200 Bloom·g; and the second gelatin has a gel strength value of greater than or equal to 200 Bloom·g.

[0023] In one specific embodiment of the present invention, the gel strength of the first gelatin is preferably 100 to 150 Bloom·g; optionally, the gel strength of the first gelatin is 100 Bloom·g, 110 Bloom·g, 120 Bloom·g, 130 Bloom·g, 140 Bloom·g, 150 Bloom·g or any two of the above values.

[0024] In one specific embodiment of the present invention, the first gelatin may be one or more of the following: gel strength value less than 200 Bloom·g, without any particular limitation.

[0025] In one specific embodiment of the present invention, the gel strength of the second gelatin is preferably 200 to 240 Bloom·g; optionally, the gel strength of the first gelatin is 200 Bloom·g, 210 Bloom·g, 220 Bloom·g, 230 Bloom·g, 240 Bloom·g or any two of the above values.

[0026] In one specific embodiment of the present invention, the second gelatin may be one or more of the following: a gel strength value greater than or equal to 200 Bloom·g. There are no particular limitations.

[0027] In one specific embodiment of the present invention, the mass ratio of the first gelatin to the second gelatin is preferably 0.5 to 2.5:1; optionally, the mass ratio of the first gelatin to the second gelatin is 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.2:1, 1.5:1, 1.8:1, 2.0:1, 2.2:1, 2.5:1, or any two of the above ratios; in some embodiments of the present invention, the mass ratio of the first gelatin to the second gelatin is specifically 2:1, 0.8:1, or 0.6:1.

[0028] In a specific embodiment of the present invention, the total gel strength of the first gelatin and the second gelatin is 1200-1900 Bloom g; the total gel strength of the first gelatin and the second gelatin is specifically calculated according to the following formula: G=F1×m1+F2×m2; where G is the total gel strength, F1 is the gel strength of the first gelatin, m1 is the mass of the first gelatin in g, F2 is the gel strength of the second gelatin, and m2 is the mass of the second gelatin in g.

[0029] Optionally, the total gel strength of the first gelatin and the second gelatin is 1200 Bloom g, 1300 Bloom g, 1400 Bloom g, 1500 Bloom g, 1600 Bloom g, 1700 Bloom g, 1800 Bloom g, 1900 Bloom g, or any two of the above values; in some embodiments provided by the present invention, the total gel strength of the first gelatin and the second gelatin is specifically 1320 Bloom g, 1600 Bloom g, or 1700 Bloom g.

[0030] This invention uses gelatin with different gel strengths as a colloid, which is used as a stabilizer in the preparation of dairy products, thereby improving the texture, sensory properties and stability of dairy products.

[0031] The present invention provides a colloidal composition with thixotropic properties, comprising a first gelatin and a second gelatin; the gel strength of the first gelatin is less than 200 Bloom g; the gel strength of the second gelatin is greater than or equal to 200 Bloom g; and the total gel strength of the first gelatin and the second gelatin is 1200 to 1900 Bloom g.

[0032] In one specific embodiment of the present invention, the gel strength of the first gelatin is preferably 100 to 150 Bloom·g; optionally, the gel strength of the first gelatin is 100 Bloom·g, 110 Bloom·g, 120 Bloom·g, 130 Bloom·g, 140 Bloom·g, 150 Bloom·g or any two of the above values.

[0033] In one specific embodiment of the present invention, the gel strength of the second gelatin is preferably 200 to 240 Bloom·g; optionally, the gel strength of the first gelatin is 200 Bloom·g, 210 Bloom·g, 220 Bloom·g, 230 Bloom·g, 240 Bloom·g or any two of the above values.

[0034] In one specific embodiment of the present invention, the mass ratio of the first gelatin to the second gelatin is preferably 0.5 to 2.5:1; optionally, the mass ratio of the first gelatin to the second gelatin is 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.2:1, 1.5:1, 1.8:1, 2.0:1, 2.2:1, 2.5:1, or any two of the above ratios; in some embodiments of the present invention, the mass ratio of the first gelatin to the second gelatin is specifically 2:1, 0.8:1, or 0.6:1.

[0035] The total gel strength of the first gelatin and the second gelatin is 1200–1900 Bloom g; optionally, the total gel strength of the first gelatin and the second gelatin is 1200 Bloom g, 1300 Bloom g, 1400 Bloom g, 1500 Bloom g, 1600 Bloom g, 1700 Bloom g, 1800 Bloom g, 1900 Bloom g, or any two of the above values; in some embodiments provided by the present invention, the total gel strength of the first gelatin and the second gelatin is specifically 1320 Bloom g, 1600 Bloom g, or 1700 Bloom g.

