M. Vizzotto

Caracterização físico-química e capacidade antioxidante de pitanga (Eugenia uniflora L.)

Este estudo foi realizado para obter mais informacoes sobre as propriedades fisico-quimicas, composicao e atividade antioxidante de frutos de pitanga (Eugenia uniflora L.), especialmente os do Rio Grande do Sul (Brasil). Foram comparadas pitangas com diferentes coloracoes de polpa (roxa, vermelha e laranja) de selecoes cultivadas na Embrapa Clima Temperado (RS-Brasil). Foram observadas pequenas diferencas nos parâmetros de qualidade e na composicao centesimal e de acidos graxos entre as frutas com diferentes coloracoes de polpa. Os extratos de pitanga roxa apresentaram maiores conteudos totais de fenolicos e de antocianinas, bem como, a maior capacidade antioxidante. A capacidade antioxidante (valores de DPPH e FRAP) dos extratos metanolicos de pitanga apresentou alta correlacao com o conteudo de fenolicos totais, mas nos extratos etanolicos, o conteudo de antocianinas correlacionou-se apenas com a capacidade antioxidante avaliada pelo metodo de FRAP. A pitanga de cor laranja apresentou maiores teores de β-criptoxantina e β-caroteno, enquanto que a de cor vermelha continha alto teor de licopeno. Os resultados indicam que a pitanga de cor roxa, cultivada no Rio Grande do Sul, e uma fonte rica de compostos fenolicos e possui alta capacidade antioxidante. As de cor vermelha e laranja, por outro lado, sao fontes ricas de carotenoides.

Antioxidant capacity and composition of pitanga seeds

Food industry generates a significant amount of seed wastes from the juice production, frozen pulps and jams. Considering that the characterization of wastes is the first step to determine their potential use, the aim of the present study was to determine the composition and the antioxidant capacity of seeds from pitanga fruits with different flesh colors (purple, red and orange). Chemical composition results revealed that pitanga seeds are a good source of insoluble dietary fiber, with low protein and fat levels, and no relevant differences were found among pitanga seeds from different flesh colors. Pitanga seed extracts had powerful antioxidant capacity that was partially correlated to their high phenolic content and showed some variation according to the pitanga flesh colors. Accordingly, it’s suggested that this low value waste of pitanga processing, could be used as a source of natural antioxidants and dietary fiber, for animal and/or human nutrition.

Preventive supplementation with fresh and preserved peach attenuates CCl4-induced oxidative stress, inflammation and tissue damage

The present study was elaborated to comparatively evaluate the preventive effect of different peach-derived products obtained from preserved fruits (Syrup and Preserve Pulp Peach [PPP]) and from fresh peels and pulps (Peel and Fresh Pulp Peach [FPP]) in a model of liver/renal toxicity and inflammation induced by carbon tetrachloride (CCl4) in rats. Tissue damage (carbonyl, thiobarbituric acid reactive species and sulfhydril), antioxidant enzymes activity (catalase and superoxide dismutase) and inflammatory parameters [tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels, and receptor for advanced glycation end-products (RAGE) and nuclear factor (NF)κB-p65 immunocontent] were investigated. Our findings demonstrated that Peel, PPP and FPP (200 or 400 mg/kg) daily administration by oral gavage for 30 days conferred a significant protection against CCl4-induced antioxidant enzymes activation and, most importantly, oxidative damage to lipids and proteins as well as blocked induction of inflammatory mediators such as TNF-α, IL-1β, RAGE and NFκB. This antioxidant/anti-inflammatory effect seems to be associated with the abundance of carotenoids and polyphenols present in peach-derived products, which are enriched in fresh-fruit-derived preparations (Peel and FPP) but are also present in PPP. The Syrup - which was the least enriched in antioxidants - displayed no protective effect in our experiments. These effects cumulated in decreased levels of transaminases and lactate dehydrogenase leakage into serum and maintenance of organ architecture. Therefore, the herein presented results show evidence that supplementation with peach products may be protective against organ damage caused by oxidative stress, being interesting candidates for production of antioxidant-enriched functional foods.

