阅读说明：本技术 一种益生元酸奶粉和制备方法 (Prebiotics yoghurt powder and preparation method thereof ) 是由 冯仲笑 杨新球 曾宪维 吴剑锋 于 2021-07-21 设计创作，主要内容包括：本发明公开了一种益生元酸奶粉和制备方法,涉及食品加工的技术领域。制备方法包括：将奶制品溶液预热后与白砂糖、功能性糖、稳定剂和风味物质依次混合后搅拌,随后均质、杀菌和过滤,得到乳液；在冷却后的乳液中加入发酵乳杆菌,发酵后即得酸奶；将酸奶经真空低温带式连续干燥机进行干燥和粉碎,即得益生元酸奶粉。本申请的益生菌酸奶粉在制备过程中采用真空低温带式连续干燥机进行处理,干燥温度低,确保了产品中益生菌的活性和产量,其属于粉状的奶制品,受温度、水分和时间的影响较小,制备、保存、运输的成本较低,方便食用且富含营养,具有经济效益。(The invention discloses prebiotics yoghurt powder and a preparation method thereof, relating to the technical field of food processing. The preparation method comprises the following steps: preheating a milk product solution, mixing the milk product solution with white granulated sugar, functional sugar, a stabilizer and flavor substances in sequence, stirring, homogenizing, sterilizing and filtering to obtain an emulsion; adding lactobacillus fermentum into the cooled emulsion, and fermenting to obtain yogurt; and drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer to obtain the prebiotics yoghourt powder. The probiotic yogurt powder is processed by the vacuum low-temperature belt type continuous drying machine in the preparation process, the drying temperature is low, the activity and the yield of probiotics in the product are ensured, the probiotic yogurt powder belongs to powdery dairy products, the influence of temperature, moisture and time is small, the preparation, storage and transportation costs are low, the probiotic yogurt powder is convenient to eat and rich in nutrition, and economic benefits are achieved.)

1. The preparation method of the prebiotics yoghurt powder is characterized by comprising the following steps:

s1, preheating the milk product solution, mixing the milk product solution with other raw materials except the lactobacillus fermentum in sequence, stirring, homogenizing, sterilizing and filtering to obtain emulsion;

s2, adding lactobacillus fermentum into the cooled milk, and fermenting to obtain yogurt;

and S3, drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer to obtain the prebiotics yoghourt powder.

2. The method for preparing prebiotics yoghurt powder as claimed in claim 1, wherein the drying temperature of the vacuum low-temperature belt type continuous dryer is 20-58 ℃.

3. The method for preparing prebiotics yoghurt powder as claimed in claim 1, wherein the vacuum low-temperature belt type continuous dryer comprises a belt dryer body (3), a crawler belt (5) for continuously transporting yoghurt is arranged in the belt dryer body (3), a plurality of heating units are arranged in the belt dryer body (3) close to an inlet end, the temperature of the heating units is controlled to be 30-58 ℃, a plurality of cooling units are arranged in the belt dryer body (3) close to an outlet end, and the temperature of the cooling units is controlled to be 20-45 ℃.

4. The preparation method of prebiotic yoghurt powder as claimed in claim 3, wherein a heating plate (6) is arranged in the machine body (3) of the belt dryer and below the caterpillar track (5), the heating plate (6) is provided with a first heating unit, a second heating unit, a third heating unit, a fourth heating unit, a first cooling unit and a second cooling unit in sequence from the feeding end to the discharging end, the temperature of the first heating unit and the second heating unit is 40-58 ℃, the temperature of the third heating unit and the fourth heating unit is 30-48 ℃, the temperature of the first cooling unit is controlled to be 25-45 ℃, and the temperature of the second cooling unit is controlled to be 20-25 ℃.

5. The method for preparing prebiotics yoghurt powder as claimed in claim 1, which is characterized in that:

in the S1, the preheating temperature of the milk is 45-55 ℃, the stirring time is 15-20 min, the milk is filtered by a 80-mesh screen, the homogenizing pressure is 9.5-24.5 MPa, the sterilization temperature is 90 ℃, and the sterilization time is 15-25 min;

in the S2, the fermentation temperature is 40-43 ℃, the fermentation time is 2.5-3 h, and the final acidity of the fermentation is 0.7-0.8%.

