Gas-Diffusion Microextraction (GDME) Combined with Derivatization for Assessing Beer Staling Aldehydes: Validation and Application

Abstract

In this work, a gas-diffusion microextraction (GDME) methodology was optimized and validated for the analysis of selected staling aldehydes (furfural (FURF), 2-methylpropanal (2-MP), 2-methylbutanal (2-MB), 3-methylbutanal (3-MB), and acetaldehyde (ACET)) during natural and forced aging of beer. The methodology was optimized considering time, temperature of extraction, and derivatizing agent. Using 4-hydrazinobenzoic acid (HBA) as a derivatizing agent, the performance of the method was evaluated by assessing several parameters such as detection limits (ranging from 1.2 to 1857.7 µg/L for 2-MB and ACET, respectively), quantification limits (ranging from 3.9 to 6192.4 µg/L for 2-MB and ACET, respectively), recoveries (higher than 96%), intraday and interday precisions (lower than 3.4 and 9.2%, respectively), and linearity (r2 ≥ 0.995). During beer aging, higher content of Strecker aldehydes and FURF were found, while no significant variations in ACET levels were observed. In general, the aldehydes content assessed for beers stored at 37 ± 1 °C for 7 and 14 days mimics that observed for beers stored at 20 ± 2 °C for 3 and 6 months, respectively. Lower temperatures of storage (4 ± 1 °C) delayed the development of staling aldehydes. Based on PCA analysis, the content of staling aldehydes and beer color were responsible for 91.39% of the variance among the analyzed samples, and it was demonstrated that these are key parameters to discriminate fresh from aged beers. The results herein presented showed that the proposed analytic methodology is a valuable strategy for the characterization and quantification of important staling aldehydes in beer with a potential application in the quality control of beer during storage.

Volatile profile of two monovarietal white wines under different antioxidant environments during storage in bottle

“…Each sample was analysed in duplicate (antioxidant dose combinations and presence or absence of bentonite on fermentation). Duplicates are indeed enough, since according to recently published works with comparable matrices (Almeida Santos et al, 2020;Ferreira et al, 2021;Saracino et al, 2021;Pereira et al, 2021;Ferreira et al, 2022) results showed that duplicates instead of triplicates do not jeopardize the associated error of the measurement and the resulted error for both cases was very similar. This fact allows to perform more analysis by time unit promoting the throughput of samples, an important issue in routine analysis, when needed.…”

Volatile Carbonyl Compounds Emission in Dry-Process Fibreboard: Identification through a Selective GDME-HPLC-DAD-MS/MS Method

“…Three mobile phases were tested: (i) acetonitrile (A) and water (B); (ii) acetonitrile (A) and 0.1% formic acid (B); and (iii) acetonitrile (A) and 10 mmol L −1 ammonium acetate buffer (B). The gradient elution method used in this study was adapted from a previous work [27,30] and was as follows: 50% to 65% A from 0 to 20 min, 65% to 100% A from 20 to 45 min, 100% to 50% A from 45 to 55 min, and 50% A from 55 to 60 min. The flow rate was set at 0.450 mL min −1 , the sample volume injected was 20 µL, and the detection was performed at 360 nm.…”

“…For preliminary tests, the gradient elution method used for this study was adapted from a previous work [27,30]. However, due to the changes introduced in the mobile phase and chromatographic column, certain derivatized carbonyl compounds co-elute when using these conditions.…”

Innovative Solutions for Food Analysis: Microextraction Techniques in Lipid Peroxidation Product Detection

“…GDME exhibits high sensitivity, when coupled with sensitive detection methods like GC-MS or high-performance liquid chromatography-ultraviolet (HPLC-UV). This empowers the quantification of tracelevel compounds in food analyses [10,48,[54][55][56][57][58][59][60][61][62].…”

“…This extraction process utilized a derivative solution containing 3 g DNPH in 100 mL of water-acetonitrile (1:1) at pH 2.0. Optimal conditions were established, involving the use of 10 mL of beer and 750 µL of the derivative solution as the acceptor phase, with extraction for 5 min at 30 • C. Aldehyde-DNPH derivatives were analyzed using HPLC-UV, and the presence of these aldehydes was confirmed using HPLC-APCI-MS. Conversely, Ferreira et al [55] focused on the simultaneous extraction of 2-methyl butanal, 2-methyl propanal, 3-methyl butanal, acetaldehyde, and furfural from beer. They evaluated various parameters affecting the extraction process, such as time, temperature, derivatizing agent (DNPH and HBA), and two extraction approaches (headspace or immersed module).…”