Dow Water & Process Solutions

Industries & Applications

Citrus Juice Debittering

All oranges contain limonic acid. As shown below, over time, this acid naturally esterifies to limonin, a highly bitter compound with very low organoleptic detection limits.

See How Orange
Juice is Debittered to
Have a Sweet Taste

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For most commercial oranges, limonin resides in the membrane structures and is extracted when trying to enhance juice yield through such techniques as core, pulp and peel washing. A similar bitter compound called naringin is found in grapefruit. By using a combination of ultrafiltration (UF) and polymeric adsorbents from Dow Water & Process solutions, citrus juice suppliers can debitter citrus juice to improve both the quality of their products and the yield from their raw materials.

Learn how Dow's resin technology helps take oranges from the grove to the jug, by clicking the image to the right.

This schematic also shows the debittering process. Pulp is separated from the juice using UF. Then the juice is contacted with an AMBERLITE™ FPX66 in a packed bed column and the pulp is returned to the juice prior to packaging or evaporation. 

AMBERLITE FPX66 is the ideal adsorbent for this application because it has the perfect balance of properties:

  • Selectivity – preferentially removes limonin while leaving other flavor components in the juice
  • High capacity – the high surface area results in high limonim capacity, and throughputs are not limited by adsorbent capacity.
  • Stability – the physical and oxidative stability allow the adsorbent to perform well for many years.

This combination of properties results in a robust and economical process. Typical breakthrough data is shown here.


Limonin Formation

Schematic of Citrus Juice Debittering Processes
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Typically 60 bed volumes are treated. While more volumes could be treated with effective limonin removal, there are other less selectively adsorbed flavoniods that can break through. In the absences of accurate analysis of these flavoniods, the run time is determined by juice taste.

Typical Operating Conditions
Mode Step Solution Time Volume (BV) Rate (BV/h) Temp (oC)
Service Debittering Filtered Juice 10 – 12 hr. 60-70 6 By customer
Regeneration Sweeten-off Soft Water 50 2 2.4 Ambient - 60
Strip 1% KOH 50 2 2.4 Ambient - 60
Strip 0.3% H2O2 50 2 2.4 90 - 95
Strip Soft Water 50 2 2.4 90 - 95
Strip 1% H3PO4 50 2 2.4 90 - 95
Strip Soft Water 50 2 2.4 ambient

Recommended Products
AMBERLITE FPX66

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