6. The prebiotics yoghurt powder is characterized by being obtained by the preparation method of the prebiotics yoghurt powder as claimed in any one of claims 1 to 5, and comprising the following raw material components:

white granulated sugar: 2-8 wt%;

functional sugar: 1.5 wt% -2 wt%;

lactobacillus fermentum: 0.02 wt% -0.08 wt%;

a stabilizer: 0.01 wt% -0.15 wt%;

flavor substances: 0 to 1 wt%;

milk product solution: and (4) the balance.

7. The prebiotic yoghurt powder of claim 6 wherein the dairy solution is one or more of cow's milk, reconstituted milk and goat's milk.

8. The prebiotic yoghurt powder of claim 6 wherein the functional sugar is two or more of fructo-oligosaccharide, galacto-oligosaccharide, psicose, oat beta-glucan.

9. The prebiotic yoghurt powder of claim 6 wherein the Lactobacillus fermentum is two or more of Lactobacillus rhamnosus, Lactobacillus casei, Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus paracasei, or Bifidobacterium.

10. The prebiotic yoghurt powder of claim 6 wherein the stabilizer is xanthan gum and pectin.

Technical Field

The invention relates to the technical field of food processing, in particular to prebiotics yoghurt powder and a preparation method thereof.

Background

The probiotics change the flora composition of a host in a human body through colonization, the host mucous membrane and system immune function are adjusted, the food rich in the probiotics such as yoghourt and the like is properly supplemented, the flora balance in the intestinal tract can be adjusted, single microorganisms or mixed microorganisms with definite compositions which are beneficial to health are generated, and the nutrition absorption is effectively promoted and the intestinal tract health is maintained.

Present acidophilus milk is mostly fermentation products generally, and the product form to the acidophilus milk is mainly liquid, needs short-time storage in low temperature environment, sells, and shelf life is shorter, and the transportation needs the cold chain, and whole saving, transportation's with high costs, the save cycle is short, and some acidophilus milk products that adopt glass package suffer to collide with in addition just easy breakage after. In addition, some commercially available fermentation powders, namely milk powder and fermentation strains, are prepared, and need to be fermented in families after water is added independently by individuals, and the fermentation powders are mostly purchased and used by families.

Therefore, the fermented milk product which is convenient to transport, eat and store is researched, and particularly, the milk product is rich in probiotics.

Disclosure of Invention

The invention provides prebiotics yoghurt powder and a preparation method thereof, belongs to a powdery fermented dairy product, has the advantages of low transportation cost and convenient use, has rich probiotic content, can be directly taken or taken with warm water during eating, is convenient to drink and rich in nutrition, and has high economic benefit.

In order to solve the technical problem, one embodiment of the present invention provides a preparation method of prebiotics yoghurt powder, comprising the following steps:

s1, preheating the milk product solution, mixing the milk product solution with other raw materials except the lactobacillus fermentum in sequence, stirring, homogenizing, sterilizing and filtering to obtain emulsion;

s2, adding lactobacillus fermentum into the cooled milk, and fermenting to obtain yogurt;

and S3, drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer to obtain the prebiotics yoghourt powder.

By adopting the scheme, the prebiotics yoghurt powder is a powdery fermented milk product, fermented yoghurt is subjected to low-temperature mild drying by adopting a vacuum low-temperature continuous dryer, compared with the traditional freeze drying and spray drying, the drying temperature of the prebiotics yoghurt powder is controlled within the temperature range which can be tolerated by probiotics, the influence of the drying process on the activity and content reduction of the probiotics in the yoghurt is reduced, the probiotics in the probiotic yoghurt powder product has high activity and rich content, the manufacturing cost is low, and the powdery product is easy to store, transport and eat, is nutritious and delicious; in addition, the traditional yoghourt drying is static drying, and the vacuum low-temperature continuous dryer in the scheme can be used for continuous drying treatment, so that the enlarged continuous production of the capacity is facilitated; meanwhile, the vacuum low-temperature continuous dryer enables dried yoghourt to form a porous loose shape, has a certain loose effect, has micropores inside in a microstructure view, and is strong in particle fluidity after being crushed and good in instant effect.

Preferably, in the S3, the drying temperature of the vacuum low-temperature belt-type continuous dryer is 20 ℃ to 58 ℃.

