Abstract:During storage of coffee, the key aroma 2-furfurylthiol becomes less active, the mechanisms of this loss and ways to mitigate it were investigated. Aroma profiles were analyzed using GC-MS and sensory properties were evaluated by Quantitative Descriptive Analysis. Quinones, as the oxidation products of hydroxydroquinone, was found to actively bind 2-furfurylthiol, which accounted for the loss of 2-furfurylthiol.To mitigate this loss, ingredients were screened for their ability to prevent 2furfurylthiol from lo… Show more
“…Notably, two of the three pyrazines, 2-ethyl-3,5-dimethylpyrazine and 2,3-dimethylpyrazine, were identified in all comparative models. Consistently, thiols such as 2-furfurylthiol and pyrazines, including 2-ethyl-3,6-dimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine are key odor-relevant compounds that have previously been shown to generate roasty, earthy, sulfurous and chocolaty aromas which are associated with important freshness perception in coffee brews ( Sun et al, 2020 , Sunarharum et al, 2014 , Poisson et al, 2009 , Mayer and Grosch, 2001 ). Fig.…”
“…Notably, two of the three pyrazines, 2-ethyl-3,5-dimethylpyrazine and 2,3-dimethylpyrazine, were identified in all comparative models. Consistently, thiols such as 2-furfurylthiol and pyrazines, including 2-ethyl-3,6-dimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine are key odor-relevant compounds that have previously been shown to generate roasty, earthy, sulfurous and chocolaty aromas which are associated with important freshness perception in coffee brews ( Sun et al, 2020 , Sunarharum et al, 2014 , Poisson et al, 2009 , Mayer and Grosch, 2001 ). Fig.…”
“…As expected, this process was slightly accelerated in the samples stored at 60 °C compared to those at 30 °C. The high concentration in combination with the high reactivity of IV is in accordance with reports from the literature and depicts hydroxyhydroquinone as one of the key precursors for aroma binding. ,, In contrast, the concentrations of catechol ( III ) and 4-ethylcatechol ( V ) remained relatively stable within the same storage time, and the different storage temperatures showed no significant influence on the concentrations of III and V . Quantitative precursor studies therefore clearly indicated the high reactivity of especially hydroxyhydroquinone, while other precursor compounds showed only minor changes in the concentration during 60 min of storage.…”
A holistic ultraperformance
liquid chromatography (UPLC)–time
of flight (TOF)–mass spectrometry-based approach was used to
screen for storage-induced reaction products consisting of the volatile
key coffee thiols methanethiol, 2-furfurylthiol, 2-methyl-3-furanthiol,
3-mercapto-3-methylbutanol, and 3-mercapto-2-butanone and low-molecular
weight phenolic constituents of coffee beverages including chlorogenic
acid, caffeic acid, and their thermal degradation products hydroxyhydroquinone,
catechol, and 4-ethylcatechol. Multiple marker compounds could be
detected in thiol-enriched coffee brews after UPLC-TOF-MS profiling
and statistical data analysis. Subsequently, marker compounds were
synthesized and structurally characterized via high-resolution mass
spectrometry and 1D- and 2D-NMR experiments. Quantification of these
reaction products in fresh and stored coffee beverages was realized
in native coffee and after stir bar sorptive extraction with liquid
desorption by means of UHPLC-MS/MS. The quantitative data revealed
the biggest influence of storage time on the formation of reaction
products between hydroxyhydroquinone and methanethiol and 2-furfurylthiol,
while other reaction products were only slightly affected by storage
and thus most likely formed during the roasting process.
“…Another study 15 also found that pre‐treatment with acetic acid could decrease pyrazines while increasing furans. In addition, the addition of l ‐cysteine to green coffee beans reduces the loss of 2‐furfurylthiol 18 …”
Section: Introductionmentioning
confidence: 99%
“…In addition, the addition of L-cysteine to green coffee beans reduces the loss of 2-furfurylthiol. 18 In the case of leucine, it is one of the non-polar amino acids and has lower reactivity in the Maillard reaction than the other amino acids. 19,20 This study was conducted to reduce the bitter aroma (pyrazines, pyrroles and phenols) of Robusta beans by adding L-leucine powder (LP).…”
L-leucine powder (LP) were added to improve the aroma of Robusta coffee beans. Treatment was a short soaking (M1) or spraying procedure (M2), then LP was added at varying levels up to 3% (w/w). All samples were roasted (240 °C/15 min) and extracted using an espresso machine. Volatile compounds were analysed by solid-phase microextraction−gas chromatography−mass selective detection. Thirty volatile compounds (6 pyrroles, 8 pyrazines, 3 phenols, 9 furans, 2 ketones, 2 aldehydes) were analysed. In 15 coffee samples, the levels of total volatile compounds (based on peak area ratios) ranged from 8.9 (M1-1) to 15.5 (non-treated Robusta: NTR). Robusta coffee has lower levels of bitter aroma compounds when pre-treated with LP. The sum of bitter volatiles (phenols, pyrroles, pyrazines) was lowest in M1-5 (3% LP), M2-1 (1% LP; both dried at 50 °C/15 min) and M2-7 (3% LP, dried at 70 °C/15 min) compared with NTR (p < 0.05). NTA 5.02±0.01 a 33.17±0.01 a 14.50±0.05 f 27.74±0.05 a 45.61±0.03 a M1-1 5.28±0.01 c 37.55±0.01 c 13.73±0.04 d 30.04±0.02 c 50.01±0.02 c M1-2 5.28±0.01 c 38.46±0.00 e 13.63±0.04 c 30.80±0.03 d 51.13±0.03 e M1-3 5.31±0.01 e 40.70±0.09 f 13.35±0.04 a 31.59±0.13 f 53.22±0.15 g M1-4 5.30±0.01 d 37.17±0.00 b 13.71±0.04 d 29.92±0.00 b 49.65±0.01 b M1-5 5.27±0.01 b 38.39±0.00 d 13.89±0.04 e 31.02±0.03 e 51.28±0.02 f M2-1 5.28±0.01 b 39.85±0.02 j 13.64±0.04 c 31.44±0.07 g 52.56±0.04 i M2-2 5.33±0.01 e 37.15±0.00 e 13.63±0.00 b,c 29.67±0.03 c 49.46±0.02 d M2-3 5.30±0.00 c 35.37±0.01 c 13.62±0.05 b,c 28.65±0.03 b 47.52±0.01 b M2-4 5.32±0.01 d 39.04±0.01 i 13.48±0.04 a 30.63±0.02 f 51.42±0.01 h M2-5 5.33±0.01 e 37.46±0.00 f 13.91±0.04 e 30.41±0.03 e 50.21±0.02 e M2-6 5.32±0.01 d 35.31±0.01 b 13.72±0.05 d 28.68±0.02 b 47.52±0.01 b M2-7 5.28±0.01 b 38.07±0.01 g 13.72±0.05 d 30.56±0.05 f 50.71±0.02 g M2-8 5.31±0.01 c 35.51±0.01 d 13.57±0.05 b 28.70±0.02 b 47.64±0.01 cAll levels are represented as mean ± standard deviation (S.D.) (n=3) (p<0.05).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