[0036] According to the present invention, the colloidal composition with thixotropic properties can be an acidic solidified food or a neutral solidified food.

[0037] In a specific embodiment of the present invention, the thixotropic colloidal composition further includes a fermenting agent; the fermenting agent can be any fermenting agent well known to those skilled in the art, and there are no special limitations. In the present invention, *Lactobacillus* and / or *Streptococcus* are preferred, more preferably *Lactobacillus delbrueckii* subsp. bulgaricus and / or *Streptococcus salivarius* subsp. thermophilicus, and even more preferably *Lactobacillus delbrueckii* subsp. bulgaricus and *Streptococcus salivarius* subsp. thermophilicus; the mass ratio of *Lactobacillus delbrueckii* subsp. bulgaricus to *Streptococcus salivarius* subsp. thermophilicus is preferably 1:1; the viable count of the fermenting agent is ≥1×10⁻⁶. 9 CFU / g; In the embodiments provided by the present invention, the fermentation agent of strain DSM Pioneer02 is specifically used as an example for illustration; The mass of the fermentation agent is preferably 0.01% to 0.1% of the colloidal composition, more preferably 0.02% to 0.08%, even more preferably 0.04% to 0.06%, and most preferably 0.05%.

[0038] In a specific embodiment of the present invention, the thixotropic colloidal composition further includes particulate matter; the mass of the particulate matter is preferably 5% to 20% of the mass of the thixotropic colloidal composition, more preferably 10% to 20%; the particulate matter can be any particulate matter known to those skilled in the art, and there are no special limitations. In the present invention, it is preferably fruit granules and / or powdered substances; the size of the fruit granules is preferably 1mm×1mm×1mm to 15mm×15mm×15mm, more preferably 5mm×5mm×5mm to 10mm×10mm×10mm, and even more preferably 8mm×8mm×8mm; the particle size range of the powdered substances is preferably 0.01 to 0.15mm.

[0039] In one specific embodiment of the present invention, the dairy product further includes liquid milk; the liquid milk can be any liquid milk known to those skilled in the art, and there are no special limitations. In the present invention, it is preferably one or more of cow milk, goat milk and reconstituted milk.

[0040] The present invention also provides a method for preparing the above-mentioned colloidal composition with thixotropic properties, comprising the following steps: S1) heating and mixing a first gelatin and a second gelatin in a solution to form a colloidal solution; S2) subjecting the colloidal solution to rapid cooling and refrigeration for ripening to obtain a colloidal composition with thixotropic properties.

[0041] In this invention, there are no special restrictions on the source of any raw materials; commercially available materials are acceptable. The types and proportions of the first gelatin and the second gelatin are the same as described above and will not be repeated here.

[0042] The first gelatin and the second gelatin are heated and mixed in a solution to form a colloidal solution. The solution can be any solution known to those skilled in the art and can be selected according to the type of colloidal composition to be prepared, and may include water and / or liquid emulsion. The liquid emulsion can be any liquid emulsion known to those skilled in the art and is not particularly limited; in this invention, it is preferably one or more of cow's milk, sheep's milk, and reconstituted milk. The solution may also preferably include other flavor additives, such as sweeteners, fruit juice, or flavorings. The total mass of the first gelatin and the second gelatin is preferably 0.5% to 1.5% of the mass of the colloidal composition, more preferably 0.6% to 1.2%, even more preferably 0.8% to 1.0%, and most preferably 0.9%. The heating and mixing temperature is preferably 60℃ to 75℃, more preferably 65℃ to 75℃, even more preferably 70℃ to 75℃, and most preferably 73℃ to 75℃. The heating and mixing time is preferably 20 to 40 minutes, more preferably 25 to 35 minutes, even more preferably 28 to 32 minutes, and most preferably 30 minutes.

