Effects of Vine or Bunch Shading on the Glycosylated Flavor Precursors in Grapes of Vitis vinifera L. Cv. Syrah

• Published in: Journal of agricultural and food chemistry Vol. 48; no. 4; pp. 1290 - 1297
• Main Authors: Bureau, Sylvie M, Baumes, Raymond L, Razungles, Alain J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.04.2000
• Subjects: Agriculture - methods; Agronomy. Soil science and plant productions; Alcohols - analysis; Biological and medical sciences; Economic plant physiology; Food engineering; Fruit; Fundamental and applied biological sciences. Psychology; Glycoconjugates - analysis; Glycosylation; Life Sciences; Nitrogen metabolism and other ones (excepting carbon metabolism); Nutrition. Photosynthesis. Respiration. Metabolism; Phenols - analysis; Rosales; Sunlight; Taste; Terpenes - analysis; Volatile compound; Light effect; Cultural practice; Berry; Environmental factor; Shadow; Sunshine; Isoprenoid; Vitis vinifera; Vitidaceae; Fruit crop; Dicotyledones; Grape; Angiospermae; Spermatophyta; Chemical composition; Glycoside; Aroma; Carotenoid; Secondary metabolism; Cultivar
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf990507x

Effects of the modification of vine or bunch environment on glycoconjugates were studied in Syrah berries over two years. Vines were shaded from berry set to maturity, with black polyethylene nets of different mesh size to obtain 30 and 50% of the direct sunlight. Bunches were naturally shaded by the leaves or artificially with 90% shade bags. Sun-exposed berries were chosen as control berries. A quantitative decrease in levels of glycoconjugates was observed in shaded bunches, particularly for phenolic and C13-norisoprenoidic glycosides. In the same way, vine shading caused a decrease in the contents of glycosides of terpenols, phenols, and C13-norisoprenoids in berries, but the grape environment (microclimate) affected the berry composition more than the vine environment. A cluster thinning experiment confirmed the independence of grapes with regard to the plant for the biosynthesis of the C13-norisoprenoid glycosides. Keywords: Vitis vinifera; shade; sun exposure; glycoconjugate; aroma