Percorrer por autor "Genena, Aziza Kamal"
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- Caracterização das propriedades químicas da semente, germinados, folha, flores e fruto de abóbora (Cucurbita pepo L.)Publication . Boschi, Keila; Pereira, J.A.; Genena, Aziza Kamal; Fernandes, Luana; Ramalhosa, ElsaO seguinte trabalho teve como objetivo principal proceder à caracterização química da semente, germinados (folha e raiz), folha, flores e fruto de abóbora da variedade Cucurbita pepo L.. As sementes foram adquiridas a um produtor local, tendo a germinação das sementes sido realizada em laboratório, e o cultivo da planta sido efetuado em estufa. Todas as amostras (sementes, germinados, folha, flores e fruto) foram congeladas e liofilizadas para a realização das análises posteriores. As amostras foram analizadas quanto ao seus valores de humidade, pH, acidez titulável (AT), açúcares totais, cinzas, proteínas, fibras, gordura, ácido ascórbico e carotenóides totais. Os valores de humidade variaram entre 5,79 - 95,64%, tendo sido a semente a amostra que apresentou a menor percentagem, valores de pH entre 5,47- 7,90, e uma AT entre 0,26 - 1,83 g de ácido cítrico/100 g de matéria seca, tendo sido o maior valor obtido para a folha do germinado. Quanto ao teor de açúcares totais, o fruto foi aquele que apresentou o maior conteúdo em açúcares (371±18 mg de glucose/g de matéria seca). A flor apresentou o maior teor em cinzas, 12,87±0,66%, ao contrário da semente que apresentou o menor valor, 4,38±0,02%. Já na análise de fibras, observou-se o oposto, apresentando a semente a maior percentagem (32,7±1,4%), em oposição à flor (9,1±0,1%). A semente também apresentou o maior teor de gordura de entre as amostras, 50,3±0,5%, e a flor a maior quantidade de proteínas, 8,8±1,7%. Em termos de ácido ascórbico, a flor foi a que apresentou o maior valor (114±1 mg Ac Ascórbico/100 g matéria seca), enquanto que a folha desenvolvida foi a que apresentou o maior teor de carotenóides totais (4,4±0,3 mg de β-caroteno/g de amostra). Em termos gerais, os diversos componentes apresentaram composições significativamente diferentes, tendo a flor se destacado como uma boa fonte de ácido ascórbico (vitamina C), e a folha desenvolvida como uma boa fonte de carotenoides.
- Caracterização fenólica da casca do fruto de Ficus carica L. por LC-DAD-ESI/MSPublication . Backes, Emanueli; Pereira, Carla; Leichtweis, Maria Gabriela; Barros, Lillian; Genena, Aziza Kamal; Barreiro, M.F.; Ferreira, Isabel C.F.R.Os efeitos adversos causados por alguns aditivos artificiais têm conduzido a um interesse crescente pela procura de alternativas naturais e sem toxicidade associada [1]. As antocianinas têm sido descritas como uma excelente fonte de corantes naturais para aplicação alimentar, aspeto impulsionado pela diversidade de cores que estas podem apresentar (vermelho, violeta, roxo e azul) e pelo facto de não existirem restrições quanto à sua utilização [2]. O processamento industrial de fruta gera grandes quantidades de resíduos (por exemplo frutos não conformes, restos de polpa, casca, caroços ou sementes), que poderão ser uma fonte importante de pigmentos e/ou moléculas bioativas, nomeadamente compostos fenólicos. Neste contexto, no presente trabalho a casca do fruto de Ficus carica L. (figo) foi estudada visando a sua valorização como fonte de corantes naturais, em particular como fonte de antocianinas, para aplicação na indústria alimentar. A sua caracterização foi efetuada por cromatografia líquida de alta eficiência acoplada a um detetor de díodos e a um espetrómetro de massa (LC-DAD-ESI/MS). A identificação dos compostos detetados foi realizada por comparação com os tempos de retenção, padrão de fragmentação e espectros UV-Vis de compostos padrão, ou recorrendo a dados existentes na literatura. Os cromatogramas foram adquiridos a 520 nm e a quantificação dos compostos identificados, através do uso de retas de calibração obtidas a partir de padrões comerciais. A casca de figo apresentou apenas uma antocianina, a cianidina-3-rutinósido ([M-H]- a m/z 595), sendo esta a molécula responsável pela coloração apresentada. Em síntese, esta matriz pode ser valorizada como uma fonte de ingredientes corantes, constituindo uma alternativa aos corantes artificiais.
