Table 5.
Phenolic acids, flavonoids, and resveratrol contents of special beers by HPLC-DAD (mg/L).
| Beer Code | WALN | CHES | GTEA | COFF | COCO | HONE | LIQU |
|---|---|---|---|---|---|---|---|
| Phenolic Acids: | |||||||
| Chlorogenic | tr | nd | nd | 1.56 ± 0.10 | nd | nd | nd |
| Vanillic | |||||||
| Free | 0.92 ± 0.12 | 1.57 ± 0.03 | 0.87 ± 0.04 | 0.78 ± 0.03 | 1.14 ± 0.09 | 0.80 ± 0.05 | 1.03 ± 0.10 |
| Total | 2.16 ± 0.26 | 5.09 ± 0.06 | 2.82 ± 0.15 | 2.03 ± 0.14 | 3.39 ± 0.17 | 3.09 ± 0.22 | 2.32 ± 0.11 |
| Caffeic | |||||||
| Free | 0.52 ± 0.01 | 0.24 ± 0.01 | tr | 0.57 ± 0.02 | 0.50 ± 0.02 | tr | 0.56 ± 0.07 |
| Total | 3.16 ± 0.15 | 3.47 ± 0.03 | 1.48 ± 0.18 | 9.20 ± 0.21 | 3.69 ± 0.01 | 2.37 ± 0.17 | 3.71 ± 0.04 |
| Syringic | |||||||
| Free | tr | 0.40 ± 0.03 | 0.62 ± 0.02 | tr | 0.54 ± 0.02 | 0.27 ± 0.01 | 0.40 ± 0.03 |
| Total | tr | 1.24 ± 0.05 | 0.96 ± 0.04 | tr | 1.42 ± 0.05 | 1.24 ± 0.10 | 0.67 ± 0.03 |
| p-Coumaric | |||||||
| Free | 0.68 ± 0.01 | 1.02 ± 0.06 | 0.11 ± 0.01 | 0.36 ± 0.02 | 1.38 ± 0.08 | 0.21 ± 0.01 | 1.06 ± 0.06 |
| Total | 4.32 ± 0.24 | 3.36 ± 0.07 | 2.24 ± 0.16 | 1.93 ± 0.08 | 3.26 ± 0.13 | 1.75 ± 0.03 | 2.95 ± 0.14 |
| Ferulic | |||||||
| Free | 1.05 ± 0.02 | 1.81 ± 0.20 | 0.15 ± 0.01 | 0.63 ± 0.02 | 1.16 ± 0.03 | 0.43 ± 0.01 | 1.32 ± 0.08 |
| Total | 8.22 ± 0.17 | 27.55 ± 0.43 | 14.30 ± 0.40 | 20.50 ± 0.64 | 22.10 ± 0.73 | 19.20 ± 0.33 | 20.63 ± 0.87 |
| Sinapic | |||||||
| Free | 0.45 ± 0.01 | 0.97 ± 0.12 | 0.49 ± 0.01 | 0.24 ± 0.02 | 0.44 ± 0.01 | 0.55 ± 0.01 | 1.03 ± 0.04 |
| Total | 2.68 ± 0.06 | 4.74 ± 0.04 | 4.48 ± 0.08 | 2.52 ± 0.02 | 4.89 ± 0.05 | 6.73 ± 0.03 | 6.66 ± 0.07 |
| Totalphenolic Acids a | 20.54 ± 0.88 | 45.45 ± 0.68 | 26.28 ± 1.01 | 36.18 ± 1.09 | 38.75 ± 1.14 | 34.38 ± 0.88 | 36.94 ± 1.26 |
| Flavonoids: | |||||||
| Catechin | tr | 4.65 ± 0.13 | 2.98 ± 0.09 | tr | 4.58 ± 0.02 | tr | tr |
| Epicatechin | 1.80 ± 0.11 | 3.68 ± 0.12 | 3.09 ± 0.05 | 1.30 ± 0.07 | 1.83 ± 0.11 | 0.94 ± 0.05 | tr |
| Rutin | nd | nd | 0.68 ± 0.02 | nd | nd | 1.29 ± 0.02 | 0.92 ± 0.10 |
| Myricetin | 4.44 ± 0.27 | tr | 1.69 ± 0.05 | 0.39 ± 0.03 | 0.65 ± 0.02 | 2.67 ± 0.18 | 8.82 ± 0.07 |
| Quercetin | 6.55 ± 0.31 | tr | 1.17 ± 0.09 | 0.54 ± 0.02 | 1.52 ± 0.06 | 4.67 ± 0.23 | 2.63 ± 0.15 |
| Stilbenes: | |||||||
| Resveratrol | 0.26 ± 0.20 | 0.35 ± 0.02 | 0.32 ± 0.02 | 0.23 ± 0.01 | 0.31 ± 0.01 | 0.24 ± 0.01 | 0.20 ± 0.01 |
Values are means ± SE (n = 3). Nd, not detectable and tr, traces amount.a Total phenolic acids content was calculated by the sum of single phenolic acids content obtained after alkaline hydrolysis.