Dynamic Changes in Phenolics and Antioxidant Capacity during Pecan (Carya illinoinensis) Kernel Ripening and Its Phenolics Profiles
Abstract
:1. Introduction
2. Results and Discussion
2.1. Changes of Total Phenolic Content, Condensed Tannins, and Total Flavonoid Content
2.2. Antioxidant Capacity
2.3. Identification of Phenolics in Pecan Kernels Using UPLC-Q/TOF-MS
2.4. Quantification of Phenolics in Pecan Kernels Using HPLC
2.5. The Correlation of Antioxidant Capacity and Phenolics
3. Materials and Methods
3.1. Pecan Samples
3.2. Chemicals
3.3. Sample Extraction
3.4. Total Phenolic Content
3.5. Condensed Tannins
3.6. Total Flavonoid Content
3.7. Antioxidant Capacity
3.8. UPLC-Q/TOF-MS
3.9. HPLC
3.10. Statistical Analysis
4. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Sample Availability: Samples of the compounds gallic acid, ellagic acid, (+)-catechin, (−)-epicatechin, rutin, and EGCG are available from the authors. |
Peak No. | RT (min) | Molecular Ion (m/z) | Fragment Ions (m/z) | Neutral Loss (amu) | Tentative Structural Assignment | Reference | Molecular Formula | ∆m (ppm) |
---|---|---|---|---|---|---|---|---|
1 | 0.65 | 341.0879 | 179 | 162 | Caffeic acid hexoside | [9] | C15H18O9 | −1.76 |
2 | 0.84 | 331.0684 | 169 | 162 | Gallic acid hexoside | [9] | C13H16O10 | −5.74 |
3 | 0.94 | 481.0643 | 301 | 180 | HHDP-glucose | [9] | C20H18O14 | −5.20 |
4 | 1.15 | 169.0146 | 125 | 44 | Gallic acid | Standard a | C7H6O5 | −5.33 |
5 | 1.30 | 137.0229 | 107 | 30 | p-Hydroxybenzoic acid | [9] | C7H6O3 | 7.30 |
6 | 2.05 | 783.0727 | 481-301 | 302-482 | Bis-HHDP-glucose (pedunculagin/casuariin isomer) * | [30] | C34H24O22 | −5.87 |
7 | 2.75 | 451.1263 | 289 | 162 | Catechin hexoside | [9] | C21H24O11 | −5.10 |
8 | 3.13 | 451.1242 | 289 | 162 | Catechin hexoside | [9] | C21H24O11 | −0.44 |
9 | 3.20 | 783.0684 | 481-301 | 302-482 | Bis-HHDP-glucose (pedunculagin/casuariin isomer) * | [30] | C34H24O22 | −0.38 |
10 | 3.27 | 951.0760 | 907-783-481-301 | 44-168-470-650 | HHDP-valoneoyl-glucose (praecoxin A/platycariin isomer) * | [30] | C41H28O27 | −2.10 |
11 | 3.40 | 577.1337 | 425 | 152 | Procyanidin dimer B-type [(E)C→B→(E)C] | [9] | C30H26O12 | 1.56 |
12 | 3.75 | 183.0310 | 124 | 59 | Methyl gallate ∆ | [31] | C8H8O5 | −8.74 |
13 | 3.90 | 865.2006 | 577-289 | 288-576 | Procyanidin trimer (C1) [(E)C→B→(E)C→B→(E)C] | [9] | C45H38O18 | −3.01 |
14 | 3.97 | 483.0773 | 331-169 | 152-314 | Digalloyl-glucose | [30,32] | C20H20O14 | 0.41 |
15 | 4.04 | 289.0732 | 245-205-179 | 44-84-110 | (+)-Catechin | Standard | C15H14O6 | −6.92 |
16 | 4.59 | 633.0756 | 301 | 332 | Galloyl-HHDP-glucose (strictinin/isostrictinin) | [30,32] | C27H22O18 | −4.42 |
17 | 5.45 | 785.0768 | 483-301 | 302-484 | Digalloyl-HHDP-glucose (tellimagrandin I) | [30,32] | C34H26O22 | 8.92 |
18 | 5.64 | 289.0722 | 245-205-179 | 44-84-110 | (−)-Epicatechin | Standard | C15H14O6 | −3.46 |
19 | 5.78 | 463.0508 | 301 | 162 | Ellagic acid hexoside | [9] | C20H16O13 | 1.08 |
20 | 6.36 | 300.9961 | 217 | 84 | Ellagic acid | Standard | C14H6O8 | 7.64 |
21 | 6.51 | 433.0413 | 301 | 132 | Ellagic acid pentose | [9] | C19H14O12 | −1.39 |
22 | 6.64 | 565.2089 | 403 | 189 | Glansreginin B * | [33] | C24H38O15 | 7.78 |
23 | 6.70 | 615.1000 | 463-301 | 152-314 | Digalloyl ellagic acid | [9] | C28H24O16 | −2.28 |
24 | 6.79 | 477.0692 | 315-300 | 162-177 | Methyl ellagic acid hexoside | [9] | C21H18O13 | −4.82 |
25 | 6.90 | 609.1041 | 301 | 308 | Ellagic acid rutinoside # | [34] | C26H26O17 | 8.37 |
