Percorrer por autor "Silva, Marcos Vieira da"
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- Antioxidants extraction from Pinhão (Araucaria angustifolia (Bertol.) Kuntze) coats and application to zein filmsPublication . Freitas, Tânia Barbedo de; Santos, Carlos Henrique Koslinski; Silva, Marcos Vieira da; Shirai, Marianne Ayumi; Dias, Maria Inês; Barros, Lillian; Barreiro, M.F.; Ferreira, Isabel C.F.R.; Gonçalves, Odinei Hess; Leimann, Fernanda VitóriaSeeds from Araucaria angustifolia (Bertol.) Kuntze are consumed after cooking and their coats discarded. Both coats and the cooking water present phenolic compounds, which may be used to improve mechanical properties and provide antioxidant characteristics to films. The objective of this work was to obtain and pinhão coat extracts and to apply these polyphenolic-rich extracts in zein films. Phenolic compounds composition, extraction yield and antioxidant activity (DPPH, ABTS and FRAP) of the extracts were determined. The most abundant molecules present in the hydroethanolic extract were (+)-catechin and an (epi)catechin dimer, whereas protocatechuic acid were predominant in the both cooking water and ethanolic extracts. Glass transition temperature of zein was not found in the extract-loaded films. Morphological changes were also caused by the presence of the extracts yielding smoother surfaces. The extracts added to zein films led to a three-fold increase in tensile strength (from 5.80 MPa to 17.65 MPa) and two-fold increase in the elongation at break (from 1.60% to 3.18%).
- Efeito do teor de etanol na composição de compostos fenólicos extraídos da casca de sementes de pinhãoPublication . Santos, Carlos Henrique Koslinski; Dias, Maria Inês; Barros, Lillian; Baqueta, Michel Rocha; Coqueiro, Aline; Barreiro, M.F.; Gonçalves, Odinei Hess; Bona, Evandro; Silva, Marcos Vieira da; Ferreira, Isabel C.F.R.; Leimann, Fernanda VitóriaAs sementes de Araucaria angustifolia (Bertol.) Kuntze, designadas por pinhão, são normalmente consumidas após cozedura, sendo as cascas descartadas. Contudo, estes bioresíduos podem ser aproveitados como fonte de compostos antioxidantes. Neste trabalho, procedeu-se à extração e caracterização de antioxidantes a partir da casca de pinhão, previamente submetida a cozedura. As cascas, secas e trituradas, foram submetidas a extração (8,75 gcascas/100 mLsolvente) com misturas etanol:água (97% e 38%; v/v etanol) em homogeneizador Ultra-Turrax (a 12.000 rpm, 15 min e temperatura controlada num banho termostático a 42,5ºC). Os extratos foram posteriormente analisados quanto ao perfil fenólico (HPLC-DAD-ESI/MS), de acordo com um procedimento previamente otimizado por alguns dos autores [1]. Adicionalmente, foi avaliado o rendimento em volume de extrato obtido em relação ao volume inicial de solvente utilizado na extração, e analisada a microestrutura (Microscopia Eletrónica de Varrimento, MEV) das amostras após o processo de extração. Foram identificados treze compostos fenólicos, dez proantocianidinas (catequina e derivados de epicatequina), dois ácidos fenólicos (ácido protocatéquico e derivados de ácido ferúlico), um flavonol (quercetina-3-O-glucósido) e uma flavona (eriodictiol-O-hexósido). A extração usando um teor superior de etanol (97%) conduziu a uma concentração de compostos fenólicos extraídos superior (60,66±0,83 mg/gextrato), comparativamente com a extração efetuada com 38% de etanol (22,28±0,13 mg/gextrato). Quanto ao rendimento em volume foram obtidos os seguintes resultados: 44% e 62% para 97% e 38% de etanol, respetivamente. Com as imagens de MEV concluiu-se que um teor superior de água no solvente de extração favoreceu o inchamento e o dilaceramento das amostras. Em conclusão, a utilização de teores superiores em etanol favoreceu a extração de compostos fenólicos e conduziu à recuperação de um volume de extrato final superior.
- Systematic study on the extraction of antioxidants from pinhão (araucaria angustifolia (bertol.) Kuntze) coatPublication . Santos, Carlos Henrique Koslinski; Baqueta, Michel Rocha; Coqueiro, Aline; Dias, Maria Inês; Barros, Lillian; Barreiro, M.F.; Ferreira, Isabel C.F.R.; Gonçalves, Odinei Hess; Bona, Evandro; Silva, Marcos Vieira da; Leimann, Fernanda VitóriaFood by-products containing bioactive substances have attracted attention due to the possibility of adding values to residues of the food industry. In this work, the extraction of phenolic compounds from pinhão seed coats (Araucaria angustifolia (Bertol.) Kuntze) using a central composite rotatable design was applied to obtain prediction models for the extract volume yield, total phenolic content, total phenolic acids and total flavonoids. Principal component analysis and hierarchical cluster analysis were implemented showing an evident poor effect of the temperature on phenolic compounds extraction, which is in accordance with the prediction model obtained by the experimental design for total phenolic acids. Volume yield presented a high positive correlation with extraction temperature, followed by solvent composition. Scanning electron microscopy showed that higher temperatures and lower ethanol percentages resulted in highly defibrillated pinhão coats that retained more extract after the extraction process, leading to lower volume yield percentages.
- TPCS/PBAT blown extruded films added with curcumin as a technological approach for active packaging materialsPublication . Campos, Sabrina Silva; Oliveira, Anielle; Moreira, Thaysa Fernandes Moya; Silva, Tamires Barlati Vieira; Silva, Marcos Vieira da; Pinto, João A.; Bilck, Ana Paula; Gonçalves, Odinei Hess; Fernandes, Isabel P.; Barreiro, M.F.; Yamashita, Fabio; Valderrama, Patrícia; Shirai, Marianne Ayumi; Leimann, Fernanda VitóriaThe development of active packaging is a relevant topic demanding the development of films with diverse properties to preserve specific foodstuff. The objective of this work was to obtain extruded TPCS/PBAT films containing curcumin and evaluate it as an active antimicrobial and antioxidant packaging to protect chia oil from oxidative degradation. Morphology, thermal, mechanical, antimicrobial, and antioxidant evaluation of the films were conducted to determine whether the presence of curcumin affected the film’s properties. Infrared Spectroscopy indicated that curcumin addition affected the crosslinking reaction between citric acid and starch, which explains the changes in hydrophilicity and mechanical strength of the films. The incorporation of curcumin conferred antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria, as well as antioxidant activity. Films were tested as chia oil packaging, being verified that they successfully prevented oil degradation under accelerated stability test (60 °C for 7 days), demonstrating the feasibility of using TPCS/PBAT biodegradable films containing curcumin to obtain active packaging materials.