Dry matter is a key quality parameter for French fries and other potato-based food products. Processors must comply with legal requirements as well the desired dry matter levels demanded by the customers. Having good control over this parameter is key to maximize overall yield while maintaining optimal product quality.
While manufacturers of potato chips can use Near Infrared Technology to control moisture content, a similar solution for french fry manufacturer was out of reach - despite significant efforts to develop such a solution.
And since the production process for french fries is quite complex and can be influenced by various process parameters and raw material variability, it is typically not possible to have a constant moisture content of the fries with fixed production settings.
The current quality control requires human involvement and takes 20-30 minutes before results are known which makes it impossible to adjust the production process in real-time. Therefore, an inline moisture sensor providing split-second real-time feedback makes a big difference.
Recently a new sensor to measure dry matter content has been introduced by the Belgian company Aquantis - Moisture-Sense - based on microwave technology to track the moisture or dry matter levels after drying or frying French fries. Moisture-Sense comes in the single- and double-plow versions for either plastic or metal belts, respectively. The sensors are made of polished stainless steel and food-grade plastic materials to fulfill the highest hygienic standards.
The Moisture-Sense sensor emits very low-power microwaves. As the waves penetrate through the product, the water absorbs a part of the energy. The energy loss as a result of the moisture content is further processed to determine the dry matter content of the product. With the help of additional peripheral sensors, the Moisture-Sense determines the dry matter content of fries with an accuracy of < ±1 %.