21 results on '"Estevinho, Leticia M."'
Search Results
2. Revolutionizing fruit juice: exploring encapsulation techniques for bioactive compounds and their impact on nutrition, flavour and shelf life
- Author
-
Gómez-Gaete, Carolina, Avendaño-Godoy, Javier, Escobar-Avello, Danilo, Campos-Requena, Víctor H., Rogel-Castillo, Cristian, Estevinho, Leticia M., Martorell, Miquel, Sharifi-Rad, Javad, and Calina, Daniela
- Published
- 2024
- Full Text
- View/download PDF
3. Quality of bee pollen submitted to drying, pasteurization, and high-pressure processing – A comparative approach
- Author
-
Anjos, Ofélia, Seixas, Natália, Antunes, Carlos A.L., Campos, Maria Graça, Paula, Vanessa, and Estevinho, Letícia M.
- Published
- 2023
- Full Text
- View/download PDF
4. Fermented Grapevine Leaves: Potential Preserving Agent in Yogurt.
- Author
-
Freitas, Lais, Sousa-Dias, Miguel, Paula, Vanessa B., Dias, Luís G., and Estevinho, Leticia M.
- Subjects
YOGURT ,GRAPES ,VITIS vinifera ,LACTIC acid bacteria ,MICROBIAL growth ,SACCHAROMYCES cerevisiae - Abstract
In this study, we monitored the fermentative process of Vitis vinifera L. leaves (grapevine), spontaneously or promoted by Saccharomyces cerevisiae, in both solid and liquid media. We also aimed to evaluate the effect on the bioactivity and shelf life of yogurt incorporating fermented and non-fermented grapevine leaves compared to yogurt produced with the preservative potassium sorbate. The results revealed that fermented grapevine leaf extracts increased their bioactive compounds and antioxidant activity, particularly in fermentations in a solid medium. In yogurt samples with incorporation extract from solid spontaneous fermentation and extract from solid yeast fermentation, even in small quantities, they exhibited higher levels of total phenols (1.94 and 2.16 mg GAE/g of yogurt, respectively) and antioxidant activity (5.30 and 5.77 mg TroloxE/g of yogurt; and 1.33 and 1.34 mg Fe(II)E/g of yogurt, respectively) compared to control yogurt (1.44 mg GAE/g of yogurt, 4.00 mg TroloxE/g of yogurt, and 1.01 mg Fe(II)E/g of yogurt). Additionally, yogurts supplemented with fermented grapevine leaves demonstrated the potential to inhibit microbial growth without impairing the multiplication of lactic acid bacteria. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. The High Pressure Preservation of Honey: A Comparative Study on Quality Changes during Storage.
- Author
-
Scepankova, Hana, Majtan, Juraj, Estevinho, Leticia M., and Saraiva, Jorge A.
- Subjects
HONEY ,HONEYBEES ,HEAT treatment ,OXIDANT status ,AMYLASES ,COMPARATIVE studies - Abstract
In commercially available honey, the application of a heat treatment to prevent spoilage can potentially compromise its beneficial properties and quality, and these effects worsen with extended storage. The high-pressure processing (HPP) of honey is being explored, but its long-term impact on honey quality has not been characterised yet. This study evaluated the effects of HPP and thermal processing on the microbial load, physicochemical quality (i.e., hydroxymethylfurfural content and diastase activity), and antioxidant capacity of honey after treatment and following extended storage (6, 12, and 24 months) at 20 °C. Pasteurization (78 °C/6 min) effectively eliminated the microorganisms in honey but compromised its physicochemical quality and antioxidant activity. HPP initially showed sublethal inactivation, but storage accelerated the decrease in yeasts/moulds and aerobic mesophiles in honey (being <1 log CFU/g after 24 months of storage) compared to unprocessed honey and honey thermally treated under mild conditions (55 °C/15 min). The physicochemical characteristics of the quality of HPP-treated honey and raw unprocessed honey did change after long-term storage (24 months) but remained within regulatory standards. In conclusion, HPP emerged as a more suitable and safe preservation method for Apis mellifera honey, with a minimal risk of a loss of antioxidant activity compared to traditional industrial honey pasteurization. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Antibacterial and Healing Effect of Chicha Gum Hydrogel (Sterculia striata) with Nerolidol
- Author
-
Lima, Idglan Sá de, primary, Ferreira, Maria Onaira Gonçalves, additional, Barros, Esmeralda Maria Lustosa, additional, Rizzo, Marcia dos Santos, additional, Santos, Jailson de Araújo, additional, Ribeiro, Alessandra Braga, additional, Anteveli Osajima Furtini, Josy, additional, C. Silva-Filho, Edson, additional, and Estevinho, Leticia M., additional
- Published
- 2023
- Full Text
- View/download PDF
7. Antimicrobial Activity of Propolis from the Brazilian Stingless Bees Melipona quadrifasciata anthidioides and Scaptotrigona depilis (Hymenoptera, Apidae, Meliponini)
- Author
-
Campos, Jaqueline Ferreira, primary, Bonamigo, Thaliny, additional, Rocha, Paola dos Santos da, additional, Paula, Vanessa Marina Branco, additional, Santos, Uilson Pereira dos, additional, Balestieri, José Benedito Perrella, additional, Silva, Denise Brentan, additional, Carollo, Carlos Alexandre, additional, Estevinho, Leticia M., additional, de Picoli Souza, Kely, additional, and Santos, Edson Lucas dos, additional
