Abstract This study aimed to optimize the extraction solvents for Bordo grape (Vitis labrusca) seeds by response surface methodology regarding to the antioxidant activity (AA) and trans-resveratrol content. Fatty acids (FA) and AA of the oil obtained by pressing cold method were also determined. The extraction optimization was determined by the statistical simplex-centroid mixing scheme, enabling the analysis of solvents effects (water, ethanol and acetone) and their mixtures on the responses. AA was performed by DPPH, ABTS and FRAP methods, and by total phenolic compounds and flavonoids. FA were determined by GC and trans-resveratrol by HPLC. The extracts containing ternary fraction of solvents showed greater AA, increasing about 20 times compared to pure solvent. The composition that showed the best response ranged between 45-48% of water, 14-20% of ethanol and 35-38% of acetone for both grape seeds, with polarity ranged from 0.705 to 0.706. The oil from seeds showed high concentrations of PUFA, particularly linoleic acid. The optimized extraction method improved the use of this residue as a potential antioxidant source for food industry.

Resumo A erva-mate possui compostos biologicamente ativos com aplicação industrial. Cafeína, rutina e ácido clorogênico presentes neste produto possuem atividade antioxidante e o último ainda é antimicrobiano. Este estudo objetivou avaliar a atividade biológica do extrato de erva-mate e quantificar compostos bioativos, bem como aplicar o extrato em hambúrguer de peixe para determinar seu poder conservante. A atividade antioxidante foi avaliada por DPPH (2,2-difenil-1-picrihidrazila) e FRAP (poder de redução do ferro). Foram quantificados compostos fenólicos totais e flavonoides por espectrofotometria, e cafeína, rutina e ácido clorogênico, por cromatografia líquida de ultraeficiência. A atividade antimicrobiana foi determinada pela concentração inibitória mínima (CIM). Testaram-se associações de extrato com o conservante sintético butil-hidroxi-anisol (BHA). Hambúrgueres de peixe foram incorporados com extrato de erva-mate e foram feitas análises de composição centesimal, oxidação lipídica e microbiológica por 28 dias. O extrato apresentou para DPPH IC50 de 7,91 µg mL-1, FRAP de 4.922,67 µmol de Fe (II) g-1, 104,54 EAG g-1 de fenólicos totais, 23,11 EQ g-1 de flavonoides e 49,6, 34,5 e 23,1 mg g-1 de ácido clorogênico, cafeína e rutina, respectivamente. O extrato mostrou CIM de 10, 5 e 10 mg mL-1 contra Escherichia coli, Staphylococcus aureus e Salmonella enterica, respectivamente. A combinação de extrato com BHA reduziu a quantidade de conservante sintético para a mesma atividade antioxidante e mostrou caráter aditivo para S. aureus. Os hambúrgueres de peixe com 1% de extrato ou com BHA exibiram diferença estatística na contagem de mesófilos em relação ao controle. Assim, observou-se que o extrato de erva-mate apresentou atividade biológica e o crescimento de mesófilos foi inibido nos hambúrgueres de peixe incorporados com BHA ou 1% de extrato, de forma que os compostos fenólicos quantificados seriam os prováveis agentes conservantes.

Abstract The yerba mate has a high content of biologically active compounds with industrial application. Caffeine, rutin and chlorogenic acid present in this product have antioxidant activity and the latter one is also an antimicrobial agent. This \paper aimed to assess the biological activity of yerba mate extract and quantify its bioactive compounds, as well as apply the extract in fish hamburger to determine its preservative activity. The antioxidant power was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power). Total phenolic compounds and flavonoids were quantified by spectrophotometry, and caffeine, rutin and chlorogenic acid by ultra-performance liquid chromatography. The antimicrobial activity was assessed by Minimum Inhibitory Concentration (MIC). Associations of extract with the synthetic preservative butyl hydroxyanisole (BHA) were tested. Fish hamburgers incorporated with yerba mate were prepared; centesimal composition, lipid and microbiological oxidation were carried out during 28 days. Results: DPPH IC50 of 7.91 µg mL-1 in the extract, FRAP of 4922.67 µmol for Fe (II) g-1, 104.54 EAG g-1 of total phenolics, 23.11 EQ g-1 of flavonoids, and 49.6, 34.5 and 23.1 mg g-1 of chlorogenic acid, caffeine and rutin, respectively. The extract presented a CIM of 10, 5 and 10 mg mL-1 against Escherichia coli, Staphylococcus aureus and Salmonella enterica, respectively. The combination of extract and BHA reduced the amount of synthetic preservative for the same antioxidant activity and presented an additive effect to S. aureus. The fish hamburgers with 1% of extract or with BHA showed statistical difference in mesophiles counting from the control group. Thus, the yerba mate extract presented biological activity and the growth of mesophiles was inhibited in fish hamburguers incorporated with BHA or 1% of extract, indicating that the quantified phenolic compounds are likely to be preservative agents.

