Characterization of the aroma profile of quinoa (Chenopodium quinoa Willd.) and assessment of the impact of malting on the odor-active volatile composition

Abstract

Background: Quinoa (Chenopodium quinoa Willd.) is a gluten-free pseudocereal, rich in starch and high-quality proteins. It can be used as a cereal. Recently, a variety of nontraditional food products were developed; however, the sharp bitterness and the earthy aroma of unprocessed quinoa interfered with the acceptance of these products. Malting of cereals is known to improve their processing properties and enhance their sensory quality. To evaluate the acceptance and potential of quinoa malt as a raw material for beverage production, malt quality indicators (e.g., soluble protein) and the aroma profiles of different quinoa malts were compared. Results: Initial sensory assessment of quinoa in its native and malted state identified differences in their aroma profiles and revealed that pleasant nutty 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 34 and 62 odor-active regions in native quinoa and quinoa malt, respectively. In the second part, storage and the impact of three malting parameters on volatile formation were examined. By varying the malting parameters, seven additional odor-active malting byproducts were revealed. Conclusion: Three naturally occurring methoxypyrazines were identified as important contributors to the characteristic quinoa aroma. In all fresh quinoa malts a similar number of volatile compounds was perceived but their intensity and composition varied. Higher germination temperature promoted the formation of lipid oxidation products. Fatty smelling compounds and carboxylic acids, formed during storage, were classified as aging indicators of quinoa malt. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.