Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online
Journal website www.isnff-jfb.com

Original Research

Volume 14, June 2021, pages 60-74

Characterization and profiling of polyphenolics of Brassica microgreens by LC-HRMS/MS and the effect under LED light

Figures

Figure 1.
Figure 1. Peak area averages of the extracted ion chromatograms (XIC) of polyphenolic extracts of representative Brassica microgreens [B. rapa (mizuna), B. juncea (mustard) and R. sativus (radish)]. The detected polyphenolics are identified according to their fragmentation patterns and retention times, and their content levels are generally identified with a larger intensity. *, other non-polyphenolic compounds eluting with detected polyphenolics; quercetin (Qn); kaempferol (Km); caffeoyl malate, 9; hydroxyferuloyl malate, 10; coumaroyl malate, 11; sinapoyl malate, 12; feruloyl malate, 13; salicylic acid glucoside, 16a/b/c; dihydroxybenzoic acid glucoside, 17a/b/c; feruloyl glucoside, 19a/b; sinapoyl gentiobioside, 20a/b/c/d; disinapoyl gentiobioside, 21a/b; sinapoyl glucoside, 22a/b/c/d; Km 3-diglucoside, 24b; Km 3,7-dirhamnoside, 26; Km glucoside rhamnoside, 28a/b; Km hydroxyferuloyl diglucoside glucoside, 30a; qn feruloyl diglucoside glucoside, 30b; km sinapoyl diglucoside glucoside, 33; Km caffeoyl-diglucoside glucoside, 35; Qn dirhamnoside, 37; Qn sinapoyl diglucoside glucoside, 39a; Qn caffeoyl diglucoside glucoside, 44.
Figure 2.
Figure 2. Extracted ion chromatograms (XIC) of three sub-groups of detected polyphenolics (flavonol glycosides/conjugated phenolic acids/free phenolic acids) under each treatment in Brassica microgreens. Control is 4.73A(amber):20.52B(blue):74.36R(red) and bars represent the peak area averages ± SD of three replicates per microgreen.
Figure 3.
Figure 3. Hydroxycinnamic acids (HCA) (top) and malate esters of HCA (bottom) detected in Brassica microgreens under amber, blue and red LED.

Tables

Table 1. LC–HRMS/MS-ESI identification of polyphenolics in eight Brassica microgreens
 
