BRS Violeta (BRS Rúbea × IAC 1398-21) grape juice powder produced by foam mat drying. Part I: Effect of drying temperature on phenolic compounds and antioxidant activity.

The BRS Violeta grape presents pulp and skin with high content of phenolic compounds (PCs) and intense purplish color. It was used as raw material for the production of juice and dehydrated products using foam mat drying at 60, 70 and 80 °C and freeze drying (control). HLPC-DAD-ESI-MSn allowed the evaluation of the quantitative and qualitative changes of the main PCs (anthocyanins, flavonols and hydroxycinnamic acid derivatives (HCAD)) present in the grapes during the processing. The use of the steam extraction method to obtain grape juice allowed a greater extraction of flavonols and, mainly derivatives of hydroxycinnamic acids, when compared with anthocyanins. Drying at 70 °C was the most suitable for the preservation of the PCs and, at the same time, for the reduction of the processing time. The powdered products presented considerable concentrations of total PCs (3-5 mg/g) and antioxidant activity (32-79 (DPPH) or 17-27 (FRAP) mg/g).

Maria de Carvalho Tavares I ，Bonatto Machado de Castilhos M ，Aparecida Mauro M ，Mota Ramos A ，Teodoro de Souza R ，Gómez-Alonso S ，Gomes E ，Da-Silva R ，Hermosín-Gutiérrez I ，Silva Lago-Vanzela E ... -  《-》

Storage stability of the phenolic compounds, color and antioxidant activity of jambolan juice powder obtained by foam mat drying.

Jambolan (Syzigium cumini (L.) Skeels) stands out among the Brazilian fruits that are rich in bioactive compounds with potential for the production of dehydrated product. Therefore, jambolan juice powder was produced by foam mat drying method and stored for 150 days at three temperatures (4, 25, 35 °C). The effect of time, temperature and the interaction of these two factors on the qualitative and quantitative profile of phenolic compounds were determined after analysis of the powders by using HPLC-DAD-ESI-MSn. For the powders submitted to the different study condition, the concentration of flavonols did not differ from the control sample, and only a small reduction in the anthocyanins concentrations was seen (7-9%), only being significantly affected by storage time. Additionally, the molar profiles of these compounds were influenced more by time than storage temperature, however none of the compounds identified was totally degraded. The percentages of antioxidant activity oscillated during the storage time, however, without major losses after 150 days at all storage temperatures. The results showed that jambolan juice powder is very stable in terms of anthocyanins and flavonols concentrations at all three temperatures of the storage. This and the attractive color (purplish-red) make it a potential ingredient to enrich differentiated foods.

Tavares IMC ，Sumere BR ，Gómez-Alonso S ，Gomes E ，Hermosín-Gutiérrez I ，Da-Silva R ，Lago-Vanzela ES ... -  《-》

Effect of the pre-treatment and the drying process on the phenolic composition of raisins produced with a seedless Brazilian grape cultivar.

The grape is an important fruit regarding economic and health benefit parameters, because of its large consumption around the world and their bioactive phenolic compounds. The drying process of BRS Morena grapes, whether pre-treated or not with olive oil for producing raisins, resulted in qualitative and quantitative changes in their phenolic composition (anthocyanins, flavonols, stilbenes, hydroxycinammic acid derivatives, flavan-3-ols and proanthocyanidins). The raisins with the pre-treatment preserved more anthocyanins and proanthocyanidins than the raisins not pre-treated. Moreover, the total dehydration time accelerated by approximately 40% in the raisins pre-treated. Therefore, the production of raisins of BRS Morena grapes pre-treated with olive oil as a natural surfactant constitutes an interesting process from both the industrial and health points of view, because of the remarkable reduction in the processing time and the preservation of high concentrations of flavonoids, which have important claims to health benefits from biological activities.

Olivati C ，de Oliveira Nishiyama YP ，de Souza RT ，Janzantti NS ，Mauro MA ，Gomes E ，Hermosín-Gutiérrez I ，da Silva R ，Lago-Vanzela ES ... -  《-》

Phenolic compounds profile of different berry parts from novel Vitis vinifera L. red grape genotypes and Tempranillo using HPLC-DAD-ESI-MS/MS: A varietal differentiation tool.

The detailed phenolic composition of different berry parts from two novel V. vinifera L. red grape genotypes (Moribel and Tinto Fragoso), together the well-known Tempranillo, was established using high performance liquid chromatography-diode array detection-electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) over two consecutive vintages (2016 and 2017). More than 50 phenolic compounds were identified and quantified: 25 anthocyanins, 17 flavonols, 7 hydroxycinnamic acid derivatives, 2 stilbenes, and several flavan-3-ols. As far as we know, some anthocyanin and flavonol dihexosides were reported for the first time in V. vinifera L. grapes. Application of Principal Component Analysis (PCA) to experimental data showed a good separation of the novel grape genotypes and Tempranillo according to the phenolic profile of skins and seeds, mainly based on the proportion of trisubstituted anthocyanin derivatives, flavonols and flavan-3-ols, being a useful tool to differentiate these grape varieties.

Pérez-Navarro J ，Izquierdo-Cañas PM ，Mena-Morales A ，Martínez-Gascueña J ，Chacón-Vozmediano JL ，García-Romero E ，Hermosín-Gutiérrez I ，Gómez-Alonso S ... -  《-》

Dehydration of jambolan [Syzygium cumini (L.)] juice during foam mat drying: Quantitative and qualitative changes of the phenolic compounds.

Jambolan [Syzygium cumini (L.)] berries are a popular fruit in Brazil, renowned for their high phenolic compound (PC) content. These PCs have antioxidant, antibacterial, and other characteristics that may be beneficial to human health. The objective of the study was to evaluate the quantitative and qualitative changes of the main phenolic compounds (PCs) (anthocyanins, flavonols, and hydrolysable tannins) in the jambolan fruit, the produced fruit juice, and in the corresponding dehydrated powders obtained by foam mat drying (60, 70, and 80°C) and lyophilization (control). The PCs were analyzed using high-performance liquid chromatography with a diode array detection coupled with an electrospray ionization mass spectrometry (HPLC-DAD-ESI-MSn). Juice production resulted in a more pronounced degradation of anthocyanins than flavonols, and facilitated the extraction of hydrolysable tannins. Elevation of the dehydration temperature negatively impacted the anthocyanin content of the products; on the other hand, the flavonols and hydrolysable tannins were more sensitive to oxidation and heating time during dehydration, respectively, than dehydration temperature. In summary, it can be concluded that processing at 70°C is most suitable, in light of the least loss of nutritional quality of the product with processing time. This study directly informs further investigations into preparation of high-quality jambolan fruit products.

Iasnaia Maria de Carvalho T ，Nogueira TYK ，Mauro MA ，Gómez-Alonso S ，Gomes E ，Da-Silva R ，Hermosín-Gutiérrez I ，Lago-Vanzela ES ... -  《-》