Milene Teixeira Barcia

Antioxidant activity of hydrophilic and lipophilic extracts of Brazilian blueberries.

Hydrophilic and lipophilic extracts of ten cultivars of Highbush and Rabbiteye Brazilian blueberries (Vaccinium corymbosum L. and Vacciniumashei Reade, respectively) that are used for commercial production were analysed for antioxidant activity by the FRAP, ORAC, ABTS and β-carotene-linoleate methods. Results were correlated to the amounts of carotenoids, total phenolics and anthocyanins. Brazilian blueberries had relatively high concentration of total phenolics (1,622-3,457 mg gallic acid equivalents per 100 g DW) and total anthocyanins (140-318 mg cyanidin-3-glucoside equivalents per 100 g DW), as well as being a good source of carotenoids. There was a higher positive correlation between the amounts of these compounds and the antioxidant activity of hydrophilic compared to lipophilic extracts. There were also significant differences in the level of bioactive compounds and antioxidant activities between different cultivars, production location and year of cultivation.

Phenolic composition of grape and winemaking by-products of Brazilian hybrid cultivars BRS Violeta and BRS Lorena.

The phenolic composition of grapes and winemaking by-products (skins from grape marc, and lees) from Brazilian hybrid cultivars BRS Violeta (red) and BRS Lorena (white) was studied. Two vintages, five classes of phenolic compounds, and recovery yields using three dehydration techniques were considered: oven-drying at 50°C (D50); spray-drying (SD); and freeze-drying (FD). Recovery yields were higher using FD, although less expensive SD was a good alternative for Violeta lees. D50 caused great recovery reduction in Violeta but yielded similar results for Lorena. Violeta winemaking by-products were excellent sources of anthocyanins (mainly non-acylated and p-coumaroylated diglucosides), flavonols (mainly myricetin-based) and hydroxycinnamic derivatives (mainly caffeic-based). Lorena winemaking by-products contained lesser amounts of phenolic compounds, around a tenth of the values found in Violeta grapes for flavonols (mainly quercetin-based), hydroxycinnamic derivatives (mainly caffeic-based) and condensed tannins. Lorena cultivar contained small amounts of trans-resveratrol and its 3-glucoside, which were missing in Violeta cultivar.

Comprehensive characterization of lipids from Amazonian vegetable oils by mass spectrometry techniques

An integrative approach in mass spectrometry (MS) comprising gas chromatography coupled to MS (GC-MS), ultra-efficiency liquid chromatography coupled to MS (UPLC-MS) and easy ambient sonic-spray ionization MS (EASI-MS) is proposed for the comprehensive characterization of Amazonian oils. Coconut, andiroba and castor seed oils, which are vastly sold in markets of the Amazonian region of Brazil, were selected as a representative test set. These oils were found to contain several lipids such as triacylglycerides (TAGs), fatty acids (FAs), phytosterols and limonoids. In the analyzed samples 30 different TAGs, 11 FAs, 6 phytosterols and 7 limonoids were identified. The antioxidant capacity (AOC) of the oils, as measured by their oxygen radical absorbance capacity (ORAC), was also used to evaluate their potential biological properties as well as their possible consumption as food. Edible virgin coconut oil was the most active (0.720±0.001 Trolox eq./mmol), whereas considerable lower activity was observed for andiroba and castor seed oils. The antimicrobial activities of the oils were also recorded against a panel of pathogenic bacteria and fungi in which andiroba oil was the only one that was active, solely against Enterococcus aeruginosa.

Polyphenol extraction optimisation from Ceylon gooseberry (Dovyalis hebecarpa) pulp

Originally from Asia, Dovyalis hebecarpa is a dark purple/red exotic berry now also produced in Brazil. However, no reports were found in the literature about phenolic extraction or characterisation of this berry. In this study we evaluate the extraction optimisation of anthocyanins and total phenolics in D. hebecarpa berries aiming at the development of a simple and mild analytical technique. Multivariate analysis was used to optimise the extraction variables (ethanol:water:acetone solvent proportions, times, and acid concentrations) at different levels. Acetone/water (20/80 v/v) gave the highest anthocyanin extraction yield, but pure water and different proportions of acetone/water or acetone/ethanol/water (with >50% of water) were also effective. Neither acid concentration nor time had a significant effect on extraction efficiency allowing to fix the recommended parameters at the lowest values tested (0.35% formic acid v/v, and 17.6 min). Under optimised conditions, extraction efficiencies were increased by 31.5% and 11% for anthocyanin and total phenolics, respectively as compared to traditional methods that use more solvent and time. Thus, the optimised methodology increased yields being less hazardous and time consuming than traditional methods. Finally, freeze-dried D. hebecarpa showed high content of target phytochemicals (319 mg/100g and 1,421 mg/100g of total anthocyanin and total phenolic content, respectively).

Biochemical Characterization of Dovyalis hebecarpa Fruits: A Source of Anthocyanins with High Antioxidant Capacity

UNLABELLED Dovyalis hebecarpa, which is also known as the Ceylon gooseberry, is an attractive exotic purple berry that is produced in the southwest of Brazil with high yields. Current literature lacks information about the nutritional composition and antioxidant capacity of this fruit. As such, this work aimed to evaluate and compare the proximate composition, phytochemical content, and antioxidant capacity of D. hebecarpa over two seasons through the application of a range of different methods, including FRAP, ABTS, and ORAC assays. The proximate composition and biometric parameters were monitored for quality purposes. The results significantly changed between seasons in accordance with variations in rain incidence and average temperatures. The Ceylon gooseberry contained a similar or higher content of anthocyanins (ACY) than other berries commonly consumed in human diet. These ACY were identified at higher levels in the fruits skin (284 to 351 mg of cyanidin-3-glucoside equivalents/100 g of fresh weight [FW]) than in its pulp (49 to 69 mg/100 g of FW). The use of an ORAC assay identified higher antioxidant activity (145 μmol of Trolox equivalents [TE]/g in the skins and 179 μmol of TE/g in the pulp on a FW basis) than all other methods used to determine antioxidant activity. Thus, D. hebecarpa is a rich source of ACY that demonstrates high antioxidant activity against the peroxyl radicals formed in ORAC assay conditions. PRACTICAL APPLICATION Ceylon gooseberry fruit is a source of phytochemicals that could be used in the human diet providing defense against free radicals damage. Moreover, the skins of the fruit, which are not typically consumed, contained higher levels of polyphenols than the pulp. This indicates that the skins of the Ceylon gooseberry may represent a promising source of natural pigments and antioxidants for industrial applications.

Effect of drying methods on the phenolic content and antioxidant capacity of Brazilian winemaking byproducts and their stability over storage

Abstract This work aimed to study the antioxidant capacity by different methods, the total content of polyphenols and the stability over time of dried byproducts from Brazilian hybrids and Vitis vinifera varieties. Oven-dried at 50 °C and spray-dried samples were monitored for 90 days of storage. Under testing conditions, BRS Violeta grapes showed the greatest stability and initial high levels of total phenolics and anthocyanins remained almost unchanged until the end of storage period. The same behavior was observed in BRS Violeta freeze-dried skins, seeds and lees (8557, 9520 and 4261 mg GAE/100 g DM, respectively, and 829 and 257 mg mv-3-glc/100 g DM in skin and lees, respectively). In all methodologies tested, BRS Violeta also showed higher values for antioxidant capacity. These results suggest that dried winemaking byproducts can be used as rich sources of polyphenol compounds for industrial extractions with high stability and antioxidant capacity.