26 | 7.02 | 441.0782 | 289 | 152 | (Epi)catechin gallate | [9] | C22H18O10 | 9.07 |
27 | 7.21 | 491.0811 | 328 | 163 | Dimethyl ellagic acid hexoside | [9] | C22H20O13 | 3.05 |
28 | 7.37 | 649.0724 | 605-481-301 | 44-168-348 | Valoneoyl-glucose * | [35] | C27H22O19 | −7.24 |
29 | 7.44 | 447.0595 | 301 | 146 | Ellagic acid rhamnoside # | [36] | C20H16O12 | −6.93 |
30 | 7.48 | 315.0153 | 301 | 14 | Methyl ellagic acid | [19] | C15H8O8 | −3.81 |
31 | 7.51 | 447.0578 | 315 | 132 | Methyl ellagic acid pentose | [9] | C20H16O12 | −3.13 |
32 | 7.79 | 592.2066 | 403-343-241 | 189-249-351 | Glansreginin A * | [33] | C28H35NO13 | −6.08 |
33 | 7.86 | 585.0507 | 433-301 | 152-284 | Ellagic acid galloyl pentose | [9] | C26H18O16 | 1.71 |
34 | 8.09 | 457.0808 | 293-163 | 164-294 | Epigallocatechin gallate (EGCG) | Standard | C22H18O11 | −8.09 |
35 | 8.28 | 487.0124 | 469-425-301 | 18-62-186 | Valoneic acid dilactone hydrate | [9] | C21H12O14 | 5.13 |
36 | 8.44 | 599.0625 | 447-315 | 152-284 | Methyl ellagic acid galloyl pentose | [9] | C27H20O16 | 8.01 |
37 | 8.67 | 599.0670 | 447-315 | 152-284 | Methyl ellagic acid galloyl pentose | [9] | C27H20O16 | 0.50 |
38 | 8.86 | 599.0684 | 447-315 | 152-284 | Methyl ellagic acid galloyl pentose | [9] | C27H20O16 | −1.84 |
39 | 9.17 | 329.0271 | 314-301 | 15-28 | Dimethyl ellagic acid | [9] | C16H10O8 | 7.90 |
40 | 9.34 | 329.0325 | 314-301 | 15-28 | Dimethyl ellagic acid | [9] | C16H10O8 | −8.51 |
Antioxidant Capacity | TPC | CT | TFC | Individual Phenolics 1 | ||||
---|---|---|---|---|---|---|---|---|
GA | C | EC | EGCG | EA | ||||
DPPH | 0.748 ** | 0.442 ** | 0.426 ** | 0.538 ** | 0.799 ** | 0.721 ** | 0.469 ** | 0.471 ** |
ABTS | 0.841 ** | 0.497 ** | 0.506 ** | 0.662 ** | 0.871 ** | 0.851 ** | 0.597 ** | 0.606 ** |
Sample Name | DAFB 1 | Sample Stage | Description 2 | Daily Mean Temperature of Sampling Interval (°C) 3 | Daily Mean Sunshine Duration of Sampling Interval (h) 3 |
---|---|---|---|---|---|
S1 | 85 | Water stage | Appearance of the kernel | 32.09 | 10.34 |
S2 | 95 | Water stage | Quick expansion of the kernel | 30.38 | 8.38 |
S3 | 105 | Water stage | Quick expansion of the kernel | 30.73 | 10.35 |
S4 | 115 | Milk stage | Kernel became milky | 29.67 | 6.90 |
S5 | 125 | Milk stage | Kernel became milky | 26.69 | 9.04 |
S6 | 135 | Dough stage | Kernel became oily | 24.30 | 5.10 |
S7 | 145 | Dough stage | Kernel became oily | 22.80 | 6.47 |
S8 | 155 | Dough stage | Kernel ripening | 21.93 | 3.03 |
S9 | 165 | Kernel stage | Kernel ripening | 18.27 | 2.42 |
S10 | 175 | Kernel stage | Over ripeness | 19.12 | 1.00 |
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Jia, X.; Luo, H.; Xu, M.; Zhai, M.; Guo, Z.; Qiao, Y.; Wang, L. Dynamic Changes in Phenolics and Antioxidant Capacity during Pecan (Carya illinoinensis) Kernel Ripening and Its Phenolics Profiles. Molecules 2018, 23, 435. https://doi.org/10.3390/molecules23020435
Jia X, Luo H, Xu M, Zhai M, Guo Z, Qiao Y, Wang L. Dynamic Changes in Phenolics and Antioxidant Capacity during Pecan (Carya illinoinensis) Kernel Ripening and Its Phenolics Profiles. Molecules. 2018; 23(2):435. https://doi.org/10.3390/molecules23020435
Chicago/Turabian StyleJia, Xiaodong, Huiting Luo, Mengyang Xu, Min Zhai, Zhongren Guo, Yushan Qiao, and Liangju Wang. 2018. "Dynamic Changes in Phenolics and Antioxidant Capacity during Pecan (Carya illinoinensis) Kernel Ripening and Its Phenolics Profiles" Molecules 23, no. 2: 435. https://doi.org/10.3390/molecules23020435