One-sensor electronic olfactometer for rapid sorting of fresh fruit juices

A low-cost electronic olfactometer was developed, based on virtual sensors array (an array of signals from a single metal oxide sensor) and on our proprietary semi-automated sampling system. This concept enables us to drastically improve the sensitivity and selectivity of the entire olfactometer to make it suited to food products analysis. Each step of the prototype was checked separately in earlier work, and finally the system performance was evaluated first on pure chemicals, and then at-line for grape juice during grape-harvesting in Champagne. It is shown that over a 3-week vintage period, the drift of the unique-sensor was quite low (absolute baseline value: avg., 2152; std., 150; response to test solution: avg., 5.08, std., 0.39), and the transient response to the temperature steps provided information for the discrimination and mapping of these products. The results correspond well with the separative quantification of the aroma by high speed GC analysis made in parallel on the same samples.