Resumo As atividades antioxidante e antibacteriana, e a toxicidade de produtos naturais podem mudar de acordo com a variedade vegetal, bem como a parte da planta que é analisada. Neste estudo, foram analisadas cascas, polpas e sementes de quatro variedades de abacate (Quintal, Fortuna, Margarida e Hass) no que tange às propriedades antioxidantes e antibacterianas, e à toxicidade. Existem poucos estudos na literatura comparando essas três primeiras variedades. A atividade antioxidante foi medida utilizando-se os métodos DPPH (2,2-diphenyl-1-picrylhydrazil), ABTS [2,2'-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid)] e FRAP (Ferric Reducing Ability Power), juntamente com o conteúdo de compostos fenólicos e flavonoides. A análise de componentes principais foi aplicada para testes antioxidantes. A atividade antibacteriana contra patógenos alimentares foi avaliada pelos testes de concentração inibitória mínima e concentração bactericida mínima. A toxicidade foi avaliada contra Artemia salina e também pela atividade hemolítica. O extrato etanólico da casca da variedade Quintal apresentou a maior atividade antioxidante e antibacteriana. Este mesmo extrato não mostrou toxicidade nos testes preliminares e mostra grande potencial de aplicação na indústria de alimentos como um aditivo alimentar.

Abstract The antioxidant and antibacterial activity and toxicity of natural products can change according to plant variety, as well as the part of the plant which is analyzed. In this study, peel, pulp and seed of four avocado varieties (Quintal, Fortuna, Margarida, and Hass) were analyzed for antioxidant and antibacterial properties and toxicity. There are few studies in the literature comparing these three first varieties. Antioxidant capacity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazil), ABTS [2,2'-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid)], and FRAP (Ferric Reducing Ability Power) methods, along with the content of phenolic compounds and flavonoids. Principal component analysis was applied for antioxidant tests. Antibacterial activity against food pathogens was assessed by the minimum inhibitory concentration and minimum bactericidal concentration tests. Toxicity was evaluated against Artemia salina and also by hemolytic activity. The ethanolic extract of Quintal variety peel presented the greatest antioxidant and antibacterial activity. This same extract showed no toxicity in the preliminary tests, and shows great potential for food industry application as an additive.

Este estudo descreve a triagem de extratos obtidos de 19 espécies de plantas usadas na medicina tradicional brasileira para o tratamento de várias doenças. Os extratos foram testados contra formas amastigota axênica e promastigota de Leishmania (L.) amazonensis, e formas epimastigota de Trypanosoma cruzi in vitro na concentração de 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, e Tanacetum vulgare apresentaram efeito significante contra um ou ambos parasitas, com a porcentagem de inibição de crescimento entre 49,5 e 99%. Os extratos não mostraram efeito citotóxico em hemácias de carneiro. Essas plantas medicinais podem ser fontes alternativas de novos compostos clinicamente ativos contra L. amazonensis e T. cruzi.

This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L.) amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, and Tanacetum vulgare showed significant effects against one or both parasites, with a percentage of growth inhibition between 49.5 and 99%. The extracts showed no cytotoxic effect on sheep erythrocytes. These medicinal plants may be sources of new compounds that are clinically active against L. amazonensis and T. cruzi.