CN103493884A - Preparation method of instant-brew-yogurt milk powder - Google Patents

Abstract

The invention discloses a preparation method of freshly brewed yogurt-type milk powder, belonging to the technical field of food processing, comprising: 1) adding white sugar to raw milk, sterilizing after homogenizing, and concentrating to obtain concentrated milk; 2) fermenting the activated yogurt Bacteria were inoculated into the enriched culture solution. After the primary culture, the supernatant was removed by centrifugation, and the enriched culture solution was continuously added to the precipitated bacteria sludge for secondary culture. Then the supernatant was removed by centrifugation, and the enriched culture solution was added to the sludge. After homogenizing 1/3 volume of concentrated milk of enriched culture medium, high-bacteria concentrated yogurt fermentation broth is obtained; 3) After mixing concentrated milk and high-bacteria concentrated yogurt fermentation broth, homogenize, and then spray-dry to obtain Milk powder for processing freshly brewed yogurt. The production process of the present invention is simple, low in cost, and environment-friendly, and is suitable for large-scale industrial production. Healthy, safe and convenient, suitable for all ages.

Description

A kind of preparation method of instant brewed yoghurt type milk powder

technical field

The invention belongs to the technical field of food processing, and relates to a method for preparing milk powder, in particular to a method for preparing ready-to-brew yogurt-type milk powder.

Background technique

Because yogurt contains active lactic acid bacteria or probiotics, its health effects have been fully confirmed and recognized by consumers. It is known as "immortal bacteria" and "human health guard". The application share of lactic acid bacteria or probiotics in dairy products is as high as more than 80%. The main product types are liquid dairy products such as yogurt and yogurt drinks. There are many varieties of them and they are very popular among consumers.

However, due to the high requirements for product storage conditions and the short retention period of bacterial activity (1 week for yogurt and 1 to 3 months for yogurt drinks under refrigeration at 0°C to 8°C), it is safe to use in transportation, storage, sales, drinking, etc. Hidden dangers occur from time to time, resulting in the inability to truly exert and reflect the health effects of lactic acid bacteria or probiotics.

With the improvement and improvement of people's living standards, the concept of consumers has undergone tremendous changes. People's awareness of safety, health and nutrition has become stronger and stronger. Freshly brewed yogurt has become the new favorite of fermented milk consumption. Freshly brewed yogurt It has also gradually become a fashionable and healthy food, and more and more fans of freshly brewed yogurt are attracted by the flavor, nutrition and health effects of freshly brewed yogurt.

At present, fresh milk is used as raw material for fresh milk, adding appropriate amount of white sugar, etc., after pasteurization and cooling, pure lactic acid bacteria starter is added, sub-packaged, fermented for about 6 hours to 8 hours, and refrigerated for 12-48 hours. After hours, the finished product. During the production process, the technical and hygienic conditions of fresh milk procurement, refrigeration, transportation, sterilization, cooling, packaging and other links are very high. At present, freshly brewed yogurt is mostly made on-site in sales stores, and the environment, equipment, aseptic operation and other conditions are difficult to meet the standards, and safety hazards occur from time to time; in addition, pure lactic acid bacteria starters need to be added during fermentation, which is very dependent on starters . Thereby affecting the quality of freshly brewed yogurt, restricting the development of freshly brewed yogurt.

Contents of the invention

In order to overcome the defects in the above-mentioned prior art, the object of the present invention is to provide a method for preparing ready-to-brew yogurt-type milk powder. The method is simple to operate, and the prepared milk powder contains yogurt fermentation bacteria, which can directly prepare ready-to-brew yogurt.

The present invention is achieved through the following technical solutions:

A preparation method of instant brewed yogurt type milk powder, comprising the following steps:

1) Inoculate the activated yogurt fermentation bacteria into the enriched culture medium with an inoculum amount of 1ml/100ml for a primary culture, then centrifuge to remove the supernatant, continue to add the enriched culture medium to the precipitated bacteria sludge, and perform a secondary culture , and then centrifuge to remove the supernatant, add 1/3 of the enriched culture solution volume concentrated milk to the precipitated bacteria sludge, after homogenization, obtain the high-bacteria concentrated yogurt fermented bacteria solution;

Wherein, the enriched culture solution includes, by mass fraction, 1-7% corn steep liquor, 1-3% yeast powder, 10-30% cucumber juice, and the balance is water; The volume of enriched culture medium used for subcultivation is equal;

2) Mix the concentrated milk and the high-bacteria concentrated yogurt fermented liquid in a volume ratio of 100:1-10, homogenize, and then spray dry to obtain milk powder for processing freshly brewed yogurt.

