Flavored Milk Processing Line

Flavored milk is a ready-to-drink product produced from raw fresh milk, mixed with sugar and natural flavors (e.g. banana, pineapple, orange, chocolate etc), then homogenized, pasteurized/UHT sterilized and degassed, filled into the containers for direct consumption.

The flavored milk can be made as a pasteurized refrigerated product; or as an ultra-high temperature (UHT) processed product that does not require refrigeration according to different sterilizing processes and packaging containers.

The raw ingredients for flavored milk processing can be fresh milk or milk powder and other powder ingredients.

The flavored milk production process typically involves several stages, including raw milk reception, milk standardization, the addition of flavors, sweeteners, and colors in the milk, pasteurization, homogenization, cooling, filling into containers, and packaging.

Industrial flavored milk processing machines include raw milk receiving system, raw milk standardization tank, flavored milk blending system, high-pressure milk homogenizer, milk degasser, milk pasteurizer/UHT sterilizer, flavored milk carton/bottle filling and packing machines, hot water generating system, RO water generating system, CIP cleaning system.

The flavored milk processing machines are made of food-grade SUS304/SUS316L material to ensure producing high-quality products.

The whole processing line has the characteristic of highly flexibility, high automatic degree, save labor and energy. The product flavor, end package and production process can be customized according to clients’ requirements and budgets.

The capacity of the flavored milk production is from 500L/H to 10000L/H, and the end products can be filled into bottles, metal cans, tetra pak cartons or pouches.

When we produce flavored milk, the raw milk, flavors and sweeteners, stabilizers, vitamins and minerals are the main ingredients.

—Fresh Milk/Milk Powder: Milk is the primary ingredient in flavored milk and provides the base for the beverage, it contains protein, calcium, and vitamins, which are important for maintaining good health. To ensure the quality and consistency of the final product, the milk used in flavored milk processing is typically standardized to a specific fat content.

—Flavors and sweeteners: Flavors and sweeteners are added to milk to create a unique taste and aroma. Flavors mainly include all kinds of fruit juice, vanilla, chocolate, strawberry, and many others; Sweeteners, such as sugar, sugar substitute, corn syrup, are added to enhance the flavor and make the milk more appealing to consumers. The selection of flavors and sweeteners depends on consumer preferences and market trends.

—Stabilizers and emulsifiers: Stabilizers and emulsifiers are added to flavored milk to improve its texture and prevent separation. Stabilizers help to thicken the milk and prevent the flavors and sweeteners from settling at the bottom of the container. Common stabilizers include carrageenan, xanthan gum, and pectin. Emulsifiers help to mix the milk and flavorings evenly, so that the final product has a consistent texture. Some commonly used emulsifiers include lecithin and mono- and diglycerides.

—Vitamins and minerals: Some manufacturers may also fortify flavored milk with vitamins and minerals to make it more nutritious. For example, vitamin D and calcium may be added to enhance bone health, while vitamin A and iron may be added to support eye health and prevent anemia.

—Preservatives: In some cases, preservatives may be added to flavored milk to extend its shelf life and prevent spoilage. Common preservatives used in flavored milk processing include potassium sorbate and sodium benzoate.

The production process for flavored milk is similar to that of pasteurized milk/UHT production process, but with a few additional steps. The following is a step-by-step guide to the flavored milk production process:

1. Raw milk reception: Raw milk is received from the farm and undergoes testing to ensure it meets the quality standards for milk production. The milk is received and weighed by tanks then cooled and stored in milk silos where it is kept at a cool temperature(5℃) to prevent spoilage.
2. Milk standardization: The milk is standardized to ensure consistent quality and fat content. The fat content of the milk is adjusted to the desired level by adding cream or separating the fat with the centrifuge milk separator.
3. Milk flavoring and mixing: The ingredients such as flavors, sugar and emulsifiers are added to the milk in a mixing tank according to the recipe, and then start stirring to mix all ingredients evenly.
4. Flavored milk homogenization: The flavored milk is heated to 55℃for homogenization, the process can break down the fat globules and to ensure that the flavoring and sweetening agents are evenly distributed throughout the milk to obtain a smooth and consistent texture of the end products.
5. Flavored milk degassing: after the milk is homogenized, then flow to a vacuum degasser, the degassing helps to improve the shelf life of flavored milk by reducing the amount of air trapped in the product. This can help to prevent spoilage and improve the overall quality of the product.
6. Flavored milk pasteurization/sterilization: The flavored milk is pasteurized or UHT sterilized to eliminate harmful bacteria and extend the shelf life according to clients’ process flowchart, end package and shelf life of the end products.
7. Flavored milk filling and packaging: After the milk is sterilized, then cooled down to the filling temperature, and the milk can be aseptically filled into cartons or hot-filled into bottles for distribution.