[0043] In a specific embodiment of the present invention, the colloidal solution preferably further undergoes homogenization and sterilization treatment; the homogenization treatment can employ any homogenization method well-known to those skilled in the art, without any particular limitation, but a two-stage homogenization process is preferred in this invention; the pressure of the first-stage homogenization in the two-stage homogenization process is preferably 30-50 bar, more preferably 35-45 bar, even more preferably 38-42 bar, and most preferably 40 bar; the pressure of the second-stage homogenization in the two-stage homogenization process is preferably 150-250 bar, more preferably 180-220 bar, and even more preferably 200 bar; the temperature of the homogenization treatment is preferably... The temperature is selected as 50℃~70℃, more preferably 55℃~70℃, even more preferably 60℃~86℃, even more preferably 60℃~65℃, and most preferably 63℃; the sterilization treatment method can be any method well known to those skilled in the art and there are no special limitations. In this invention, the sterilization treatment temperature is preferably 75℃~100℃, more preferably 80℃~95℃, even more preferably 85℃~95℃, even more preferably 90℃~95℃, and most preferably 95℃; the sterilization treatment time is preferably 100~600s, more preferably 200~500s, even more preferably 200~400s, even more preferably 250~350s, and most preferably 300s.

[0044] In a specific embodiment of the present invention, the sterilized colloidal solution can be cooled and inoculated with a fermenting agent for fermentation, depending on the type of colloidal composition to be obtained; the cooling temperature is preferably 40℃~45℃; optionally, the cooling temperature is 40℃, 41℃, 42℃, 43℃, 44℃, 45℃ or any two of the above values; the fermenting agent can be any fermenting agent known to those skilled in the art, and there are no special limitations. In the present invention, Lactobacillus and / or Streptococcus are preferred, more preferably Lactobacillus delbrueckii subsp. bulgaricus and / or Streptococcus salivarius subsp. thermophilicus, and even more preferably Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilicus; the mass ratio of Lactobacillus delbrueckii subsp. bulgaricus to Streptococcus salivarius subsp. thermophilicus is preferably 1:1; the viable count of the fermenting agent is ≥1×10⁻⁶. 9 CFU / g; In the embodiments provided by the present invention, the fermentation agent of strain DSM Pioneer02 is specifically used as an example for illustration; the mass of the fermentation agent is preferably 0.01% to 0.1% of the colloidal composition, more preferably 0.02% to 0.08%, even more preferably 0.04% to 0.06%, and most preferably 0.05%; the fermentation temperature is preferably 40℃ to 45℃; optionally, the fermentation temperature is 40℃, 41℃, 42℃, 43℃, 44℃, 45℃ or any two of the above values; the fermentation is preferably carried out until the acidity is ≥70°T.

[0045] In another specific embodiment of the present invention, the sterilized colloidal solution can be cooled according to the type of colloidal composition to be obtained; the cooling temperature is preferably 40°C to 45°C; optionally, the cooling temperature is 40°C, 41°C, 42°C, 43°C, 44°C, 45°C or any two of the above values.

[0046] In one specific embodiment of the present invention, a cooled colloidal solution or a fermented colloidal solution is mixed with particulate matter; the particulate matter can be any particulate matter well known to those skilled in the art and is not particularly limited, but is preferably fruit granules and / or powdered material; the size of the fruit granules is preferably 1mm×1mm×1mm to 15mm×15mm×15mm, more preferably 5mm×5mm×5mm to 10mm×10mm×10mm, and even more preferably 8mm×8mm×8mm; the particle size range of the powdered material is preferably 0.01 to 0.15mm; the mass of the particulate matter is preferably 5% to 20% of the mass of the colloidal composition, more preferably 10% to 20%.

[0047] Since the colloidal composition needs to be stored in a container, in a specific embodiment of the present invention, it is preferable to fill the cooled colloidal solution, the fermented colloidal solution, or the colloidal solution of mixed particles; during the filling process, it is preferable to maintain the temperature of the cooled colloidal solution, the fermented colloidal solution, or the colloidal solution of mixed particles at 40°C to 45°C; optionally, it is 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, or any two of the above values.

[0048] The above-mentioned cooled colloidal solution, fermented colloidal solution, colloidal solution of mixed particles, or packaged colloidal solution are subjected to rapid cooling and refrigerated ripening to obtain a colloidal composition with thixotropic properties. Specifically, the rapid cooling process involves lowering the temperature of the colloidal solution from above 40°C to 20°C to 30°C within 2–4 hours. Preferably, the rapid cooling time is 3.5–4 hours, more preferably 3–4 hours; the rapid cooling temperature is preferably 20°C to 28°C, more preferably 20°C to 25°C; the refrigerated ripening temperature is preferably 2°C to 10°C, more preferably 2°C to 8°C, and even more preferably 4°C to 6°C; the refrigerated ripening time is preferably at least 8 hours, more preferably 8–20 hours, even more preferably 10–20 hours, and most preferably 12–18 hours. During the cooling process, the colloidal composition undergoes a transformation from liquid to solid.

