°Brix Measurement with Inline Refractometers

Refractometers measure Brix in juice
Refractometers are used to measure Brix in various juices.
A wide variety of food and beverage products rely on sweetness as a standard of consistency and quality. The unit of measurement to determine the concentration of sugar in food and beverage is °Brix (degrees Brix). Commercial processors of juices, wine, beer, soft drinks, tomato products, dairy, maple syrup, honey, jams and jellies implement the use of some form of refractometry to determine °Brix in their products.

°Brix (symbol °Bx) is the percentage of sugar dissolved in the subject product. One degree Brix equals 1 gram of sucrose in 100 grams of solution. °Bx is a degree scale from 1-100. A solution that is 15°Bx is 15 percent sucrose by weight. Measuring °Bx is based on the index of refraction or the density of the process media at specific reference temperatures of 20°C.

inline industrial refractometers
Inline industrial refractometer with control electronics.
One type of instrument used to measure °Bx is called a refractometer. Smaller food and beverage producers use hand-held refractometers to determine °Brix in product batches. Large scale producers, with continuous processing or high volume batches, use highly accurate, rugged, inline industrial refractometers which are installed on the process piping and become part of their overall control scheme.

All refractometers use the refractive index (RI) of the food/beverage concentration as the measurement method to determine °Bx.  The refractive index (or index of refraction) of a material is a dimensionless number that describes how fast light propagates through the material, or in other words, how much the path of light is bent, or refracted, when entering a material.

Refractometers often require some type of correction or linearization based upon the substance they are measuring. To account for other undissolved solids, organic acids or ethanol in the process media, specialized curves must be used. Inline process refractometers include these custom curves in the microprocessor programming, and can be selected through the refractometers user interface for varying product runs.

For more information about the measurement and control of °Brix using inline refractometers, contact Electron Machine Corporation.