Centro de Ciências Exatas e Tecnológicas
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/9791
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Item Chromatic characteristics and color-related phenolic composition of Brazilian young red wines made from the hybrid grape cultivar BRS Violeta (“BRS Rúbea” × “IAC 1398-21")(Food Research International, 2013-11) Ramos, Afonso Mota; Stringheta, Paulo César; Lago-Vanzela, Ellen Silva; Rebello, Ligia Portugal Gomes; Da-Silva, Roberto; García-Romero, Esteban; Gómez-Alonso, Sergio; Hermosín-Gutiérrez, IsidroThe color characteristics and the phenolic composition related to color of young red wines elaborated with the hybrid grape cultivar BRS Violeta, developed for its adaptation to sub-tropical climates in Brazil, have been studied. These wines are characterized with a deep red-purplish color, reaching color intensity averaging 24 units. In spite of being young red wines elaborated with short maceration time, their content in total polyphenols was very high (around 3692 mg/L, as gallic acid equivalents), especially when compared to similar Vitis vinifera young red wines. Within polyphenols, anthocyanins predominated (around 2037 mg/L, as malvidin 3,5-diglucoside equivalents) and they were almost exclusively anthocyanidin 3,5-glucosides (ca. 97%), mainly built from B-ring tri-substituted anthocyanidins (delphinidin > petunidin ≈ malvidin) and having high proportion of p-coumaroylated derivatives (ca. 28%) that confer higher stability. The content of hydroxycinnamic acid derivatives was also remarkable (ca. 95 mg/L, as caffeic acid equivalents) and unknown glucose derivatives of p-coumaric acid accounted for ca. 42% of total HCAD. Finally, these found flavonols were mainly based on myricetin whereas kaempferol derivatives were missing, their total content being within the ranges usually found for V. vinifera wines, but reaching their top values (ca. 91 mg/L, as quercetin 3-glucoside equivalents). All the aforementioned data suggest that Violeta wine could be considered an important dietary source of healthy polyphenols with a moderate alcoholic content (ca. 11.6%).Item Essential oils from pequi fruits from the brazilian Cerrado ecosystem(Food Research International, 2013-11) Geőcze, K. C.; Barbosa, L. C. A.; Fidêncio, P. H.; Silvério, F. O.; Lima, C. F.; Barbosa, M. C. A.; Ismail, Fyaz M. D.The composition of the essential oils of pequi fruits gathered from the Brazilian Cerrado ecosystem in the states of Maranhão (MA), Minas Gerais (MG) and Tocantins (TO) was investigated. The oils were obtained by steam distillation, and each component was speciated using GC-MS. The oil content varied from 0.13% to 1.15%. Interestingly, the major substance found within samples from two of the states was ethyl hexanoate (MA, MG), whereas isopropyl hexanoate and isopentyl-2-methylbutanoate were specific for the samples from TO. Both principal components analysis (PCA) and hierarchical cluster analysis (HCA) were used for exploratory analysis of the oils, and, consequently, the pequi fruits were classified according to their place of origin. The PCA showed that 51.5% of the variance accumulated in the PC1 and PC3, and the group formation obtained using HCA confirmed that the oil composition is influenced by geographic and/or plant genetic factors. Such analyses could assist in the selection of more flavoursome and healthy variants of pequi.Item Nanostructured hydrocerussite compound (Pb 3 (CO 3) 2 (OH) 2) prepared by laser ablation technique in liquid environment(Materials Research Bulletin, 2014-01) Felix, J. F.; Cunha, D. L. da; Pereira, G. F. C.; Aguiar, J. Albino; Azevedo, W. M. deThis article presents a chemical bottom-up synthesis of highly crystalline and nanostructured hydrocerussite (Pb3(CO3)2(OH)2) with hexagonal morphology prepared by laser ablation in liquid. The results demonstrate that is possible to use laser ablation in liquid to prepare complex chemical compounds. The experiment consisted of a high power second harmonic of an Nd:YAG laser incidence on the surface of a Pb target immersed in primary alcohols. Three different values of fluency and four different primary alcohols were used in order to investigate the influence of fluency delivered to the target surface and the chemical composition of the liquid environment on the properties of the prepared materials. Crystalline and nanostructured hexagonal particles of hydrocerussite, with average widths of 1.0 ± 0.3 μm and average thickness of 80 ± 20 nm, were obtained when laser ablation was done in methanol and ethanol whereas hydrocerussite and metallic lead were obtained when 1-propanol or 1-butanol were used. Additionally, it was shown that the values of the laser fluency used in this study do not modify the sample morphology and composition. In order to explain the observed results a photochemical reaction model induced by laser ablation of a metallic Pb surface immersed in alcohol solution is presented.Item Phenolic composition of the berry parts of hybrid grape cultivar BRS Violeta (BRS Rubea × IAC 1398-21) using HPLC–DAD–ESI-MS/MS(Food Research International, 2013-11) Rebello, Ligia Portugal Gomes; Lago-Vanzela, Ellen Silva; Barcia, Milene Teixeira; Ramos, Afonso Mota; Stringheta, Paulo César; Da-Silva, Roberto; Castillo-Muñoz, Noelia; Gómez-Alonso, Sergio; Hermosín-Gutiérrez, IsidroThe grape is considered a major source of phenolic compounds when compared to other fruits and vegetables, however, there are many cultivars with distinct characteristics directly linked to phenolic profile. Thus, the present study aimed to identify and quantify, for the first time and in detail, the phenolic compounds present in the skin, flesh and seeds of BRS Violeta grape berry using combination of SPE methodologies and analytical HPLC–DAD–ESI-MS/MS. The study was extended to the different berry parts and the most important grape and wine phenolic families, and has revealed interesting features. Violeta grape has a very thick skin (46% of grape weight) that accumulated the most of grape phenolic compounds: great amount of anthocyanins (3930 mg/kg, as malvidin 3,5-diglucoside), together with also important amounts of flavonols (150 mg/kg, as quercetin 3-glucoside), hydroxycinnamic acid derivatives (HCAD; 120 mg/kg, as caftaric acid), and proanthocyanidins (670 mg/kg, as (+)-catechin); in contrast, it seems to be a low resveratrol producer. Violeta grape seeds accounted for similar proportions of low molecular weight flavan-3-ols (mainly monomers; 345 mg/kg, as (+)-catechin) and proanthocyanidins (480 mg/kg, as (+)-catechin). Violeta grape is a teinturier cultivar, but it only contained traces of anthocyanins and low amounts of all the other phenolic types in its red-colored flesh. The anthocyanin composition of Violeta grape was dominated by anthocyanidin 3,5-diglucosides (90%). Within flavonols, myricetin-type predominated and kaempferol-type was missing. In addition to expected hydroxycinnamoyl-tartaric acids, several isomeric esters of caffeic and p-coumaric acids with hexoses were tentatively identified, accounting for relevant proportions within the pool of HCAD. Although pending of further confirmation over successive vintages, the aforementioned results suggest that BRS Violeta grape cultivar could be considered an interesting candidate for the elaboration of highly colored and antioxidant-rich grape juices and wines.