- Published
- 2022
- Full Text
- View/download PDF
8. Modulation of Lipid Profile and Lipoprotein Subfractions in Overweight/Obese Women at Risk of Cardiovascular Diseases through the Consumption of Apple/Berry Juice
- Author
-
Habanova, Marta, primary, Holovicova, Maria, additional, Scepankova, Hana, additional, Lorkova, Marta, additional, Gazo, Jan, additional, Gazarova, Martina, additional, Pinto, Carlos A., additional, Saraiva, Jorge A., additional, and Estevinho, Leticia M., additional
- Published
- 2022
- Full Text
- View/download PDF
9. Semi‐Quantitative Discrimination of Honey Adulterated with Cane Sugar Solution by an ETongue
- Author
-
Dias, Luís G., primary, Bruni, Andressa R. S., additional, Anizelli, Camilla P., additional, Zangirolami, Marcela, additional, Lima, Patrícia C., additional, Estevinho, Leticia M., additional, and Bona, Evandro, additional
- Published
- 2022
- Full Text
- View/download PDF
10. Potential Wound Healing Effect of Gel Based on Chicha Gum, Chitosan, and Mauritia flexuosa Oil
- Author
-
Ferreira, Maria Onaira Gonçalves, primary, Ribeiro, Alessandra Braga, additional, Rizzo, Marcia S., additional, de Jesus Oliveira, Antonia Carla, additional, Osajima, Josy Anteveli, additional, Estevinho, Leticia M., additional, and Silva-Filho, Edson C., additional
- Published
- 2022
- Full Text
- View/download PDF
11. Atividades biológicas de fungos endofíticos isolados de Annona muricata Linnaeus: uma revisão sistemática
- Author
-
Silva, I.M.M., Silva, Reanne M.M., Paula, Vanessa B., and Estevinho, Leticia M.
- Subjects
Soursop ,Mycology ,Biological products ,Biotechnology - Abstract
This systematic review integrates the data available in the literature regarding the biological activities of the extracts of endophytic fungi isolated from Annona muricata and their secondary metabolites. The search was performed using four electronic databases, and studies’ quality was evaluated using an adapted assessment tool. The initial database search yielded 436 results; ten studies were selected for inclusion. The leaf was the most studied part of the plant (in nine studies); Periconia sp. was the most tested fungus (n = 4); the most evaluated biological activity was anticancer (n = 6), followed by antiviral (n = 3). Antibacterial, antifungal, and antioxidant activities were also tested. Terpenoids or terpenoid hybrid compounds were the most abundant chemical metabolites. Phenolic compounds, esters, alkaloids, saturated and unsaturated fatty acids, aromatic compounds, and peptides were also reported. The selected studies highlighted the biotechnological potentiality of the endophytic fungi extracts from A. muricata. Consequently, it can be considered a promising source of biological compounds with antioxidant effects and active against different microorganisms and cancer cells. Further research is needed involving different plant tissues, other microorganisms, such as SARS-CoV-2, and different cancer cells. © 2024, Instituto Internacional de Ecologia Esta revisão sistemática integra os dados disponíveis na literatura sobre as atividades biológicas dos extratos de fungos endofíticos isolados de Annona muricata e seus metabólitos secundários. A busca foi realizada em quatro bases de dados eletrônicas e a qualidade dos estudos foi avaliada por meio de instrumento de avaliação adaptado. A pesquisa inicial no banco de dados gerou 436 resultados; dez estudos foram selecionados para inclusão. A folha foi a parte mais estudada da planta (em nove estudos); Periconia sp. foi o fungo mais testado (n = 4); a atividade biológica mais avaliada foi anticâncer (n = 6), seguida de antiviral (n = 3). As atividades antibacteriana, antifúngica e antioxidante também foram testadas. Terpenóides ou compostos híbridos de terpenóides foram os metabólitos químicos mais abundantes. Compostos fenólicos, ésteres, alcalóides, ácidos graxos saturados e insaturados, compostos aromáticos e peptídeos também foram relatados. Os estudos selecionados destacaram a potencialidade biotecnológica dos extratos de fungos endofíticos de A. muricata. Por conseguinte, esta planta pode ser considerada uma fonte promissora de compostos biológicos com efeitos antioxidantes e ativos contra diversos micro-organismos e células cancerígenas. Mais pesquisas são necessárias envolvendo diferentes tecidos vegetais, outros microorganismos, como SARS-CoV-2, e diferentes células cancerosas. info:eu-repo/semantics/publishedVersion
- Published
- 2022
12. Anti-bacterial activity of Annona muricata Linnaeus extracts: a systematic review
- Author
-
SILVA, Ricardo Mendes da, primary, SILVA, Isabella de Matos Mendes da, additional, ESTEVINHO, Maria Manuela, additional, and ESTEVINHO, Leticia M., additional
- Published
- 2022
- Full Text
- View/download PDF
13. Antimicrobial Activity of Propolis from the Brazilian Stingless Bees Melipona quadrifasciata anthidioides and Scaptotrigona depilis (Hymenoptera, Apidae, Meliponini).
