Continuous Concentration Measurement of Pectin

Continuous Concentration Measurement of Pectin

Pectin is a thickening and stabilising agent used in the food industry. During its industrial production, pectin is extracted at high temperatures from the dried skins of citrus fruits by hydrolysis. After its separation it is filtered and concentrated by evaporation and then finally precipitated into alcohol.

The correct preparation of the pectin solution is a basic requirement for achieving the required product quality. Continuous concentration measurements are essential to ensure optimum control of the continuous process without any system downtimes. As in many sectors of the food industry and also within the production of pectin, random laboratory testing of the refractive index is a common method for determining concentration levels of many liquids - an accurate but rather costly method of quality assurance.

However, transferring the laboratory testing methods into the process places high demands on the operational safety of the process measuring instruments used.
After extensive testing of various measuring instruments from different manufacturers, the operators of the here described pectin production plant decided on the PIOX R Process Refractometer.

PIOX R differs from other Process Refractometers in the fact, that it does not employ the critical angle measurement principle but the transmitted light method. As a result, it is considerably less susceptible to formation of deposits on the prism, which are often leading to measurement drift on critical angle refractometers.

As PIOX R is practically independent of deposit formation on the prism, it is thus also free from subsequent measurement drift. Further, by utilizing its innovative two-beam differential measurement principle, it automatically compensates for temperature changes that could affect the measurement.
Intelligent tools for self-diagnosis guarantee the utmost process safety. This also convinced the pection plant operator, who is now utilizing the PIOX R Process Refractometers to oversee the complete pectin production process: after filtration, before evaporation and after evaporation.


  • Precise measurement of pectin concentration without measurement drift
  • Reliable, continuous process control
  • Continuous protection of product quality with no system downtimes
  • Optimum process control due to very high measurement accuracy, consistent with laboratory measurements

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