Yoghourt crisp chips and preparation method thereof

Abstract

The invention relates to the technical field of dairy products, and particularly provides yoghourt crisp chips and a preparation method thereof. The preparation method comprises the following steps: adding colloid and filler into cow milk, then adding a leavening agent for fermentation to obtain fermented milk, and drying the fermented milk to obtain the yoghourt crisp chips. The solid content of the fermented milk is 20.0 g / 100 ml to 24.0 g / 100 ml; when the temperature is 25 to 35 DEG C, the viscosity of the fermented milk is 8000 to 10000 Pa.s. According to the method provided by the invention, proportioning, fermentation forming and freeze-drying are integrated, so that the production energy consumption can be greatly saved, the texture of the fermented milk is reserved to the greatest extent while the overall texture and viscosity of the fermented milk are not damaged, and the moisture in the fermented milk is removed through a freeze-drying technology; the leisure snack yoghurt crisp chip which is high in nutrition and easy to absorb is successfully obtained.

Description

Technical Field

[0001] The invention relates to the technical field of dairy products, and in particular to a yogurt crisp and a preparation method thereof. Background Art

[0002] Crisp snacks are mostly fruit and vegetable crisps, potato chips, etc. With the prosperity of casual snack consumption, more people have focused on health and nutrition, and consumers are particularly concerned about the nutritional health of snack products. Yogurt is naturally nutritious and healthy, and can supplement high-quality protein and calcium. If yogurt is prepared as a crisp snack, it can not only expand the application field of dairy products and increase product categories; it can also make snacks take into account health and nutritional functions.

[0003] According to Innova's 2020 consumer survey, more than 50% of consumers said that the epidemic has prompted them to start investing their energy in learning knowledge and methods to enhance immune health. In addition to maintaining adequate sleep and a healthy physique, consumers believe that consuming foods rich in nutrients such as protein, vitamins, and probiotics is one of the important factors in enhancing immunity.

[0004] Milk, yogurt and other dairy products have always been regarded as ideal foods for the human body to supplement protein, calcium and various minerals. With the increasing demand for health during the epidemic, yogurt, which carries the aura of "nutrition and health", has become the only choice for consumers to enhance their physical fitness.

[0005] Through fermentation, the lactose and protein in milk can be broken down, making it easier for the human body to digest and absorb. At the same time, fermentation can break down about 20% of the sugar and protein in milk into small molecules that are easier for the human body to absorb. After fermentation, the fatty acids in the fat in the milk can be greatly increased. These changes can make yogurt easier to digest and absorb, and the utilization rate of various nutrients can also be improved. In addition to retaining all the nutrients of fresh milk, yogurt can also produce a variety of vitamins necessary for the human body during the fermentation process, such as vitamin B1, vitamin B2, vitamin B6, vitamin B12, etc. The lactic acid produced after fermentation can effectively improve the utilization rate of calcium and phosphorus in the human body and so on.

[0006] The texture of milk changes significantly through fermentation, from fluid to soft gel, and the production of a large amount of viscosity is a prerequisite for the formation of crisp texture. Yogurt crisp dairy snacks made from yogurt can meet consumers' dual needs for nutrition and leisure. Summary of the invention

[0007] The invention provides a high-protein yogurt crisp and a preparation method thereof. The yogurt crisp provided by the invention is room-temperature yogurt crisp.

[0008] In a first aspect, the present invention provides a method for preparing yogurt chips, comprising: adding a colloid and a filler to cow's milk, then adding a starter to ferment to obtain fermented milk, and drying the fermented milk to obtain yogurt chips; the filler contains sugar;

[0009] The solid content of the fermented milk is 20.0 g / 100 ml-24.0 g / 100 ml; at 25-35° C., the viscosity of the fermented milk is 8000-10000 Pa·s.