The concentrated milk is to add white sugar with a mass of 3-10% of the raw milk to the pasteurized raw milk, homogenize, sterilize, and then concentrate to a concentration of 12-16°Be', and the milk solid content is Obtained after 40-50%.

The sterilization adopts the ultra-high temperature instantaneous sterilization method at 120-150° C. for 1-2 seconds.

The concentration is carried out under reduced pressure in a vacuum concentrated acid tank, the degree of vacuum is 15.33×10 ³ Pa～16.00×10 ³ Pa, and the temperature is 51～56°C.

The primary cultivation is at 30-45° C. for 12-24 hours, and the secondary cultivation is at 30-40° C. for 12-24 hours.

The centrifugation in step 1) is carried out at 4-10° C. and at a speed of 3000-6000 rpm for 10-30 minutes.

The homogenization described in step 2) is carried out at 45-50°C.

Step 2) Set the inlet air temperature of the spray dryer at 130-150°C, the tower temperature at 75-80°C, and the outlet air temperature at 75-80°C.

Compared with the prior art, the present invention has the following beneficial technical effects:

The present invention first adopts continuous enrichment to cultivate yogurt fermentation strains, and can obtain high-bacteria concentrated yogurt fermentation bacterial liquid with a viable count of more than 10 ¹⁰ cfu/ml, thereby ensuring higher bacterial activity in the product; secondly, obtaining The high-bacteria thick yogurt fermented liquid is mixed with concentrated milk, homogenized and then spray-dried, making full use of the protective effect of concentrated milk, preventing the bacteria from being damaged by high temperature and maintaining the activity of the bacteria, so as to obtain high activity for use Processing the milk powder of freshly brewed yogurt eliminates the cumbersome links and high requirements for fresh milk pre-treatment, and also eliminates the dependence on pure lactic acid bacteria starter.

The production process of the present invention is simple, low in cost and friendly to the environment, and is suitable for large-scale industrial production. , nutritious and healthy, safe and convenient, suitable for all ages.

Detailed ways

The present invention will be further described in detail below in conjunction with specific embodiments, which are explanations of the present invention rather than limitations.

Example 1

A preparation method of instant brewed yogurt type milk powder, comprising the following steps:

1) Add white granulated sugar with 3% mass of raw milk to the pasteurized raw milk, after homogenization, sterilize by high-temperature instant sterilization, and then concentrate in vacuum at 51°C to a concentration of 12°Be ', milk solids content is 40%, obtain concentrated milk, standby;

2) Inoculate the activated yogurt fermentation bacteria into the enriched culture medium with an inoculum amount of 1ml/100ml. After culturing once for 24 hours at 30°C, centrifuge at 3000 rpm for 30min at 4°C to remove For the supernatant, continue to add the enriched culture solution to the precipitated bacteria sludge. After secondary cultivation for 24 hours at 30°C, centrifuge at 3000 rpm for 30 minutes at 4°C to remove the supernatant. Add 1/3 of the concentrated milk of the volume of enriched culture solution to the mud, and after homogenization, the high-bacteria concentrated yoghurt fermented liquid is obtained;

Wherein, the enriched culture solution, in terms of mass fraction, includes 1% corn steep liquor, 3% yeast powder, 20% cucumber juice, and the balance is water; The volume of culture medium is equal;

3) Mix the concentrated milk and the high-bacteria concentrated yogurt fermentation broth in a volume ratio of 100:3, homogenize at 45°C, and then spray dry (set the inlet air temperature of the spray dryer to 130°C, and the tower temperature to 75°C, and the outlet air temperature is 75°C), to obtain milk powder for processing freshly brewed yoghurt.

