Inline Process Refractometers in Tomato Processing

Inline Process Refractometers in Tomato Processing

It's obvious that tomato processors have a need to predict product yield, consistency and quality, as these variables directly affect sales and profitability. However, consistency and quality in tomato products is fairly difficult to control because of the fruit variation, harvest maturity, and farming area.

Consumers often select tomato sauces, pastes, purees and dressings based on sweetness levels, so it's very important food producers to accurately control sweetness. The common method for measuring sweetness in this industry is by reading Brix. Degrees Brix (°Bx) is the measure of the amount of sugar in an aqueous solution and is used because it's reliable and fast.

Refractometry is used to determine degrees Brix, and refractometers are the instruments used for the measurement. Very basically, refractometers use a prism to determine how light bends through a substance. The change in light direction is then used to repeatably determine certain values - in this case Brix.

There are several types of refractometers in food processing. Many food processing labs do batch sampling through the use of hand-held refractometers. Another type is the inline process refractometer.  It is used to provide a Brix measuring control loop right on the production line, and can be employed anywhere in the overall process from evaporation stages up to the concentrated final product.

Inline Process Refractometer

Inline process refractometers are installed using a sanitary-type pipe adapter, designed and manufactured to appropriate 3-A Sanitary Standards. Should the tomato product be known to produce stubborn coatings on the refractometer prism, a steam port is added to the adapter to allow the prism to be steam cleaned at specific intervals.

The head of the refractometer is mounted directly in the processing line and provides real-time detection of Brix with a measurable output. The refractometer's circuitry then conditions the head's output and compares it to a desired value in a controller. The controller provides a corrective output signal, such as 4-20mA, to a final control element, such as a control valve. The control valve increases or decreases the amount of an ingredient to keep things in balance. Not unlike any other process control variable (pressure, temperature, level or flow), Brix measurement is determined and controlled via it's own control loop by the inline process refractometer,  providing the tomato processor greater control over product quality and consistency.

For more information on the use of inline process refractometers in tomato processing, contact Electron Machine at 352-669-3101 or visit http://electronmachine.com.