[0010] In the prior art, conventional fermented milk can produce freeze-dried yogurt blocks, but does not produce yogurt chips with a hard and crispy texture. The present invention adds colloids and fillers before fermentation, and uses them together with milk as a fermentation substrate for a starter, and finally obtains solidified yogurt to prepare yogurt chips. More specifically, the present invention utilizes the gel texture formed by cow's milk during the fermentation process, and on this basis, uses colloids and sugars to enhance the overall gel texture and solids, thereby increasing the hardness and viscosity of the fermented milk to reach the final texture that can form yogurt chips.

[0011] In the preparation method of the yogurt crisps provided by the present invention, the drying is vacuum freeze drying at a temperature of -20 to -23°C for 16 to 20 hours.

[0012] In the method for preparing the yogurt crisps provided by the present invention, the colloid accounts for 2-4‰ of the mass of the fermented milk, and the filler accounts for 10-20% of the mass of the fermented milk.

[0013] In the preparation method of yogurt crisps provided by the present invention, the colloid is one or more of gellan gum, low-ester pectin, microcrystalline cellulose, citrus fiber, gelatin, and carrageenan;

[0014] Preferably, the colloid contains gellan gum and low-ester pectin in a mass ratio of (0.4-0.6):(2.2-2.6).

[0015] In the preparation method of the yogurt crisps provided by the present invention, the filler is one or more of whey protein powder, starch, inulin, maltodextrin, white sugar, and fructose syrup;

[0016] Preferably, the filler contains whey protein powder, starch and white sugar in a mass ratio of (0.5-1):(0.1-0.15):(0.7-0.9).

[0017] In the present invention, the basic structure of the yogurt crisps is the micelle polymer formed by milk fermentation, and the filler and the colloid further enhance the fermented milk curd system, so that the yogurt crisps have the yogurt texture.

[0018] The method for preparing yogurt chips provided by the present invention comprises:

[0019] (1) adding gellan gum, low-ester pectin, white sugar, starch, and whey protein powder into milk by high shearing and stirring to obtain a uniform slurry raw material;

[0020] (2) preheating, degassing, homogenizing, and then sterilizing the uniform slurry obtained in step (1);

[0021] (3) adding a starter to the sterilized uniform slurry raw material, stirring and mixing, and then injecting into a fixed mold under sterile conditions, and fermenting at a temperature of 41-43° C. for 4-5 hours to obtain fermented milk;

[0022] (4) The temperature of the fermented milk is lowered to -20 to -23°C and maintained for 16 to 20 hours to perform ice crystal sublimation dehydration to obtain a finished yogurt crisp.

[0023] In the method for preparing yogurt chips provided by the present invention, the fermented milk in step (3) is solidified yogurt with a thickness of 8-10 mm.

[0024] In the method for preparing yogurt chips provided by the present invention, the sterilization conditions are a temperature of 137-142° C. for 4-6 seconds, and the degassing conditions are a temperature of 60-65° C. and a degassing pressure of -0.5 to -0.8 bar.

[0025] In a second aspect, the present invention provides a yogurt crisp, which is prepared by the above-mentioned preparation method.

[0026] As a specific embodiment of the present invention, the preparation method of the yogurt chips provided by the present invention is as follows:

[0027] (1) Raw material mixing: gellan gum, low-ester pectin, starch, whey protein powder and white sugar are added to milk one by one by high shearing, and stirred thoroughly to obtain a uniform slurry raw material.

[0028] (2) Sterilization of feed liquid: After the raw materials are mixed, they are calibrated and tested for physical and chemical indicators that meet the standards before entering the sterilization process. After preheating, degassing (degassing temperature 60-65°C; degassing pressure -0.5 to -0.8 bar), and homogenization, they are sterilized at a temperature of 137-142°C for 4-6 seconds. After ensuring that the feed liquid is sterile, the temperature is lowered to 41-43°C before entering the next process.