Example 2

A preparation method of instant brewed yogurt type milk powder, comprising the following steps:

1) Add white granulated sugar with 7% mass of raw milk to the pasteurized raw milk, after homogenization, sterilize by high-temperature instant sterilization, and then concentrate in vacuum at 53°C to a concentration of 14°Be ', milk solids content is 45%, obtain concentrated milk, standby;

2) Inoculate the activated yogurt fermentation bacteria into the enriched culture medium with an inoculum amount of 1ml/100ml. After culturing once for 18 hours at 40°C, centrifuge at 4500 rpm for 20min at 6°C to remove For the supernatant, continue to add enriched culture solution to the precipitated bacteria sludge, and after secondary cultivation for 18 hours at 35°C, centrifuge at 4500 rpm for 20 minutes at 6°C, remove the supernatant, Add 1/3 of the concentrated milk of the volume of enriched culture solution to the mud, and after homogenization, the high-bacteria concentrated yoghurt fermented liquid is obtained;

Wherein, the enriched culture solution, in terms of mass fraction, includes 3% corn steep liquor, 2% yeast powder, 30% cucumber juice, and the balance is water; The volume of culture medium is equal;

3) Mix the concentrated milk and the high-bacteria concentrated yogurt fermentation broth at a volume ratio of 100:1, homogenize at 45°C, and then spray dry (set the inlet air temperature of the spray dryer to 140°C, and the tower temperature to 78°C, and the outlet air temperature is 78°C), to obtain milk powder for processing freshly brewed yoghurt.

Example 3

A preparation method of instant brewed yogurt type milk powder, comprising the following steps:

1) Add white granulated sugar with 5% mass of raw milk to the pasteurized raw milk, homogenize, sterilize by high temperature instant sterilization, and then vacuum concentrate at 56°C to a concentration of 16°Be ', milk solids content is 50%, obtain concentrated milk, standby;

2) Inoculate the activated yogurt fermentation bacteria into the enriched culture medium with an inoculum amount of 1ml/100ml. After culturing once for 12 hours at 45°C, centrifuge at 5000 rpm for 18min at 10°C to remove For the supernatant, continue to add the enriched culture solution to the precipitated bacteria sludge, and after secondary cultivation for 12 hours at 40°C, centrifuge at 5000 rpm for 18 minutes at 10°C, remove the supernatant, and remove the supernatant. Add 1/3 of the concentrated milk of the volume of enriched culture solution to the mud, and after homogenization, the high-bacteria concentrated yoghurt fermented liquid is obtained;

Wherein, the enriched culture solution, in terms of mass fraction, includes 5% corn steep liquor, 1% yeast powder, 15% cucumber juice, and the balance is water; The volume of culture medium is equal;

3) Mix the concentrated milk and the high-bacteria concentrated yogurt fermentation broth in a volume ratio of 100:7, homogenize at 48°C, and then spray dry (set the inlet air temperature of the spray dryer to 150°C, and the tower temperature to 80°C, the outlet air temperature is 80°C) to obtain milk powder for processing freshly brewed yoghurt.

Example 4

A preparation method of instant brewed yogurt type milk powder, comprising the following steps:

1) Add white sugar with 10% mass of raw milk to the pasteurized raw milk, after homogenization, sterilize by high-temperature instant sterilization, and then concentrate in vacuum at 55°C to a concentration of 15°Be ', milk solids content is 48%, obtain concentrated milk, standby;

2) Inoculate the activated yogurt fermentation bacteria into the enriched culture medium with an inoculum amount of 1ml/100ml. After culturing once for 18h at 40°C, centrifuge at 6000 rpm for 10min at 8°C to remove For the supernatant, continue to add the enriched culture solution to the precipitated bacteria sludge. After secondary culture for 12 hours at 40°C, centrifuge at 6000 rpm for 10 minutes at 8°C to remove the supernatant. Add 1/3 of the concentrated milk of the volume of enriched culture solution to the mud, and after homogenization, the high-bacteria concentrated yoghurt fermented liquid is obtained;

Wherein, the enriched culture solution, in terms of mass fraction, includes 7% corn steep liquor, 1% yeast powder, 12% cucumber juice, and the balance is water; The volume of culture medium is equal;

3) Mix the concentrated milk and high-bacteria concentrated yogurt fermentation broth in a volume ratio of 100:10, homogenize at 50°C, and then spray dry (set the inlet air temperature of the spray dryer to 150°C, and the tower temperature to 75°C, and the outlet air temperature is 75°C), to obtain milk powder for processing freshly brewed yoghurt.

Compared with ordinary milk powder, the instant brewed yogurt type milk powder prepared by the present invention has more eating methods:

Edible method 1: brew and drink directly.

