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.
Consumers are increasingly looking for healthy foods without the addition of synthetic additives. The aim of this study was to evaluate the efficiency of coffee extracts as a natural antioxidant in ...fresh pork sausage. Firstly, the conditions for obtaining coffee green extracts were optimized (Central Composite Rotatable Design 2
, variables: extraction time, ethanol-water ratio, and sample-solvent ratio) in an ultrasound bath (70 °C). The response variables were the bioactive compounds levels and antioxidant activity. Valid models were obtained (
≤ 0.05, R
> 0.751), with higher bioactive content and antioxidant activity in the central point region. Extracts of Robusta and Arabica coffee green (RG and AG) and medium roast (RR and AR) obtained, and central point (10 min, an ethanol concentration of 30%, and a sample-solvent ratio of 10 g/100 mL) and optimized (14.2 min, 34.2%, and 5.8 g/100 mL) parameters were characterized. The RG presented a significantly (
≤ 0.05) higher content of caffeine (3114.8 ± 50.0 and 3148.1 ± 13.5 mg/100 g) and 5-CQA (6417.1 ± 22.0 and 6706.4 ± 23.5 mg/100 g) in both extraction conditions, respectively. The RG and RR coffee presented the highest antioxidant activity. Two concentrations of RG and RR coffee extracts were tested in fresh pork sausage. The Robusta coffee extract presented the highest antioxidant activity in both roasted and green states. However, when applied to a meat product, the extract prepared with RG coffee showed better results, with efficiency in replacing synthetic antioxidants (content of malonaldehyde/kg of sample below 0.696 ± 0.059 in 20 days of storage), without altering the sensory attributes of the product (average scores above 7.16 ± 1.43 for all attributes evaluated). Therefore, the RG coffee extract was a suitable alternative as a natural antioxidant applied to fresh pork sausage.
The purpose of this study was to evaluate the effects of salinity and plant-based diet or animal-plant combination diet on the performance and metabolic status of juvenile Nile tilapia (Oreochromis ...niloticus). The experimental design was completely randomized in a 4 × 2 factorial scheme with four replicates. The treatments were established by the combination of salinities of 0, 10, 20, and 30 g L-1 with an animal-plant combination diet (AP) or plant-based diet (P). The replicates were 60 L tanks with 12 fish per tank. Diets were provided for 32 days, and the fish were fed three times a day (8, 12, and 17 h) until apparent satiety. Daily feed intake (DFI) was measured, body weight (BW) was recorded at the beginning and end of the trial, and total length (TL) and standard length (SL) were measured at the end of the trial. Average daily gain (ADG), specific growth rate (SGR), feed conversion ratio (FCR), and survival rate were calculated. After the biometric measurements were made at the end of the trial, blood samples were collected to determine the plasma concentrations of total protein (TP), glucose, cholesterol, and triglycerides (TG). The fish were euthanized, and the hepatopancreas was collected and weighed; thereafter, the hepatosomatic index (HSI) was calculated. An interaction was detected between salinity and diet type for final BW, ADG, TL, and SL. These traits were not influenced by salinity when it was associated with the AP diet, but reduced linearly with salinity in the P diet. DFI and survival rate were independently affected by salinity: DFI reduced linearly with salinity levels and survival rate was higher at a salinity of 10 g L-1. HSI increased linearly with salinity levels and was lower in the P diet than in the AP diet. Salinity had a quadratic effect on plasma TP, and the maximum value for this metabolite (2.96 g dL-1) is attained at a salinity of 10.26 g L-1. There was an independent effect of diet on the plasma concentrations of cholesterol and TG, which were lower in the P diet than in the AP diet. The salinity of 10 g L-1 associated with diet composed of animal and plant ingredients led to a better performance, higher survival rate, and less stressful environmental conditions for juvenile Nile tilapia.
Fatty acid methyl ester (FAME) preparation is an important step to determine fatty acid composition of oils and fats. Transesterification with boron trifluoride (BF sub( 3)) in methanol has been ...widely used; however, the transesterification of triacylglycerols usually involves a long heating time, whereas much shorter reaction times may be sufficient when microwave irradiation is used. The purpose of this paper was to optimize FAME preparation with BF sub( 3) by microwave irradiation. A three-factor central composite routable (CCRD) design was used to study the effect of the heating time (A), irradiation power (B), and volume of sodium hydroxide (C) on FAME concentration. A second-order polynomial model was employed to generate a surface response. Optimum conditions obtained for FAME preparation were time of 60 s, irradiation power of 220 W, and base volume of 1.5 mL. Compared to conventional methods, the advantages of this method are the quick result and the accuracy.
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.
In this work, the antimicrobial and antioxidant activity of some essential oils (EOs) and their synergistic effects with synthetic preservatives against foodborne pathogenic bacteria were evaluated. ...Nine EOs were screened against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella enterica serotype Typhi, and six of these were associated with methylparaben (MTP) and sodium metabisulfite (MTBS). Essential oils of cinnamon and oregano showed potential antibacterial activity. The combinations of cinnamon + MTP, coriander + MTP, and oregano + MTP, showed synergism against S. enterica ser. Typhi, E. coli, and S. aureus, respectively. Clove oils exhibited higher radical scavenging activity against DPPH. Moreover, clove leaves + MTP presented a synergistic antimicrobial interaction against E. coli and S. enterica ser. Typhi. These findings showed a reduction in the minimal inhibitory concentration (MIC) of the synthetic preservative with a low concentration of EOs, highlighting an alternative source as preservatives in embedded foods and derivatives for the food industry.
Novelty impact statement
The use of essential oils in combination with the synthetic preservative methylparaben (MTP) promoted synergistic antimicrobial effects against foodborne bacteria. The clove leaf oil showed synergism with MTP against Gram‐negative bacteria (FICI = 0.49) and high antioxidant activity (IC50 = 8.06 μg/ml), and this can be used as an alternative source for delaying the oxidative process and for the preservation of food products.
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.
O mercado de própolis brasileiro sofreu grande expansão, levando o setor de beneficiamento a buscar a melhor forma de produzir extratos com atividades biológicas. O objetivo deste trabalho foi ...otimizar a extração de própolis verde pela atividade antifúngica e realizar a incorporação em um biofilme de quitosana. Os extratos foram preparados utilizando etanol, acetona, acetato de etila e isopropanol, de acordo com três planejamentos, e a concentração inibitória mínima (CIM) e a concentração fungicida mínima (CFM) foram determinadas contra Candida albicans, Candida tropicalis e Candida glabrata. A partir da CIM, realizou-se a análise de superfície de resposta, para encontrar as condições ótimas de extração para cada planejamento. Os extratos otimizados foram incorporados em biofilmes de quitosana que, posteriormente, foram avaliados quanto a espessura, permeação de vapor de água, solubilidade em água e atividade anti-Candida. Verificou-se que todos os extratos testados apresentaram atividade antifúngica contra as três espécies de Candida. Destacou-se o extrato obtido com acetona/etanol que apresentou os menores valores de CIM e CFM (0,76 - 2,50 mg/mL). Observou-se que os pontos ótimos de extração de cada planejamento foram as misturas de: acetona/isopropanol, acetona/etanol e acetato de etila/isopropanol e os biofilmes incorporados com estes extratos mostraram poucas diferenças de espessura, permeabilidade de vapor e solubilidade em água em relação ao controle. O biofilme contendo extrato obtido por acetona/isopropanol foi o que demonstrou maior atividade anti-Candida. Estes resultados mostram a importância da otimização dos processos de extração de própolis para aplicação e desenvolvimento de produtos.
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.
PDF