[0029] (3) After adding the fermentation bacteria online, the mixture is injected into a fixed mold under sterile conditions and fermented at a temperature of 41-43° C. for 4-5 hours to obtain a solidified yogurt (with a thickness of 8-10 mm).

[0030] (4) Place the fermented yogurt and the mold into a vacuum chamber with a vacuum degree of 130 Pa.

[0031] (5) Vacuum freeze drying: After pre-freezing, the temperature of the freeze drying chamber is adjusted again, and the temperature is lowered to -20 to -23°C and maintained for 16 to 20 hours to perform ice crystal sublimation dehydration to obtain a standard product.

[0032] (6) The high-protein yogurt chips are vacuum-packed with tin foil and the packaging bags are put into boxes to obtain the finished products.

[0033] The beneficial effects of the present invention are:

[0034] (1) The present invention realizes that dairy products are dried to obtain yogurt chips, which are high in protein and rich in calcium.

[0035] (2) The present invention establishes a texture system of hard and crisp yogurt chips suitable for freeze-drying; wherein, a skeleton that can form a chip is established by combining colloids and micelle polymers produced by milk fermentation, and fillers are added to fill the skeleton. At the same time, the sugars in the fillers act as adhesives to make the skeleton and the fillers more firmly bonded, and finally the chip can reach a certain hardness. Moreover, this process is completed during the fermentation process, further saving the preparation process.

[0036] (3) The present invention establishes a freeze-drying process suitable for preparing yogurt crisps, which increases the overall viscosity and solid content on the basis of the texture of the fermented milk itself, reduces the moisture and air in the fermented milk before freeze-drying through processes such as degassing, and reduces a large number of pores left due to the evaporation of water after freeze-drying, turning them into uniform and fine pores, further increasing the crispness of the crisps.

[0037] (4) One-stop fermentation and molding no longer requires demulsification and stirring, which preserves the texture and viscosity of the fermented milk formed by natural fermentation to the greatest extent. At the same time, this is also the best state for freeze-drying, which can obtain the best crispy taste. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The present invention adds a colloid to enhance the scaffold structure before fermentation, adds a filler (whey protein powder, starch) for filling between the skeletons, and adds an adhesive sugar that can make the skeleton and the filler more firmly combined. After sufficient mixing, homogenization and sterilization are performed, and a starter is added for fermentation. The desired texture is formed during the fermentation process. Functional raw materials or flavor raw materials can be optionally added to finally obtain fermented milk that can be made into crisp chips.

[0040] Example 1 Yogurt chips formula and preparation process

[0041] In this embodiment, gellan gum and low-ester pectin are used as colloids to enhance the scaffold structure of yogurt crisps. In terms of mass, gellan gum is 0.5‰ of the fermented milk raw material, and low-ester pectin is 2.2‰ of the fermented milk raw material;

[0042] Starch, whey protein and white sugar are used as fillers for the yogurt crisps support structure. By mass, starch accounts for 1.2% of the fermented milk raw material, whey protein accounts for 6% of the fermented milk raw material, and white sugar accounts for 8% of the fermented milk raw material. The fermented milk raw materials also include cow's milk and starter.

[0043] The leavening agent used in this example is Chr. Hansen Pre.11, and the addition amount is 100U / T.

[0044] The preparation method of the yogurt chips used in this embodiment is as follows:

[0045] (1) Raw material mixing: gellan gum, low-ester pectin, starch, whey protein powder and white sugar are added to milk one by one by high shearing, and stirred thoroughly to obtain a uniform slurry raw material.

[0046] (2) Sterilization of the feed liquid: The uniform slurry raw materials obtained in step (1) are mixed and calibrated, and then enter the sterilization process after the physical and chemical index inspection is carried out in accordance with the standards. After preheating, degassing (degassing temperature 60-65°C; degassing pressure -0.5 to -0.8 bar), and homogenization, sterilization is carried out at a sterilization temperature of 137-142°C for 4-6 seconds. After ensuring that the feed liquid is sterile, the temperature is lowered to 41-43°C and enters the next process.

