Open Innovation Submission Portal

In-field Tools to Accurately Measure Citrus Raw Juice Quality

Request Number 174421 | Author PepsiCo


Citrus fruit must be harvested when they are mature (ripe) and quickly processed so as not to compromise quality or incur yield losses due to fruit drop, pests, and diseases. Citrus fruit is non-climacteric and cannot be matured after it has been detached from the tree. Maturity is rated directly by measuring accumulated brix and titratable acidity both of which are important juice quality characteristics. The State of Florida defines maturity for oranges at a minimum brix of 9%. There are further definitions of processed orange juice by the FDA which define grades and products specifications. The brix and titratable acidity (TA) measurements in the field must be accurate to inform timely harvesting decisions. While there are available tools in the market to measure TA, brix or both parameters, they provide approximate values that are difficult to ascertain or may require complex machines, reagents and skilled end-users. Our goal is to identify or develop tools which can accurately measure TA and brix in the field expediently without requiring expert training.

Key Success Criteria


  • Accurate measurement in-field of Brix and Titratable acidity (2 decimal place accuracy)
  • Ease of use in field and training of personnel
  • Ease of transportation to use in the US and in other proxy environments (i.e. Does not require reagents that are difficult to transport or acquire)


  • A measure of as-is Limonene
  • Records sample meta data and metrics device (tablet), Wi-Fi upload to a system.
  • Easy to transport (size and weight)
  • Cost effective
Approaches not of interest

We have previously explored color-indicator acid-base tools to measure titratable acidity (TA). Our experience from this is the tools do not meet our needs because they do not have the requisite TA ranges, ph does not correlate well to TA, or require complex machines and reagents that cannot be easily used in the field. Moreover, we would like the flexibility to travel to regions of interest, and tools relaying on liquid reagents could be present problems.

Preferred Collaboration types

PepsiCo is open to a range of collaboration types, but proof of concept is required in either the beverage industry or an adjacent industry (e.g. pharmaceuticals).