An overview will be presented of the emerging real time SIFT-MS technique for monitoring volatiles down to the parts per trillion level (pptv) and how it has been applied to characterize coffee aroma and parmesan cheese. Over 1000 volatile organic compounds (VOCs) have been identified in the head space of coffee grounds and brews, with a smaller number identified as key aroma compounds. SIFT-MS is ideally suited to process-line analysis of products such as coffee which have VOC signatures that vary significantly with process changes, country of origin and seasonal conditions. The study demonstrates that various commercial coffees (both ground and freeze- dried) are readily distinguishable using a combined approach of SIFT-MS and multivariate statistical analysis. The investigation also examines the suitability of SIFT-MS for monitoring and therefore optimizing the coffee roasting process. The target compounds analyzed include pyrazines, furan derivatives, alcohols, aldehydes, ketones and organic acids, which are all easily monitored in real time in a single analysis. The same SIFT-MS instrument was also used to monitor trace VOCs that characterize New Zealand and Italian parmesan cheese. The New Zealand parmesans often do not provide a good representation of the aroma of genuine Italian parmesans such as Parmigiano Reggiano and Grana Padano. In a single run, SIFT-MS provided a straightforward analysis over a diverse range of compound classes including organic acids, esters, aldehydes, organosulfurs and pyrazines without any sample preparation. The headspace concentrations varied from single-digit parts-per-billion (ppbv) to tens of parts-per-million (ppmv). For some compounds, headspace aroma concentrations were even found to vary significantly for cheeses from the same country of origin as well as between countries of origin. The work demonstrates that SIFT-MS could easily be used as a quality assessment tool in cheese manufacture.

Application of selected ion flow tube mass spectrometry (SIFT-MS) to classifying coffee and parmesan cheese

247th National Meeting (2014)

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