The system typically includes raw milk receiving tanks, weighing tanks, plate milk coolers, raw milk silo storage tanks, and milk standardization tanks. After receiving, fresh milk is accurately measured and transferred through a plate heat exchanger for rapid cooling to maintain milk quality and inhibit microbial growth. The cooled milk is then stored in insulated milk silo tanks before entering the standardization process.

During milk standardization, the fat content and other milk components are adjusted according to the requirements of the final product, ensuring consistent quality for products such as UHT milk, pasteurized milk, yogurt, and flavored milk.

All product-contact tanks are manufactured from food-grade stainless steel, typically SUS304 or SS304, with SS316L available for higher hygiene requirements. The tank capacity, configuration, and automation level can be customized according to the customer’s processing capacity, production requirements, and factory layout.

The milk blending and flavoring system is an essential part of a flavored milk processing line, designed for the preparation of various dairy beverages, including chocolate milk, strawberry milk, vanilla milk, and other flavored milk products.

The system is used to combine milk base, sugar, milk powder, cocoa, flavors, fruit ingredients, stabilizers, and other functional additives according to the product formulation. Through accurate ingredient dosing, efficient mixing, and precise temperature control, the system ensures consistent product composition, uniform flavor distribution, and stable product quality.

Sugar, milk powder, cocoa powder, and other powdered ingredients are typically dissolved in a high-shear mixing tank or water powder mixing system using hot water. The high-shear mixer operates at a high rotational speed, typically 1,400–2,900 rpm, generating strong turbulence and shear forces to rapidly disperse and dissolve solid ingredients into the liquid phase. This process helps prevent powder agglomeration, improves dissolution efficiency, and ensures a smooth ingredient solution.

After complete dissolution and hydration, the liquid flavor concentrate is transferred by a sanitary pump into the milk blending tank, where it is combined with standardized milk according to the product recipe. The blending system provides thorough mixing of all ingredients, ensuring uniform distribution of sugar, flavors, and functional additives throughout the milk base.

The flavored milk processing system integrates vacuum degassing, homogenization, pasteurization/UHT sterilization, and filling processes for producing chocolate milk, strawberry milk, vanilla milk, and other dairy beverages.

The vacuum degasser uses a vacuum system to remove dissolved oxygen and unwanted volatile compounds from flavored milk, improving flavor stability and shelf life. The system includes a vacuum tank, vacuum pump, condenser, and automatic control system. It is made of SS304 stainless steel and operates at approximately 55°C.

The high-pressure homogenizer reduces fat globule size to improve product stability and texture. It is made of SS304 stainless steel, with a maximum pressure of 25 MPa and a normal working pressure of 18–20 MPa, equipped with Schneider electrical components and frequency conversion control.

Flavored milk can be processed by a plate pasteurizer or UHT sterilizer:

• Pasteurization: 75–85°C holding for 15 seconds, then cooling to 4°C for chilled filling.
• UHT sterilization: 135°C holding for 3–5 seconds, then cooling to 25°C for aseptic filling.

The system includes a balance tank, heat exchanger, sanitary pumps, hot water tank, electrical cabinet, CIP cleaning system, and automatic control system. All product-contact parts are made of food-grade stainless steel and can be customized according to production capacity and packaging requirements.

After pasteurization or UHT sterilization, flavored milk is transferred to the filling system for packaging according to customer requirements. The finished product can be filled into various types of containers, including aseptic cartons, metal cans, PET bottles, PP/PE plastic bottles, and glass bottles.

For flavored milk packaged in plastic cups or bottles, the filling system can be equipped with an aluminum foil sealing machine installed between the filling and capping stations. The foil sealing process provides a hygienic seal, improves product protection, and helps extend shelf life.

The filling temperature depends on the selected sterilization process, packaging type, and product shelf-life requirements:

• Hot filling: typically performed at elevated temperatures after pasteurization, commonly around 80–90°C for suitable products.
• Cold filling: the product is cooled before filling, usually under hygienic or aseptic conditions.
• Aseptic filling: UHT-treated flavored milk is cooled and filled into sterilized packaging under aseptic conditions, allowing long shelf life at ambient temperature.

A complete flavored milk filling system typically includes:

• Bottle/cup feeding system
• Automatic filling machine
• Aluminum foil sealing unit (optional)
• Capping system
• Date coding system
• Conveyor system
• CIP-compatible hygienic design

The filling equipment can be customized according to production capacity, packaging format, and market requirements.

When using the milk powder as raw products to produce the flavored milk, the flavored milk is filled into cans, PE bottles or glass bottles, then after filling, the flavored milk will be fed into the retort sterilizer for secondary sterilizing to get a stable shelf life, the sterilizing process will be 121℃ for 15-20 minutes.