TY - JOUR T1 - Catecholase Activity in Australian White Grape Varieties JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 203 LP - 206 DO - 10.5344/ajev.1985.36.3.203 VL - 36 IS - 3 AU - Rodney L. Hooper AU - Graham G. Collins AU - Bryce C. Rankine Y1 - 1985/01/01 UR - http://www.ajevonline.org/content/36/3/203.abstract N2 - Catecholase activity, total phenolic content, initial optical density, and the browning capacity of grape juice from 14 white Vitis vinifera grape varieties were measured. Influence of site on these factors was studied for four of the varieties. Varietal differences, as well as some regional differences, were found for all measured variables. Catecholase activity was highest in Semillon and Traminer, and lowest in Rhine Riesling and Rkaziteli. Crouchen and Traminer were the most susceptible varieties to browning, while Sauvignon blanc was least susceptible. Although catecholase activity appeared to be an important factor in browning of juices, both the initial optical density, and, to a lesser extent, total phenolic content, also exerted some influence. A high proportion (63%) of the variability in browning by the juices examined could be explained by the interaction between catecholase activity, total phenol content, and initial absorbance of juices. Influence of clonal selection on browning is briefly discussed, as well as possible implications for the Australian white wine industry. ER -