Ice cream and preparation method thereof

Abstract

The invention provides ice cream and a preparation method thereof, and relates to the technical field of food processing. The ice cream comprises the following raw material components in parts by weight: 40-70 parts of partially skimmed milk, 10-40 parts of single cream and 3-20 parts of auxiliary materials, the fat content of the partially skimmed milk is 0.5 to 1.5 percent. According to the ice cream disclosed by the invention, the partial skimmed milk with the fat content of 0.5-1.5% is used as a main raw material, and the partial skimmed milk can replace a stabilizer, an emulsifying agent and a thickening agent, so that a good emulsifying and stabilizing effect is achieved, the stability and the melting resistance of the ice cream are improved, and the ice cream is endowed with rich and unique milk fragrance and basic flavor like cream cheese; the ice cream is mellow in milk fragrance, smooth in taste and full in fragrance, has nutrition and health, and meets the requirements of consumers for cleaning labels and natural flavor.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to an ice cream and its preparation method. Background Technology

[0002] Ice cream is a popular frozen beverage among consumers, prized for its smooth texture, rich milky flavor, refreshing taste, and easy absorption. Market demand has been growing year by year. As people's living standards improve, their demands for ice cream quality are also increasing. They not only seek authentic flavors but also prioritize health, nutrition, and natural ingredients.

[0003] Currently, ice cream on the market is mainly divided into soft-serve ice cream and hard ice cream. Hard ice cream's main ingredients include drinking water, raw milk, milk powder, and animal or plant-based cream. In the prior art, CN202210125384.4 discloses an ice cream and its preparation method; CN201911039818.3 discloses a soybean ice cream and its preparation method; and CN202311632154.8 discloses ice cream and its preparation method. It is evident that stabilizers and thickeners are typically added during the ice cream making process to enhance the rich, smooth texture and stability of the ice cream.

[0004] However, stabilizers and thickeners are mostly chemically synthesized or semi-synthetic products, such as carrageenan, xanthan gum, and guar gum. Although they can improve the texture and stability of ice cream to some extent, the addition of these ingredients deviates from modern consumers' demand for "natural and pure" food. They are not only difficult to align with the core claims of clean labels, but may also raise concerns among some consumers who are concerned about the purity of raw materials. They cannot fully meet the market's demand for simple and natural food ingredients. Moreover, with the change in consumer attitudes, the role of ice cream is not only to provide deliciousness, but also to provide nutrition and health. Therefore, ice cream containing stabilizers and other additives can no longer meet consumers' demands for clean labels. Summary of the Invention

[0005] This invention provides an ice cream and its preparation method. The ice cream has a clean and pure raw material formula, a rich flavor, a smooth texture, and a full aroma. It is also nutritious and healthy, meeting consumers' demand for clean labels.

[0006] In a first aspect, the present invention provides an ice cream comprising, by weight, the following raw material components: 40-70 parts of partially skimmed milk, 10-40 parts of light cream, and 3-20 parts of auxiliary ingredients; The fat content of the partially skimmed milk is 0.5% to 1.5%.

[0007] The ice cream of this invention uses partially skimmed milk with a fat content of 0.5-1.5% as the main raw material. The natural milk protein and fat globule membrane components in this partially skimmed milk play a good emulsifying and stabilizing role. This not only helps to form a fine texture with smaller ice crystals and improves melt resistance, but also effectively and quickly adsorbs onto the oil and water surface during emulsification, significantly reducing interfacial tension, forming a stable interfacial film, preventing the accumulation of fat in the product, and thus enhancing the stability of the ice cream.

[0008] This portion of skim milk can also replace the functions of stabilizers, emulsifiers, and thickeners. Furthermore, the ice cream of this invention does not contain flavorings, colorings, or other food additives, achieving an additive-free clean formula. This fully leverages the advantages of a clean formula, combining nutrition and health, meeting consumers' demands for clean labels and natural flavors, and aligning with the sustainable development concept of resource recycling.

[0009] Preferably, the partially skimmed milk is obtained by using separated cream from raw milk as raw material and performing multiple milk fat separation processes by heating.

