Rapid determination of flavonoids and phenolic acids in grape juices and wines by RP-HPLC/DAD: Method validation and characterization of commercial products of the new Brazilian varieties of grape

Abstract

A method for rapid determination of phenolic compounds by reversed-phase high-performance liquid chromatography (RP-HPLC), using a new column of faster resolution was validated and used to characterize commercial products produced with new grape Brazilian varieties of Northeast of Brazil. The in vitro antioxidant activity was also measured. The method showed linearity (R>0.9995), good precision (CV%<2.78), recovery (91.8-105.1%) and limits of detection (0.04-0.85mgL) and quantification (0.04-1.41mgL) according to other methods previously published with the difference of a run time of only 25min. The results obtained in the characterization of the samples differed for juices and wines from other world regions, mainly because of the high values of (-)-epigallocatechin and trans-caftaric acid. The products analyzed showed high antioxidant activity, especially the wine samples with values higher than those from wines of different regions of the world.

Simultaneous analysis of sugars and organic acids in wine and grape juices by HPLC: Method validation and characterization of products from northeast Brazil

“…The main varieties used in wine production are Cabernet Sauvignon, Syrah, Tempranillo, Touriga Nacional, Moscato Canelli, Chenin Blanc, Verdejo (Vitis vinifera L.) (Padilha et al, 2016). In recent years, in the SFV, there has also been investment in the production of grape juice from new Brazilian varieties developed for the preparation of high quality juices, such as Isabel Precoce (Vitis labrusca) and hybrids (V. labrusca x V. vinifera) BRS Violeta, BRS Cora and BRS Magna, and currently five companies produce around 1.5 million liters/ year of commercial juices with these varieties (Lima et al, 2014;Padilha et al, 2017).…”

Processing methods with heat increases bioactive phenolic compounds and antioxidant activity in grape juices

“…A new world region, the São Francisco Valley (SFV), in the northeast of Brazil, has been highlighted by the production of grape juices with typically Brazilian varieties of grape, such as "Isabel Perecoce" ( Vitis labrusca ) and the hybrids “BRS Violeta,” “BRS Cora,” and “BRS Magna” (Dutra, Rodrigues, et al, ). The SFV grape juices have high antioxidant activity associated with their phenolic compounds (Dutra, De Souza, et al, ; Lima et al, ; Padilha et al, ). One of the ways to evaluate the influence of factors such as processing methods, geographical origin, crop systems and grape varieties in the bioactive content and antioxidant activity of the juices have been through chemometrics techniques, such principal components analysis (PCA) (Granato et al, ; Granato, Koot, Schnitzler, & Ruth, ; Lima et al, ; Margraf, Santos, Andrade, & F., Van Ruth, S.M.…”

Development and validation of an analytical method for quantification of total flavonoids in Alternanthera brasiliana by ultraviolet-visible absorption spectrophotometry

“…Precision represents the dispersion of results between independent and repeated assays of the same sample, similar samples or standards, under defined conditions (Padilha et al, 2017). For the validation, the precision was considered in three distinct levels: repetitiveness (intra-run), intermediate precision (inter-run) and reproducibility (inter-laboratory).…”