The manufacturing and production of fully automatic yogurt production line equipment provides a complete set of turnkey engineering machinery to better meet the needs of modern enterprises for dairy manufacturing.

Processing process of fully automatic yogurt production line

After the raw milk is pretreated and cooled to the inoculation temperature, the further processing technology depends on whether it produces solidified, stirred, drinkable, frozen or concentrated yogurt. The tissue state and flavor of yogurt are important indicators that determine the quality of yogurt.
The pre treated milk is cooled to the cultivation temperature, and then continuously pumped into the fermentation tank along with the required volume of production starter. After the tank is full, start stirring for a few minutes to ensure that the starter is evenly dispersed. The fermentation tank is insulated to ensure constant temperature throughout the entire cultivation period. In order to check the acidity development inside the tank, a pH meter can be installed on the tank. The typical cultivation time for the production of stirred yogurt is 2.5-3 hours, 42-43 ℃, and ordinary fermentation agents (inoculation amount of 2.5-3%) are used. In order to obtain the best product, bacterial fermentation must be terminated when the pH value reaches the ideal value, and the temperature of the product should be cooled from 42-43 ℃ to 15-22 ℃ within 30 minutes. At the same time, to ensure that the finished product has ideal viscosity, the mechanical treatment of clots must be gentle. Cooling is carried out in a plate heat exchanger with special plates, which ensures that the product is not subjected to strong mechanical disturbances. After cooling to 15-22 ℃, the yogurt is ready for packaging. Fruits and spices can be added during the transportation of yogurt from the buffer tank to the packaging machine. This is achieved by continuously adding these ingredients to yogurt through a variable speed metering pump and mixing them through a mixing device. The design of the mixing device is static and hygienic, ensuring thorough mixing of fruit ingredients with yogurt. The fruit metering pump and yogurt feeding pump operate synchronously.

Yogurt production process: milk → standardization → blending → sterilization homogenization → fermentation → cooling → filling → cold storage

The production process of yogurt can be summarized as several steps, including ingredient preparation, preheating, homogenization, sterilization, cooling, inoculation (filling: used for solidified yogurt), fermentation, cooling (stirring: used for stirred yogurt), packaging, and post ripening. Modified starch is added during the ingredient preparation stage, and its application effect is closely related to the control of the process

Ingredients: Select the required raw materials according to the material balance sheet, such as fresh milk, sugar, and stabilizers. Modified starch can be added separately during ingredient preparation or mixed with other food gums before addition. Considering that starch and food gums are mostly hydrophilic polymers, they should be mixed with an appropriate amount of sugar and dissolved in hot milk (55 ℃~65 ℃, the specific temperature depends on the instructions for using modified starch) under high-speed stirring to improve their dispersibility.

Preheating: The purpose of preheating is to improve the efficiency of the next process – homogenization. The selection of preheating temperature should not be higher than the gelatinization temperature of starch (to avoid damage to the particle structure during homogenization after starch gelatinization).

Homogenization: Homogenization refers to the mechanical treatment of milk fat globules to make them uniformly dispersed in the milk as smaller fat globules. During the homogenization stage, materials are subjected to three types of forces: shear, collision, and void effects. Modified starch, due to its strong mechanical shear resistance after cross-linking, can maintain its intact particle structure, which is beneficial for maintaining the viscosity and body shape of yogurt.

Sterilization: Generally, pasteurization is used, and dairy factories commonly use a sterilization process of 95 ℃ and 300S. During this stage, the modified starch fully expands and gelatinizes, forming viscosity.

Cooling, inoculation, and fermentation: Modified starch is a type of high molecular weight substance that retains some of the properties of the original starch, namely polysaccharide properties, compared to the original starch. In the pH environment of yogurt, starch is not utilized or degraded by bacterial strains, thus maintaining the stability of the system. When the pH value of the fermentation system drops to the isoelectric point of Zhi casein, casein denatures and solidifies, forming a three-dimensional network system skeleton connected to water and forming a gelatinous emulsion. At this time, the gelatinized starch can fill the skeleton, bind free water, and maintain system stability.

Cooling, stirring, and post ripening: The purpose of cooling stirred yogurt is to rapidly inhibit the growth of microorganisms and enzyme activity, mainly to avoid excessive acid production during fermentation and dehydration during stirring. Due to the diverse sources of raw materials and varying degrees of denaturation, different types of modified starch have different effects when used in yogurt production. Therefore, corresponding modified starch can be provided according to different requirements for yogurt quality.

Yogurt Processing Line Classification

According to the finished product status:

—Set yogurt: Set yogurt is fermented after filling into the packaging container, and the finished product is curd-like.

—Stirred yogurt: Stirred yogurt is a fluid product with a certain viscosity made by stirring the fermented curd before filling it into the container, with or without adding fruit materials.

—Drinking Yogurt: Similar to stirred yogurt, the curd is decomposed into liquid type before filling and packing.

According to the flavor of the finished product:

—Natural pure yogurt: a product made from fresh milk or milk powder, skimmed or non-skimmed, after fermentation. The yogurt does not contain any auxiliary materials and additives. The shelf life of this product can be stored for 15-18 days at a temperature of 2-6°C.

– Flavored yogurt: yogurt made by adding sugar, natural fruit materials, vitamins, etc. to raw milk or milk powder, and then fermented by probiotics. The shelf life is about 25 days with cold storage conditions. The amount of fruit added is about 15%, of which the sugar content is 50%.

According to storage conditions:

-Chilled yogurt: Fresh milk after pasteurization and fermentation, the end products will be filled into cups, cartons, or bottles. The filling, distribution and storage processes are all in a chilled environment.

-Room temperature aseptic yogurt: Fresh milk after sterilization and fermentation to obtain the yogurt, then the yogurt will feed into a sterilizer for the UHT treatment to make into aseptic yogurt, and the aseptic yogurt will be filled into aseptic cartons, bottles or cups aseptically.