[0049] In a specific embodiment of the present invention, the preparation method of the thixotropic colloidal composition is as follows: a first gelatin and a second gelatin are added to an appropriate amount of solution and heated. The solution is stirred at 60°C to 75°C for 20 to 40 minutes to form a colloidal solution. After mixing with particulate matter, the solution is filled into a container or directly filled into a container. The solution is then rapidly cooled to 20°C to 30°C for 2 to 4 hours, and finally further cooled to 2 to 10°C. The solution is then subjected to refrigeration and ripening at this temperature for at least 8 hours. During the cooling process, the colloidal composition completes the transformation from liquid to solid, thus obtaining the colloidal composition.

[0050] In another specific embodiment of the present invention, the preparation method of the thixotropic colloidal composition is as follows: a first gelatin and a second gelatin are added to an appropriate amount of solution and heated. The solution is stirred at 60°C to 75°C for 20 to 40 minutes to form a colloidal solution. The solution is then cooled and inoculated with a fermenting agent for fermentation. After being mixed with particulate matter, the solution is filled into a container or directly into a container. The solution is then rapidly cooled to 20°C to 30°C for 2 to 4 hours. Finally, the solution is further cooled to 2 to 10°C and subjected to refrigeration for at least 8 hours. During the cooling process, the colloidal composition completes the transformation from liquid to solid, thus obtaining the colloidal composition.

[0051] This invention combines hot filling and a two-stage cooling process. When the colloidal composition is at 30℃ to 45℃, it begins to form a gel network, exhibiting weak gel properties. This ensures that foreign particles do not all float or sink, and also resists external forces such as shear, maintaining gelation and giving the colloidal composition good processing performance. When the colloidal composition is cooled to 20℃ to 30℃, it is in a critical period of liquid-to-solid phase transformation, which further enhances gel performance, giving the colloidal composition good textural strength and reducing the precipitation of whey and other liquids. The staged cooling at 20℃ to 30℃ and 2℃ to 10℃ further endows the colloidal composition with good thixotropic properties and structural characteristics. Applying this composition and its preparation method to dairy product processing can impart good texture, sensory characteristics, and stability to dairy products.

[0052] The colloidal composition provided by this invention contains gelatin with low gel strength (<200 Bloom·g) and gelatin with high gel strength (≥200 Bloom·g). By studying the addition ratio and total amount of low-strength and high-strength gelatin, a colloidal composition with thixotropic properties is prepared. In addition, by adjusting the operating temperature of the above composition and converting it from the liquid phase to the solid phase, the composition can exhibit specific structural characteristics. It has a firm tissue state at low temperatures and exhibits good fluidity when subjected to external forces at temperatures close to human body temperature.

[0053] The present invention also provides a dairy product comprising the above-described colloidal composition having thixotropic properties.

[0054] In one specific embodiment of the present invention, the dairy product is preferably a fermented dairy product or a dairy pudding.

[0055] In a specific embodiment of the present invention, the dairy product further includes particulate matter; the mass of the particulate matter is preferably 5% to 20% of the mass of the dairy product, more preferably 10% to 20%; the particulate matter can be any particulate matter known to those skilled in the art, and there are no special limitations. In the present invention, it is preferably fruit granules and / or powdered substances; the size of the fruit granules is preferably 1mm×1mm×1mm to 15mm×15mm×15mm, more preferably 5mm×5mm×5mm to 10mm×10mm×10mm, and even more preferably 8mm×8mm×8mm; the particle size range of the powdered substances is preferably 0.01 to 0.15mm.

[0056] In one specific embodiment of the present invention, the fruit pieces are fruit jam; the net fruit piece content of the fruit jam is ≥30%.

[0057] In one specific embodiment of the present invention, the dairy product further includes liquid milk; the liquid milk can be any liquid milk known to those skilled in the art, and there are no special limitations. In the present invention, it is preferably one or more of cow milk, goat milk and reconstituted milk.

[0058] In one specific embodiment of the present invention, the dairy product further includes a starter culture agent; the starter culture agent can be any starter culture agent known to those skilled in the art, and there are no special limitations. In the present invention, Lactobacillus and / or Streptococcus are preferred, more preferably Lactobacillus delbrueckii subsp. bulgaricus and / or Streptococcus salivarius subsp. thermophilus; the mass of the starter culture agent is preferably 0.01% to 0.1% of the colloidal composition, more preferably 0.02% to 0.08%, even more preferably 0.04% to 0.06%, and most preferably 0.05%.