- Author
-
Campos, Jaqueline Ferreira, Bonamigo, Thaliny, Rocha, Paola dos Santos da, Paula, Vanessa Marina Branco, Santos, Uilson Pereira dos, Balestieri, José Benedito Perrella, Silva, Denise Brentan, Carollo, Carlos Alexandre, Estevinho, Leticia M., de Picoli Souza, Kely, and Santos, Edson Lucas dos
- Subjects
PROPOLIS ,ANTI-infective agents ,APIDAE ,STINGLESS bees ,HYMENOPTERA ,GALLIC acid ,LINEZOLID - Abstract
Melipona quadrifasciata anthidioides and Scaptotrigona depilis are species of stingless bees capable of producing propolis, which has considerable bioprospecting potential. In this context, the objective of this study was to determine the chemical compositions and evaluate the antimicrobial activity of propolis produced by M. q. anthidioides and S. depilis. The ethanolic extracts of propolis of M. q. anthidioides (EEP-M) and S. depilis (EEP-S) were prepared, and their chemical constituents were characterized by HPLC-ESI-MS. The antimicrobial activity was evaluated against bacteria and fungi, isolated from reference strains and hospital origin resistant to the action of antibiotics. From EEP-M, phenolic compounds were annotated, including gallic acid, ellagic acid, and flavonoids, as well as diterpenes and triterpenes. EEP-S showed mainly triterpene in its chemical composition. Both extracts inhibited the growth of medically relevant bacteria and fungi, including hospital-acquired and antimicrobial-resistant. In general, EEP-S showed better antimicrobial activity compared to EEP-M. The MIC of EEP-S against vancomycin-resistant Enterococcus faecalis was 3.50 mg/mL, while the MIC of EEP-M was 5.33 ± 0.16 mg/mL. In conclusion, this study shows that propolis produced by M. q. anthidioides and S. depilis has the potential to be used for the prevention or treatment of microbial infections. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. Use of the electronic tongue as a tool for the characterization of Melipona scutellaris Latreille honey.
- Author
-
do Nascimento, Andreia Santos, Silva, Fabiane de Lima, Machado, Cerilene Santiago, Cavalcante da Silva, Samira Maria Peixoto, Estevinho, Leticia M., Dias, Luís G., and Carvalho, Carlos Alfredo Lopes de
- Abstract
This study aimed to characterize honey of Melipona scutellaris regarding its physicochemical parameters using the electronic tongue (e-tongue) technique combined with the multivariate statistical analysis for honey differentiation. Physicochemical parameters were evaluated following official methods of chemical analyses. A potentiometric electronic tongue with 16 cross-sensitivity sensors was used for the analysis. The Principal Component Analysis and the Cluster Analysis distinguished two groups for the sample set in the evaluation of physicochemical parameters, similar to results found using the electronic tongue. We verified a correlation greater than 0.70 between the profile of potentiometric signals and values of pH, ashes, electrical conductivity, HMF, diastase activity, reducing sugars, and apparent sucrose. The combined use of the electronic tongue with the statistical analysis showed the similarity between samples through the formation of two groups of the sample set. The electronic tongue may be used as a complement to traditional techniques of analyses to determine honey physicochemical parameters, constituting a promising tool in association with the multivariate statistical analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
15. Use of the electronic tongue as a tool for the characterization of Melipona scutellarisLatreille honey
- Author
-
do Nascimento, Andreia Santos, Silva, Fabiane de Lima, Machado, Cerilene Santiago, Cavalcante da Silva, Samira Maria Peixoto, Estevinho, Leticia M., Dias, Luís G., and Carvalho, Carlos Alfredo Lopes de
- Abstract
This study aimed to characterize honey of Melipona scutellarisregarding its physicochemical parameters using the electronic tongue (e-tongue) technique combined with the multivariate statistical analysis for honey differentiation. Physicochemical parameters were evaluated following official methods of chemical analyses. A potentiometric electronic tongue with 16 cross-sensitivity sensors was used for the analysis. The Principal Component Analysis and the Cluster Analysis distinguished two groups for the sample set in the evaluation of physicochemical parameters, similar to results found using the electronic tongue. We verified a correlation greater than 0.70 between the profile of potentiometric signals and values of pH, ashes, electrical conductivity, HMF, diastase activity, reducing sugars, and apparent sucrose. The combined use of the electronic tongue with the statistical analysis showed the similarity between samples through the formation of two groups of the sample set. The electronic tongue may be used as a complement to traditional techniques of analyses to determine honey physicochemical parameters, constituting a promising tool in association with the multivariate statistical analysis.
- Published
- 2022
- Full Text
- View/download PDF
16. Electrical impedance spectroscopy for potassium content analysis and botanical origin identification of honey.
- Author
-
Elamine, Youssef, Inácio, Pedro M.C., da Graça Miguel, Maria, Carlier, Jorge D., Costa, Maria Clara, Estevinho, Leticia M., and Gomes, Henrique L.
