Consumption of fruit juices has increased significantly in recent years and is growing rapidly, as consumers are interested in practical, ready-to-drink health products. To produce fruit juices, it is fundamental to improve safety and quality, nutritional value, and product, and reasonably reduce process costs.

Why Do Juices Need to Be Filtered?

The purpose of filtration is to remove solid particles from a liquid medium. Filters are used to remove sediment, clarify juice, reduce or remove spoilage organics, protect products stored in tanks, and even filter process gases used in the production process.

In juice processing, the largest particles are removed by passing the juice from the press through a mesh screen or a continuous self-cleaning centrifuge.

For unclarified products, this step is sufficient. To obtain a fully clarified product, the juice must undergo a second step of mechanical filtration.

Advantages of Clarification Using Microfiltration

Traditional juice clarification processes are often expensive and difficult, but the introduction of membrane filtration technology has changed the landscape. By enzymatically treating and preclarifying the juice, membrane filtration ensures high yields, high capacity and excellent quality.

Juice producers can now use membrane filtration equipment to clarify and concentrate a wide range of juices, including strawberry, orange juice, blackcurrant, pear, hawthorn, pineapple and date.

Conventional methods for producing single-concentration or concentrated juices involve multiple batch operations that are labour-intensive and time-consuming. In addition, these methods are unable to remove microorganisms and bacteria, thus limiting the shelf life of the product.

The use of microfiltration has several advantages: it provides high clarity, maintains a good flavor and nutrient content, ensures good retention of vitamin C, retains soluble proteins, and achieves a small degree of browning. In addition, it is cost-effective and requires low maintenance.

Microfiltration (membrane filtration) enables the production of filtered juices with unprecedented clarity and quality. The juice clarification and filtration processes traditionally used by the industry are often both expensive and difficult.

The juice needs to be treated with enzymes to degrade the pectin substances and can subsequently be pre-clarified to optimize the membrane filtration process. This ensures high yields, high productivity and excellent quality.

• Treated juice is of high quality in terms of colour, clarity and mouthfeel
• High juice recovery of approx. 98-99%
• No need to add gelatin, bentonite or diatomaceous earth
• Low operating costs (labor, energy, chemicals)
• Continuous/batch/semi-batch plant operation
• Hygienic design

Fruit Juice Filtration Process

Fruit and vegetable juice is generally divided into clarified fruit and vegetable juice, turbid fruit and vegetable juice and concentrated fruit and vegetable juice.

The general production process is raw material cleaning and selection, pressing or extraction, clarification, filtration, blending, sterilization, and filling.

1. Cleaning and selection

The production of fruit and vegetable juice, should choose fresh, ripe, fragrant raw materials, the raw materials after rinsing, cleaning and then selecting raw materials, remove decayed fruits, in order to ensure the production of high-quality fruit and vegetable juice.

2. Pressing and extraction

There are two methods of extracting juice from fruits and vegetables: pressing and extraction. Fruits and vegetables with more juice are generally pressed and must be crushed before juicing, while fruits and vegetables with less juice and more pectin are generally juiced by pressing.

3. Clarification

Before the clarification process, the original juice is screened and filtered, mainly to remove coarse particles and suspended matter dispersed in the fruit and vegetable juice. Fruit and vegetable juice filtration methods are mainly divided into natural precipitation and adding clarifiers precipitation.

Raw juice contains a large number of particles and organic matter, even after extensive filtration. The cartridge filter shown in Figure 1 is used to the Gradual removal of particles and organic matter that may adversely affect the quality and safety of clear juice beverages.

Raw juice is usually clarified immediately after substantial pulp removal. Small particles not captured by batch filtration are removed as the raw juice and other ingredients enter the juice production process for blending.

Removing the particles helps prevent undesirable flavors from appearing in the product. Once the larger particles have been removed, the clarification step is used to reduce the number of smaller particles and improve product clarity.

4. Filtration

Following the clarification process of fruit and vegetable juice, a plate and frame filter can be employed for initial coarse filtration. Subsequently, a combination of microfiltration and ultrafiltration systems is utilized for fine filtration.

The microfiltration system typically consists of a security filtration setup comprising filter elements or bags and stainless steel filters. Meanwhile, the ultrafiltration system integrates ultrafiltration membrane components for enhanced filtration efficiency.

5. Sterilization and Filling

Filtration plays a crucial role in removing organic matter, including heat-stable contaminants that can withstand pasteurization. In instances of non-pasteurized products, additional filtration may be necessary, particularly when bacterial loads are elevated.

Sterilization techniques encompass autoclaving, pasteurization, and high-temperature instantaneous sterilization. Subsequently, fruit and vegetable juices are packaged, employing either hot or cold filling methods, depending on specific packaging requisites.

It’s worth noting that heat-resistant organics may infiltrate the processing system via external components. For instance, sugar may serve as a carrier for spores of Bacillus and other microbial species. Therefore, effective juice filtration systems are vital to mitigate such risks and ensure product safety and quality.

6. Tank vents and process gas filtration

The air in a juice processing plant can contain bacteria and spores, so preventing them from entering the storage tanks further protects product quality.

Quality. Process gas filters protect against particles and bacteria that may be carried in the process gas.

These filters prevent particles and bacteria carried by the process gas from being deposited in the container during filling.

Some plants also use process gases in storage tanks, and we filter process gases to prevent potential contaminants from entering the product in the tank. Almost all process gas filters and tank vent filters have a pore size rating of 0.22 microns.

How Can Sanitek Help You?

If you want to save money and get the best juice filtration solution for your needs, contact our experts. They will work with you to calculate the return on investment of your microfiltration solution and walk you through the steps of replacing your filter media.