title: Cooking impact in color, pigments and volatile composition of grapevine leaves (Vitis vinifera L. var. Malvasia Fina and Touriga Franca).
abstract: Grapevine leaves (Vitis vinifera L. var. Malvasia Fina and Touriga Franca) under culinary treatment (blanching and boiling at 60, 75 and 90min) were studied for their color, pigments and volatile fraction changes. Blanching and boiling caused a decrease in luminosity and a loss of green coloration in both varieties, while a yellow-brownish color arose. Significant correlations were established between the loss of green color (monochromatic variable a∗) and the total chlorophylls content. The main volatiles in fresh leaves [(Z)-3-hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate] were drastically reduced by blanching and suppressed by boiling. Other compounds like pentanal and 6-methyl-5-hepten-2 one arose from blanching and boiling. A boiling time of 60min is adequate for the culinary process of grapevine leaves, since the product is considered edible and the pigments and volatile changes are not as drastic as observed at 75 and 90min of boiling.
authors.affiliation: School of Agriculture, Polytechnic Institute of Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal; Universidade Tecnológica Federal do Paraná, Campus Medianeira, Avenida Brasil, 4232, Bairro Independência, CEP 85884-000 Medianeira, Paraná, Brazil.
authors.forename: Adriano
authors.initials: A
authors.lastname: Lima
authors.affiliation: REQUIMTE/LAQV, School of Agriculture, Polytechnic Institute of Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal.
authors.forename: José Alberto
authors.initials: JA
authors.lastname: Pereira
authors.affiliation: Universidade Tecnológica Federal do Paraná, Campus Medianeira, Avenida Brasil, 4232, Bairro Independência, CEP 85884-000 Medianeira, Paraná, Brazil.
authors.forename: Ilton
authors.initials: I
authors.lastname: Baraldi
authors.affiliation: REQUIMTE/LAQV, School of Agriculture, Polytechnic Institute of Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal. Electronic address: rmalheiro@ipb.pt.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Malheiro
mesh_terms: D000085:Acetates / Q000032:analysis; D000447:Aldehydes / Q000032:analysis; D003116:Color; D003296:Cooking; D000441:Hexanols / Q000032:analysis; D010860:Pigments, Biological / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D027843:Vitis / Q000737:chemistry*; D014835:Volatilization
chemical_list: D000085:Acetates; D000447:Aldehydes; D000441:Hexanols; D010860:Pigments, Biological; C051918:3-hexen-1-ol; C586688:3-hexenal; C425828:3-hexenylacetate
keywords: Blanching; Boiling; Composition; Grapevine leaves; Volatile profile