Compound #Name/Tentative IdentificationRT (min)FormulaObserved [M-H]−FragmentsRef.
Km, kaempferol; Qn, quercetin, Iso, isorhamnetin
Free phenolic acids
  1p-coumaric acid18.28C9H8O3163.0401119.0501, 93.0344, 120.0534, 117.0347, 145.0291Koley et al. 2020; Sinosaki et al. 2020
  2m-coumaric acid21.04119.0501, 91.0554, 93.0346, 120.0535, 145.0293, 135.0452, 117.0348
  3o-coumaric acid23.45119.0501, 117.0347, 120.0533, 93.0343, 91.0553, 65.0396
  4sinapic acid21.59C11H12O5223.0612208.0376, 193.0141, 179.0713, 164.0479, 152.0115,149.0244
  5ferulic acid20.46C10H10O4193.0506178.0269, 149.0606, 134.0372, 137.0242
  6caffeic acid13.72C9H8O4179.0350135.0451, 134.0373, 136.0486, 107.0500, 117.0347, 161.0238
  7chlorogenic acid14.08C16H18O9353.0870191.0559, 161.0246, 179.0349, 275.8323, 154.9462
  8neochlorogenic acid8.90191.0561, 179.0350, 135.0453, 161.0245, 173.0456, 155.0351
Phenolic acid derivatives
  9caffeoyl malate (phaselic acid)17.36C13H12O8295.0460133.0146, 115.0440, 179.0353, 135.0455Harbaum et al. 2007; Oszmiański et al. 2013; Tang et al. 2016; Oulad El Majdoub et al. 2020
  10hydroxyferuloyl malate19.61C14H14O9325.05651133.0146, 209.0458, 115.0040, 150.0325, 194.0221, 165.0560
  11coumaroyl malate21.02C13H12O7279.0510163.0403, 133.0145, 119.0504, 115.0039, 71.0139
  12sinapoyl malate23.38C15H16O9339.0722223.0613, 164.0482, 71.0139, 115.0040, 208.0379, 179.0716, 149.0246
  13feruloyl malate22.70C14H14O8309.0616193.0507, 134.0376, 71.0139, 115.0039, 149.0610, 178.0273
  14a/bcaffeic acid glucoside9.55C15H18O9341.0880161.0249, 179.0354, 135.0456Kramberger et al. 2020
caffeic acid glucoside12.52179.0354, 135.046, 161.0252
  15hydroxyferulic acid glucoside10.95C16H20O10371.0988191.0354, 209.040, 176.0118, 165.0558Huang et al. 2015
  16a/b/csalicylic acid glucoside6.11C13H16O8299.0773137.0250, 93.035Blazics et al. 2010; Sarkar et al. 2012; Torras-Claveria, et al. 2012; Zhang et al. 2013; Liu et al. 2016
salicylic acid glucoside7.36137.0250, 89.0249, 179.0359, 299.0771, 119.0354, 101.0249
salicylic acid glucoside10.65137.0250, 93.035, 71.0140
  17a/b/cdihydroxybenzoic acid glucoside6.26C13H16O9315.0723153.0197, 109.0298Gómez-Caravaca et al. 2016
dihydroxybenzoic acid glucoside7.09152.0119, 315.0724, 153.0197, 108.0220, 109.0298
dihydroxybenzoic acid glucoside8.84153.0197, 315.0724, 152.0118, 109.0298
  183-benzoyloxy-2-hydroxypropyl glucopyranosiduronic acid17.51C16H20O10371.0984249.0618, 121.0299, 113.0247, 85.0297, 75.0088, 371.0997, 231.0518Wang et al. 2018
  19a/bferuloyl glucoside12.99C16H20O9355.1037193.0507, 149.0611, 134.0376, 178.0271Olsen et al. 2009; Sun et al. 2013
feruloyl glucoside14.41175.0402, 193.0507, 160.0168, 217.0508, 134.0378
  20a/b/c/d/esinapoyl gentiobioside9.33C23H32O15547.1671205.0513, 223.0618, 427.1258, 265.0728Harbaum et al. 2007; Sousa et al. 2008; Lin et al. 2011; Engels et al. 2012; Sun et al. 2013; Shao et al. 2014; Qu et al. 2020
sinapoyl gentiobioside9.98205.0513, 223.0618, 179.8829, 427.1258, 265.0728
sinapoyl gentiobioside13.92205.0513, 223.0618, 164.0482, 89.0248, 247.0612
sinapoyl gentiobioside14.75205.0508, 190.0273, 89.0246, 223.0614
sinapoyl gentiobioside18.63205.0508, 223.0615, 265.0721, 427.1244, 325.0929
  21a/bdisinapoylgentiobioside19.53C34H42O19753.2263205.0510, 223.0616, 190.0276Ferreres et al. 2008
disinapoylgentiobioside26.76205.0510, 223.0616, 190.0276, 529.1561
  22a/b/c/dsinapoyl glucoside12.26C17H22O10385.1143205.0512, 223.0616, 247.0614, 265.0719Lin et al. 2011; Oszmiański et al. 2013; Morreel et al. 2014; Truchado et al. 2015
sinapoyl glucoside14.21205.0509, 247.0612, 223.0614, 164.0468
sinapoyl glucoside15.15223.0614, 208.0378, 179.0717, 164.0486
sinapoyl glucoside15.61205.0509, 190.0275, 223.0615, 89.0247
  23a/b/csinapoyl feruloyl gentiobioside26.37C33H40O18723.2151205.0508, 193.0511, 190.0275, 175.0405, 134.0377Harbaum et al. 2007; Sousa et al. 2008; Olsen et al. 2009; Chakraborty and Mandal 2013; Sun et al. 2013
sinapoyl feruloyl gentiobioside26.57175.0404, 205.0509, 223.0609, 193.0509
sinapoyl feruloyl gentiobioside27.23175.0404, 205.0509, 193.0509, 223.0618, 499.1479
Flavonol derivatives
