Integrated analyses of phenolic compounds and minerals of Brazilian organic and conventional grape juices and wines: Validation of a method for determination of Cu, Fe and Mn

• Published in: Food chemistry Vol. 269; pp. 157 - 165
• Main Authors: Dutra, Maria da Conceição Prudêncio, Rodrigues, Lucicleide Leonice, de Oliveira, Débora, Pereira, Giuliano Elias, Lima, Marcos dos Santos
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.12.2018
• Subjects: Anthocyanins; Bioactive compounds; Brazil; Copper - analysis; Food analysis; Fruit; Hydrogen Peroxide; Iron - analysis; Manganese - analysis; Minerals; Minerals - analysis; Organic agriculture; Polyphenols - analysis; Vitis - chemistry; Vitis labrusca L; Wine - analysis; Brazil; Minerals; Food analysis; Organic agriculture; Bioactive compounds; Vitis labrusca L
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2018.07.014

•“Organic vs. conventional” grape juices and wines were characterized.•There was no difference in phenolics, antioxidant activity and Cu, Fe and Mn.•A method for transition metals Cu, Fe and Mn by FAAS was validated.•The method was adequate for characterization of grape juices and wines. The phenolic profile and antioxidant activity (AOX) of “organic vs. conventional” Brazilian wines and grape juices were analyzed. A simple method for the determination of minerals Cu, Fe and Mn by F-AAS was validated and used to characterize the samples studied. In the validation of the Cu, Fe and Mn determination method, the protocol for samples preparation by hot digestion with HNO3 + H2O2 proved to be more suitable for the grape juice and wine matrices. The validation parameters were considered satisfactory. Conventional products presented higher anthocyanins content, and no significant differences were observed on other phenolic compounds, AOX and Cu, Fe and Mn minerals. All the evaluated samples presented similar results between the same cultivars and in products from grapes of the two cultivation systems. The AOX of juices and wines, organic and conventional, was high, and correlated with procyanidin B1, petunidin-3-glucoside and cyanidin-3,5-diglucoside.