[0010] In the preparation of partially skimmed milk, multiple heating processes are used to separate the milk fat. During the heating and separation process, the milk fat globule membrane ruptures, allowing some of the flavor substances produced by the Maillard reaction to remain in the partially skimmed milk. Through continuous heating and concentration, the flavor substances are continuously enriched, making the partially skimmed milk itself a flavor concentrate. As a result, without the addition of additional flavorings, it imparts a rich and unique milky aroma and a basic flavor similar to cream cheese to ice cream, reducing the use of artificial flavorings and making the ice cream have a rich milky aroma, smooth texture, and full fragrance.

[0011] Furthermore, the partially skimmed milk accounts for 40-70% of the total mass of the raw materials. Controlling the content of partially skimmed milk in the raw materials within the above range can give the ice cream a better taste.

[0012] Furthermore, the protein content of the partially skimmed milk is ≥2.9%.

[0013] Furthermore, the raw materials do not contain any one or more combinations of stabilizers, thickeners, and emulsifiers. Using the partially skimmed milk as a raw material can completely replace stabilizers, thickeners, and emulsifiers, effectively avoiding the use of additives and improving the health quality of the ice cream.

[0014] Furthermore, the light cream has a fat content of 35-45% and an acidity of ≤30. o T.

[0015] Furthermore, the excipients include 1-5 parts milk powder, 1-10 parts condensed milk, and 1-5 parts anhydrous butter.

[0016] Furthermore, the ice cream has a protein content of ≥3.5%, a fat content of ≥10.0%, and a total solids content of ≥30%.

[0017] A second aspect of the present invention provides a method for preparing ice cream as described above, comprising the following steps: (1) Mix the partially skimmed milk, light cream and excipients with a fat content of 0.5-1.5% to obtain a mixture; (2) The mixture is subjected to sterilization, homogenization, aging and hardening treatment.

[0018] In the preparation of the ice cream of the present invention, partially skimmed milk containing 0.5-1.5% fat is used. Due to the synergistic effect between the natural milk proteins and fat globule membranes and other natural surfactants in the partially skimmed milk, a more stable emulsion system is formed during homogenization and aging. This allows for the formation of finer and more uniform ice crystals and bubble distribution during hardening, resulting in an extremely delicate and smooth texture and better resistance to melting in the final product.

[0019] Furthermore, the method for preparing the partially skimmed milk with a fat content of 0.5-1.5% includes the following steps: a. Using separated cream from raw milk as raw material, the separated cream is heated and then centrifuged to separate the milk fat, resulting in concentrated cream and partially skimmed milk. b. Perform the milk fat separation step on the concentrated cream again, and then repeat the milk fat separation step on the separated concentrated cream or concentrated cream; if the fat content of the separated portion of skim milk is not in the range of 0.5~1.5% during milk fat separation, mix the portion of skim milk with concentrated cream or concentrated cream and then perform the milk fat separation again. c. Combine the partially skimmed milk with a fat content of 0.5-1.5% obtained from the milk fat separation and use it as a raw material for preparing ice cream.

[0020] This invention has discovered that by repeatedly heating concentrated cream or condensed butter after milk fat separation, the aroma of partially skimmed milk can be continuously enriched through multiple heating and separation processes. This also yields partially skimmed milk with a fat content of 0.5-1.5%. Using partially skimmed milk with a fat content of 0.5-1.5% obtained through multiple heating and separation processes as raw material can improve the stability and melt resistance of ice cream and impart a rich and mellow unique flavor similar to cream cheese.

[0021] Preferably, step b is repeated 1 to 4 times. When the number of repetitions is 1 to 4, flavor substances can be continuously enriched, making the milk flavor of the partially skimmed milk more mellow, and partially skimmed milk with a fat content of 0.5% to 1.5% can be obtained.

[0022] More preferably, in step b, the number of repetitions is 1 or 2.

[0023] Preferably, the heating temperature is 60~80℃, and the temperature is maintained for 15~60s after reaching 60~80℃.

[0024] Preferably, the centrifugation speed is 4000~6500 r / min and the centrifugation time is 1~30 s, more preferably the centrifugation time is 1~15 s.

[0025] Preferably, the raw milk has a fat content of ≥3.1% and a protein content of ≥2.9%.

[0026] Furthermore, during the preparation of the partially skimmed milk, if the fat content of the partially skimmed milk obtained from the milk fat separation is not in the range of 0.5-1.5%, then the concentrated light cream or concentrated butter separated at the same time as the partially skimmed milk is first homogenized, and then the homogenized concentrated light cream or concentrated butter is mixed with the partially skimmed milk whose fat content is not in the range of 0.5-1.5%, and then the milk fat separation is performed.

