Table 1.
Total phenolic content (TPC) and AO activity of coffees and coffee substitutes brews as determined using DC polarographic (HPMC), DPPH, FRAP and ABTS assays
| Sample no. | HPMC (%/mL) | TPC (g GAE/L) | DPPH (mM TE/L) | FRAP (mM Fe(II)/L) | ABTS (mM TE/L) |
|---|---|---|---|---|---|
| Coffees | |||||
| 1. Instant | 2391 ± 94f | 9.614 ± 0.205o | 12.66 ± 0.57n | 91.88 ± 0.70l | 44.73 ± 0.42o |
| 2. Instant | 2300 ± 100ef | 9.386 ± 0.114n | 13.24 ± 0.06o | 94.13 ± 0.61m | 47.41 ± 0.33q |
| 3. Instant | 2247 ± 114e | 9.159 ± 0.023m | 10.58 ± 0.47l | 92.26 ± 0.42lm | 46.50 ± 0.40p |
| 4. Instant* | 2229 ± 42e | 7.727 ± 0.000l | 10.75 ± 0.23l | 76.39 ± 0.28j | 37.51 ± 0.42m |
| 5. Instant* | 2197 ± 127e | 7.182 ± 0.227k | 11.57 ± 0.15m | 83.69 ± 0.56k | 40.56 ± 0.62n |
| 6. Turkish | 635 ± 36d | 3.523 ± 0.023ef | 6.40 ± 0.15j | 43.20 ± 0.33i | 21.40 ± 0.46kl |
| 7. Turkish | 618 ± 38cd | 3.795 ± 0.114g | 6.86 ± 0.54k | 44.51 ± 0.51i | 20.71 ± 0.26jk |
| 8. Espresso | 603 ± 22cd | 4.432 ± 0.205j | 7.03 ± 0.54k | 42.64 ± 0.80i | 20.12 ± 0.40j |
| 9. Turkish | 598 ± 19cd | 4.000 ± 0.182h | 6.99 ± 0.06k | 40.10 ± 0.27h | 22.15 ± 0.52l |
| 10. Espresso | 589 ± 30cd | 3.614 ± 0.023ef | 6.43 ± 0.32j | 36.18 ± 0.61g | 18.08 ± 0.33gh |
| 11. Turkish | 578 ± 20cd | 4.227 ± 0.045i | 5.60 ± 0.27gh | 32.81 ± 0.70f | 19.10 ± 0.52i |
| 12. Turkish | 571 ± 29cd | 3.795 ± 0.023g | 5.73 ± 0.26h | 38.05 ± 0.33gh | 17.66 ± 0.47fg |
| 13. Filter | 551 ± 26bcd | 3.500 ± 0.0 91ef | 4.91 ± 0.31d | 36.60 ± 2.34g | 15.62 ± 0.33c |
| 14. Turkish | 547 ± 14bcd | 3.591 ± 0.455ef | 5.44 ± 0.12fg | 29.96 ± 0.19e | 18.25 ± 0.20gh |
| 15. Turkish | 543 ± 17bcd | 3.295 ± 0.295cd | 6.01 ± 0.13i | 36.28 ± 0.70g | 16.69 ± 0.13de |
| 16. Filter | 542 ± 32bcd | 3.205 ± 0.295bc | 6.89 ± 0.15k | 31.36 ± 0.28ef | 18.35 ± 0.20ghi |
| 17. Turkish | 538 ± 25bcd | 3.455 ± 0.364de | 3.72 ± 0.46b | 24.12 ± 0.23c | 18.57 ± 0.67hi |
| 18. Filter | 527 ± 32bcd | 3.182 ± 0.182bc | 3.99 ± 0.11c | 27.12 ± 0.92d | 16.53 ± 0.26de |
| 19. Turkish | 525 ± 39bcd | 3.205 ± 0.068bc | 5.19 ± 0.39e | 30.27 ± 0.45e | 16.91 ± 0.20ef |
| 20. Turkish | 498 ± 29bcd | 3.636 ± 0.045fg | 2.58 ± 0.12a | 20.75 ± 0.49b | 8.56 ± 0.40a |
| 21. Turkish | 494 ± 16bc | 3.545 ± 0.182ef | 5.72 ± 0.23h | 37.17 ± 0.75g | 16.10 ± 0.72cd |
| 22. Turkish | 483 ± 13bc | 3.455 ± 0.045de | 5.32 ± 0.25ef | 33.00 ± 0.61f | 17.60 ± 0.20fg |
| 23. Turkish | 413 ± 22a | 3.068 ± 0.114b | 5.80 ± 0.13hi | 32.89 ± 0.27f | 15.73 ± 0.35c |
| 24. Filter* | 401 ± 16a | 2.295 ± 0.114a | 4.20 ± 0.25c | 16.15 ± 0.23a | 10.97 ± 0.27b |
| Ingredients for coffee substitutes | |||||
| 1. Carob | 517 ± 42f | 7.827 ± 0.091f | 44.82 ± 3.59g | 73.52 ± 3.67f | 37.58 ± 0.39g |
| 2. Barley | 457 ± 24e | 6.609 ± 0.036d | 36.96 ± 0.63f | 66.65 ± 0.28d | 29.36 ± 0.99e |
| 3. Chickpea | 437 ± 15d | 5.382 ± 0.039b | 34.14 ± 1.85d | 62.87 ± 6.89c | 25.77 ± 1.15c |
| 4. Chicory | 432 ± 8c | 5.309 ± 0.040a | 31.07 ± 1.21b | 51.58 ± 7.06b | 23.88 ± 2.26b |
| 5. Pea | 395 ± 15b | 5.091 ± 0.037c | 31.29 ± 0.73c | 50.24 ± 0.65a | 23.33 ± 0.12a |
| 6. Fig | 367 ± 10a | 5.291 ± 0.020a | 29.01 ± 0.40a | 50.05 ± 3.09a | 27.39 ± 1.07d |
| CV | 6.74 | 7.33 | 6.36 | 7.65 | 9.27 |
Data represent the means of a triplicate experiment ± standard deviation
CV coefficient of variation
* Decaffeinated samples
a–m, Values with the same letter in column, are not statistically different at the p < 0.05 level, 95% confidence limit, according to Tukey’s HSD test