Characterizing relationship between chemicals and in vitro bioactivities of teas made by six typical processing methods using a single Camellia sinensis cultivar, Meizhan

Figures & data

Figure 1. Flow chart illustrating the different stages in the manufacture of six teas

Table 1. The content (mg/g) of catechin components, caffeine, theaflavins, and total polyphenols in the control sample and six categories of teas

Tea	CAF	Catechin			Esters-catechin			Total Catechins	TF	TF-3-G	TF-3’-G	TFDG	Total TFs	Total TPs
		EGC	C	EC	EGCG	GCG	ECG
Control	36.29 ± 1.70a	61.96 ± 4.39e	1.41 ± 0.05d	14.54 ± 0.86 f	99.30 ± 5.78 f	0.71 ± 0.04bc	19.15 ± 1.20d	198.40 ± 2.01 f	0.34 ± 0.04a	0.05 ± 0.00a	0.16 ± 0.01a	0.29 ± 0.02a	0.84 ± 0.02a	245.15 ± 13.31a
Green	37.31 ± 1.00a	49.77 ± 1.67d	1.08 ± 0.05 c	11.35 ± 0.35e	91.87 ± 4.06e	0.62 ± 0.03b	18.08 ± 0.72d	175.10 ± 6.95e	1.42 ± 0.10 c	0.30 ± 0.02 c	0.25 ± 0.01 c	0.37±0.02ab	2.34 ± 0.15b	238.20 ± 9.14a
White	36.80 ± 1.91a	23.81 ± 1.24b	0.96 ± 0.08b	4.81 ± 0.25b	61.54 ± 3.48b	1.52 ± 0.14e	14.09 ± 0.80b	107.97 ± 6.03b	3.43 ± 0.20 f	0.99 ± 0.08e	0.40 ± 0.02e	0.74 ± 0.04 c	5.55 ± 0.33d	236.36 ± 36.77a
Yellow	38.20 ± 0.36a	39.48 ± 0.43 c	1.04 ± 0.02bc	9.60 ± 0.09 cd	86.46 ± 1.10e	0.75 ± 0.03 c	18.44 ± 0.17d	159.16 ± 1.81d	1.24 ± 0.02bc	0.30 ± 0.01 c	0.28 ± 0.00d	0.39 ± 0.01b	2.22 ± 0.03b	233.03 ± 5.48a
Oolong	36.10 ± 2.61a	43.18 ± 3.09 c	1.08 ± 0.08 c	9.97 ± 0.72d	71.90 ± 4.78 c	1.06 ± 0.04d	16.07 ± 1.25 c	145.36 ± 10.11 c	2.02 ± 0.13d	0.56 ± 0.04d	0.44 ± 0.01 f	0.67 ± 0.04 c	3.68 ± 0.19 c	224.47 ± 8.74a
Black	35.72 ± 0.62a	0.00 ± 0.00a	0.42 ± 0.01a	0.29 ± 0.01a	1.09 ± 0.01a	1.05 ± 0.02d	0.73 ± 0.02a	3.53 ± 0.04a	2.24 ± 0.05e	2.80 ± 0.10 f	1.14 ± 0.03 g	3.13 ± 0.11d	9.30 ± 0.28e	133.46 ± 1.86b
Dark	36.28 ± 2.61a	26.11 ± 0.76b	0.99 ± 0.04bc	8.75 ± 0.48 c	79.00 ± 3.77d	0.35 ± 0.01a	18.25 ± 1.01d	135.93 ± 5.78 c	1.22 ± 0.08b	0.19 ± 0.01b	0.22 ± 0.00b	0.36 ± 0.01ab	2.00 ± 0.10b	218.98 ± 4.93a

C, catechin; GCG, (-)-gallocatechin gallate; TF, theaflavin; TF-3-G, theaflavin-3-gallate; TF-3’-G, theaflavin-3’-gallate; TFDG, theaflavin-3,3’-digallate; The total catechins (TCs) content = the total amount of EGC, C, EC, CG, GC, EGCG, GCG, and ECG. The total TFs content = the total amount of TF, TF-3-G, TF-3’-G, and TFDG. Values were expressed as mean ± standard deviation (n = 3). Similar letters represented no significant difference within a column and vice versa (Duncan’s test, P < 0.05).