- Subjects
- *
PLANT identification , *ELECTRIC impedance , *EUCALYPTUS , *IMPEDANCE spectroscopy , *ATOMIC emission spectroscopy , *HONEY , *POTASSIUM , *MAGNESIUM - Abstract
Minerals are reported to dominate the electrical properties of honey and indicate its botanical and geographical origins. In this study, Electrochemical Impedance Spectroscopy (EIS) was used to assess the relation between mineral elements, electrical properties and botanical origin using three honey varieties - Citrus sp., Eucalyptus sp., and Erica sp. These varieties are identified through pollen analysis and market labelling. Flame atomic absorption and emission spectroscopies were used to quantify the concentrations of eight elements (potassium, sodium, calcium, magnesium, manganese, zinc, copper, and iron). Among all the mineral elements, potassium showed a consistent correlation with impedance. The potassium estimation in honey and standard solutions (calibration curve) had similar sensitivities of 153.43 nF/mM and 132.68 nF/mM, respectively. Additionally, the analysis revealed that potassium dominates the mineral composition, with the other species present in minimal quantities. The EIS technique showed high sensitivity to potassium and other ionisable species, making it possible to classify the botanical origin of these three honey types. The EIS technique proved to be both time and cost effective, yielding a classification rate higher than that achieved by analysing mineral composition. [Display omitted] • Potassium is the predominant element influencing the electrical properties of honey. • Electrochemical impedance measurements provide a quantitative assessment of potassium concentration in honey. • An impedance-based sensor classifies honey samples according to their botanical origin. • The impedance-based sensor is time and cost-effective, when compared with mineral composition analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Study of Saccharomyces cerevisiae growth: screen the best conditions and evaluate the effects of wine and histamine
- Author
-
Slama, Rym, Dias, L.G., and Estevinho, Leticia M.
- Subjects
Tramazeira fruit ,Vinho branco ,Saccharomyces cerevisiae growth ,Histamina ,Grape juice ,Crescimento de Saccharomyces cerevisiae ,Culture media composition ,Fruta da Tramazeira ,White wine ,Domínio/Área Científica::Ciências Agrárias::Biotecnologia Agrária e Alimentar ,Sumo de uva ,Composição de meios de cultura ,Histamine - Abstract
Mestrado de dupla diplomação com a Université Libre de Tunis The rowanberries (Sorbus aucuparia, also called Tramazeira fruits in Portugal) are small orange-red “fruits” of a rowan tree, which are highly resistant to cold climates. They have been traditionally used in various processed foods due to their high relevance to human health. These berries have been described as an important source of phenolic compounds and a source of bacteria/yeasts, being suitable for the production of health-food products. In this work, the microbiology quality of Tramazeira fruit samples was evaluated to select the one with higher microbial quality that could be used to isolate/select a yeast for further assays. After yeast identification as Saccharomyces cerevisiae (API method), an experimental design was applied to define optimal experimental conditions in a culture media for its growth. For this purpose, a fractional factorial design with 4 factors, 3 levels (including the center points) was applied varying the culture medium composition in glucose (10, 15 and 20 g/L), peptone (5, 7.5 and 10 g/L) and yeast extract (1, 3 and 5 g/L), as well, the inoculum quantity (105 , 106 and 107 CFU/mL). The optimal culture media (standard media) had 10 g/L of glucose, 5 g/L of peptone, 1 g/L of extract yeast, and 107 CFU/mL of inoculum quantity, which allowed to obtain a growth value of 22.8 CFU, in logarithmic scale. To test Saccharomyces cerevisiae growth, different matrices as grape juice or a mixture of grape juice and white wine (1:1), together with different concentrations of histamine (2, 5, 10, and 20 mg/L), were tested. It was shown that the Saccharomyces cerevisiae growth was delayed in the culture media with the presence of alcohol. Also, there was no evidence that histamine levels did affected the overall of Saccharomyces cerevisiae growth. Considering the overall results, there was a reduction in growth in the culture medium prepared with grape juice in comparison to the standard culture media (85.3% of the result obtained in the standard media), while for the culture medium with the mixture of grape juice and white wine, the growth was 67.0% of the standard media. A sorveira-brava (Sorbus aucuparia, também chamada de Tramazeira em Portugal), que produz uma pequena “fruta” laranja-avermelhada, é muito resistente aos climas frios. A Tramazeira têm sido tradicionalmente usada em vários alimentos processados devido à sua alta relevância para a saúde humana. As frutas têm sido descritas como uma importante fonte de compostos fenólicos e uma fonte de bactérias/leveduras, adequadas para a produção de produtos alimentares saudáveis. Neste trabalho, a qualidade microbiológica do fruto da Tramazeira foi avaliada para selecionar a amostra com a maior qualidade microbiana que poderia ser usada para isolar/selecionar uma levedura para testes posteriores. Após a identificação da levedura como Saccharomyces cerevisiae (método API), um delineamento experimental foi aplicado para definir o meio de cultura ótimo para o seu crescimento. Para isso, foi aplicado um desenho fatorial fracionário com 4 fatores, 3 níveis (incluindo os pontos centrais), variando a composição do meio de cultura em glicose (10, 15 e 20 g/L), peptona (5, 7,5 e 10 g/L) e extrato de levedura (1, 3 e 5 g/L), bem como a quantidade de inóculo (105 , 106 e 107 UFC/mL). O meio de cultura ótimo (meio padrão) continha 10 g/L de glicose, 5 g/L de peptona, 1 g/L de extrato de levedura e 107 UFC/mL de quantidade de inóculo, o que permitiu obter um valor de crescimento de 22,8 UFC, na escala logarítmica. Para testar o crescimento de Saccharomyces cerevisiae, diferentes matrizes, como sumo de uva ou uma mistura de sumo de uva e vinho branco, com diferentes concentrações de histamina (2, 5, 10 e 20 mg/L), foram testados. Foi demonstrado que o crescimento de Saccharomyces cerevisiae foi retardado em meios de cultura com presença de álcool. Além disso, não houve evidências de que os níveis de histamina afetaram o crescimento geral da Saccharomyces cerevisiae. Considerando os resultados gerais, houve redução no crescimento do meio de cultura de sumo de uva (85,3% do resultado obtido com o meio de cultura padrão), enquanto para o meio de cultura de mistura de sumo de uva e vinho branco, o crescimento foi de 67,0% do obtido com o meio padrão.
