Decrease in the Antioxidant Capacity in Beverages Containing Tea Extracts during Storage
Table 1
Results of ACW determination in individual groups of samples. Mean values are expressed as equivalents of ascorbic acid (mmol/L) when stored at the temperature = 4°C and = 22°C, and storage time = 0, 4, and 7 days, respectively.
Sample
Storage time (days)
Temperature (°C)
0
4
7
A1
0.250 ± 0.010
0.240 ± 0.006
0.232 ± 0.004Δ
4
0.228 ± 0.002*
0.201 ± 0.002*Δ
22
A2
1.042 ± 0.027
0.950 ± 0.042
0.912 ± 0.018*Δ
4
0.880 ± 0.029*
0.840 ± 0.020*Δ
22
A3
0.016 ± 0.001
0.015 ± 0.003
0.014 ± 0.002
4
0.013 ± 0.002
0.012 ± 0.001*
22
A4
0.575 ± 0.014
0.528 ± 0.016*
0.480 ± 0.009*
4
0.498 ± 0.011*
0.474 ± 0.012*
22
A5
0.522 ± 0.001
0.520 ± 0.003
0.492 ± 0.004*
4
0.508 ± 0.005*
0.486 ± 0.009*
22
A6
0.598 ± 0.019
0.582 ± 0.002
0.440 ± 0.021*
4
0.534 ± 0.022*
0.410 ± 0.029*
22
A7
8.496 ± 0.171
7.355 ± 0.029*Δ
7.330 ± 0.037*Δ
4
6.435 ± 0.041*Δ
6.115 ± 0.069*Δ
22
B1
8.915 ± 0.075
8.420 ± 0.059*Δ
8.080 ± 0.032*Δ
4
7.890 ± 0.036*Δ
7.690 ± 0.016*Δ
22
B2
15.650 ± 0.057
12.050 ± 0.041*Δ
11.400 ± 0.016*Δ
4
11.350 ± 0.113*Δ
10.950 ± 0.036*Δ
22
C1
9.087 ± 0.108
8.864 ± 0.091*Δ
8.310 ± 0.029*Δ
4
7.115 ± 0.051*Δ
6.280 ± 0.054*Δ
22
C2
11.230 ± 0.041
9.030 ± 0.022*Δ
8.640 ± 0.036*Δ
4
6.650 ± 0.04*Δ
6.400 ± 0.029*Δ
22
C3
5.380 ± 0.075
5.100 ± 0.090*Δ
4.280 ± 0.054*Δ
4
4.480 ± 0.075*Δ
4.070 ± 0.033*Δ
22
The values are means of 3 measurements ± S.D. (standard deviation).
*Statistically significant dependence on the storage time. ΔStatistically significant differences between storage temperatures.
