Total phenolic content (TP) and total antioxidant capacity (AC) were analysed in shoots of Phyllostachys aureosulcata (PA), P aureosulcata f. aureocaulis (PAA), P. aureosulcata f. spectabilis (PAS), P. bissetii (PB), P. flexuosa (PF), P. humilis (PH), P. iridescens (PI), P. nigra var. nigra (PNN), P. nigra var. henonis (PNH), P. mannii (PM), P. sulphurea var. sulphurea (PSS), P. violascens (PVI), P. viridiglaucescens (PVG), P. vivax f. aureocaulis (PVA), collected on four harvest dates. Both TP and AC were determined following three processing methods, fresh, boiled and pickled in shoots of PF. Comparative study of TP and AC in the above Phyllostachys species shoots has not been reported before. The highest TP (1,227.6 μg GA/ml) and AC (154.0 μg AA/ml) values were measured in fresh shoots and the lowest in pickled ones. The highest values of TP were measured in the case of PA (1,321.95 μg GA/ml). The other taxa followed in decreasing order: PF, PVI, PI, PAA, PB, PAS, PNN, PNH, PM, PH, PSS and PVA. The highest AC values were obtained in the case of PI (184.24 μg AA/ml). The other taxa followed in decreasing order: PA, PF, PSS, PNN, PNH, PVG, PB, PAA, PAS, PV, PVA, PM and PH. The highest TP values were measured in taxa harvested on the first collection date and the values consequently decreased in taxa collected at later harvest dates. Our findings suggest that the earlier harvest date, through the influence of lower temperatures, could enhance the phytochemical content of bamboo shoots.

Total phenolic content (TP) and total antioxidant capacity (AC) were analysed in shoots of Phyllostachys aureosulcata (PA), P aureosulcata f. aureocaulis (PAA), P. aureosulcata f. spectabilis (PAS), P. bissetii (PB), P. flexuosa (PF), P. humilis (PH), P. iridescens (PI), P. nigra var. nigra (PNN), P. nigra var. henonis (PNH), P. mannii (PM), P. sulphurea var. sulphurea (PSS), P. violascens (PVI), P. viridiglaucescens (PVG), P. vivax f. aureocaulis (PVA), collected on four harvest dates. Both TP and AC were determined following three processing methods, fresh, boiled and pickled in shoots of PF. Comparative study of TP and AC in the above Phyllostachys species shoots has not been reported before. The highest TP (1,227.6 μg GA/ml) and AC (154.0 μg AA/ml) values were measured in fresh shoots and the lowest in pickled ones. The highest values of TP were measured in the case of PA (1,321.95 μg GA/ml). The other taxa followed in decreasing order:

Changes in total phenolic content (TP) and total antioxidant capacity (AC) during the vegetation period (April-November) were analysed in Phyllostachys aureosulcata f. aureocaulis (PAA), P. flexuosa (PF), P. humilis (PH), P. sulphurea var. sulphurea (PSS). Different extraction methods were compared: infusion or decoction with water or aqueous methanol. The highest significant value for TP was measured in the case of infusion at 90 °C for 5 min, which lead to the highest value for AC. During the vegetation period the highest values of TP were measured in April and May in the case of PAA (409.5; 314.9 and 258.7; 119.0 µg GA/ml) and PH (388.4; 411.6 and 252.9; 253.3 µg GA/ml). There was a clear trend in the changes of TP, with high values in April and November and a peak during August-September. Similar to TP, the highest values of AC were measured in April and May in PH (519.7; 566.3 and 513.5; 510.4 µg AA/ml) and PAA (534.5; 337.8 and 394.9; 275.4 µg AA/ml). We compared the change of TP in all taxa with stress index values derived from daily maximum and minimum air temperature, cumulative precipitation plus irrigation and cumulative evapotranspiration values. A close correlation R 2 = 0.32 (p=0.001) was found between stress index values and the change in TP of all taxa. The correlation is even closer R 2 = 0.52 (p=0.001) with PF, PH and PSS. Our results with PAA can be explained by possible inter/intra-specific differences in freeze tolerance and cold-acclimation.