[0027] Furthermore, the cream separated from raw milk can also be used as a raw material for making ice cream, and this portion of cream used as a raw material needs to be sterilized.

[0028] Furthermore, the parameters of the homogenization include: a first-stage total pressure of 120~150 bar, a second-stage pressure of 20~30 bar, and a temperature of 65~75℃; And / or, the aging parameters include: temperature of 2~6℃ and time of 2~24h; And / or, the hardening includes: cooling the aged material at a temperature of -18 to -45°C until the core temperature rapidly drops below -18°C.

[0029] This invention provides an ice cream and its preparation method. The ice cream of this invention uses partially skimmed milk with a fat content of 0.5-1.5% as the main raw material. This partially skimmed milk can replace stabilizers, emulsifiers, and thickeners, playing a good role in emulsification and stabilization, improving the stability and anti-melting properties of the ice cream. It also gives the ice cream a rich and unique milky aroma and a basic flavor similar to cream cheese, making the ice cream creamy, smooth, and full of aroma. It fully utilizes the advantages of a clean formula, combining nutrition and health, meeting consumers' demand for clean labels and natural flavors, and conforming to the sustainable development concept of resource recycling. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a melting diagram of the ice cream prepared in Example 1.

[0032] Figure 2 This is a melting diagram of the ice cream prepared in Example 2.

[0033] Figure 3 This is a melting diagram of the ice cream prepared in Example 3.

[0034] Figure 4 This is a melting diagram of the ice cream prepared in Comparative Example 1.

[0035] Figure 5 This is a melting diagram of the ice cream prepared in Comparative Example 2.

[0036] Figure 6 This is a melting diagram of the ice cream prepared in Comparative Example 3.

[0037] Figure 7 This is a melting diagram of the ice cream prepared in Comparative Example 4.

[0038] Figure 8 This is a graph showing the melting of ice cream in the control group.

[0039] Figure 9 These are melting rate curves for ice cream from the examples, comparative examples, and control group. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0042] The following are the raw material information used in the examples and comparative examples: Raw milk: sourced from Ningxia Saizan Dairy Co., Ltd., with a protein content ≥2.9% and a fat content ≥3.1%. Milk powder: sourced from Ningxia Saizan Dairy Co., Ltd., with a protein content ≥ 34% non-fat milk solids and a fat content ≤ 1.5%. Condensed milk: sourced from Ningxia Saizan Dairy Co., Ltd., with a protein content ≥ 34% non-fat milk solids and a fat content ≥ 8.0%. Anhydrous butter: sourced from Ningxia Saizan Dairy Co., Ltd., with a fat content of ≥99.8%. In the examples, mono- and diglyceride fatty acid esters, phospholipids, sucrose fatty acid esters, carrageenan, guar gum, CMC, and flavorings are all purchased raw materials that provide corresponding emulsification, thickening, and flavoring effects.

[0043] Example 1 This embodiment provides a method for preparing ice cream, the steps of which are as follows: (1) Fresh raw milk is sterilized and centrifuged at a speed of 4000 r / min to obtain separated cream (fat content 40.0~45.0%, acidity ≤30). o T) and skim milk (fat content ≤0.1%, protein content >2.9%).

[0044] (2) A portion of the separated cream is sterilized at 75°C for 25 seconds to obtain pasteurized separated cream; another portion of the separated cream is heated to 70°C, held for 15 seconds, cooled to 50°C, and then centrifuged at 4500 r / min for 15 seconds to obtain concentrated cream and partially skimmed milk (fat content 0.5-1.5%, protein content 3.0-4.0%). The partially skimmed milk meets the requirement of a fat content of 0.5-1.5%. The partially skimmed milk obtained in this step contains less fat globule membrane substances and has a lower fat aroma.

[0045] (3) Store the partially skimmed milk obtained in step (2) at 2~8°C.

[0046] (4) Continue heating the concentrated cream obtained in step (2) to 70°C, keep it for 15 seconds, put it into a separator, and then centrifuge it at 5500 r / min for 15 seconds to obtain primary concentrated cream and secondary partially skimmed milk (fat content > 1.5%, protein content 3.2~4.0%). The fat content in the secondary partially skimmed milk is higher than 1.5%, which does not meet the requirement of a fat content of 0.5~1.5%.