As a preferred scheme, the vacuum low-temperature belt type continuous dryer comprises a belt dryer body, a caterpillar belt for continuously transporting yoghourt is arranged in the belt dryer body, a plurality of heating units are arranged in the belt dryer body close to an inlet end, the temperature of the heating units is controlled to be 30-58 ℃, a plurality of cooling units are arranged in the belt dryer body close to an outlet end, and the temperature of the cooling units is controlled to be 20-45 ℃.

As a preferred scheme, a heating plate is arranged in the machine body of the belt dryer and below the belt, a first heating unit, a second heating unit, a third heating unit, a fourth heating unit, a first cooling unit and a second cooling unit are sequentially arranged on the heating plate from the feeding end to the discharging end, the temperatures of the first heating unit and the second heating unit are 40-58 ℃, the temperatures of the third heating unit and the fourth heating unit are 30-48 ℃, the temperature of the first cooling unit is controlled to be 25-45 ℃, and the temperature of the second cooling unit is controlled to be 20-25 ℃.

By adopting the scheme, the slurry yoghourt continuously moves in the machine body of the belt dryer through the crawler belt, so that continuous drying treatment can be realized, and in the process of slowly moving the crawler belt, the heating plate is adopted to carry out staged heating and cooling treatment on the slurry yoghourt, so that the mild drying temperature is ensured, the situation that the survival of probiotics is greatly influenced by the temperature difference of cold and heat exchange is avoided, and the activity and the content of the yoghourt in a final product are ensured.

Preferably, in the S1, the milk is preheated at 45-55 ℃ and stirred for 15-20 min, and is filtered by a 80-mesh screen, the homogenizing pressure is 9.5-24.5 MPa, the sterilization temperature is 90 ℃ and the sterilization time is 15-25 min; in the S2, the fermentation temperature is 40-43 ℃, the fermentation time is 2.5-3 h, and the final acidity of the fermentation is 0.7-0.8%.

In order to solve the technical problems, one embodiment of the invention provides prebiotics yoghurt powder, which comprises the following raw material components:

white granulated sugar: 5-8 wt%;

functional sugar: 1.5 wt% -2 wt%;

lactobacillus fermentum: 0.02 wt% -0.08 wt%;

a stabilizer: 0.05 wt% -0.15 wt%;

flavor substances: 0 to 1 wt%;

milk product solution: and (4) the balance.

By adopting the scheme, fresh milk or other milk products are taken as raw materials, the prebiotics yoghurt powder has rich protein and probiotics, the probiotics can utilize functional oligosaccharide as a proliferation raw material in the early fermentation stage and generate lactic acid and butyric acid to denature the protein, and the fermented yoghurt has rich dietary fiber, protein, vitamin B1, vitamin B2, minerals such as iron and calcium and beneficial substances produced by fermentation of various lactic acid, butyric acid, calcium and beneficial bacteria, and has the characteristics of nutrition and delicious taste.

Preferably, the milk product solution is one or more of cow milk, reconstituted milk and goat milk.

Preferably, the functional sugar is two or more of fructo-oligosaccharide, galacto-oligosaccharide, psicose and oat beta-glucan.

Preferably, the lactobacillus fermentum is two or more of lactobacillus rhamnosus, lactobacillus casei, streptococcus thermophilus, lactobacillus bulgaricus, lactobacillus paracasei and bifidobacterium.

Preferably, the stabilizer is xanthan gum and pectin.

Compared with the prior art, the embodiment of the invention has the following beneficial effects:

1. the prebiotics yoghurt powder is a powdery fermented milk product, is easy to store, transport and eat, the fermented yoghurt is subjected to low-temperature mild drying by a vacuum low-temperature continuous dryer, the drying temperature is mild, and the product has high probiotic activity, rich content and delicious nutrition.

2. The pasty yoghourt continuously moves in the machine body of the drier through the crawler, and in the process of slowly moving the crawler, the heating plate is adopted to carry out staged heating and cooling treatment on the pasty yoghourt, so that the mild drying temperature is ensured, the activity and the content of probiotics in the yoghourt of the final product are ensured, and meanwhile, the continuous feeding and discharging treatment can be carried out in the drying process, thereby being beneficial to the amplification continuous production of the yoghourt capacity.

3. The prebiotics yoghurt powder has rich protein and probiotics, the probiotics at the initial fermentation stage can utilize functional oligosaccharide as a proliferation raw material, and the fermented yoghurt has rich dietary fiber, protein, vitamin B1, vitamin B2, minerals such as iron, calcium and the like, and various lactic acid, butyric acid, calcium and beneficial substances produced by the fermentation of the beneficial bacteria, and has the characteristics of nutrition and delicious taste.