[0059] To further illustrate the present invention, the following describes in detail, with reference to embodiments, a colloidal composition with thixotropic properties provided by the present invention and its applications.

[0060] All reagents used in the following examples are commercially available; the mass ratio of *Lactobacillus delbrueckii* subsp. bulgaricus to *Streptococcus salivarius* subsp. *thermophilus* in the fermentation spores used in the examples and comparative examples is 1:1, and the viable count is ≥1×10⁻⁶. 9 CFU / g, strain type DSMPioneer02, and net fruit particle content of the jam ≥30%.

[0061] Example 1

[0062] This embodiment provides a fermented dairy product containing a colloidal composition, as detailed below.

[0063] I. Raw material formula (per 1000g):

[0064]

[0065] The colloid consists of 6g of 100 Bloom·g gelatin and 3g of 240 Bloom·g gelatin; the total gel strength of the colloid is 1320 Bloom g; the jam contains strawberry particles of 8mm×8mm×8mm; and the starter culture consists of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0066] II. Preparation method:

[0067] (1) Mixing: Heat the milk to 73°C, then add the colloidal mixture into the milk and circulate the mixture for 30 minutes to obtain a mixture.

[0068] (2) Homogenization and sterilization: The mixture obtained in step (1) is preheated to 63°C and homogenized. The first pressure is 40 bar and the second pressure is 200 bar. Then the homogenized liquid is sterilized at 95°C for 300 seconds.

[0069] (3) Inoculation and fermentation: Add the fermenting agent to the above liquid, stir for 5 minutes, and then let it stand at 43°C for 6 hours. The fermentation endpoint is when the acidity is ≥70°T. Stop the fermentation.

[0070] (4) Filling: The temperature of the fermented liquid is controlled at 43°C. The jam and the above liquid are mixed by an online addition system and then filled into containers.

[0071] (5) Rapid cooling: The temperature of the above products is rapidly cooled to 25°C within 3 hours and then transferred to a cold storage.

[0072] (6) Post-fermentation of finished product: After refrigeration at 4-6℃ for 12 hours, fermented dairy products are obtained.

[0073] Example 2

[0074] This embodiment provides a fermented dairy product containing a colloidal composition, as detailed below.

[0075] I. Raw material formula (per 1000g):

[0076] Colloid: 9g;

[0077] Fermentation agent: 0.5g;

[0078] Milk: Remaining amount (i.e., replenish to 1000g);

[0079] The colloid is 4g of 100 Bloom·g gelatin or 5g of 240 Bloom·g gelatin, with a gel strength of 1600 Bloom g; the fermenting agent is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0080] II. Preparation method:

[0081] (4) Filling: The temperature of the fermented liquid is controlled at 43°C and directly filled into containers. Other steps are the same as in Example 1.

[0082] Example 3

[0083] This embodiment provides a milk pudding containing a colloidal composition, as detailed below.

[0084] I. Raw material formula (per 1000g):

[0085] Colloid: 9g;

[0086] Jam: 200g;

[0087] Milk: Remaining amount (i.e., replenish to 1000g);

[0088] The colloid is composed of 1g of 100 Bloom·g gelatin, 2g of 150 Bloom·g gelatin, and 5g of 240 Bloom·g gelatin, with a gel strength of 1600 Bloom g; the jam contains strawberry particles of 8mm×8mm×8mm.

[0089] II. Preparation method:

[0090] (1) Mixing: Heat the milk to 75°C, then add the colloidal mixture into the milk and circulate the mixture for 30 minutes to obtain a mixture.

[0091] (2) Homogenization and sterilization: The mixture obtained in step (1) is preheated to 63°C and homogenized. The first pressure is 40 bar and the second pressure is 200 bar. Then the homogenized liquid is sterilized at 95°C for 300 seconds.

[0092] (3) Cooling: Cool the homogenized and sterilized mixture obtained in step (2) to 40°C.

[0093] (4) Filling: The jam and the above liquid are mixed by an online adding system and then filled into containers. The temperature of the liquid is kept above 40°C during the filling process.

[0094] (5) Rapid cooling: The temperature of the above products is rapidly cooled to 20°C within 4 hours and then transferred to a cold storage.

[0095] (6) Finished product ripening: After refrigeration at 4-6℃ for 18 hours, dairy pudding is obtained.

[0096] Example 4

[0097] This embodiment provides a milk pudding containing a colloidal composition, as detailed below.

