Lehrstuhl für Brau- und Getränketechnologie, Technische Universität München Weihenstephan, Freising, Germany.
J Food Sci. 2023 Sep;88(9):3773-3785. doi: 10.1111/1750-3841.16717. Epub 2023 Aug 2.
Barley (Hordeum vulgare L.) is the traditional malting cereal and is primarily used for beverages, whereas rye (Secale cereale L.) is mainly used in baked goods. Conversely, quinoa (Chenopodium quinoa Willd.) is a gluten-free pseudocereal, rich in starch and high-quality proteins, and can be used in a similar manner to cereals. The sharp bitterness of unprocessed rye and the earthy aroma of native quinoa interfere with the acceptance and development of food products. Malting of barley is known to improve its processing properties and enhance its sensory quality. Therefore, the effect of germination and kilning on malt quality (e.g., viscosity) as well as the volatile composition of barley, rye, and quinoa were monitored. Moreover, temporal changes on the volatile patterns of rye and quinoa at the different stages of malting were compared to barley. In total, 34 volatile compounds were quantified in the three (pseudo)cereals; the alcohol group dominated in all unprocessed samples, in particular, compounds contributing grassy notes (e.g., hexan-1-ol). These grassy compounds remained abundant during germination, whereas kilning promoted the formation of Maillard reaction volatiles associated with malty and roasted notes. The volatile profiles of kilned barley and quinoa were characterized by high concentrations of the malty Strecker aldehyde, 3-methylbutanal. In contrast, green, floral notes imparted by phenylacetaldehyde remained dominant in rye malt. Hierarchical cluster analysis of the volatile data discriminated the samples into the different stages of malting, confirmed the similarities in the volatile patterns of barley and rye, and indicated clear differences to the quinoa samples. PRACTICAL APPLICATION: In this study, the effect of germination and kilning on the chemical and volatile composition of barley, rye, and quinoa was examined. Temporal changes on the volatile patterns of rye and quinoa at different stages of malting were compared to barley. Understanding the differences among the (pseudo)cereals as well as the influence of processing on malt quality and aroma development can help find new food applications.
大麦（Hordeum vulgare L.）是传统的麦芽谷物，主要用于饮料，而黑麦（Secale cereale L.）主要用于烘焙食品。相反，藜麦（Chenopodium quinoa Willd.）是一种无麸质的假谷物，富含淀粉和高质量蛋白质，可用于类似谷物的方式。未经加工的黑麦的强烈苦味和土生藜麦的泥土香气会干扰食品的接受度和开发。已知大麦发芽和干燥可改善其加工性能并提高其感官质量。因此，监测了发芽和干燥对麦芽质量（例如粘度）以及大麦、黑麦和藜麦挥发性成分的影响。此外，还比较了不同发芽阶段黑麦和藜麦的挥发性模式的时间变化与大麦。总共在三种（假）谷物中定量了 34 种挥发性化合物；在所有未经处理的样品中，醇类物质占主导地位，特别是对草味有贡献的化合物（例如己-1-醇）。这些草味化合物在发芽过程中仍然丰富，而干燥则促进了与麦芽和烤味相关的美拉德反应挥发性物质的形成。干燥的大麦和藜麦的挥发性特征是高浓度的麦芽Strecker 醛，3-甲基丁醛。相比之下，绿香、苯乙醛赋予的花香在黑麦麦芽中仍然占主导地位。挥发性数据的层次聚类分析将样品分为不同的发芽阶段，证实了大麦和黑麦挥发性模式的相似性，并表明与藜麦样品有明显差异。实际应用：在这项研究中，研究了发芽和干燥对大麦、黑麦和藜麦的化学成分和挥发性成分的影响。比较了不同发芽阶段黑麦和藜麦挥发性模式的时间变化与大麦。了解（假）谷物之间的差异以及加工对麦芽质量和香气发展的影响有助于寻找新的食品应用。
