Real time detection of beer defects with a hand held electronic nose

A hand held wireless portable electronic nose (e-nose) has been developed for general purpose applications. It is based on non-specific micromechanized semiconductor sensors. It has been applied to the real time detection of two common aromatic defects in beer: acetaldehyde and ethyl acetate. Several measurements are made in order to check the discrimination capability of the system in the quantitative and qualitative classification these compounds in beer. Principal Component Analysis (PCA) and classification with Artificial Neural Networks are made as data processing methods.