[0098] I. Raw material formula (per 1000g):

[0099] Colloid: 9g;

[0100] Milk: Remaining amount (i.e., replenish to 1000g);

[0101] The colloid is composed of 2g of 120 Bloom·g gelatin, 2g of 150 Bloom·g gelatin, and 5g of 240 Bloom·g gelatin; the gel strength of the colloid is 1700 Bloom g.

[0102] II. Preparation method:

[0103] (4) Filling: The liquid is directly filled into the container, and the temperature is kept above 40°C during the filling process. Other procedures are the same as in Example 3.

[0104] Comparative Example 1

[0105] This comparative example provides a fermented dairy product, as detailed below.

[0106] I. Raw material formula (per 1000g):

[0107]

[0108] The colloid is composed of 1.6g of 100 Bloom·g gelatin and 6g of 240 Bloom·g gelatin; the gel strength of the colloid is 1600 Bloom g; the jam contains strawberry particles of 8mm×8mm×8mm; the starter is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0109] II. Preparation method: Same as in Example 1.

[0110] Comparative Example 2

[0111] This comparative example provides a fermented dairy product, as detailed below.

[0112] I. Raw material formula (per 1000g):

[0113]

[0114] Among them, the agar gel strength is 500±100 g / cm. 2 The jam contains strawberry pieces measuring 8mm × 8mm × 8mm; the starter culture is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0115] II. Preparation method: Same as in Example 1.

[0116] Comparative Example 3

[0117] This comparative example provides a fermented dairy product, as detailed below.

[0118] I. Raw material formula (per 1000g):

[0119]

[0120]

[0121] The gelatin is 240 Bloom g gelatin; the agar gel strength is 500 ± 100 g / cm³. 2 The jam contains strawberry pieces measuring 8mm × 8mm × 8mm; the starter culture is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0122] II. Preparation method: Same as in Example 1.

[0123] Comparative Example 4

[0124] This comparative example provides a fermented dairy product, as detailed below.

[0125] I. Raw material formula (per 1000g):

[0126]

[0127] The jam contains strawberry pieces measuring 8mm × 8mm × 8mm; the starter culture is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0128] II. Preparation method: Same as in Example 1.

[0129] Comparative Example 5

[0130] This comparative example provides a fermented dairy product, as detailed below.

[0131] I. Raw material formula (per 1000g):

[0132]

[0133] The gelatin is 240 Bloom·g gelatin, the jam contains strawberry particles of 8mm×8mm×8mm, and the starter is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0134] II. Preparation method: Same as in Example 1.

[0135] Comparative Example 6

[0136] This comparative example provides a fermented dairy product, as detailed below.

[0137] I. Raw material formula (per 1000g):

[0138]

[0139]

[0140] The gelatin is 240 Bloom·g gelatin with a gel strength of 1704 Bloom·g; the jam contains strawberry particles of 8mm×8mm×8mm; the starter culture is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0141] II. Preparation method: Same as in Example 1.

[0142] Comparative Example 7

[0143] This comparative example provides a fermented dairy product, as detailed below.

[0144] I. Raw material formula (per 1000g):

[0145]

[0146] The colloid is 5g of 100 Bloom·g gelatin or 5.5g of 150 Bloom·g gelatin; the gel strength of the colloid is 1325 Bloom·g; the jam contains strawberry particles of 8mm×8mm×8mm; the starter is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0147] II. Preparation method: Same as in Example 1.

[0148] Comparative Example 8

[0149] This comparative example provides a fermented dairy product, as detailed below.

[0150] I. Raw material formula (per 1000g):

[0151]

[0152] The colloid is composed of 2g of 100 Bloom·g gelatin, 2g of 150 Bloom·g gelatin, and 2g of 240 Bloom·g gelatin; the gel strength of the colloid is 980 Bloom g; the jam contains strawberry particles of 8mm×8mm×8mm; and the starter culture is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0153] II. Preparation method: Same as in Example 1.

[0154] Comparative Example 9

[0155] This embodiment provides a fermented dairy product, as detailed below.

[0156] I. Raw material formula (per 1000g):

[0157]

[0158] The colloid is composed of 3g of 100 Bloom·g gelatin, 4g of 150 Bloom·g gelatin, and 5g of 240 Bloom·g gelatin; the gel strength of the colloid is 2100 Bloom g; the jam contains strawberry particles of 8mm×8mm×8mm; and the starter culture is Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus.

[0159] II. Preparation method: Same as in Example 1.