[0047] (5) The concentrated cream obtained in step (4) is homogenized. The homogenization parameters are: temperature 65~75℃, first-stage total pressure 120~150 bar, second-stage pressure 20~30 bar. Then, the homogenized concentrated cream is mixed with the second-stage partially skimmed milk in step (4) and heated to 70℃ again. It is held for 15s and then centrifuged at 6000r / min for 15s to obtain the second-stage concentrated cream and the third-stage partially skimmed milk (fat content 0.5~1.5%, protein content 3.0~4.0%). The third-stage partially skimmed milk meets the requirement of fat content of 0.5~1.5%.

[0048] (6) Mix the first-stage skimmed milk stored in step (3) with the third-stage skimmed milk obtained in step (5). The skimmed milk obtained after mixing has a fat content of 1.2% and a protein content of 3.5%. Send the skimmed milk into the ingredient tank and store it at 2~8℃ as a raw material for subsequent ice cream preparation.

[0049] (7) Mix 60 parts of the skim milk from step (6) with 32 parts of the separated cream after slaughtering from step (2) to obtain a milk mixture.

[0050] (8) Heat the milk mixture to 45°C, then add 3 parts milk powder, 2 parts condensed milk and 3 parts anhydrous butter and mix to obtain a mixture with protein content >3.5%, fat content >10.0% and total solids ≥32%.

[0051] (9) Heat the mixture to 90°C and sterilize it to obtain the sterilized complex.

[0052] (10) The complex was homogenized. The homogenization parameters were: first-stage total pressure of 120~150 bar, second-stage pressure of 20~30 bar, and temperature of 65~75℃.

[0053] (11) Cool the homogenized material to 2~6℃ and store it for 12h for aging; (12) Harden the aged material at a temperature of -18~-45℃ to rapidly reduce the core temperature to below -18℃, inhibit the recrystallization of ice crystals, and obtain ice cream. Store the ice cream at -18℃.

[0054] Example 2 This embodiment is basically the same as embodiment 1, except that: The steps of heating and centrifuging the secondary concentrated cream obtained in step (5) are as follows: (6) The secondary concentrated cream obtained in step (5) is heated again to 70°C and held for 15 seconds. Then it is centrifuged at 6500 r / min for 15 seconds to obtain the tertiary concentrated cream and the fourth partially skimmed milk. The fat content of the fourth partially skimmed milk obtained in this step is 0.5~1.0% and the protein content is 3.0~3.3%, which meets the requirement of a fat content of 0.5~1.5%.

[0055] (7) Mix the first-stage skimmed milk stored in step (3), the third-stage skimmed milk obtained in step (5), and the fourth-stage skimmed milk obtained in step (6). The skimmed milk obtained after mixing has a fat content of 0.8% and a protein content of 3.2%. The skimmed milk is sent to the ingredient tank and stored at 2~8℃ as a raw material for subsequent ice cream preparation.

[0056] (8) Mix 60 parts of the skim milk from step (7) with 32 parts of the separated cream after slaughtering from step (2) to obtain a milk mixture.

[0057] (9) Heat the milk mixture to 45°C, then add 3 parts milk powder, 2 parts condensed milk and 3 parts anhydrous butter and mix to obtain a mixture with protein content >3.5%, fat content >10.0% and total solids ≥32%.

[0058] Then, the same sterilization, homogenization, aging and hardening steps as in Example 1 are performed in sequence, and finally the resulting ice cream is stored frozen at -18°C.

[0059] Example 3 This embodiment is basically the same as embodiment 1, except that it does not include steps (4) to (7), but includes: Mix 60 parts of partially skimmed milk stored in step (3) of Example 1 with 32 parts of separated cream after slaughter to obtain a milk mixture; then perform the same steps (8) to (12) as in Example 1.

[0060] Comparative Example 1 This comparative example is basically the same as Example 1, except that steps (2) to (7) are not included, and the milk mixture in step (8) is replaced with a milk fat mixture consisting of 32 parts of separated cream after slaughter and 60 parts of skim milk, and then the same steps (8) to (12) as in Example 1 are performed.

