Changes in phytochemical composition of Merlot grape and wine induced by the direct application of boron.

In this study the effect of the direct application of different concentrations of boron in grape bunches on the phytochemical composition of grapes and wine was evaluated. The experiment was carried out by direct application to the grape bunch of different concentrations (0, 1.0, 2.0, 4.0 and 8.0 g/L) of boron solution, in two consecutive vintages, 2018 and 2019. The wines were elaborated by the same microvinification method. Histological analyzes by optical microscopy and phenolic profile by HPLC-DAD were performed on the grapes. The wines were analyzed by HPLC-DAD and ICP-MS for phenolic profile and elemental composition, respectively. Histological analyzes of the grape skin showed an increase in the presence of polyphenols in the cellular tissue of grapes treated with different concentrations of boron when compared to the control samples in both vintages. The addition of boron influenced the phenolic profile of the grapes, resulting in an increase in the content of anthocyanins and flavanols. Regarding to wines, the treatment of grapes by direct application of boron significantly influenced the chemical composition of wines. In 2018, the application of 2 g/L of boron showed a significant increase in the concentration of malvidin and delphinidin in wines. The application of 1 g/L showed the highest concentration of malvidin, delphinidin and peonidin in the 2019 vintage. The boron content increased in the wine samples according to the boron concentrations applied to the grape. Thus, it is possible to produce chemically distinct wines with the direct application of boron to the grapes.

Cassava-based materials for matrix solid phase dispersion: An alternative for sample preparation in food analysis.

Cassava-based food ingredients were evaluated as candidate materials to be used as matrix solid phase dispersion (MSPD) for sample preparation. Cassava starch, tapioca, and tapioca pearls (TP) were applied in MSPD sample preparation of several food matrices such as mussels, fish, cooked ham, sausages, and animal feed (laying mash) for the determination of pharmaceuticals, preservatives, and polycyclic aromatic hydrocarbons by liquid chromatography coupled to tandem mass spectrometry or capillary electrophoresis. The performance of the new cassava-based solid phases was compared to other materials, such as diatomaceous earth, cellulose, cork powder, and a commercial polymer (Q-matrix® Hydra). The following parameters were used to select the most appropriate solid phases for each assay: fat removal, accuracy for certified reference material analysis, interferents presence in blank samples extract, signal to noise ratio, signal enhancement, and signal suppression. Best results were observed for cassava starch, except for nitrite and nitrate analysis, where the use of cellulose have led to the best sample preparation performance. Electronic microscopy of the materials and the mixture matrix and solid phase confirmed the adequate dispersion of the matrix on cassava starch. In conclusion, cassava-based solid phases were suitable for MSPD, allowing cheaper, greener, and abundant alternatives to sample preparation.