Detection of adulteration, contamination or inconsistencies in food and flavor samples should be accurate and fast. Chemical sensors are ideal for these types of applications because they provide fast measurements. While analysis times are crucial, accuracy and precision of the analysis should never be compromised. It is therefore desirable to use a reliable and stable technology that is robust to environmental changes such as humidity or temperature. Quadrupole mass spectrometry is a robust technique that has been widely used in food and flavor applications.
In this study, mass spectral fingerprints of orange juice and wine samples were obtained by direct transfer of their headspace into a mass spectrometer without chromatographic separation. For the beer samples a GERSTEL ChemSensor System that includes a GC was used. Standard samples were used to train the chemical sensor with acceptable mass spectral profiles. Adulteration of wine samples was modeled with two different types of wines; contamination was detected by spiking orange juice with diacetyl and inconsistencies in products was modeled by analyzing beer samples freshly opened and aged 3 and 6 days.
Detection of contamination, adulteration and product inconsistencies was easily determined using chemometric models. In particular, principal component analysis (PCA) easily detected anomalies by projection of the mass spectral fingerprints into the space of the first three or two principal components. Adulteration of the wine standards was detected in the percentage range while diacetyl concentrations in orange juice were detected at the low ppm range. Slight differences between beer samples freshly opened and aged 3 and 6 days were also detected and identified.
