PT - JOURNAL ARTICLE AU - Jean C. Sapis AU - Jean J. Macheix AU - Robert E. Cordonnier TI - The Browning Capacity of Grapes. II. Browning Potential and Polyphenol Oxidase Activities in Different Mature Grape Varieties AID - 10.5344/ajev.1983.34.3.157 DP - 1983 Jan 01 TA - American Journal of Enology and Viticulture PG - 157--162 VI - 34 IP - 3 4099 - http://www.ajevonline.org/content/34/3/157.short 4100 - http://www.ajevonline.org/content/34/3/157.full SO - Am J Enol Vitic.1983 Jan 01; 34 AB - For a large number of grape varieties, browning potential and polyphenol oxidase activities were measured at maturity. Classification in accordance to these criteria was made. It was confirmed that polyphenol oxidase of the grape is a strongly bound enzyme and that browning is concentrated for a large part in the non-soluble fractions of the juice. Phenolic substrate appears to be the limiting factor in browning.