Blog: Year 1 of Food Circle 1

In short – Food Circle 1

The project partners involved in Food Circle 1 ‘Low oxygen juice extraction and mild preservation’ cooperated on development, construction and assessment of the down-scaled mobile and modular unit for juice processing. Prototypes of the units will be tested in the Lake Constance (Bodensee) region in Germany.

What has happened in year 1?

Strategy performance for down-scaling of chosen innovative technologies
Concept development of new small-scale processing line
Full design of new small-scale processing line

The down-scaled technologies

The main challenge was down-scaling innovative technologies for low oxygen juice extraction and mild juice preservation. The two core technologies are explained below:

What is a vacuum spiral filter press?

Vacuum spiral filter press is used for gentle low oxygen juice and puree preparation under vacuum conditions.

This technology minimises the contact of freshly pressed product and air which results in more intense and more authentic colour, aroma and flavour. Furthermore, juice/puree processed this way has better consistency (viscosity) and richer nutritional composition, resulting in overall better sensorial and nutritional characteristics. This system provides better extraction and preservation of valuable compounds (no oxidation) in juice, compared to more traditional methods commonly being used (e.g. belt filter press).

What is Pulsed Electric Field (PEF)?

Pulsed Electric Field (PEF) is a food preservation technology enabling the inactivation of spoilage and pathogenic microorganisms in liquid products, such as juices, purees, smoothies, milk, etc while minimally influencing (affecting) its fresh character.

The advantages of PEF technique compared to classical heat pasteurization are lower energy consumption (it is more sustainable), higher efficiency (treatment lasts few milliseconds) and due to low heat treatment preservation of original colour, flavour and nutritional composition of juices/purees.

The FOX juice processing line

The design of the down-scaled vacuum spiral filter press and Pulsed Electric Field (PEF) prototypes is completed. Based on these two core technologies the whole processing line has been developed. The following scheme explains the processing line:

The idea is that apples are manually fed into the washing elevator (01) where they are being washed and transported directly to funnel of a multicut unit (02). In the Multicut apples are being crushed in the presence of nitrogen to reduce the contact with oxygen, and the mash is being transported to vacuum spiral filter press (03). In the spiral filter press, the juice is being extracted under vacuum and via vacuum pump transported to a product buffer tank (04). After being stored at the appropriate temperature for a desired time, it is pre-heated in Liquid Handling System (LHS) (06) to a desired temperature suitable for PEF treatment and then pumped into the PEF machine (05). Immediately after the PEF preservation step, the juice is cooled down to a desired temperature to reduce the thermal load and prevent loss of thermally sensitive compounds (usually below 10 °C). Cooled juice ends up in a second buffer tank (08), where it can be pumped to filling unit (07), suitable for two options: BAG-in-BOX (an airtight container for transporting and storing liquids, the container consists of a plastic bag in a cardboard box) or glass bottles. From Control panel (09) electricity is distributed to machines and optimal functioning of juice extraction process is controlled.

Download poster (DU)

Up next: year 2

In the following two years realisation of precompetitive „FOX juice box“ prototype is planned. In the second year, based on developed concepts down-scaled vacuum spiral filter press and PEF unit will be built. In the third year the whole FOX juice processing line should be completed, tested and their functioning will be optimized.

Feasibility and practicability study under realistic (farm) conditions will follow in the fourth year of the project when FOX juice unit will be placed in Lake Constance (Bodensee) region in Germany.