Investigating the thermal stability of six caffeoylquinic acids employing rapid-resolution liquid chromatography with quadrupole time-of-flight tandem mass spectrometry

Multivariate Analysis Illuminates the Effects of Vacuum Drying on the Extractable and Nonextractable Polyphenols Profile of Loquat Fruit

“…during the vacuum drying of loquat fruit (Figure S2A). Based on the molecular structure of chlorogenic acid (ester of caffeic acid and (‐)‐quinic acid, Nayak, Liu, & Tang, ), caffeic acid and quinic acid should be thermal degradation products of chlorogenic acid (Figure ; Li et al., ; Xie et al., ). As expected, there was a strong negative correction between chlorogenic acid and caffeic acid ( R 2 = 0.93, Figure A), suggesting that chlorogenic acid degraded to caffeic acid during the vacuum drying of loquat fruit.…”

“…Cryptochlorogenic acid (4‐ O ‐caffeoylquinic acid) is an isomer of chlorogenic acid (5‐ O ‐caffeoylquinic acid; Xu, Hu, & Liu, ). Interestingly, chlorogenic acid can transform into cryptochlorogenic acid via acyl migration under heating conditions (Figure , Li et al., ; Xie et al., ). We found that the total content of cryptochlorogenic acid in loquat fruit was elevated with an increase in vacuum drying temperature (Figure S2D).…”

“…Representation of the degradation and isomerization mechanism of chlorogenic acid (Li et al., ; Xie et al., ).…”

Determination of caffeoylquinic acids in feed and related products by focused ultrasound solid–liquid extraction and ultra-high performance liquid chromatography–mass spectrometry

“…The determination of CQAs is usually performed by reverse-phase liquid chromatography with UV detection and/or mass spectrometry [5][6][7][8][9][10][14][15][16][17][18][19][20]. In most cases, the extraction of CQAs from the freeze-dried vegetable is carried out with 50-80% methanol or ethanol-water mixtures [6][7][8]14,15,18,20] at temperatures between room temperature and 50 • C for times ranging from 30 min to 2 h. The extraction can also be assisted by ultrasounds [14].…”

“…Chlorogenic acid ((1S,3R,4R,5R)-3-((E)-3-(3,4-dihydroxyphenyl)acryloyloxy)-1,4,5-trihydroxycyclohexanecarboxylic acid, also known as 3-O-caffeoylquinic acid) (CA) and cynarin (1R,3R,4S,5R) -1,3-bis((E)-3-(3,4-dihydroxyphenyl)acryloyloxy)-4,5-dihydroxycyclohexanecarboxylic acid, also known as 1, isomerize to each other and degradate to mono-CQAs, caffeic acid and compounds with the formulae C 15 H 14 O 16 [10]. Chemical structures of the mentioned compounds are shown in Fig.…”