  24aKm 3,7-diglucoside19.30C27H30O16609.1470285.0408, 446.0860, 283.0253, 447.0938, 609.1451Harbaum et al. 2007; Ferreres et al. 2008;Negri et al. 2012
  24bKm 3-glucosyl glucoside23.43284.0331, 285.0416, 609.1492, 446.0882
  24cQn rhamnosyl glucoside23.26446.0854, 301.0354, 299.0196, 447.0931, 463.0885, 609.1473
  25a/bQn rhamnoside pentoside24.64C26H28O15579.1360446.0857, 299.0199, 301.0358, 447.0931, 579.1356, 433.0779Lin et al. 2011; Li et al. 2016
Qn rhamnoside pentoside24.40446.0857, 301.0350, 299.0201, 447.0941, 433.0771
  26Km 3,7-dirhamnoside27.88C27H30O14577.1563285.0406, 430.0905, 431.0986, 283.0248, 577.1534Ferreres et al. 2008; Negri, Santi et al. 2012; Oszmiański et al. 2013
  27Km rhamnosyl pentoside25.76C26H28O14563.1411430.0906, 283.0250, 285.0406, 431.1000, 417.0834, 563.1396Barros et al. 2011
  28aKm glucoside rhamnoside24.88C27H30O15593.1513430.0907, 447.0935, 285.0406, 283.0249, 593.1518Gonzales et al. 2014; Onkokesung et al. 2014; Zhang et al. 2018
  28bKm 3-glucoside-7-rhamnoside25.58
  29Km triglucoside glucoside13.29C39H50O26933.2532771.2006, 284.0329, 285.0405, 446.0865Gonzales et al. 2014; Onkokesung et al. 2014; Zhang et al. 2018
  30aKm hydroxyferuloyl diglucoside glucoside15.05C43H48O25963.2424609.1472, 284.0332, 191.0354, 801.1872Li et al. 2018; Youssif et al. 2019
  30bQn feruloyl diglucoside glucoside16.49462.0811, 625.1418,
300.0210, 787.1981
  31aKm feruloyl triglucoside glucoside17.23C49H58O291109.3011284.0329, 771.2015, 947.2467, 753.1925Schmidt et al. 2010; Li et al. 2018; Koley et al. 2020
  31bKm feruloyl triglucoside glucoside18.26771.2015, 284.0329, 947.2387, 753.1855
  32Km feruloyl diglucoside glucoside18.06C43H48O24947.2474284.0327, 609.1465, 446.0856, 785.1943
  33Km sinapoyl diglucoside glucoside17.91C44H50O25977.2584284.0329, 609.1470, 446.0860, 815.2054
  34a/bKm sinapoyl triglucoside glucoside17.10C50H60O301139.3110284.0329, 771.2005, 977.2578, 753.1903
Km sinapoyl triglucoside glucoside18.00771.2004, 977.2589, 284.0331, 753.1899
  35Km caffeoyl diglucoside glucoside15.58C42H46O24933.2314609.1464, 284.0326, 161.0247, 771.1784
  36aQn 3,7-diglucoside16.99C27H30O17625.1414462.0810, 463.0880, 301.0359, 299.0202, 625.1433Llorach et al. 2003; Lin et al. 2011; Sun et al. 2013; Li et al. 2016
  36bQn 3-diglucoside21.57300.0278, 301.0355, 625.1411
  37Qn dirhamnoside25.77C27H30O15593.1513446.0857, 301.0354, 447.0934, 299.0197, 593.1514Barros et al. 2011
  38Qn triglucoside glucoside11.78C39H50O27949.2480462.0809, 787.1954, 300.0278, 949.2516Lin and Harnly 2010
  39aQn sinapoyl diglucoside glucoside16.31C44H50O26993.2535462.0810, 625.1422, 299.0200, 787.1956, 831.2026Lin and Harnly 2010; Gonzales et al. 2015
  39bQn sinapoyl triglucoside21.55300.0277, 787.1934, 178.9994
  40a/bQn 3-sinapoyltriglucoside-7-glucoside16.63C50H60O311155.3054787.1922, 462.0810, 300.0275, 993.2586, 625.1424Llorach et al. 2003; Sun et al. 2013
Qn 3-sinapoyltriglucoside-7-glucoside15.65787.1922, 462.0810, 300.0275, 769.1866, 607.1309
  41Qn coumaroyl diglucoside glucoside16.70C42H46O24933.2314462.0805, 624.4000, 300.0272, 787.1967Schmidt et al. 2010; Koley et al. 2020
  42aQn hydroxyferuloyl diglucoside glucoside13.54C43H48O26979.2379462.0807, 625.1415, 787.1943, 300.0276Schmidt et al. 2010; Benayad et al. 2014
  42bQn hydroxyferuloyl diglucoside-7-glucoside16.61625.1415, 462.0807, 300.0276, 787.1943
  43aQn 3-feruloyl-diglucoside-7-diglucoside16.87C49H58O301125.2957787.1957, 462.0808, 300.0278, 299.0199, 463.0876, 769.1835, 963.2440Li et al. 2018; Yang et al. 2018
  43bKm 3-hydroxyferuloyl-diglucoside-7-diglucoside15.17771.2006, 284.0330, 191.0354, 963.2426, 609.1447
  44Qn caffeoyl diglucoside glucoside13.84C42H46O25949.2274625.1420, 462.0811, 787.1959, 300.0278Schmidt et al. 2010; Chen et al. 2019
  45Iso glucoside rhamnoside25.98C28H32O16623.1624315.0512, 460.1014, 313.0352, 461.1094, 477.1034Arimboor and Arumughan 2012; Sun et al. 2013; Chen et al. 2015
  46Iso 3,7-diglucoside20.02C28H32O17639.1570315.0514, 476.0966, 313.0358, 477.0142, 639.1595Lin et al. 2011; Arimboor and Arumughan 2012; Sun et al. 2013; Chen et al. 2015; Li et al. 2016; Oulad El Majdoub et al. 2020

