Luiz Claudio Corrêa

Phenolic compounds, organic acids and antioxidant activity of grape juices produced from new Brazilian varieties planted in the Northeast Region of Brazil

The phenolic compounds, organic acids and the antioxidant activity were determined for grape juice samples from new Brazilian varieties grown in the Sub-middle São Francisco Valley in the Northeast Region of Brazil. The results showed that the Brazilian grape juices have high antioxidant activity, which was significantly correlated with the phenolic compounds catechin, epicatechin gallate, procyanidin B1, rutin, gallic acid, caffeic acid, p-coumaric acid, pelargonidin-3-glucoside, cyanidin-3-glucoside, cyaniding-3,5-diglucoside and delphinidin-3-glucoside. The produced juice samples showed higher concentrations of trans-resveratrol than those observed in juices made from different varieties of grapes from traditional growing regions. Organic acids concentrations were similar to those of juices produced from other classical varieties. It was demonstrated that it is possible to prepare juices from grapes of new varieties grown in the Northeast of Brazil containing a high content of bioactive compounds and typical characteristics of the tropical viticulture practised in the Sub-middle São Francisco Valley.

Phenolic compounds, organic acids and antioxidant activity of grape juices produced in industrial scale by different processes of maceration

The effect of maceration process on the profile of phenolic compounds, organic acids composition and antioxidant activity of grape juices from new varieties of Vitis labrusca L. obtained in industrial scale was investigated. The extraction process presented a high yield without pressing the grapes. The use of a commercial pectinase resulted in an increase on extraction yield and procyanidins B1 and B2 concentrations and a decrease on turbidity and concentration of catechins. The combination of 60 °C and 3.0 mL 100 kg(-1) of enzyme resulted in the highest extraction of phenolic compounds, reducing the content of acetic acid. The juices presented high antioxidant activity, related to the great concentration of malvidin, cyanidin, catechin and caffeic, cinnamic and gallic acids. Among the bioactive compounds, the juices presented high concentration of procyanidin B1, caffeic acid and trans-resveratrol, with higher levels compared to those reported in the literature.

Bioactive compounds of juices from two Brazilian grape cultivars

BACKGROUND Grape juice consumption may prevent several chronic diseases owing to the presence of phenolic compounds, which have an important role in the reduction of oxidative stress. This study investigated the polyphenol content and antioxidant activities of grape juices from two cultivars: BRS-Cora and Isabella. Total polyphenol content (TPC), anthocyanins, antioxidant capacity (oxygen radical absorbance capacity, ferric reducing antioxidant power and 1,1-diphenyl-2-picrylhydrazyl), and phenolic profile (high-performance liquid chromatography with diode array and fluorescence detection--HPLC-DAD-FLD) were determined. RESULTS BRS-Cora grape juice showed higher concentrations of total polyphenols and anthocyanins, as well as higher antioxidant potential, than those of Isabella grape juice. A significant positive correlation was found in TPC or anthocyanin contents when correlated with the remaining antioxidant assays. In addition, HPLC-DAD-FLD showed a higher total phenolic content in BRS-Cora grape juice compared to Isabella. CONCLUSION The present results show BRS-Cora as a promising cultivar for grape juice production with an improved functional potential.

Polyphenols, antioxidants, and antimutagenic effects of Copaifera langsdorffii fruit.

Copaifera langsdorffii (copaiba) is a Brazilian exotic fruit, poorly studied regarding its bioactive composition. The aim of this study was to determine bioactive compounds, antioxidant and antimutagenic activities of copaiba pulp. The samples were extracted with different solvents in order to analyze polyphenol compounds (Folin Ciocalteau and HPLC-DAD), total flavonoids (reaction with AlCl3) and antioxidant capacity (FRAP, ORAC, DPPH). The copaiba fruit showed high polyphenol content and antioxidant capacity. Phenolic compounds, such as gallic acid, epicatechin gallate, catechin, epicatechin and isoquercitrin, were identified in the copaiba pulp. Despite the antioxidant capacity, the highest dose of copaiba showed no antimutagenic effects in the in vivo study. The dose which showed antimutagenic activity was 100 mg kg(-1).

Phenolics from Winemaking By‐Products Better Decrease VLDL‐Cholesterol and Triacylglycerol Levels than Those of Red Wine in Wistar Rats

Winemaking by-products account for more than 30% of the grape production, but this inexpensive feedstock has not yet been fully exploited. Accordingly, we evaluated the potential biological activity of winemaking by-products produced with Syrah grapes in comparison with those of the wine produced using the same grape cultivar. Winemaking by-products showed higher contents of total anthocyanins, flavonols, stilbenes, and flavanols than red wine as evaluated by HPLC-DAD-FD (on a dry weight basis). In contrast, red wine was a better source of phenolic acids. However, the contribution of phenolic acids was minor for both samples. Furthermore, equivalent concentration of winemaking by-products (100 mg/kg/d) showed greater biological activity by than that of red wine by decreasing the levels of VLDL-cholesterol and triacylglycerols in Wistar rats. Therefore, this study supports the use of winemaking by-products as an economical source of bioactive phenolics with potential use in the food and nutraceutical industries.