[0047] (3) After adding the fermentation bacteria (Chr. Hansen Pre.11) online, the material liquid is injected into a fixed mold under sterile conditions, and fermented at a temperature of 41-43°C for 4-5 hours, and the fermentation is terminated by the acidity and pH value. The fermentation is terminated when the acidity reaches 75°T or the pH value reaches 4.2-4.4, and a fermented milk with a thickness of 8-10 mm is obtained, and the fermented milk is a solidified yogurt.

[0048] (4) Pre-freezing: Place the mold plate in a vacuum chamber with a vacuum degree of 130 Pa.

[0049] (5) Vacuum freeze drying: After pre-freezing, the temperature of the freeze drying chamber is adjusted again, and the temperature is lowered to -20 to -23°C and maintained for 16 to 20 hours to perform ice crystal sublimation dehydration to obtain high-protein yogurt chips.

[0050] (6) vacuum-packing the yogurt chips with tin foil and placing the packaging bags into boxes to obtain the finished products.

[0051] The indicators of the fermented milk obtained in this embodiment are as follows: protein is 5-8g / 100ml, fat is 4.2-4.4g / 100ml, solid content of the fermented milk is 20.0-22.0g / 100ml, and calcium is 150-160mg / 100ml.

[0052] The viscosity of the fermented milk in this embodiment is 8300 Pa·s.

[0053] Example 2 Using gellan gum, low-ester pectin and carrageenan as colloids

[0054] The formula of this embodiment is different from that of Embodiment 1 in that gellan gum, low-ester pectin and carrageenan are used as colloids in this embodiment. In terms of mass, gellan gum accounts for 0.5‰ of the fermented milk raw material, low-ester pectin accounts for 1‰ of the fermented milk raw material, and gellan gum accounts for 1‰ of the fermented milk raw material.

[0055] The indicators of the fermented milk obtained in this embodiment are as follows: protein is 5-8g / 100ml, fat is 4.2-4.4g / 100ml, solid content of the fermented milk is 20.0-22.0g / 100ml, and calcium is 150-160mg / 100ml.

[0056] The viscosity of the fermented milk in this embodiment is 8000 Pa·s.

[0057] The preparation method of the yogurt chips used in this embodiment is the same as that in Example 1.

[0058] Example 3 Yogurt chips formula and preparation process

[0059] In this embodiment, gellan gum and low-ester pectin are used as colloids to enhance the scaffold structure of yogurt crisps. In terms of mass, gellan gum is 0.5‰ of the fermented milk raw material, and low-ester pectin is 2.2‰ of the fermented milk raw material;

[0060] Starch, whey protein and white sugar are used as fillers for the yogurt crisps support structure. By mass, starch accounts for 1.2% of the fermented milk raw material, whey protein accounts for 6% of the fermented milk raw material, and white sugar accounts for 8% of the fermented milk raw material. The fermented milk raw materials also include cow's milk and leavening agent.

[0061] The indicators of the fermented milk obtained in this embodiment are as follows: protein is 5-8g / 100ml, fat is 4.2-4.4g / 100ml, solid content of the fermented milk is 20.0-22.0g / 100ml, and calcium is 150-160mg / 100ml.

[0062] The viscosity of the fermented milk in this embodiment is 8100 Pa·s.

[0063] The preparation method of the yogurt chips used in this embodiment is the same as that in Example 1.

[0064] Example 4 Yogurt chips recipe and preparation process

[0065] In this embodiment, gellan gum and low-ester pectin are used as colloids to enhance the scaffold structure of yogurt crisps. In terms of mass, gellan gum is 0.5‰ of the fermented milk raw material, and low-ester pectin is 2.2‰ of the fermented milk raw material;

[0066] Starch, whey protein and white sugar are used as fillers for the yogurt crisps support structure. By mass, starch accounts for 1.8% of the fermented milk raw material, whey protein accounts for 6% of the fermented milk raw material, and white sugar accounts for 8% of the fermented milk raw material. The fermented milk raw material also includes cow's milk and starter.

