STiR coffee and tea magazine

34 STiR coffee and tea / Issue 3, 2021 (June / July) A By Peter Keen ll teas, regardless of their type, have a distinct and unique aroma. It's a ma- jor determinant of quality and a differentiator for both high end loose leaf and commodity machine-processed crops. For premium teas, there is a very strong correlation between aroma and price. Electronic noses offer an increasing de- gree of understanding of aromas and how to use this to authenticate teas and deter- mine their precise grade and quality dimensions. Tea bag and iced teas compete in a brutal, competitive export market, marked by overcapacity, margin erosion, and crop yield pressures. Here, a small advantage in qual- ity can be decisive for the economic health of regions and even countries. Electronic noses provide insight and tools to improve the processing of categories of tea, espe- cially the timing of oxidation in black tea, by far the largest market segment. In all these situations, aroma is one of the most critical elements of quality. Aroma detection and analysis Aroma is extraordinarily complex in so many ways. It is created by the interaction among molecular volatile compounds that evaporate. This generates responses in the human brain through electrical pulses that act at the cellular level. These are affected by ambiance, psychochemical evaluation, mood, and other contextual factors. The typical tea contains around 200 volatiles, which form molecular pathways connecting, creat- ing and releasing classes of chemical compound – theaflavins, leafy alcohols, nitrous sulfides, etc. A few have 600 identified volatiles. Electronic noses play a major role in applied research in identifying the full range of volatiles for a given target category of tea, and uncovering more and more through the analytic, statistical, and artificial intelligence tools built into them. They also provide higher levels of assessment than the skilled panels of human tasters who rate quality but must rely on subjective 1-10 rating scales and words like "oaky" or "floral." Alexander Electronic noses are devices that, as the name implies, mimic human smelling and evaluation of aromas. For close to a decade, they have produced striking results in more and more areas of tea processing and quality management. Electronic Noses: Electronic Noses: the Emerging Science the Emerging Science of Tea Aromas of Tea Aromas Enose prototype analytical dept chemical faculty GUT Gdansk. "Did you ever try to measure a smell?" Alexander Graham Bell:

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