Determination of optimal sample preparation for aldehyde extraction from pale malts and their quantification via headspace solid-phase microextraction followed by gas chromatography and mass spectrometry

• Published in: Journal of Chromatography A Vol. 1612; p. 460647
• Main Authors: Filipowska, Weronika, Jaskula-Goiris, Barbara, Ditrych, Maciej, Schlich, Johanna, De Rouck, Gert, Aerts, Guido, De Cooman, Luc
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 08.02.2020
• Subjects: Aldehydes; Aldehydes - analysis; Aldehydes - isolation & purification; Beer - analysis; Beer staling; Extraction parameters; Flavoring Agents - analysis; Flavoring Agents - isolation & purification; Gas Chromatography-Mass Spectrometry; HS-SPME-GC-MS; Pale malt; Sample preparation; Solid Phase Microextraction; HS-SPME-GC-MS; Sample preparation; Aldehydes; Extraction parameters; Beer staling; Pale malt
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2019.460647

•Evaluating sample preparation for a fast quantification of aldehydes in pale malts.•Malting technology influences the content of beer staling aldehydes in pale malts.•Quantity of beer staling aldehydes introduced into the brewing could be controlled. Aldehydes originating from malt play an important role in beer flavour deterioration. In order to better understand the influence of malting process on beer staling, it is necessary to acquire a reliable analytical methodology for determination of beer staling aldehydes in malt. Therefore, the aim of this study was to evaluate extraction parameters, which allow quantification of beer staling aldehydes present in pale malts. The method was validated with respect to linearity (R > 0.9988), limit of detection (0.28 – 0.99 μg/L), limit of quantification (0.92 – 3.31 μg/L), accuracy (± 5%), repeatability (1.3 – 5.3%) and intermediate precision (>20%). The following parameters of sample preparation were evaluated: sample amount, extraction time and temperature, ultrasonication time and oxygen level. Consequently, the best extraction conditions were successfully applied on pale malts. After extraction, the samples were analysed by headspace solid-phase microextraction (HS-SPME) with on fibre carbonyl derivatisation followed by gas chromatography and mass spectrometry (GC–MS). In addition, the salting-out effect during HS-SPME was studied. The method application allowed to identify significant differences (p ≤ 0.05) in the levels of aldehydes among various industrial scale, pale malts. The optimised method could give the information on the aldehyde content introduced into the brewing process and its potential contribution to the overall beer quality.