Drawings

FIG. 1: is a schematic structural diagram of a vacuum low-temperature belt type continuous dryer in the embodiment of the invention.

Wherein the reference numbers of the drawings in the specification are as follows: 1. a feed tank; 2. a secondary steam discharge pipe; 3. a belt dryer body; 4. a feed tube; 5. a crawler belt; 6. heating plates; 7. a material receiving tank; 8. and (4) rotating the cutter.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The application provides a powdery fermented milk product, the fermented yoghourt is dried and crushed by a vacuum low-temperature belt type continuous dryer to prepare, the mild drying temperature which can be endured by probiotics is adopted in the drying process, the activity and the content of the probiotics in the product are ensured, the continuous feeding and discharging problem in a vacuum state is broken through, the amplified continuous production of the productivity is facilitated, and the obtained prebiotics yoghurt powder has the characteristics of low transportation and storage cost, convenience in eating, nutrition, delicacy and the like.

Example one

A prebiotics yoghurt powder is prepared by the following steps with reference to figure 1:

s1, preheating 93.9 wt% of milk product solution to 45 ℃, sequentially mixing and stirring with 4 wt% of white granulated sugar, 2 wt% of functional sugar and 0.05 wt% of stabilizer for 20min, homogenizing, sterilizing and filtering, controlling the homogenizing pressure to be 9.5MPa, the sterilizing temperature to be 90 ℃, and the sterilizing time to be 15min to obtain emulsion;

s2, cooling the emulsion to 40 ℃, then adding 0.05 wt% of lactobacillus fermentum for fermentation, controlling the fermentation temperature to 40 ℃, controlling the fermentation time to 3 hours, and stopping fermentation when the acidity of the fermentation reaches 0.7% to obtain the yoghourt;

and S3, drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer, controlling the drying temperature to be 40 ℃, and quantitatively packaging the obtained materials to obtain the prebiotics yoghourt powder.

Wherein the milk product solution is milk, and the functional sugar is composed of fructo-oligosaccharide and galacto-oligosaccharide in a mass ratio of 7: 3, the content of kestose in the fructo-oligosaccharide is more than or equal to 60 w/% (calculated on a dry basis), and the content of kestose in the fructo-oligosaccharide is preferably 80 w/% (calculated on a dry basis); the stabilizer is prepared from xanthan gum and pectin according to a mass ratio of 1: 1 in proportion; the lactobacillus fermentum is compounded by streptococcus thermophilus, lactobacillus bulgaricus and lactobacillus paracasei, and the inoculation amount of the streptococcus thermophilus, the lactobacillus bulgaricus and the lactobacillus paracasei is 1 multiplied by 106 cfu/g.

Example two

A prebiotics yoghurt powder is prepared by the following steps with reference to figure 1:

s1, preheating 96.47 wt% of milk product solution to 55 ℃, sequentially mixing and stirring with 2 wt% of white granulated sugar, 1.5 wt% of functional sugar and 0.01 wt% of stabilizer for 15min, homogenizing, sterilizing and filtering, controlling the homogenizing pressure to be 20MPa, the sterilizing temperature to be 90 ℃, and the sterilizing time to be 20min to obtain emulsion;

s2, cooling the emulsion to 45 ℃, then adding 0.02 wt% of lactobacillus fermentum for fermentation, controlling the fermentation temperature to 43 ℃, controlling the fermentation time to 2.5h, and stopping fermentation when the acidity of the fermentation reaches 0.8% to obtain the yoghourt;

and S3, drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer, controlling the drying temperature to be 55 ℃, and quantitatively packaging the obtained materials to obtain the prebiotics yoghourt powder.

Wherein the milk product solution is prepared from milk and reconstituted milk according to a mass ratio of 1: 1 in proportion; the functional sugar is prepared from galactooligosaccharide and psicose according to the mass ratio of 5: 5 in proportion; the stabilizer is prepared from xanthan gum and pectin according to a mass ratio of 1: 1 in proportion; the lactobacillus fermentum is compounded by streptococcus thermophilus, lactobacillus bulgaricus and lactobacillus paracasei, and the inoculation amount of the streptococcus thermophilus, the lactobacillus bulgaricus and the lactobacillus paracasei is 1 multiplied by 106 cfu/g.

