Consumers want juice that tastes like fresh fruit, with no cooked note. Pasteurisation, even optimised, slightly changes flavour. Hence the growth of so-called non-thermal treatments, which reduce microbial load without heating the product.

High pressure processing (HPP)

The juice, already filled in flexible (PET) bottles, is placed in a water-filled vessel and subjected to very high pressure, typically around 400 to 600 MPa for a few minutes. Pressure acts uniformly and instantly: yeasts, moulds and vegetative bacteria are inactivated, while aroma and vitamins are very well preserved.

  • Benefits: taste close to fresh juice, a 'clean' process valued by premium brands
  • Limits: batch process, high capital cost, flexible packaging required
  • Bacterial spores are not destroyed: the product must stay chilled
  • The enzyme behind cloud loss is partly resistant: cloud stability needs checking

Pulsed electric fields (PEF)

The juice flows between two electrodes and receives very short, intense electrical pulses that perforate the membranes of micro-organisms. Unlike HPP, PEF is a continuous process placed before filling, and it fits more easily into an existing line.

  • Benefits: continuous treatment, small temperature rise, high throughput
  • Limits: pumpable liquids only, settings to validate product by product
  • As with HPP, shelf life is that of a chilled product

UV-C

UV-C light works well on water and clear liquids. In cloudy, coloured orange juice penetration is low: thin-film and turbulent-flow reactors exist, but their use is more limited than HPP or PEF.

Questions to ask before investing

  • Which market: local chilled, export, modern retail?
  • Is the cold chain controlled from filling to point of sale?
  • What shelf life do customers expect, and has it been validated by trials?
  • Does the volume justify your own equipment, or should you use a toll-processing service?
  • Are the HACCP plan and microbiological validation ready for customer audit?

We support these projects from market and profitability study through to process validation and team training.