Ripening of fermented sausages by an advanced controller
By Jacint Arnau
Drying of fermented sausages requires the supervision of an expert who manually readjusts air temperature (T) and relative humidity (RH) set-point of the drying process, allowing obtaining the final desired meat product.
An increase in T and a decrease in RH helps, among other factors, to accelerate the drying process, but there is a critical point at which an unwanted surface crust can develop due to the higher drying rate of the surface compared to the drying rate of the inner part of the product.
- Figure 1: Scheme of the control system
- Figure 2: NIR measuring aW on the product
In the Q-PorkChains project an on-line instrumental measurement of parameters related to the expert evaluation, which would be useful for the improvement of the control system to avoid crust formation has been studied. One of the most promising technologies for on-line product evaluation is near-infrared spectroscopy (NIR). It enables a rapid, simple, and simultaneous on-line determination of different meat properties on the surface, like moisture content and water activity (aW).
- Figure 3: Sausages in the dryer
An advanced controller, which processes information from the sausages Near-Infrared spectra (NIR) and from the drying air humidity and temperature probes, allowing calculating and modifying air relative humidity set-points during the drying process of the fermented sausages has been developed.
The controller allows maintaining the required superficial water activity of fermented sausages and its proper drying process