[0067] The indicators of the fermented milk obtained in this embodiment are as follows: protein is 5-8g / 100ml, fat is 4.2-4.4g / 100ml, solid content of the fermented milk is 22.0-24.0g / 100ml, and calcium is 150-160mg / 100ml.

[0068] The viscosity of the fermented milk in this embodiment is 9000 Pa·s.

[0069] The preparation method of the yogurt chips used in this embodiment is the same as that in Example 1.

[0070] Comparative Example 1: Using gellan gum as colloid

[0071] The difference between this comparative example and the formula of Example 1 is that only gellan gum is used as the colloid in this comparative example, and the gellan gum accounts for 0.5‰ of the fermented milk raw material by mass.

[0072] The indicators of the fermented milk obtained in the comparative example are as follows: protein is 5-8g / 100ml, fat is 4.2-4.4g / 100ml, solid content of the fermented milk is 20.0-22.0g / 100ml, and calcium is 150-160mg / 100ml.

[0073] The viscosity of the fermented milk in this comparative example was 6000 Pa·s.

[0074] The preparation method of the yogurt chips used in this comparative example is the same as that in Example 1.

[0075] Comparative Example 2 uses low-ester pectin as colloid

[0076] The difference between this comparative example and the formula of Example 1 is that only low-ester pectin is used as the colloid in this comparative example, and the low-ester pectin accounts for 2.2‰ of the fermented milk raw material by mass.

[0077] The indicators of the fermented milk obtained in the comparative example are as follows: protein is 5-8g / 100ml, fat is 4.2-4.4g / 100ml, solid content of the fermented milk is 20.0-22.0g / 100ml, and calcium is 150-160mg / 100ml.

[0078] The viscosity of the fermented milk in this comparative example is 7800 Pa·s. The preparation method of the yogurt chips used in this comparative example is the same as that of Example 1.

[0079] Comparative Example 3 No Starch Addition

[0080] The difference between this comparative example and the formulation of Example 1 is that starch as a filler is omitted in this comparative example.

[0081] The indicators of the fermented milk obtained in the comparative example are as follows: protein is 5-8g / 100ml, fat is 4.2-4.4g / 100ml, solid content of the fermented milk is 20.0-22.0g / 100ml, and calcium is 150-160mg / 100ml.

[0082] The viscosity of the fermented milk in this comparative example was 7500 Pa·s.

[0083] The preparation method of the yogurt chips used in this comparative example is the same as that in Example 1.

[0084] Comparative Example 4: Omitting the dehydration and degassing process

[0085] The formula of this comparative example is the same as that of Example 1. The difference from Example 1 is that in the preparation method of the yogurt chips used in this comparative example, the dehydration and degassing processes are omitted.

[0086] The viscosity of the fermented milk in this comparative example was 8100 Pa·s.

[0087] Comparative Example 5 Vacuum freezing conditions are different

[0088] The formula of this comparative example is the same as that of Example 1. The difference from Example 1 is that the vacuum freezing condition of the yogurt chips used in this comparative example is -10 to -15°C and maintained for 8 to 12 hours.

[0089] The viscosity of the fermented milk in this comparative example was 8200 Pa·s.

[0090] Comparative Example 6 Fermented Milk Solid Content

[0091] In this comparative example, gellan gum and low-ester pectin are used as colloids to enhance the scaffold structure of yogurt crisps. By mass, gellan gum is 0.5‰ of the fermented milk raw material, and low-ester pectin is 2.2‰ of the fermented milk raw material;

[0092] Starch, whey protein and white sugar are used as fillers for the yogurt crisps support structure. By mass, starch accounts for 0.8% of the fermented milk raw material, whey protein accounts for 6% of the fermented milk raw material, and white sugar accounts for 8% of the fermented milk raw material. The fermented milk raw material also includes cow's milk and starter.