EXAMPLE III

A prebiotics yoghurt powder is prepared by the following steps with reference to figure 1:

s1, preheating 89.97 wt% of milk product solution to 50 ℃, sequentially mixing and stirring 8 wt% of white granulated sugar, 1.8 wt% of functional sugar and 0.15 wt% of stabilizer for 15min, homogenizing, sterilizing and filtering, controlling the homogenizing pressure to be 24.5MPa, the sterilizing temperature to be 90 ℃, and the sterilizing time to be 25min to obtain emulsion;

s2, cooling the emulsion to 40 ℃, adding 0.08 wt% of lactobacillus fermentum for fermentation, controlling the fermentation temperature to 42 ℃, controlling the fermentation time to 3 hours, and stopping fermentation when the acidity of the fermentation reaches 0.7% to obtain the yoghourt;

and S3, drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer, controlling the drying temperature to be 50 ℃, and quantitatively packaging the obtained materials to obtain the prebiotics yoghourt powder.

Wherein the milk product solution is milk prepared by dissolving milk powder in water; the functional sugar is prepared from fructo-oligosaccharide and galacto-oligosaccharide in a mass ratio of 7: 3, the content of kestose in the fructo-oligosaccharide is more than or equal to 60 w/% (calculated on a dry basis), and the content of kestose in the fructo-oligosaccharide is preferably 80 w/% (calculated on a dry basis); the stabilizer is prepared from xanthan gum and pectin according to a mass ratio of 1: 1 in proportion; the lactobacillus fermentum is compounded by streptococcus thermophilus, lactobacillus bulgaricus and lactobacillus paracasei, and the inoculation amount of the streptococcus thermophilus, the lactobacillus bulgaricus and the lactobacillus paracasei is 1 multiplied by 106 cfu/g.

Example four

A prebiotics yoghurt powder is prepared by the following steps with reference to figure 1:

s1, preheating 92.14 wt% of milk product solution to 45 ℃, sequentially mixing and stirring with 6 wt% of white granulated sugar, 1.7 wt% of functional sugar and 0.1 wt% of stabilizer for 20min, homogenizing, sterilizing and filtering, controlling the homogenizing pressure to be 24.5MPa, the sterilizing temperature to be 90 ℃, and the sterilizing time to be 15min to obtain emulsion;

s2, cooling the emulsion to 40 ℃, then adding 0.06 wt% of lactobacillus fermentum for fermentation, controlling the fermentation temperature to 42 ℃, controlling the fermentation time to 3h, and stopping fermentation when the acidity of the fermentation reaches 0.7% to obtain the yoghourt;

and S3, drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer, controlling the drying temperature to be 50 ℃, and quantitatively packaging the obtained materials to obtain the prebiotics yoghourt powder.

Wherein 77 wt% of 92.14 wt% of the milk product solution is cow milk powder dissolved in water to prepare cow milk 22.14 wt% of the goat milk prepared by goat milk powder dissolved in water; the functional sugar is prepared from fructo-oligosaccharide, psicose and oat beta-glucan according to the mass ratio of 3: 3: 4, the content of kestose in the fructo-oligosaccharide is more than or equal to 60 w/% (calculated on a dry basis), and the content of kestose in the fructo-oligosaccharide is preferably 80 w/% (calculated on a dry basis); the stabilizer is prepared from xanthan gum and pectin according to a mass ratio of 1: 1 in proportion; the lactobacillus fermentum is compounded by streptococcus thermophilus and lactobacillus bulgaricus, and the inoculation amount of the streptococcus thermophilus and the lactobacillus bulgaricus is 1 multiplied by 106 cfu/g.

EXAMPLE five

A prebiotics yoghurt powder is prepared by the following steps with reference to figure 1:

s1, preheating 89.16 wt% of milk product solution to 45 ℃, sequentially mixing and stirring 8 wt% of white granulated sugar, 1.7 wt% of functional sugar, 1 wt% of flavor substances and 0.08 wt% of stabilizer for 20min, homogenizing, sterilizing and filtering, controlling the homogenizing pressure to be 24.5MPa, the sterilizing temperature to be 90 ℃, and the sterilizing time to be 15min to obtain emulsion;

s2, cooling the emulsion to 40 ℃, then adding 0.06 wt% of lactobacillus fermentum for fermentation, controlling the fermentation temperature to 42 ℃, controlling the fermentation time to 3h, and stopping fermentation when the acidity of the fermentation reaches 0.7% to obtain the yoghourt;

and S3, drying and crushing the yoghourt by a vacuum low-temperature belt type continuous dryer, controlling the drying temperature to be 50 ℃, and quantitatively packaging the obtained materials to obtain the prebiotics yoghourt powder.