Mix the freshly brewed yoghurt-type milk powder prepared by the present invention with warm boiled water at 50°C to 70°C in a ratio of 1:5-7 to make probiotic reconstituted milk, which can be drunk directly, except that it has the nutrition of ordinary milk powder , also has the health benefits of probiotics.

Edible method 2: Prepare freshly brewed yogurt.

After the probiotic reconstituted milk is made according to the eating method 1, it is packaged separately, and it is incubated and fermented at 41°C-45°C for about 6 hours to 8 hours. When the milk is completely solidified and a small amount of whey appears on the surface, the fermentation is complete. Put the curd in the freezer of the refrigerator (about 2°C-5°C) overnight, and after ripening, you can make freshly brewed yogurt with excellent flavor.

Edible method 3: Prepare yogurt drink.

After making freshly brewed yogurt according to eating method 2, consumers can add strawberries, bananas, apples, grapes and other fresh fruits according to their favorite taste, or add various jams, honey beans, jelly, nuts, ice cream, etc. The assorted yogurt and yogurt drinks that best suit your own taste.

The milk powder prepared by the invention has the same properties as the common milk powder except for the internal yogurt fermenting bacteria. The market advantages of this product are: (1) The production process of the product is simple to operate, the cost is low, and it is easy to produce on a large scale; (2) The product is easy to store, transport, sell, and drink. When preparing freshly brewed yogurt, you only need to add warm water and keep it warm for fermentation. (3) The milk powder is not only used in freshly brewed yogurt sales stores, but also can be used in home-made yogurt.

Claims (8)

1. a preparation method of freshly brewed yoghurt type milk powder, is characterized in that, comprises the following steps: 1) Inoculate the activated yogurt fermentation bacteria into the enriched culture medium with an inoculum amount of 1ml/100ml for a primary culture, then centrifuge to remove the supernatant, continue to add the enriched culture medium to the precipitated bacteria sludge, and perform a secondary culture , and then centrifuge to remove the supernatant, add 1/3 of the enriched culture solution volume concentrated milk to the precipitated bacteria sludge, after homogenization, obtain the high-bacteria concentrated yogurt fermented bacteria solution; Wherein, the enriched culture solution includes, by mass fraction, 1-7% corn steep liquor, 1-3% yeast powder, 10-30% cucumber juice, and the balance is water; The volume of enriched culture medium used for subcultivation is equal; 2) Mix the concentrated milk and the high-bacteria concentrated yogurt fermented liquid in a volume ratio of 100:1-10, homogenize, and then spray dry to obtain milk powder for processing freshly brewed yogurt. 2. A method for preparing freshly brewed yogurt-type milk powder according to claim 1, characterized in that, the concentrated milk is added by adding 3 to 10% of the mass of raw milk to the pasteurized raw milk. White granulated sugar, homogenized and sterilized, then concentrated to a concentration of 12-16°Be' and a milk solid content of 40-50%. 3. A method for preparing freshly brewed yogurt-type milk powder according to claim 2, characterized in that said sterilization adopts an ultra-high temperature instantaneous sterilization method at 120-150° C. for 1-2 seconds. 4. A method for preparing freshly brewed yoghurt-type milk powder according to claim 2, characterized in that said concentration is concentrated under reduced pressure in a vacuum concentrated acid tank, and the vacuum degree is 15.33×10 ³ Pa～16.00 ×10 ³ Pa, the temperature is 51-56°C. 5. A method for preparing freshly brewed yogurt-type milk powder according to claim 1, characterized in that, the first culture is at 30-45°C for 12-24 hours, and the second culture is at Cultivate for 12-24 hours at 30-40°C. 6. The method for preparing freshly brewed yogurt-type milk powder according to claim 1, characterized in that the centrifugation in step 1) is performed at 4-10°C at a speed of 3000-6000 rpm. 10-30min. 7. The method for preparing freshly brewed yogurt-type milk powder according to claim 1, characterized in that the homogenization in step 2) is carried out at 45-50°C. 8. A method for preparing freshly brewed yogurt-type milk powder according to claim 1, characterized in that, in step 2), the air inlet temperature of the spray dryer is set at 130-150°C, the tower temperature is 75-80°C, and the outlet The wind temperature is 75-80°C.