[0160] Comparative Example 10

[0161] I. Raw material formula (per 1000g): Same as Example 1.

[0162] II. Preparation method:

[0163] The preparation method is the same as in Example 1, except that:

[0164] (4) Filling: The fermented liquid is cooled by a pipe and plate exchange to keep the temperature at 20°C. The jam and the liquid are mixed by an online addition system and then filled into containers.

[0165] (6) Finished product maturation: Since the temperature of the liquid after canning is 20℃, there is no need to go through (5) rapid cooling treatment. It can be directly refrigerated at 4~6℃ for 18 hours to obtain fermented milk.

[0166] Comparative Example 11

[0167] I. Raw material formula (per 1000g): Same as Example 1.

[0168] II. Preparation method:

[0169] The preparation method is the same as in Example 1, except that:

[0170] (4) Filling: The temperature of the fermented liquid is controlled at 43°C. The jam and the above liquid are mixed by an online addition system and then filled into containers.

[0171] (6) Finished product maturation: The product obtained in step (4) is not subjected to the rapid cooling treatment in step (5), but is directly refrigerated at 4-6℃ for 18 hours to obtain fermented milk.

[0172] Comparative Example 12

[0173] I. Raw material formula (per 1000g): Same as Example 1.

[0174] II. Preparation method:

[0175] The preparation method is the same as in Example 1, except that:

[0176] (4) Filling: The temperature of the fermented liquid is controlled at 43°C. The jam and the above liquid are mixed by an online addition system and then filled into containers.

[0177] (5) Rapid cooling: The temperature of the above products is rapidly cooled to 15°C within 3 hours and then transferred to a cold storage.

[0178] (6) Post-fermentation of finished product: After refrigeration at 4-6℃ for 18 hours, fermented milk is obtained.

[0179] Test Example 1: Experiment on the two-phase transformation process and textural properties of the composition

[0180] When the colloidal composition is completely converted into a solid phase, it can form a strong gel network. The colloidal ratio in the composition will significantly affect the gel strength and texture. Therefore, it is necessary to conduct experimental research on the amount of gelatin added for different gel strengths.

[0181] Texture testing method: The BROOKFIELD CT3 texture analyzer was used with a TA11 probe in compression mode. The test target was measured at a distance of 10 mm, the contact load was 1 g, the forward speed was 1 mm / s, and the backward speed was 1 mm / s. The hardness, adhesion, and elasticity of the product were tested. The experimental results are shown in Table 1.

[0182] Table 1. Texture Test Results

[0183] Hardness (g) Adhesion (g) elasticity Example 1 212.5 30.75 0.195 Example 2 185.5 31.05 0.175 Example 3 227.0 30.25 0.205 Example 4 187.5 30.35 0.195 Comparative Example 1 268.5 46.55 0.395 Comparative Example 2 260.5 22.75 0.155 Comparative Example 3 297.5 46.55 0.415 Comparative Example 4 285.5 45.05 0.405 Comparative Example 5 305.0 45.55 0.410 Comparative Example 6 205.5 23.25 0.125 Comparative Example 7 210.5 21.05 0.135 Comparative Example 8 150.5 20.75 0.120 Comparative Example 9 335.0 48.05 0.395 Comparative Example 10 78.5 49.45 0.165 Comparative Example 11 67.0 50.55 0.105 Comparative Example 12 50.5 52.75 0.105

[0184] Test Example 2: Experiment on the two-phase transformation process and thixotropic effect of the composition

[0185] During the transformation of a colloidal composition from a liquid phase to a solid phase, a strong gel network can be formed. Gelatin molecules with different gel strengths interact with each other and are rationally distributed within the gel network. After complete transformation to a solid phase, the colloidal composition exhibits excellent thixotropic properties. The temperature and time of transformation significantly affect the thixotropic properties of the composition, therefore, experimental studies on these factors are necessary.

[0186] Thixotropy test method: Anton-Paar RST-CC rheometer with CCT-40 probe was used. Two shear rates were set: 0-300 1 / s and 300-2 1 / s. The operating temperature was 30℃. The thixotropy of the product was tested. The experimental results are shown in Table 2.