[0093] The solid content of the fermented milk obtained in this comparative example is 18.0-20.0 g / 100 ml, and the viscosity of the fermented milk in this comparative example is 6600 Pa·s.

[0094] The preparation method of the yogurt chips used in this embodiment is the same as that in Example 1.

[0095] Experimental example

[0096] In this experimental example, the products of the embodiment and the comparative example were subjected to sensory evaluation and hardness and brittleness test of the crisps. The sensory evaluation criteria used are shown in Table 1.

[0097] Table 1 Sensory scoring criteria for crisps

[0098]

[0099] This experiment used the Shanghai Baosheng TA.XTC texture analyzer, and referred to the hardness and brittleness test of potato chips. The physical quality of yogurt chips was measured by pressing mode. Yogurt chips with basically the same thickness, puffing degree, shape and size were selected for testing. A single test was performed using a TA / 0.5S spherical probe. Each group of samples was tested three times in parallel and the average value was taken. The results are shown in Table 2.

[0100] Table 2 Sensory evaluation and hardness and brittleness test scores

[0101]

[0102]

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing yogurt chips, characterized in that: include: Colloid and filler are added to cow's milk, and then a fermentation agent is added for fermentation to obtain fermented milk, and the fermented milk is dried to obtain yogurt crisps; the solid content of the fermented milk is 20.0g / 100ml-24.0g / 100ml; at 25-35°C, the viscosity of the fermented milk is 8000-10000Pa·s.

2. The preparation method according to claim 1, characterized in that: The drying is vacuum freeze drying at -20 to -23°C for 16 to 20 hours.

3. The preparation method according to any one of claims 1 to 2, characterized in that: In terms of mass, the colloid accounts for 2-4‰ of the mass of the fermented milk, and the filler accounts for 10-20% of the mass of the fermented milk.

4. The preparation method according to any one of claims 1 to 3, characterized in that The colloid is one or more of gellan gum, low-ester pectin, microcrystalline cellulose, citrus fiber, gelatin, and carrageenan; Preferably, the colloid contains gellan gum and low-ester pectin in a mass ratio of (0.4-0.6):(2.2-2.6).

5. The preparation method according to any one of claims 1 to 4, characterized in that: The filler is one or more of whey protein powder, starch, inulin, maltodextrin, white sugar, and fructose syrup; Preferably, the filler contains whey protein powder, starch and white sugar in a mass ratio of (0.5-1):(0.1-0.15):(0.7-0.9).

6. The preparation method according to any one of claims 4 to 5, characterized in that: include: (1) adding gellan gum, low-ester pectin, white sugar, starch, and whey protein powder into milk by high shearing and stirring to obtain a uniform slurry raw material; (2) preheating, degassing, homogenizing, and then sterilizing the uniform slurry obtained in step (1); (3) adding a starter culture to the sterilized uniform slurry raw material, stirring and mixing the raw material thoroughly, and injecting the mixture into a mold under aseptic conditions, and fermenting the mixture at a temperature of 41-43° C. for 4-5 hours to obtain fermented milk; (4) The temperature of the fermented milk is lowered to -20 to -23°C and maintained for 16 to 20 hours to perform ice crystal sublimation dehydration to obtain a finished yogurt crisp.

7. The preparation method according to claim 6, characterized in that: The fermented milk in step (3) and step (4) is solidified yogurt with a thickness of 8-10 mm.

8. The preparation method according to claim 6, characterized in that: The sterilization conditions are temperature 137-142° C., 4-6 seconds.

9. The preparation method according to claim 6, characterized in that: The degassing conditions are a temperature of 60 to 65° C. and a degassing pressure of -0.5 to -0.8 bar.

10. A yogurt crisp, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 9.

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