[0061] Comparative Example 2 This comparative example is basically the same as Comparative Example 1, except that it also includes the step of adding a composite emulsifying stabilizer to the milk fat mixture to obtain a milk fat mixture containing the composite emulsifying stabilizer. Specifically, the milk fat mixture is heated to 70°C, and the composite emulsifying stabilizer is added to the milk fat mixture at an addition amount of 0.75%. The mixture is sheared for 5 minutes and mixed evenly. Then, the same steps (8) to (12) as in Example 1 are performed.

[0062] The composite emulsifying stabilizer is composed of mono- and diglyceride fatty acid esters, phospholipids, sucrose fatty acid esters, carrageenan, guar gum, microcrystalline cellulose, and sodium carboxymethyl cellulose. The composite emulsifying stabilizer, by mass percentage, comprises 0.2% mono- and diglyceride fatty acid esters, 0.15% phospholipids, 0.15% sucrose fatty acid esters, 0.05% carrageenan, 0.05% guar gum, and 0.15% microcrystalline cellulose and sodium carboxymethyl cellulose.

[0063] Comparative Example 3 This comparative example is basically the same as comparative example 2, except that the compound emulsifying stabilizer is replaced with egg yolk powder.

[0064] Comparative Example 4 This comparative example is basically the same as comparative example 2, except that when the milk fat mixture containing the compound emulsifying stabilizer is mixed with milk powder, condensed milk and anhydrous butter, milk fat flavoring is also added. The amount of milk fat flavoring added is 0.3% of the mass of the milk mixture.

[0065] Experimental Example 1 Sensory evaluations were performed on the ice creams prepared in the examples and comparative examples.

[0066] Evaluation method: Purchase a group of commercially available hard ice cream (containing additives) as a control group, and test it against the ice cream of Examples 1-3 and Comparative Examples 1-4 in terms of flavor, texture, melting time, and ice crystal texture.

[0067] Thirty people were organized to taste the food. Evaluation methods were used based on the richness of the milky flavor, the presence or absence of an icy texture, and the melt-in-your-mouth quality. Five scores were used: very much liked (10 points), somewhat liked (8 points), neutral / unliked (6 points), not really liked (4 points), and disliked at all (1 point). Customer preference was calculated based on the percentage of people who "very much liked" and "somewhat liked." The results are shown in Table 1. Table 1 Customer Preference Evaluation Results

[0068] Experiment Example 2 Evaluation of ice cream's resistance to melting Evaluation method: At room temperature (25°C), the initial weight of the ice cream was measured at 0 min and the corresponding weights at each time point (10 min, 20 min, and 30 min) after 10 min, 20 min, and 30 min. The melt resistance and surface particle state of the ice cream from the control group, Examples 1-3, and Comparative Examples 1-4 were tested. The melting rate of the ice cream was calculated using the following formula. The melting rate of ice cream = (W1 - W2) / W1 × 100%; In the formula, W1: the initial total weight of the ice cream sample before the test (g); W2: the weight of the remaining ice cream sample after being placed at room temperature for the corresponding time (g).

[0069] The melting effect of ice cream in Examples 1-3, Comparative Examples 1-4, and the control group after 30 minutes is shown in the figure. Figures 1-8 As shown, the melting rate is as follows Figure 9 As shown in Table 2, the surface particle state is as follows: Table 2 Surface Particle State

[0070] As can be seen from Tables 1 and 2, the ice cream prepared using partially skimmed milk with a fat content of 0.5% to 1.5% obtained by heating and centrifuging at different times in Examples 1 to 3 all had higher customer preference than the ice cream made with added egg yolk powder (Comparative Example 3).

[0071] In Example 1, the preference level exceeded that of ice cream with added flavorings and emulsifiers (Comparative Example 4), and the icy texture was not obvious, with no significant difference from the control group. In Example 2, the concentrated cream underwent the most heating and centrifugation treatments, resulting in a more concentrated flavor, the highest preference level, and the most fragrant ice cream.

[0072] The inventors also referred to the method of Comparative Example 1 and used 60 parts of pasteurized raw milk (protein content ≥2.9%, fat content ≥3.1%) and 32 parts of pasteurized separated cream as raw materials for the experiment. Compared with Examples 1 to 3, the ice cream obtained from milk with a fat content >1.5% had poorer flavor, texture, stability, and anti-solubility.