 

Table 2. Effect of LED treatments on the quantity of major phenolic compounds (% changes) in Brassica microgreens.
 
Compound (#)Light aPercent change (%) b
MizunasRadishesMustards
MOMRPCRRROMSFMBMG
aLED treatments: 1, 6.74A:22.68B:70.25R; 2, 9.51A:24.13B:65.91R; 3, 12.02A:26.26B:61.14R; 4,12.57A:44.31B:42.39R; 5, 14.53A:30.18B:51.82R; 6, 18.45A:33.51B:47.48R; 7, 39.46A:58.94B:0.57R. bSignificant changes (%) from control (p<0.05) (4.73A:20.52B:74.36R); NS, not significant from control.
caffeoyl malate (9)1NS−17.221.2NS−7.818.915.313.0
234.24.719.310.1−15.5NS−52.6−11.1
3NSNS18.627.3−27.327.6201.839.5
49.0−17.96.522.515.5NS−89.917.5
523.9−19.523.6−4.4−20.88.9−48.824.8
6NSNS−49.95.6−18.227.7−34.79.8
7−51.4−20.83.230.1−26.038.3−87.861.4
hydroxyferuloyl malate (10)119.1−20.79.726.25.05.7NS7.1
242.0NS17.310.9−6.4NS−54.5NS
312.9NS15.172.2−24.434.4145.2NS
413.3−17.8NS33.844.4NS−59.6NS
528.9−22.111.516.5−9.5−7.0−61.027.8
610.8−8.3−45.871.2−16.2NS−56.911.4
7−47.1−28.221.638.2−25.046.4−48.923.0
coumaroyl malate (11)17.2−10.57.5−5.9NS17.9NSNS
225.8−3.310.88.8NSNSNS−9.8
3−8.9−6.311.253.6NS12.1NS22.6
411.2−14.7NS40.227.2NSNSNS
516.6−18.216.3−5.1−30.26.3NSNS
6NS−3.7−55.53.5−21.915.1NS7.4
7−60.1−20.5−6.264.6NS26.9NS45.8
sinapoyl malate (12)127.8−22.615.119.519.417.4−5.3NS
241.9−4.920.4NSNSNS−38.316.9
3NS−3.919.3NS−28.56.035.8NS
415.1−18.25.014.229.9NS−72.322.2
531.8−14.911.2NS−9.34.7−36.3NS
6NS−13.6−42.718.8NSNS−32.614.0
7−48.8−39.14.911.7−30.49.5−35.8−10.1
feruloyl malate (13)1NS−29.9NS6.0NS10.8−13.2NS
221.3−13.89.5NS−15.8−6.3−43.7NS
37.1−2.122.331.0−26.616.733.0NS
4NS−21.024.821.312.9NS−75.1NS
511.2−22.5NSNS−23.4NS−46.223.3
6−11.2−18.9−54.1NS−20.6NS−26.6NS
7−52.3−37.419.331.0−31.724.5−63.8NS