Abstract:

【Objective】 To explore the effects of shoot density and trellis systems on free phenol compounds in wine of Vitis vinifera L. cv. Cabernet Sauvignon, a field experiment was conducted in a commercial viniyard in Longkou, Shandong province. 【Method】 Wines made from Cabernet Sauvignon at three different densities of shoots and two different trellis systems were studied. The treatments of shoots density were control (19 shoots), 10, 13 and 16 shoots per meter. Vertical shoot positioning trellis and “V” training system was studied, too. The concentrations of free phenol were assayed by means of high performance liquid chromatography (HPLC). 【Result】 The results showed that the concentration of total free phenol in wine increased with the decreasing number of shoots per meter (119.08 mg•L-1 to 146.4 mg•L-1), and statistical difference among them was significant and higher levels of total free phenol (133.47 mg•L-1) were detected in wine made from the berry in “V” training system, but no significant difference in which at vertical shoot positioning trellis (119.08 mg•L-1). The concentration of nonflavonoid compounds (100.13 mg•L-1-123.46 mg•L-1) was higher than flavonoid compounds (17.08-25.25 mg•L-1) in wine in different treatments, accounting for 81.08%-85.66% and 14.34%-18.92%, respectively. All of the 10 free phenols were detected in wine in different treatments, the primary flavonoids was catechin and the primary nonflavonoids was gallic acid. 【Conclusion】The concentration of total free phenol in wine increased with the decreasing number of shoots per meter. “V” training system can increase the concentration of total individual phenols in wine.

Key words: trellis systems, shoot density, Vitis viniferal L. cv. Cabernet Sauvignon, wine, free phenol