- Published
- 2022
18. Efeito da incorporação de bagas de sabugueiro fermentadas no pão
- Author
-
Seixas, Natália da Assunção Lisboa, Estevinho, Leticia M., and Dias, L.G.
- Subjects
Bagas de sabugueiro ,Atividade antioxidante ,Físico-químicas ,Fermentação ,Pão ,Domínio/Área Científica::Ciências Agrárias::Biotecnologia Agrária e Alimentar ,Compostos fenólicos totais ,Microbiológicas - Abstract
O objetivo do presente trabalho foi estudar a incorporação de bagas de sabugueiro fermentadas no pão. Para atingir este objetivo foi realizado um desenho experimental com vista à otimização das condições de fermentação das bagas de sabugueiro. O desenho de Plackett-Burmann foi aplicado com 15 ensaios, usando 3 níveis de 6 parâmetros: ureia (1,0 ;1,5 e 2,0 g/L), MgSO4 (0,5; 1,0 e 1,5 g/L), KH2PO4 (0,5; 1,0 e 1,5 g/L) e pH (4,50; 4,75 e 5,00) no meio de cultura; concentração de inóculo de levedura Saccharomyces cerevisiae (105, 106 e 107 UFC/mL); quantidades de baga de sabugueiro (50 150 e 250 g). Os resultados mais promissores foram aqueles em que a quantidade de inóculo foi de 105 UFC/mL, a massa de amostra foi de 50 g e o meio de cultura tinha a seguinte composição: 1,0 g/L de ureia, 0,5 g/L de MgSO4, 0,5 g/L de KH2PO4 e pH 4,50. Nas condições ótimas de fermentação foi posteriormente preparado um extrato de bagas de sabugueiro fermentadas usando uma solução hidro-etanólica com 60% de etanol e pH 0,9, para servir como aditivo na preparação do pão. No produto fermentado foi avaliada a qualidade microbiológica e determinados o conteúdo em compostos fenólicos totais (fenóis e flavonoides totais) e atividade antioxidante (DPPH e FRAP). As análises foram efetuadas no início (T0 horas) e no final da fermentação (T144 horas). Relativamente às análises microbiológicas verificou-se crescimento de bolores e leveduras, tanto no T0 como no T144 horas. Globalmente, verificou-se que o valor de compostos fenólicos totais e da atividade antioxidante aumentou do T0 para o T144 horas. Os valores médios obtidos para os fenóis totais foi de 79,63±4,39 e 178,30±1,78 mg eq de AG/ g de amostra para o T0 e T144 h respetivamente. Quanto aos flavonoides totais os valores obtidos foram de 13,66±0,69 e 27,87±0,34 mg eq de Q/g de amostra para o T0 e T144 horas respetivamente. Relativamente à atividade antioxidante pelo método de DPPH, os resultados observados foram de 62,90±1,09 e 116,05±1,89 mg eq de trolox/g de amostra para o T0 e T144 horas respetivamente. Os valores obtidos pelo método FRAP para o T0 e T144 h foram de 204,14±7,60 e 425,44±4,88 mg eq Fe II/g de amostra respetivamente. Os parâmetros avaliados no pão com adição de diferentes percentagens de extrato de bagas de sabugueiro fermentado (0,0; 0,5 e 2,0%), foram semelhantes aos referidos anteriormente. Nas amostras de pão foram ainda avaliados parâmetros físico-químicos, tais como: proteína, gordura, humidade, cinzas, pH, hidratos de carbono e valor energético para os tempos 0 e 2 dias. Em relação aos parâmetros microbiológicos no pão, apenas se verificou o crescimento pouco representativo de mesófilos totais no T2. Das análises químicas ao pão, verificou-se um aumento do valor em fenóis totais e atividade antioxidante pelo método FRAP consoante o aumento da percentagem de extrato de sabugueiro adicionado às amostras, este comportamento verificou-se nos dois tempos em estudo (T0 e T2). O valor máximo e mínimo obtido na determinação de fenóis totais da análise das amostras de pão em estudo foram, 8,63±1,23 e 20,56±0,72 mg eq AG/g de pão para a amostra de 0% e 2% EBSF no T0 respetivamente; quanto aos valores obtidos para o FRAP foram de 9,16±0,16 e 25,66±0,51 mg eq Fe II/g de pão para a amostra 0% e 2% EBSF no T0 e T2 respetivamente. Relativamente à análise dos resultados dos flavonoides totais e da atividade antioxidante pelo método DPPH, observou-se que na globalidade os valores obtidos para o T2 foram superiores aos do T0 para as amostras de pão em estudo, excetuando a amostra com 2% de EBSF em que se verificou uma diminuição do T0 para o T2 (2,36±0,12 e 1,77±0,05 mg eq Q/g de pão) na quantificação de flavonoides totais. O valor mínimo e máximo obtido para os flavonoides totais foi de 0,65±0,02 e 2,90±0,03 mg eq de Q/g de pão para a amostra 0,5% e 0,0% EBSF no T0 e T2 respetivamente; relativamente aos valores de DPPH o mínimo e máximo obtidos foram na amostra com 0,5% EBSF no T0 e T2 com resultados de 216,01±0,94 e 267,80±0,89 mg eq trolox/g de pão respetivamente. Em termos físico-químicos, os valores de proteína foram compreendidos entre 7,93 e 