A targeted and untargeted metabolomics analysis of 'Oriental Beauty' oolong tea during processing

Lin Zeng; Shan Jin; Yan-qing Fu; Lian-shuang Chen; Jun-feng Yin; Yong-quan Xu; Lin Zeng; Shan Jin; Yan-qing Fu; Lian-shuang Chen; Jun-feng Yin; Yong-quan Xu

doi:10.48130/BPR-2022-0020

Figures (5) Tables (1)

Figure 1.
Metabolite (compounds with variable importance in projection > 1) variations during enzyme reaction stage analyzed by LC/MS and GC/MS. (a) These non-volatile metabolites accumulate gradually in the enzymatic reaction stage. (b) These non-volatile metabolites decrease gradually in the enzymatic reaction stage. (c) The score scatter plots of PLS-DA of volatile metabolites. (d) Validation of the PLS-DA model. (e) Heatmap of differential volatile substances during enzyme reaction stage. VIP: variable importance projection, GA: gallic acid, EGC:(–)-epigallocatachin, ECG: (–)-epicatechin gallate, CG: (–)-catechin gallate, EC: (–)-epicatechin. Different lower case letters following the number indicate significant differences during the processing (p < 0.05). * Represents compounds that have not been validated by available standards.
Figure 2.
Metabolite (compounds with variable importance in projection > 1) variations during nonenzymatic reaction stage analyzed by LC/MS and GC/MS. (a) These non-volatile metabolites accumulate gradually in the nonenzymatic reaction stage. (b) These non-volatile metabolites decrease gradually in the nonenzymatic reaction stage. (c) The score scatter plots of PLS-DA of volatile metabolites. (d) Validation of the PLS-DA model. (e) Heatmap of differential volatile substances during nonenzymatic reaction stage. VIP: variable importance projection, EGCG: (–)-epigallocatechin gallate, EGC: (–)-epigallocatechin. Different lower case letters following the number indicate significant differences during the processing (p < 0.05). * Represents compounds that have not been validated by available standards.
Figure 3.
Dynamic variation of major metabolites. DMAPP: dimethylallyl pyrophosphate, PEP: phosphoenolpyuvate, E4P: erythrose 4-phosphate, FPP: farnesyl pyrophosphate, GPP: geranyl pyrophosphate, IPP: isopentenyl pyrophosphate, Phe: phenylalanine, IGP: indole-3-glycerol phosphate, GLVs: green leaf volatiles, the methylerythritol phosphate (MEP) pathway, the mevalonic (MVA) acid pathway, lipoxgenase (LOX) pathway.
Figure 4.
Dynamic variation of major compounds between JX and TGY during processing. (a) Dynamic changes in the content of major non-volatile metabolites in JX varieties. (b) Dynamic changes in the content of major non-volatile metabolites in TGY varieties. (c) Dynamic changes in the content of major volatile metabolites in JX varieties. (d) Dynamic changes in the content of major volatile metabolites in TGY varieties. GLVs: green leaf volatiles (hexanal, (E)-2-hexenal, cis-3-hexen-1-ol,1-hexanol, cis-3-hexenyl acetate); homoterpenes ((3E)-4,8-dimethyl-1,3,7-nonatriene); monoterpenes (β-myecene, D-limonene, β-trans-ocimene, cis-β-ocimene, linalool, hotrienol, trans-linalool 3,7-oxide, β-cyclocitral, cis-geraniol, and citral); sesquiterpenes (α-cubebene, β-bourbenene, β-cubebene, caryophyllene, α-farnesene, δ-Cadinene, nerolidol, cubenol); JX: Jinxuan, TGY: Tieguanyin.
Figure 5.
The changes of taste and aroma metabolites in Oriental Beauty during the whole production process. PPO: polyphenol oxidase, POD: peroxidase, GA: gallic acid, MEP pathway: the methylerythritol phosphate pathway.