Quantification of Several Bioactive Compounds and Antioxidant Activities of Six Cultivars of Brazilian Blueberry

The Bioactive composition of blueberries has attracted interest as a potential source of beneficial bioactive compounds, especially polyphenols, because the consumption of plant phenolics and others bioactive compounds has been recognized as lowering the risk of aging-associated diseases. Berries such as the Brazilian blueberry (Vaccinium ashei Reade) are increasingly cultivated throughout the world. In Brazil, its cultivation is rather recent and not well- known. However, Brazil has an ideal climate and has a great potential for increasing production. The study aimed to identify and quantify the major bioactive compounds in the skin, pulp and entire fruit of six Brazilian blueberry cultivars belonging to the group Rabbiteye, and to evaluate its antioxidant activity. Determinations of L-ascorbic acid, tocopherols, phenolics, individual carotenoids and antioxidant activity were done. These determinations were made on Powderblue, Briteblue, Bluebelle, Climax, Delite and Woodard cultivars, provided by Embrapa Clima Temperado, Pelotas-RS. The blueberry fruits are rich sources of phenolic compounds but other bioactive compounds such as tocopherols, carotenoids and vitamin C also were found. All phytochemicals analyzed, with the exception of some phenolic acids, were found at high levels in the peels (or skin) of blueberry cultivars tested, due to its function as plant protector, resulting in a higher antioxidant activity of fruit peel.

Effects of different products of peach (Prunus persica L. Batsch) from a variety developed in southern Brazil on oxidative stress and inflammatory parameters in vitro and ex vivo

Antioxidant, anti-glycation and anti-inflammatory activities of fresh and conserved peach fruits (Prunus persica L. Batsch) were compared. Fresh peach pulps, peels, preserve peach pulps and the preserve syrup were prepared at equal concentrations. Rat liver, kidney and brain cortex tissue slices were pre-incubated with peach samples, subjected to oxidative stress with FeSO4 and hydrogen peroxide. Fresh peach pulps and peel conferred higher protection against cytotoxicity and oxidative stress than preserve peach pulps in most tissues. Release of tumor necrosis factor-α and interleukin-1β was also significantly decreased by Fresh peach pulps and peel, followed by preserve peach pulps. Total phenolic determination and HPLC analysis of carotenoids showed that the content of secondary metabolites in Fresh peach pulps and peel is significantly higher than in preserve peach pulps, while the syrup had only small or trace amounts of these compounds. Fresh peach pulps and Peel demonstrated high antioxidant and anti-inflammatory effects preventing against induced damage.

Amora-preta (Rubus sp.): otimização do processo de extração para determinação de compostos fenólicos antioxidantes

ABSTRACT - Considering that several phenolic compounds found in blackberry are beneficial to human health because of its antioxidant action, this study was conducted in order to optimize its extraction process for analysis. Samples were subjected to different extraction process: solvent, soaking time, solvent mixtures and acidified solvents. There were no differences in the results for volume of solvent, maceration time, sol-vent mixtures and acidification for the content of phenolic compounds; however, among the tested solvents, acetone was more efficient for extraction of phenolic compounds. The antioxidant activity was not affected by maceration time and the solvent mixtures; however the volume, the type of solvent and its acidification affected the antioxidant activity. Index terms : bioactive compounds, small fruits, extraction conditions. INTRODUCAO O cultivo comercial da amora-preta teve inicio na Europa, no seculo 17, quando a cultivar Evergreen foi selecionada a partir de material nativo e, a partir dai, espalhou-se para diversos paises. No Brasil, as primeiras plantas foram introduzidas em 1972, pela Embrapa Clima Temperado, de Pelotas (RS), que selecionou cultivares adaptadas, a partir de material oriundo da Universidade de Arkansas (EUA). No Rio Grande do Sul, a amoreira-preta tem tido grande aceitacao pelos produtores, devido ao baixo custo de producao, facilidade de manejo, rusticidade e pouca utilizacao de defensivos agricolas (ANTUNES, 2002).Os fitoquimicos, encontrados naturalmente em frutas e hortalicas, apresentam efeitos beneficos

Antioxidant, antihyperglycemic, and antidyslipidemic effects of Brazilian-native fruit extracts in an animal model of insulin resistance