8,44%; teor de gordura entre 2,99×10-2 e 1,22×10-1%; teor de humidade entre 31,75 e 35,22%; cinzas entre 1,01 e 2,32%; o pH entre 4,1 e 5,6; teor em hidratos de carbono entre 85,99 e 87,21 g/100g e valor energético entre 377,47 e 381,93 Kcal/100g. The objective of the present work was to study the incorporation of fermented elderberries in bread. To achieve this objective, an experimental design was carried out with a view to optimizing the fermentation conditions of elderberries. The Plackett-Burmann design was applied with 15 assays, using 3 levels of 6 parameters: urea (1,0 ;1,5 and 2,0 g/L), MgSO4 (0,5; 1,0 and 1,5 g/L), KH2PO4 (0,5; 1,0 and 1,5 g/L) and pH (4,50; 4,75 and 5,00) in the culture medium; Saccharomyces cerevisiae yeast inoculum concentration (105, 106 and 107 CFU/ml); amounts of elderberry (50,150 and 250 g). The most promising results were those in which the inoculum amount was 105 CFU/mL, the sample mass was 50 g and the culture medium had the following composition: 1,0 g/L urea, 0,5 g/L of MgSO4, 0,5 g/L of KH2PO4 and pH 4,50. In the optimal fermentation conditions, an extract of fermented elderberries was later prepared using a hydro-ethanolic solution with 60% ethanol and pH 0,9, to serve as an additive in the preparation of bread. In the fermented product, the microbiological quality was evaluated and the content of total phenolic compounds (total phenols and flavonoids) and antioxidant activity (DPPH and FRAP) were determined. Analyzes were performed at the beginning (T0 hours) and at the end of fermentation (T144 hours). In relation to microbiological analysis, growth of molds and yeasts was verified, both at T0 and at T144 hours. Globally, it was found that the value of total phenolic compounds and antioxidant activity increased from T0 to T144 hours. The average values obtained for total phenols were 79,63±4,39 and 178,30±1,78 mg eq of AG/g of sample for T0 and T144 h respectively. As for the total flavonoids, the values obtained were 13,66±0,69 and 27,87±0,34 mg eq of Q/g of sample for T0 and T144 hours respectively. Regarding antioxidant activity by the DPPH method, the observed results were 62,90±1,09 and 116,05±1,89 mg eq of trolox/g of sample for T0 and T144 hours, respectively. The values obtained by the FRAP method for T0 and T144 h were 204,14±7,60 and 425,44±4,88 mg eq Fe II/g of sample, respectively. The parameters evaluated in bread with the addition of different percentages of fermented elderberry extract (0,0; 0,5 and 2,0%) were similar to those mentioned above. For the bread samples, physicochemical parameters were also evaluated, such as: protein, fat, moisture, ash, pH, carbohydrates and energetic value. Regarding the microbiological parameters in bread, there was only an unrepresentative growth of total mesophiles in T2 days. The chemical analysis of bread showed an increase in the value of total phenols and antioxidant activity by the FRAP method depending on the increase in the percentage of elderberry extract added to the samples, this behavior was verified in the two times under study (T0 and T2). The maximum and minimum values obtained in the determination of total phenols from the analysis of the bread samples under study were 8,63±1.23 and 20,56±0,72 mg eq AG/g of bread for the 0% and 2% EBSF in T0 respectively; as for the values obtained for the FRAP, they were 9,16±0,16 and 25,66±0,51 mg eq Fe II/g of bread for the 0% and 2% EBSF samples at T0 and T2, respectively. Regarding the analysis of the results of total flavonoids and antioxidant activity by the DPPH method, it was observed that overall the values obtained for T2 were higher than those for T0 for the bread samples under study, except for the sample with 2,0% EBSF in which there was a decrease from T0 to T2 (2,36±0,12 and 1,77±0,05 mg eq Q/g of bread) in the quantification of total flavonoids. The minimum and maximum values obtained for total flavonoids were 0,65±0,02 and 2,90±0,03 mg eq of Q/g of bread for the 0,5% and 0,0% EBSF sample at T0 and T2 respectively; regarding the DPPH values, the minimum and maximum obtained were in the sample with 0,5% EBSF at T0 and T2 with results of 216,01±0,94 and 267,80±0,89 mg eq trolox/g of bread, respectively. In physical-chemical terms, the protein values were between 7,93 and 8,44%; fat content between 2,99×10-2 and 1,22×10-1%; moisture content between 31,75 and 35,22%; ash between 1,01 and 2,32%; the pH between 4,1 and 5,6; carbohydrate content between 85,99 and 87,21 g/100g and energy value between 377,47 and 381,93 Kcal/100g.