Wherein the dairy product is goat milk; the functional sugar is prepared from fructo-oligosaccharide and galacto-oligosaccharide in a mass ratio of 4: 1, the content of kestose in the fructo-oligosaccharide is more than or equal to 60 w/% (calculated on a dry basis), and the content of kestose in the fructo-oligosaccharide is preferably 80 w/% (calculated on a dry basis); the stabilizer is prepared from xanthan gum and pectin according to a mass ratio of 1: 1 in proportion; the lactobacillus fermentum is compounded by lactobacillus rhamnosus, lactobacillus casei and bifidobacterium, and the inoculation amount of the lactobacillus rhamnosus, the lactobacillus casei and the bifidobacterium is 1 multiplied by 106 cfu/g; the flavor substances can be fruit and vegetable powder, cranberry powder, yellow peach powder, green tea powder, black tea powder and golden camellia powder, corresponding selection can be made according to actual target products, and the fruit and vegetable powder is preferably selected in the scheme.

EXAMPLE six

A vacuum low-temperature belt type continuous dryer, referring to fig. 1, is used for preparing prebiotics yoghurt powder in the above examples 1-5, and comprises a belt dryer body 3 which is in a cylindrical closed arrangement, wherein the vacuum degree in the belt dryer body 3 is more than or equal to-99 kpa, a crawler belt 5 for transporting pulpy yoghurt and a heating plate 6 for drying the pulpy yoghurt are fixedly arranged in the belt dryer body 3 in a rolling way. One side of the top of the belt drying machine body 3 is set to be a feeding end, the belt drying machine body 3 is located at the feeding end and is provided with a feeding tank 1 for loading the slurry yogurt, one side of the bottom of the belt drying machine body 3, which is far away from the feeding tank 1, is set to be a discharging end, and the belt drying machine body 3 is located at the discharging end and is provided with a material receiving tank 7 for collecting the dried yogurt. The yoghourt in the feeding tank 1 is continuously transported and dried in the belt dryer body 3 through the crawler belt 5, so that the static drying of the traditional yoghourt is successfully converted into dynamic drying, the technical problem of continuous feeding and discharging in a vacuum state is solved, the yield of a dried product is greatly improved, the production cost is comprehensively reduced, and the amplified continuous production of the yoghourt production capacity is ensured.

Specifically, feeding jar 1 is connected with filling tube 4, and the one end that feeding jar 1 was kept away from to filling tube 4 extends to the upper surface of track 5, and the upper surface of track 5 is the level setting, and the acidophilus milk that filling tube 4 dropped passes through the distributing device and can evenly spread on track 5 upper surface, then drags track 5 by transmission and rolls, and the operating frequency control of track 5 is at 20HZ-30HZ, realizes the continuous transportation to the acidophilus milk.

Specifically, the heating plate 6 is horizontally disposed, the upper track 5 is attached to the upper surface of the heating plate 6, and the heating plate 6 is divided into a heating region and a cooling region. The heating area is positioned on one side of the belt dryer body 3 close to the feeding end, heat energy of the heating plate 6 of the heating area is transmitted from bottom to top through the crawler belt 5, so that materials spread on the upper surface of the crawler belt 5 absorb heat to generate evaporation, and the pasty yoghourt forms loose flaky dried cakes in the process of slow movement of the crawler belt 5. The cooling area is positioned on one side of the machine body 3 with the dryer, which is close to the discharge end, and at the moment, the heat energy of the yoghourt is transferred from top to bottom to the heating plate 6 of the cooling area, so that the yoghourt is cooled to normal temperature and is dried.