Table 2. Antioxidant activity and antioxidant capacity composite index (ACCI) of the control sample and six categories of teas in vitro

Tea	DPPH (% scavenging rate)	ABTS (% scavenging rate)	ORAC (µmol TE/g·DW)	ACCI
Control	56.06 ± 4.61ab	98.67 ± 1.66 f	81.24 ± 0.71 c	96.10
Green	63.48 ± 3.68b	94.18 ± 2.95e	81.15 ± 0.68 c	98.44
White	57.86 ± 4.99ab	82.85 ± 0.84b	73.56 ± 3.49b	88.57
Yellow	60.59 ± 7.71ab	88.67 ± 0.56d	80.04 ± 2.27 c	94.61
Oolong	56.82 ± 4.87ab	86.41 ± 0.59 cd	78.43 ± 0.53 c	91.21
Black	52.21 ± 4.11a	41.09 ± 1.92a	41.63 ± 2.79a	58.38
Dark	51.18 ± 6.34a	83.86 ± 0.97bc	77.97 ± 0.72 c	87.19

Antioxidant index score = [(sample score/best score) × 100]; ACCI = [(sample score/best score) × 100], averaged for all three assays for each tea for the ACCI. Values were expressed as mean ± standard deviation (n = 3). Similar letters represented no significant difference within a column and vice versa (Duncan’s test, P < 0.05).

Figure 2. (a) Inhibition rate of PL by the control sample and six categories of teas. (b) Inhibition rate of HMG-COA reductase by the control sample and six categories of teas. (c) Inhibition rate of LCAT by the control sample and six categories of teas. (d) Inhibition rate of α-glucosidase by the control sample and six categories of teas. Values were expressed as mean ± standard deviation (n = 3). Similar letters represented no significant difference in the inhibition rate of each enzyme and vice versa (Duncan’s test, P < 0.05)

Table 3. Pearson’s correlation coefficients among bioactive components, antioxidant activity, inhibition rate of three lipid metabolism enzymes, and α-glucosidase inhibition rate

Item	CAF	TPs	TCs	TFs	DPPH	ABTS	ORAC	PL	HMG-COA reductase	LCAT
TPs	0.533ns
TCs	0.476 ns	0.925**
TFs	−0.441ns ns	−0.853*	−0.962**
DPPH	0.772*	0.572 ns	0.532 ns	−0.354 ns
ABTS	0.491ns	0.980**	0.981**	−0.927**	0.550 ns
ORAC	0.521 ns	0.969**	0.955**	−0.925**	0.515 ns	0.983**
PL	−0.274 ns	−0.711 ns	−0.880**	0.863*	−0.439ns	−0.817*	−0.747 ns
HMG-COA Reductase	0.340 ns	0.333 ns	0.270 ns	−0.009 ns	0.817*	0.297 ns	0.221 ns	−0.191 ns
LCAT	0.313 ns	0.902**	0.801*	−0.780*	0.235 ns	0.870*	0. 897**	−0.486 ns	0.086 ns
α-Glucosidase	−0.114 ns	−0.560 ns	−0.823*	0.857*	−0.191 ns	−0.711 ns	−0.683 ns	0.845*	−0.026 ns	−0.511 ns

CAF, caffeine content; TPs, TPs content; TC, TC content; TFs, total TFs content; DPPH, DPPH radical scavenging rate; ABTS, ABTS radical scavenging rate; ORAC, oxygen radical absorbing capacity; PL, PL inhibition rate; HMG-COA, HMG-COA reductase inhibition rate; LCAT, LCAT inhibition rate; α-Glucosidase, α-glucosidase inhibition rate. ns = non significant and *,** = significant at P < 0.05 or 0.01, respectively.