The basic production process of fruit juice
Raw material selection——cleaning¬¬——crushing——juice extraction——coarse filtration——clarification and fine filtration——homogenization and degassing——concentration——adjustment and mixing——packaging and sterilization
Washing and selection of fruits
General cleaning process:
Running water→ soaking→ brushing→ high-pressure spraying
Purpose: To remove dust, sediment, microorganisms, pesticide residues, and carried branches and leaves on the surface of fruits and vegetables.
Note: For berry fruit processing, cleaning is not required.
Washing method: soak washing, bubbling cleaning, water spray rinsing, chemical solution cleaning.
Crushing and pretreatment in the fruit juice production line
Crushing and pulping
Objective: The juice of fruit and vegetables is present in their tissue cells, and only by breaking the cell wall, the juice and soluble solids in the cells can come out. Especially for some fruit and vegetables with thick skin and dense flesh, to improve the juice yield, it must be crushed.
Extraction in the fruit juice production line
The juice extraction process of fruit and vegetables is very important in the processing of fruit and vegetable juice. According to different raw materials and products, the way of juicing is very different, mainly including:
Squeeze in the fruit juice production line
A widely used juice extraction method in fruit juice production lines.
The juice in the fruit is obtained through a certain pressure, and the juice can be squeezed by cold pressing, hot pressing, or even freeze pressing. The process of squeezing the juice out of the fruit using external mechanical pressure is pressing.
For example, apples, cherries, grapes, etc.
Centrifugation in the fruit juice production line
This is done by a horizontal screw centrifuge, which uses the principle of centrifugal force to achieve the separation of juice from the pulp.
Applicable: dried fruits such as sour dates, plums, red dates, etc., or fruits with high pectin content (such as hawthorn) that are difficult to obtain juice through the above methods, there are two extraction methods: batch type and continuous type.
Pulping in the fruit juice production line
In the processing of fruit juice, this method is suitable for the production of pulp and pulp beverages.
Coarse filtration in the fruit juice production line
In addition to the pulping method, the fruit juice obtained by other methods contains a large number of suspended particles, such as pulp fiber, peel, and fruit core. Their presence affects the appearance and flavor of the product and needs to be removed in time. Coarse filtration can be carried out during juicing or in a stand-alone operation, and coarse filtration is usually carried out using a vibrating screen in production.
Clarification and fine filtration of juice
Purpose: To remove all suspended solids and particles that are prone to precipitation.
Homogenization and degassing of fruit juice
Suitable for: cloudy juice and fruit juice with pulp
Objective: To further crush and refine the suspended pulp particles in the juice, make the size more uniform, and at the same time promote the dissolution of pectin on the pulp cell wall, so that the pectin is evenly distributed in the juice to form a stable dispersion system.
If the juice is not homogenized, due to the large suspended pulp particles in the juice, the product is unstable, and the pulp will slowly sink to the bottom of the container under the action of gravity, and the phenomenon of layering will occur after a period, and the boundaries are clear, which will affect the appearance of the product.
Equipment: high-pressure homogenizer, ultrasonic homogenizer, colloid mill, etc.
There is a certain amount of air in the pulp tissue, and the crushing, juice extraction, homogenization and pumping, and pipeline transportation during processing will bring a large amount of air into the juice, and the air needs to be removed during the production process, which is called degassing or deoxygenation.
Degassing can reduce or avoid oxidation of fruit juice, which can prevent the destruction of the color and flavor of the juice and the loss of nutrients such as vitamin C. It avoids the floating of suspended particles and adsorbed gases, as well as foam formation during filling and sterilization.
The concentration of fruit juice
Concentrate: Removes some of the moisture from the juice.
Advantages of juice concentrate: increase stability, reduce volume, meet the needs of other beverage production.
The main methods of fruit juice concentration:
(1) Vacuum concentration method
(2) Reverse osmosis concentration method
(3) Freeze concentration method
Sterilization and packaging of fruit juice
Purpose: Mainly to kill pathogenic bacteria in fruit juice.
Whether the sterilization process of fruit juice is correct not only affects the preservation of the product but also affects the quality of the product, which is a very important issue. Heating can kill spoilage-causing bacteria, molds, and yeasts present in the juice, and at the same time can inactivate the activity of enzymes. Through the appropriate heating temperature and heating time, the purpose of killing microorganisms can be achieved. However, to minimize the impact on the quality of the juice, it is necessary to choose a reasonable heating temperature and time.
- Heat sterilization:
- Pasteurization LTS
- High-temperature short-term sterilization method HTST
- Ultra-high temperature instantaneous sterilization method UHTS
In production, the general sterilization method can be used to sterilize, that is, 80 ~ 85 °C sterilization for about 30min, and then put into cold water to cool to achieve the purpose of sterilization. However, due to the long heating time, the color and flavor of the juice will be lost, especially for juices with pulp. Therefore, the juice plant often adopts the high-temperature instantaneous sterilization method, that is, 93 °C ± 2 °C to maintain 15 ~ 30s sterilization, and under special circumstances, it can be maintained at a temperature above 120 °C for 3 ~ 10s sterilization. Experiments have proved that the high-temperature instantaneous sterilization method has been widely used.
Filling in the fruit juice production line
- Hot filling
- Cold filling
- Aseptic filling
Hot filling: the juice is not cooled and filled after heating and sterilization, and the inner surface of the container is sterilized by the temperature of the juice. If the container is well sealed, the juice remains sterile. However, the time required between sterilization and filling of the juice is generally more than 3min. Therefore, the deterioration of the quality of fruit juice is difficult to avoid.
Cold filling: Juice is cooled to 5 °C immediately after heating and sterilization. After heating the juice to the sterilization temperature, keep it for a certain time, and then immediately cool it to normal temperature or below normal temperature through the heat exchanger, and fill the cooled juice, so that you can get a high-quality product.
Aseptic filling: It refers to the juice being filled under aseptic conditions after heating and sterilization, and the product is circulated and sold at room temperature and can be stored for more than 6 months. Second sterilization: In the actual production of the factory, the process conditions, including temperature and time management, are often not strict enough, the filling temperature before and after the mass production of juice is inconsistent, and the sterilization of the container lid is not thorough enough. Therefore, sterilization is still required after the juice is filled and sealed.
AGICO has a full set of juice production line machinery. If you want to set up your juice plant, you can leave a message about the type of juice you want to produce or what kind of equipment you want.