TY - JOUR T1 - Browning of White Wines and an Accelerated Test for Browning Capacity JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 157 LP - 160 DO - 10.5344/ajev.1976.27.4.157 VL - 27 IS - 4 AU - V. L. Singleton AU - T. E. Kramlinga Y1 - 1976/01/01 UR - http://www.ajevonline.org/content/27/4/157.abstract N2 - A standardized test for the browning capacity of white wines was developed. A portion of the wine is treated with 1 g of bentonite per 100 ml under nitrogen so that the developed brown pigment will stay in solution. Portions of the treated wine are incubated in sealed tubes with 25% or more headspace well sparged with oxygen and separately with nitrogen for 5 days at 55°C. The absorbance at 420 nm remains nearly unchanged for the N2-sparged samples and under oxygen measures wines' relative capacity to brown oxidatively. Evidence is presented that a wine well protected from oxidation is largely prevented from browning whereas a wine treated by adding d-catechin is considerably increased in its capacity to brown by this test. ER -