Vegetable and fruit juices require specialist manufacturing process due to their relative
lack of both physical and microbiological robustness compared to standard soft drinks.
Additives such as colours, preservatives and stabilisers are generally not permitted in fruit
and vegetables juices. They are generally of high viscosity, particularly when cold, and
frequently have a high pulp content. These characteristics require specialist pumping (e.g.
positive displacement pumps) and pasteurisation (e.g. tubular pasteuriser) equipment.
Since preservatives are not permitted in these pure juices, ambient stable packs must be
either hot filled, in-pack pasteurised or aseptically filled. Product can also have a short
shelf-life and maintained under chilled conditions. The less severe (which may be lower
temperature, shorter time) pasteurisation results in an improved flavour. Vegetable juices
must be subjected to a much more severe pasteurisation regime than fruit juices, for
example UHT or blended with a fruit juice to reduce the pH below 4, immediately following
initial production.
Discuss the application of chemical engineering principles in the production of a vegetable
juice of your choice.
Structure of the essay
Introduction:
Briefly state what the essay will try to achieve and mention some of the main points you
will consider (5 marks).
The body of the essay.
Discussion of the importance of understanding and application of chemical engineering
principles in the production of the chosen vegetable juice. In this section you should:
• Draw and label the process flowchart (10 marks)
• Present and discuss chemical engineering principles in the production of the
chosen vegetable Juice with reference to some fundamental and principles such
heat transfer, Reynolds numbers and type of flow), prevention of fouling and safely
production and manufacture of juice safe for consumption (30 marks).
Conclusion:
Concisely present key points and possible introduce new ideas that could have also been
considered. (5 marks)

Principle engineering