The production process of apple juice

The production of concentrated apple juice is a highly automated industrial process, with the core objective of removing most of the moisture from the juice through evaporation, thereby significantly reducing its volume, facilitating transportation and storage, while inhibiting microbial growth and extending shelf life.

The core production process can be summarized as the following key steps:

Raw materials ->cleaning and sorting ->crushing ->pressing ->pasteurization and enzymatic hydrolysis ->ultrafiltration ->evaporation concentration ->pasteurization ->filling and storage

1. Raw material receiving and inspection

Use specialized juiced apple varieties (such as Guoguang, Hongyu, etc.), which typically have high acidity, moderate tannin content, and high juice yield. Conduct sampling inspection on incoming apples to ensure that indicators such as pesticide residues and heavy metals meet the standards.

2. Cleaning and Sorting

Apples are transported through a sink and thoroughly cleaned by brush rollers and high-pressure spray to remove soil, dust, leaves, and residual pesticides.

The cleaned apples are screened by workers or optical sorting machines on the conveyor belt to remove rotten and moldy fruits, ensuring the quality and flavor of the final juice.

3. Crushing

Clean apples are sent into a hammer mill or crusher, where they are crushed into evenly sized apple puree (puree)

4. Squeezing

The apple pulp is transported to a press (commonly a belt press or a horizontal spiral centrifuge) for pressing. Separate fruit juice (clear juice and partially cloudy juice) from fruit pulp (skin, seeds, pulp fibers) through physical pressure. Fruit pomace is usually sold as a byproduct for the production of animal feed or pectin.

5. Pasteurization and enzymatic hydrolysis

The squeezed juice is immediately subjected to a brief pasteurization (e.g. heated to 95-98 ° C and held for 30 seconds).

After sterilization, cool the juice to around 50 ° C and add pectinase and amylase for enzymatic hydrolysis.

6. Ultrafiltration

The juice clarified by enzymatic hydrolysis is pumped into the ultrafiltration system. Ultrafiltration membrane is a precision filter with micropores that only allows small molecules of sugars, acids, flavor substances, and water to pass through, while intercepting large molecules of proteins, starch residues, colloids, etc. Thus obtaining an extremely clear, stable, and brightly colored clear juice, avoiding the burnt taste during subsequent concentration. The filtered residue returns to the fruit residue.

7. Evaporation and concentration

The clarified apple juice is sent to a multi effect falling film evaporator. Under vacuum and lower temperatures (usually 40-50 ° C), water evaporates. A vacuum environment can lower the boiling point and protect the heat sensitive flavor compounds of fruit juice from being damaged by high temperatures. During the evaporation process, volatile aromatic compounds (aroma components) will escape with water vapor. These vapors will be condensed and recovered by a specialized "aroma recovery device", and then added back to the concentrated juice in proportion to maintain its natural flavor.

8. Final pasteurization and cooling

The concentrated juice will undergo another pasteurization to ensure that any potential microorganisms are completely eliminated. Then quickly cool to low temperature and prepare for filling.

9. Aseptic Packaging and Storage

After cooling, concentrated apple juice is poured into sterile large bags (usually lined with food grade polyethylene and covered with aluminum foil and cardboard in a "sterile box" with a capacity of over 220 kilograms) or cans in a sterile environment. The filled products are stored and transported in a refrigerated warehouse (0-4 ° C) away from light to maximize quality and flavor.