- Published
- 2022
19. Chemical and biological analysis of Tramazeira
- Author
-
Mhadhbi, Chaimaa, Estevinho, Leticia M., and Dias, L.G.
- Subjects
Food additive ,Response surface methodology ,Domínio/Área Científica::Ciências Agrárias::Biotecnologia Agrária e Alimentar ,Phenolic compounds ,Central composite design - Abstract
Mestrado de dupla diplomação com a Université Libre de Tunis Rowanberries also called as Sorbus aucuparia L. fruits (Tramazeira fruits in Portugal), an ornamental tree, have been traditionally used in various processed foods due to their high relevance to human health. Scientific research demonstrates the nutritional effects of Sorbus L. fruits are determined by their unique composition of chemically and biologically active compounds. The extraction of phenolic compounds from Tramazeira fruits is of interest because they can be used as natural food additives but, extractive processes must be optimized to ensure that the relevant levels of all phenolic compounds groups are extracted from fruit pulp (lyophilized). A central composite design with two factors (percentage of Ethanol and pH values) was applied, with ethanol % in the range of 24.6 to 95.4% and pH between 0.9 and 5.1. From the response surface methodology (RSM) data treatment, the selected hydroethanolic extract solution had pH value of 3 and ethanol % of 85%, which allowed to have high amounts of the three main groups of phenolic compounds: flavonoids, hydroxybenzoic acids and hydroxycinnamic acids. Extracts of Tramazeira (Sorbus L.) fruit were applied as an additive in orange fresh juice and showed antimicrobial activity against gram positive and gram-negative bacteria, being more effective against gram-positive bacteria. The time effect on orange juice with the different concentrations of the Tramazeira fruit extract showed influence on the microbiological quality of the orange juice. However, the results suggest that the juices obtained with the highest concentration are more stable from a microbiological point of view. A fruta Tramazeira também chamada de Sorbus aucuparia L., uma árvore ornamental, tem sido tradicionalmente usada em vários alimentos processados devido à sua grande relevância para a saúde humana. Trabalhos científicas demonstram que os efeitos nutricionais das frutas Sorbus L. são determinados por sua composição única de compostos química e biologicamente ativos. A extração de compostos fenólicos dos frutos da Tramazeira é interessante porque podem ser usados como aditivos alimentares naturais, mas os processos extrativos devem ser otimizados para garantir que os níveis relevantes de todos os grupos de compostos fenólicos sejam extraídos da polpa do fruto (liofilizada). Foi aplicado um desenho compósito central com dois fatores (percentagem de etanol e valores de pH), com % de etanol na faixa de 24,6 a 95,4% e pH entre 0,9 e 5,1. A partir do tratamento dos dados com a metodologia de superfície de resposta, a solução extractora hidroetanólica selecionada apresentava valor de pH de 3 e % de etanol de 85%, o que permitiu ter quantidades elevadas dos três grupos principais de compostos fenólicos: flavonóides, ácidos hidroxibenzóico e ácidos hidroxicinâmicos . Extratos da fruta Tramazeira (Sorbus L.) foram aplicados como aditivo em sumo fresco de laranja e apresentaram atividade antimicrobiana contra bactérias gram-positivas e gramnegativas, sendo mais eficazes contra bactérias gram-positivas. O efeito do tempo nos sumos de laranja com as concentrações do extrato da fruta Tramazeira mostrou influência na qualidade microbiológica do sumo de laranja. No entanto, os resultados sugerem que os sumos obtidos com as maiores concentrações são mais estáveis do ponto de vista microbiológico.