[0187] Table 2. Thixotropic test results

[0188] Thixotropy (Pa / s) Example 1 2588.626 Example 2 2605.782 Example 3 2865.486 Example 4 2785.329 Comparative Example 1 1899.481 Comparative Example 2 1237.566 Comparative Example 3 967.251 Comparative Example 4 952.779 Comparative Example 5 958.657 Comparative Example 6 1652.293 Comparative Example 7 1253.798 Comparative Example 8 822.467 Comparative Example 9 1784.869 Comparative Example 10 1525.837 Comparative Example 11 849.665 Comparative Example 12 532.318

[0189] In texture testing, hardness represents the maximum force required for teeth to compress the product; this indicator is mainly related to the product's gel strength. Adhesion represents the force required to overcome the attraction between the product surface and surfaces that come into contact with the product, such as teeth or tongue; this indicator is mainly related to the product's viscosity and viscoelastic properties. Elasticity represents the product's ability to recover from deformation under stress; this indicator is mainly related to the product's thixotropic properties. Thixotropy testing simulates the real-time viscosity change of yogurt after it is squeezed by teeth and tongue upon entering the mouth, describing the rheological properties of the product after entry. In the above examples, the hardness, adhesion, elasticity, and thixotropic properties of the composite products are moderate. However, comparative examples 2-5 with added agar and carrageenan, and comparative examples 6-9 with adjusted gelatin composition ratios, exhibit poor thixotropic performance. Comparative examples 10-12 with adjusted filling temperature, rapid cooling temperature, or no rapid cooling treatment show a sharp decrease in thixotropy.

[0190] Test Example 3: Sensory Evaluation Test of Composition Applied to Article

[0191] Thirty professional tasters (male to female ratio of 1:1) were selected to evaluate the product in terms of texture and taste according to the evaluation criteria shown in Table 3. Each indicator was scored out of 10 points. The sensory evaluation results were the average of the scores from the 30 people. The sensory evaluation results are shown in Table 4.

[0192] Table 3 Sensory Evaluation Criteria

[0193] project Scoring Criteria Score Organizational status The tissue is uniform, elastic, and free of whey separation. 10.0 taste Tender, smooth, and melts in your mouth 10.0

[0194] Table 4. Sensory Evaluation Results Data Table

[0195]

[0196]

[0197] Sensory evaluation shows that the products composed of Examples 1-4 have a firm texture, melt in the mouth, and have a delicate taste. There is no whey separation on the surface of the products. In Examples 1 and 3 with added jam, the fruit pieces do not float on the surface or settle at the bottom, but are evenly distributed in the products. The products of Comparative Examples 1-5 and 9 are too hard, while the products of Comparative Examples 8 and 10-12 are too soft. Moreover, all the comparative examples are not smooth enough in the mouth, and the fruit pieces settle at the bottom and cannot be evenly distributed in the products. There is obvious whey separation on the surface of the products.

[0198] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A colloidal composition with thixotropic properties, characterized in that, It includes a first gelatin and a second gelatin; the gel strength of the first gelatin is less than 200 Bloom g; the gel strength of the second gelatin is greater than or equal to 200 Bloom g; and the total gel strength of the first gelatin and the second gelatin is 1200 to 1900 Bloom g.

2. The colloidal composition according to claim 1, characterized in that, The first gelatin has a gel strength of 100-150 Bloom·g; the second gelatin has a gel strength of 200-240 Bloom·g.

3. The colloidal composition according to claim 1, characterized in that, The mass ratio of the first gelatin to the second gelatin is 0.5 to 2.5:

1.

4. A method for preparing a colloidal composition with thixotropic properties as described in claim 1, characterized in that, Includes the following steps: S1) The first gelatin and the second gelatin are heated and mixed in the solution to form a colloidal solution; S2) The colloidal solution is subjected to rapid cooling and refrigeration to obtain a colloidal composition with thixotropic properties.

5. The preparation method according to claim 4, characterized in that, In step S1), the heating and mixing temperature is 60℃~75℃; the heating and mixing time is 20~40min.

6. The preparation method according to claim 4, characterized in that, The rapid cooling process specifically involves reducing the temperature of the colloidal solution from above 40°C to 20°C to 30°C within 2 to 4 hours.

7. The preparation method according to claim 4, characterized in that, The temperature for post-cold ripening is 2℃ to 10℃; the post-cold ripening time is at least 8 hours.

8. A dairy product, characterized in that, This includes the thixotropic colloidal composition according to any one of claims 1 to 3, or the thixotropic colloidal composition prepared by any one of claims 4 to 7.

9. The dairy product according to claim 8, characterized in that, The dairy product is a fermented dairy product or a dairy pudding.

10. The dairy product according to claim 8, characterized in that, The dairy product also includes particulate matter; the mass of the particulate matter is 5% to 20% of the mass of the dairy product.

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