Comparative study of the impact of malting on the aroma profiles of barley ( Hordeum vulgare L.) and rye ( Secale cereale L.)

Barley ( Hordeum vulgare L.) remains the traditional malted cereal used for beverages, whereas rye ( Secale cereale L.) is mainly used in baked goods. To evaluate the potential of rye malt for beverage production, malt quality indicators and the volatile composition of different rye malts were compared to barley malt. Sensory assessment revealed that pleasant malty and caramel aromas were formed by malting. Subsequently, three complementary isolation techniques and gas chromatography–olfactometry/mass spectrometry (GC-O/MS) were used for volatile analysis. Instrumental analysis detected 50 and 56 odor active volatiles in barley and rye, respectively. In part two, storage and the impact of three malting parameters on volatile formation were examined. Similarities in the malt volatile patterns were detected but the perceived intensity and composition varied. In barley, characteristic malty volatiles were lost during storage and staling compounds were formed. Conversely, nutty pyrazines and caramel furanones remained dominant in rye malts even after storage.