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.

Objetivou-se com este trabalho avaliar o efeito das formas de processamento e do alecrim na defumação dos troncos e filés sem pele de tilápia do Nilo sobre o rendimento e as características organolépticas. Independente da forma de processamento aplicada, os filés defumados na presença do alecrim apresentaram menor rendimento. Foi também observado que os filés obtidos a partir dos troncos defumados proporcionaram maiores rendimentos. Analisando a forma de processamento dos filés defumados, os provadores apresentaram maior aceitação para filés (FIL) (2,88) em relação aos filés a partir dos troncos defumados (FTD) (2,63). A presença de alecrim nos filés, independente da forma de obtenção do produto final, não foi significativo para aparência, cor, aroma e aceitação geral, em que as notas transformadas variaram de 2,70 a 2,77. Em relação às análises organolépticas das porções do defumado, a preferência foi maior para o consumo dos FIL em relação aos FTD. Os provadores não notaram diferenças quanto ao acréscimo de alecrim aos FIL e FTD, exceto para teor de sal.

The object of this study was to evaluate the rosemary effect on smoking of skin-less torso and fillets of Nile tilapia on yield and organoleptic characteristics. Independent of processing form applied, the smoked fillets in the rosemary presence presented smaller yield. It was also observed in the fillets from smoked torso than presented greater yield. With regard the processing forms of smoked fillets, the tasters had presented greater acceptance to fillets (FIL) (2.88) compared to fillets from smoked torso (FST) (2.63). The presence of rosemary on fillet independent of attainment form of final product was not significative to appearance, color, aroma and general acceptance, where the marks transformed was rather between 2.70 to 2.77. With regards to organoleptic analyses of smoked fillets portions, the preference was better to FIL compared to FST. The tasters had not noticed significative differences with rosemary addition to FIL and FST, except to salt rate.