ABSTRACT Objective: Insulin resistance (IR) plays an important role in the development of many diseases, such as diabetes mellitus. Therefore, the aim of the present study was to evaluate the effects of the extracts from fruits native to Brazil on metabolic parameters and hepatic oxidative markers in an animal model of insulin resistance induced by dexamethasone (DEX). Methods: Wistar rats received water or extracts of Eugenia uniflora or Psidium cattleianum, once a day for 21 days. For the last 5 days, the rats received an intraperitoneal injection of saline or DEX. Results: DEX caused a reduction in body weight gain and relative pancreatic weight, as well as glucose intolerance, and an increase in serum glucose and triacylglycerol levels. The extracts were found to prevent hyperglycemia and hypertriglyceridemia. DEX caused an increase in the levels of thiobarbituric acid-reactive substances and reactive oxygen species production in the liver of rats, and both extracts prevented these changes. In addition, hepatic glutathione peroxidase activity was reduced by DEX. However, total thiol content and activities of catalase, superoxide dismutase, and delta-aminolevulinate dehydratase were not altered in any of the tested groups. Conclusion: Fruit extracts of E. uniflora and P. cattleianum exhibited considerable antihyperglycemic, antidyslipidemic, and antioxidant effects, and may be useful in the therapeutic management of alterations due to IR.

Effect of nanoencapsulation using PLGA on antioxidant and antimicrobial activities of guabiroba fruit phenolic extract

Guabiroba fruit has been highlighted for its high phytochemical content, particularly of phenolic compounds. The stability, bioavailability, and bioactivity of these compounds can be enhanced by nanoencapsulation, to improve functionality. Poly(d,l-lactic-co-glycolic) acid (PLGA) nanoparticles containing phenolic extract of guabiroba (GPE) were synthesized by an adapted emulsion-evaporation method and their physico-chemical and functional properties were studied at two lactic to glycolic acid ratios (50:50 and 65:35). Higher (P<0.05) or equivalent antioxidant capacity compared to free GPE were observed for GPE-loaded nanoparticles. Free extract and PLGA nanoparticles were effective inhibitors of Listeria innocua, with lower (P<0.05) GPE concentrations required for inhibition when nanoencapsulated. Also, reduction of ROS generation in non-cancer cells was achieved with lower GPE concentrations (P<0.05) after encapsulation. These results suggest that PLGA nanoparticles can be used as a delivery system for phenolic compounds at lower levels than originally required for enhanced functional properties.

Eugenia uniflora fruit (red type) standardized extract: a potential pharmacological tool to diet-induced metabolic syndrome damage management

The aim of this study was to investigate the effect of Eugenia uniflora fruit (red type) extract on metabolic status, as well as on neurochemical and behavioral parameters in an animal model of metabolic syndrome induced by a highly palatable diet (HPD). Rats were treated for 150days and divided into 4 experimental groups: standard chow (SC) and water orally, SC and E. uniflora extract (200mg/kg daily, p.o), HPD and water orally, HPD and extract. Our data showed that HPD caused glucose intolerance, increased visceral fat, weight gain, as well as serum glucose, triacylglycerol, total cholesterol and LDL cholesterol; however, E. uniflora prevented these alterations. The extract decreased lipid peroxidation and prevented the reduction of superoxide dismutase and catalase activities in the prefrontal cortex, hippocampus and striatum of animals submitted to HPD. We observed a HPD-induced reduction of thiol content in these cerebral structures. The extract prevented increased acetylcholinesterase activity in the prefrontal cortex caused by HPD and the increase in immobility time observed in the forced swim test. Regarding chemical composition, LC/MS analysis showed the presence of nine anthocyanins as the major compounds. In conclusion, E. uniflora extract showed benefits against metabolic alterations caused by HPD, as well as exhibited antioxidant and antidepressant-like effects.

Genetic variability for synthesis of bioactive compounds in peppers (Capsicum annuum) from Brazil

The objective of this study was to evaluate the genetic variability for synthesis of bioactive compounds in pepper ( Capsicum annuum, Solanaceae). Total phenolics, anthocyanins, carotenoids and antioxidant activity were evaluated in 14 accessions of Capsicum annuum from the Capsicum Genebank of Embrapa Temperate Agriculture (Pelotas – RS, Brazil). Thirty plants of each accession were cultivated in the field during spring and summer. The experimental design was a complete randomized block with 14 treatments (accessions) and three replications. The laboratory evaluations followed the same experimental design to field, but with two repetitions more. Seeds were discarded and opposite longitudinal portions of fruits were manually prepared for chemical analyzes. The data obtained showed high genetic variability for phenolics, anthocyanins, carotenoids and antioxidant activity. The P39, P77, P119, P143 and P302 accessions exhibited the highest levels of antioxidants, which are strongly indicated to be used in breeding programs of Capsicum peppers.