Compounds (mg/g)	FTL	Wi-OB	1S-OB	2S-OB	3S-OB	4S-OB	5S-OB	ST-OB	FX-OB	OB
GC	8.730 ± 1.539^a	6.874 ± 0.341^b	6.394 ± 0.386^b	4.147 ± 0.363^c	3.829 ± 1.028^c	2.941 ± 0.754^d	1.445 ± 0.677^e	0.670 ± 0.514^f	0.927 ± 0.453^ef	1.126 ± 0.341^ef
EGC	49.248 ± 2.943^a	39.766 ± 3.377^b	32.811 ± 4.212^c	17.511 ± 3.132^d	16.029 ± 8.675^d	11.673 ± 6.057^e	4.117 ± 3.220^f	1.577 ± 1.380^f	2.800 ± 2.116^f	3.122 ± 1.482^f
C	34.730 ± 12.072^a	25.859 ± 4.542^b	25.784 ± 4.899^b	21.133 ± 3.301^c	20.225 ± 1.656^c	17.996 ± 1.792^ce	14.164 ± 0.725^ef	10.011 ± 1.040^f	11.188 ± 2.066^f	10.487 ± 1.299^f
EC	24.382 ± 5.110^a	22.508 ± 3.291^ab	21.541 ± 2.957^b	18.028 ± 2.620^c	15.915 ± 0.365^cd	13.624 ± 0.336^d	9.521 ± 0.851^e	6.231 ± 1.347^f	7.345 ± 0.583^ef	6.689 ± 0.306^f
EGCG	250.087 ± 3.465^a	230.995 ± 7.142^ab	214..127 ± 12.789^b	166.138 ± 12.478^c	143.142 ± 37.211^d	113.768 ± 33.531^e	55.881 ± 29.028^f	21.082 ± 14.399^g	29.749 ± 14.769^g	33.393 ± 7.166^g
GCG	0.901 ± 0.082^a	0.928 ± 0.082^a	0.858 ± 0.096^a	0.658 ± 0.059^b	0.581 ± 0.160^b	0.407 ± 0.131^c	0.211 ± 0.084^d	0.081 ± 0.037^e	0.135 ± 0.055^de	0.214 ± 0.0254^d
ECG	37.392 ± 7.412^a	34.177 ± 4.864^b	33.653 ± 3.649^b	31.376 ± 3.937^bc	28.058 ± 1.001^cd	25.238 ± 1.621^d	20.064 ± 0.703^e	14.346 ± 0.896^f	14.381 ± 1.357^f	13.458 ± 0.861^f
Total catechins	405.470 ± 30.134^a	361.106 ± 15.296^b	335.169 ± 13.269^b	258.990 ± 17.723^c	227.780 ± 44.836^e	185.647 ± 37.863^f	105.401 ± 33.025^e	53.940 ± 17.880^g	66.526 ± 14.339^g	68.489 ± 10.870^g
GA	0.680 ± 0.108^f	1.440 ± 0.277^e	1.988 ± 0.254^e	3.475 ± 0.271^d	3.584 ± 0.707^d	4.027 ± .0.730^d	5.398 ± 0.437^c	5.821 ± 0.218^c	6.755 ± 0.891^b	8.187 ± 1.247^a
Caffeine	68.601 ± 4.509^ac	71.635 ± 6.686^abc	71.447 ± 4.596^abc	73.500 ± 5.649^c	71.140 ± 4.084^abc	71.147 ± 5.983^abc	70.789 ± 5.863^abc	73.469 ± 6.177^ce	74.056 ± 4.884^bc	67.746 ± 2.673^a
Vitexin- 2-O-rhamnoside	0.205 ± 0.077^bc	0.338 ± 0.205^b	0.347 ± 0.210^b	0.354 ± 0.205^b	0.336 ± 0.198^b	0.320 ± 0.190^b	0.317 ± 0.196^b	0.325 ± 0.212^b	0.360 ± 0.320^b	0.418 ± 0.247^ab
Quercetin- 3-O-rutinoside	1.873 ± 0.339^ab	1.776 ± 0.427^b	1.746 ± 0.418^abc	1.783 ± 0.426^ab	1.688 ± 0.509^abc	1.524 ± 0.419^abc	1.508 ± 0.349^abc	1.366 ± 0.246^c	1.417 ± 0.367^bc	1.362 ± 0.345^c
Quercetin- 3-O-galactoside	0.853 ± 0.684^a	0.808 ± 0.659^a	0.798 ± 0.656^a	0.808 ± 0.661^a	0.784 ± 0.636^a	0.743 ± 0.582^a	0.722 ± 0.514^a	0.709 ± 0.485^a	0.735 ± 0.508^a	0.696 ± 0.472^a
Cynaroside	0.046 ± 0.007^acd	0.052 ± 0.011^cd	0.050 ± 0.013^acd	0.052 ± 0.010^acd	0.048 ± 0.012^acde	0.044 ± 0.009^acd	0.040 ± 0.009^abe	0.036 ± 0.007^b	0.034 ± 0.006^b	0.034 ± 0.006^b
Quercetin 3-O-rhamnoside	0.022 ± 0.010^acd	0.022 ± 0.006^acd	0.021 ± 0.005^cde	0.025 ± 0.008^d	0.019 ± 0.004^abce	0.019 ± 0.003^abce	0.016 ± 0.002^e	0.016 ± 0.001^be	0.015 ± 0.003^be	0.015 ± 0.002^be
Luteolin	0.001 ± 0.000^ac	0.001 ± 0.000^ac	0.001 ± 0.001^ac	0.002 ± 0.001^cde	0.002 ± 0.001^de	0.002 ± 0.001^e	0.004 ± 0.001^f	0.006 ± 0.001^h	0.005 ± 0.001^g	0.009 ± 0.001^b
Quercetin	0.053 ± 0.029^a	0.047 ± 0.027^a	0.052 ± 0.032^a	0.051 ± 0.031^a	0.050 ± 0.029^a	0.048 ± 0.027^a	0.044 ± 0.024^a	0.045 ± 0.025^a	0.069 ± 0.048^a	0.068 ± 0.041^a
Kaempferol	0.046 ± 0.010^a	0.042 ± 0.014^a	0.046 ± 0.018^a	0.047 ± 0.019^a	0.045 ± 0.016^a	0.43 ± .015^a	0.045 ± 0.016^a	0.050 ± 0.021^a	0.066 ± 0.035^a	0.077 ± 0.040^b
Vitexin	0.037 ± 0.008^a	0.043 ± 0.006^bcd	0.046 ± 0.006^cd	0.046 ± 0.008^d	0.043 ± 0.004^bcd	0.041 ± 0.006^abcd	0.040 ± 0.006^ab	0.039 ± 0.006^ab	0.041 ± 0.005^abcd	0.046 ± 0.004^bcd
Different lowercase letters following the number indicate significant differences during the processing (p < 0.05). The results were presented in the form of mean values followed by the standard deviation.

Table 1.

Dynamic variation of major taste compounds.