- Published
- 2022
20. Analysis of cadmium, copper and lead ions in wine by ASDPV with a lab-made graphite composite working electrode
- Author
-
Boubaker, Elyes, Dias, L.G., Estevinho, Leticia M., and Mokaddem, Yassin
- Subjects
Cyclic voltammetry ,Heavy metals ,Response surface methodology ,Differential pulse voltammetry ,Atomic absorption spectrophotometry ,Wine ,Domínio/Área Científica::Ciências Agrárias::Biotecnologia Agrária e Alimentar ,Anodic stripping ,Experimental design - Abstract
Mestrado de dupla diplomação com a Université Libre de Tunis The purpose of the current study was to quantify the concentrations of copper, cadmium, lead ions in wine using ASDPV with a lab-made graphite composite electrode. A first study involved analysis of a reversible redox solution of K3[Fe(CN)₆] with response surface methodology in order to verify the CV dependency with scan rate and potential step, as well the DPV dependency with scan rate, potential pulse and potential step. For the DPV analysis, the conditions selected were 0.03 V/s for the scan rate, 0.01 V for the step potential, and 0.04 V for the pulse potential. With these experimental conditions, the DPV data from a full factorial design using two concentration levels of the three heavy metals allowed to verify the independence between the calibrations of each metal. The analysis of 8 samples of Portuguese and Spanish wines by ETAAS allowed to verify that only copper levels were detected and quantified, obtaining Cu2+ concentrations varying between 0.011 and 0.535 mg/L. Considering the heavy metals trace levels, the ASDPV technique was selected, with the 4 min deposition step for standard calibration solution and sample solutions, which demanded an assisted digestion with HNO3 and H2O2. The ASDPV showed higher sensibility toward the copper (slope of 22 μA.L.mg-1), than cadmium (slope of 14.2 μA.L.mg-1) and lead (slope of 13.5 μA.L.mg-1). Only copper levels were measured in wine samples by ASDPV, within the range of 0.09 to 0.55 mg/L, being 0.91 times lower than those obtained by ETAAS. Overall, the cheap lab-made graphite composite working electrode allows to analyze simultaneously three heavy metals using the ASDPV technique. Its analytical performance allows considering its application in the voltammetric analysis of wines. However, there is space for improvement by optimizing the experimental procedure of solutions preparations for ASDPV analysis which will be addressed in future work. O objetivo do presente estudo foi quantificar as concentrações dos iões cádmio, cobre e chumbo no vinho usando ASDPV com um elétrodo compósito de grafite feito em laboratório. Um primeiro estudo envolveu a análise de uma solução redox reversível de K3[Fe(CN)₆] com metodologia de superfície de resposta a fim de verificar a dependência da voltametria cíclica com a velocidade de varrimento e potencial de impulso, bem como a dependência da voltametria de impulso diferencial (DPV) com a velocidade de varrimento, potencial de impulso e potencial de incremento. Para a análise DPV, as condições selecionadas foram 0,03 V/s para a velocidade de varrimento, 0,01 V para o potencial de passo e 0,04 V para o potencial de incremento. Com estas condições experimentais, os dados de DPV de um desenho fatorial completo, utilizando dois níveis de concentração para os três metais pesados, permitiram verificar a independência entre as calibrações de cada metal. A análise de 8 amostras de vinhos Portugueses e Espanhóis pela ETAAS permitiu verificar que apenas foram detetados e quantificados os teores de cobre, obtendo concentrações de Cu2+ a variar entre 0,011 e 0,535 mg/L. Considerando os níveis vestigiais dos metais pesados, foi escolhida a técnica redissolução anódica (anodic stripping, AS) com DPV, com a etapa de deposição de 4 min para as soluções padrão de calibração e soluções de amostra, após sofrerem digestão assistida com HNO3 e H2O2. A ASDPV apresentou maior sensibilidade em relação ao cobre (declive de 22 μA.L.mg-1), do que para o cádmio (declive de 14,2 μA.L.mg-1) e chumbo (declive de 13,5 μA.L.mg-1). Apenas os teores de cobre foram medidos nas amostras de vinho por ASDPV, na faixa de 0,09 a 0,55 mg / L, sendo 0,91 vezes inferior aos obtidos pelo ETAAS. No geral, o elétrodo de trabalho compósito de grafite feito em laboratório permite analisar simultaneamente três metais pesados usando a técnica ASDPV. O seu desempenho analítico permite considerar a sua aplicação na análise voltamétrica de vinhos. No entanto, há espaço para melhorias, otimizando o procedimento experimental de preparação de soluções para análise de ASDPV que será abordado em trabalhos futuros.
- Published
- 2022
21. Quantifying the Impact of High-Pressure Processing on the Phenolic Profile, Antioxidant Activity, and Pollen Morphology in Honey.
- Author
-
Scepankova H, Majtan J, Pospiech M, Moreira MM, Pinto CA, Dias LG, Estevinho LM, Delerue-Matos C, and Saraiva JA
- Abstract
Honey can benefit from non-thermal processing techniques such as high-pressure processing (HPP) to improve its quality and bioactivity. This study investigated the impact of HPP (600 MPa for 5, 10, and 15 min) on honey's quality, including the levels of hydroxymethylfurfural (HMF), antioxidant activity, total phenolic content (TPC), and phenolic profile. HPP treatment did not significantly affect HMF or TPC levels but led to selective changes in the phenolic profile. Despite a reduction in certain phenolic compound content, HPP for 5 and 15 min caused a significant increase in the antioxidant activity (2,2-diphenyl-1-picrylhydrazyl [DPPH]) of honey from the mean value of 41.8% to values of 45.4% and 49.6%, respectively. On the other hand, HPP for 10 min did not change the antioxidant activity of tested honey. A 27.5% reduction in the equatorial diameter of pollen grains was observed after HPP combined with temperature at 75°C, suggesting an improved release of bioactive compounds. The content of specific phenolic compounds, including caffeic acid, p-coumaric acid, sinapic acid, naringin, kaempferol, and the TPC, significantly affected the DPPH activity. The increment in the antioxidant activity of HPP honey may be attributed to selective changes in the content of certain phenolic compounds and improved their extraction from pollen grains., (© 2024 Wiley‐VHCA AG, Zurich, Switzerland.)
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.