Specifically, the heating area includes first heating unit, second heating unit, third heating unit and the fourth heating unit that arranges in proper order along feed end to discharge end, and every heating unit all is provided with steam inlet, adopts steam to carry out temperature regulation and control to hot plate 6, and each heating unit's steam independently circulates, and the steam after the use passes through secondary steam discharge pipe 2 and discharges and take dry quick-witted fuselage 3. The cooling area includes first cooling unit and second cooling unit, and every cooling unit all is provided with the water inlet, adopts the cooling water to carry out temperature regulation and control to hot plate 6, and the cooling water of each cooling unit independently circulates. The temperature of the first heating unit and the second heating unit is controlled to be 40-58 ℃, the temperature of the third heating unit and the fourth heating unit is controlled to be 30-48 ℃, the temperature of the first cooling unit is controlled to be 25-45 ℃, and the temperature of the second cooling unit is controlled to be 20-25 ℃. The temperature in the whole drying process is mild, and the vacuum low-temperature drying can meet the processing requirements of most heat-sensitive materials, so that the effective components of the fermented yogurt probiotics are preserved to the maximum extent.

Specifically, receive material jar 7 and be located track 5 and hot plate 6 and keep away from the terminal below in one side of feed jar 1, receive the internally mounted of material jar 7 and have a sword 8 soon, and the acidophilus milk after 5 drying of track drops to receive material jar 7 inside, and sword 8 soon is used for being loose flaky acidophilus milk drying cake after the drying and smashing. The dried yoghurt powder has a certain loosening effect, and meanwhile, micropores are formed in the yoghurt powder from the microstructure, so that after the yoghurt powder is crushed to the required particle size, the flowability and the instant solubility of the particles are good, and the grade of the product is improved. The dried yoghourt not only contains rich protein, but also retains a large amount of probiotics, and simultaneously contains rich prebiotics dietary fiber, vitamins, iron, calcium and other mineral substances, can be directly brewed and drunk, and is convenient, nutritional, healthy and delicious.

Comparative example 1

The prebiotics yoghurt powder comprises the following steps, reagents, parameters and the like which are the same as those in the first embodiment, and is characterized in that: in S03, the yogurt is dried by means of a spray dryer.

Comparative example No. two

The prebiotics yoghurt powder comprises the following steps, reagents, parameters and the like which are the same as those in the first embodiment, and is characterized in that: in S03, the yogurt is dried using a vacuum lyophilizer.

Comparative example No. three

The prebiotics yoghurt powder has the same steps and reagents, parameters and the like related to the steps as the two examples, and the differences are that: in S03, the yogurt is dried by means of a spray dryer.

Comparative example No. four

The prebiotics yoghurt powder has the same steps and reagents, parameters and the like related to the steps as the two examples, and the differences are that: in S03, the yogurt is dried using a vacuum lyophilizer.

Comparative example five

The prebiotics yoghurt powder has the same steps and reagents, parameters and the like related to the steps as those of the embodiment, and is different from the prebiotics yoghurt powder in that: in S03, the yogurt is dried by means of a spray dryer.

Comparative example six

The prebiotics yoghurt powder has the same steps and reagents, parameters and the like related to the steps as those of the embodiment, and is different from the prebiotics yoghurt powder in that: in S03, the yogurt is dried using a vacuum lyophilizer.

Performance test

And (3) detecting the content of probiotics: the total content of probiotics (cfu/g) in the yogurt of S2 and the yogurt powder of probiotics of S3 in different examples and different comparative examples was tested according to GB 4789.35-2016 national standard for food safety-food microbiology test-lactic acid bacteria test, and the test results are shown in Table 1.

TABLE 1 Total Probiotics content of yogurts and probiotic yogurt powders of examples 1-5

The detection results of examples 1-3 and comparative examples 1-6 in table 1 show that the traditional yogurt drying methods mainly include two methods of spray drying and vacuum low-temperature freeze drying, the cost of spray drying treatment is slightly low, but the traditional yogurt drying methods have insufficient preservation on original taste and live bacteria, and have no effect on products with slightly high viscosity and heat sensitivity requirements, and the table shows that the content of probiotics after drying is reduced sharply; although the probiotic content of the yogurt subjected to vacuum low-temperature freeze-drying treatment is maximally preserved, the treatment mode has the defects of low yield and high cost. The probiotic yogurt powder finally obtained by the application has the characteristics of low transportation, storage and preparation cost, convenience in eating, nutrition and delicacy.

The above-mentioned embodiments are provided to further explain the objects, technical solutions and advantages of the present invention in detail, and it should be understood that the above-mentioned embodiments are only examples of the present invention and are not intended to limit the scope of the present invention. It should be understood that any modifications, equivalents, improvements and the like, which come within the spirit and principle of the invention, may occur to those skilled in the art and are intended to be included within the scope of the invention.