[0073] Compared to using skim milk without heating and centrifugation (Comparative Example 1), this method not only enhances the aroma of ice cream, improving its flavor and customer appeal, but also improves its stability and resistance to melting. This demonstrates that partially skimmed milk with a fat content of 0.5-1.5% obtained by repeatedly heating and centrifuging concentrated cream can completely replace skim milk as a raw material for making ice cream, not only enhancing its aroma but also improving its quality.

[0074] Compared to Comparative Examples 2 and 4, which added compound emulsifiers and / or flavorings, and Comparative Example 3, which added egg yolk powder, the ice creams prepared in Examples 1 and 2 not only have better resistance to melting and stability, but also improve the taste and flavor of the ice cream. This shows that the present invention, using partially skimmed milk with a fat content of 0.5-1.5% obtained by multiple heating and centrifugation as raw material, can replace the role of emulsifiers, stabilizers, and flavorings to prepare ice cream without any additives.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ice cream, characterized in that, By weight, it includes the following ingredients: 40-70 parts partially skimmed milk, 10-40 parts light cream, and 3-20 parts auxiliary materials; The fat content of the partially skimmed milk is 0.5% to 1.5%.

2. The ice cream according to claim 1, characterized in that, The partially skimmed milk is obtained by separating cream from raw milk and then performing multiple fat separation processes through heating. Preferably, the partially skimmed milk accounts for 40-70% of the total mass of the raw materials; Preferably, the protein content of the partially skimmed milk is ≥2.9%.

3. The ice cream according to claim 1 or 2, characterized in that, The raw materials do not contain any one or more combinations of stabilizers, thickeners, and emulsifiers.

4. The ice cream according to any one of claims 1 to 3, characterized in that, The light cream has a fat content of 35-45% and an acidity of ≤30. o T.

5. The ice cream according to any one of claims 1 to 4, characterized in that, The auxiliary materials include 1-5 parts milk powder, 1-10 parts condensed milk, and 1-5 parts anhydrous butter.

6. The ice cream according to any one of claims 1 to 5, characterized in that, The ice cream contains ≥3.5% protein, ≥10.0% fat, and ≥30% total solids.

7. A method for preparing ice cream as described in any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Mix the partially skimmed milk, light cream and excipients with a fat content of 0.5-1.5% to obtain a mixture; (2) The mixture is subjected to sterilization, homogenization, aging and hardening treatment.

8. The method for preparing ice cream according to claim 7, characterized in that, The method for preparing the partially skimmed milk with a fat content of 0.5-1.5% includes the following steps: a. Using separated cream from raw milk as raw material, the separated cream is heated first and then separated to separate the milk fat, resulting in concentrated cream and partially skimmed milk; b. Perform the milk fat separation step on the concentrated cream again, and then repeat the milk fat separation step on the separated concentrated cream or concentrated cream; if the fat content of the separated portion of skim milk is not in the range of 0.5~1.5% during milk fat separation, mix the portion of skim milk with concentrated cream or concentrated cream and then perform the milk fat separation again. c. Combine steps a and b to obtain partially skimmed milk with a fat content of 0.5-1.5% obtained from the milk fat separation, and use it as a raw material for preparing ice cream; Preferably, in step b, the number of repetitions is 1 to 4. Preferably, the heating temperature is 60~80℃, and the temperature is maintained for 15~60 seconds after reaching 60~80℃; Preferably, the centrifugation speed is 4000~6500 r / min and the centrifugation time is 1~30 s; Preferably, the raw milk has a fat content of ≤0.5% and a protein content of ≥2.9%.

9. The method for preparing ice cream according to claim 8, characterized in that, When preparing the partially skimmed milk, if the fat content of the partially skimmed milk obtained by milk fat separation is not in the range of 0.5-1.5%, the concentrated light cream or concentrated butter separated at the same time as the partially skimmed milk is first homogenized, and then the homogenized concentrated light cream or concentrated butter is mixed with the partially skimmed milk whose fat content is not in the range of 0.5-1.5%, and then the milk fat separation is performed.

10. The method for preparing ice cream according to claims 7-9, characterized in that, The parameters of the homogenization include: a first-stage total pressure of 120~150 bar, a second-stage pressure of 20~30 bar, and a temperature of 65~75℃; And / or, the aging parameters include: temperature of 2~6℃ and time of 2~24h; And / or, the hardening includes: cooling the aged material at a temperature of -18 to -45°C until the core temperature rapidly drops below -18°C.

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