- Characterization and application of pomegranate epicarp extracts as functional ingredients in a typical Brazilian pastry productPublication . Veloso, Felipe da Silva; Caleja, Cristina; Calhelha, Ricardo C.; Pires, Tânia C.S.; Alves, Maria José; Barros, Lillian; Genena, Aziza Kamal; Barreira, João C.M.; Ferreira, Isabel C.F.R.Currently, there is a clear tendency to incorporate natural ingredients into food and pharmaceutical formulations. Besides being well-accepted by consumers, these ingredients have less adverse side e ects than their artificial counterparts. The pomegranate processing industry produces large quantities of by-products that are discarded as bio-residues, despite containing bioactive compounds. Accordingly, the epicarp of two pomegranate varieties (Mollar de Elche and Purple Queen) was tested as a potential source of bioactive compounds with food application. The phenolic profile was identified by HPLC–DAD–ESI/MS, revealing fourteen phenolic compounds in both varieties (Purple Queen showed also three anthocyanins), with punicalagin isomers as the major compounds. Nonetheless, Mollar de Elche presented greater antioxidant and antibacterial activities. Despite this result, Purple Queen was selected to be tested as a new natural colouring and functionalizing ingredient in a Brazilian pastry product. The incorporation of the selected extract maintained the nutritional profile and provided a higher antioxidant activity compared to the traditional product. In this way, this work confirmed the possible use of pomegranate epicarp as a natural ingredient in the food industry, conferring dyeing and functionalizing e ects, and anticipating a possible valorisation of this bio-residue.
- Ficus carica L. and Prunus spinosa L. extracts as new anthocyanin-based food colorants: a thorough study in confectionery productsPublication . Backes, Emanueli; Leichtweis, Maria Gabriela; Pereira, Carla; Carocho, Márcio; Barreira, João C.M.; Genena, Aziza Kamal; Baraldi, Ilton J.; Barreiro, M.F.; Barros, Lillian; Ferreira, Isabel C.F.R.The present work describes the evaluation of fig peels and blackthorn fruit extracts as natural purple colorants in doughnuts (icing) and in a typical Brazilian pastry called “beijinho”. The extracts were screened for their antioxidant activity as well as their antibacterial capacity. Nutritionally, the employed extracts did not induce significant changes, contrarily to the observed for the rheological features, mainly the darker purple tone observed when blackthorn extract was used in the icing solution. After 24 h, both prepared formulations showed a decrease in color intensity, with no significant differences between fig and blackthorn extracts. In turn, the firmness and consistency of the doughnuts benefited from using natural colorants in the icing solution, while “beijinhos” became softer and chewier, which are valued attributes. A significant increase in the antioxidant and antimicrobial activities was also observed for both natural extracts. Accordingly, the evaluated extracts are promising candidates as natural food colorants.
- Ficus carica L. infructescence exploitation for anthocyanin-rich extracts preparation: optimized extraction, bioactivity, and application as food colorant.Publication . Backes, Emanueli; Pereira, Carla; Barros, Lillian; Prieto Lage, Miguel A.; Genena, Aziza Kamal; Barreiro, M.F.; Ferreira, Isabel C.F.R.Given its coloration, the peel of the infructescence of Ficus carica L. a by-product of fruit processing and/or consumption, was considered as a potential source of anthocyanin compounds. In the present study, different extraction techniques (heat, ultrasound, and microwave), aiming to recover the anthocyanin pigments and optimize its extraction, were compared by response surface methodology using a circumscribed central composite design of three variables with five levels. The relevant tested and optimized variables were time, temperature, and solvent composition (ethanol/water ratio) for heat and microwave extraction methods. For ultrasound method, the variables were the ultrasonic power, time, and solvent composition. The anthocyanin profile of the extract was determined by HPLC-DAD-ESI/MS, and the used criteria responses were the quantification of cyanidin 3-rutinoside (C) in the extracted residue (R; mg C/g R) and in the dried fig peel (P; mg C/g P dw), and the extraction yield of the obtained residue (g R/g P dw). Ultrasound extraction was the most effective method, yielding 17.0 mg C/g R, 3.11 mg C/g P dw, and 0.19 g R/g P dw at the optimal global extraction conditions (21 min, 310 W, and 100% of ethanol). Regarding its bioactive properties, the fig peel optimized extract showed antioxidant activity with an EC50 value of 2,447 mg/mL in the TBARS method and EC80 values of 52 and 1.62 mg/mL, in 60 and 120 min, respectively, in the OxHLIA assay. The extract also revealed antimicrobial activity in different Gram-positive and Gram-negative bacteria and did not present cytotoxicity against non-tumour cells. Its application in a food product was carried out through the preparation of a donut topping. The obtained results highlight the potential application of F. carica peels as sources of anthocyanins to be considered in food industry, adding the benefits derived from its antioxidant and antimicrobial activity to the colorant power.
- Punica granatum L. bioresidues as a source of compounds with bioactive propertiesPublication . Caleja, Cristina; Veloso, Felipe da Silva; Pires, Tânia C.S.; Pinela, José; Calhelha, Ricardo C.; Barros, Lillian; Genena, Aziza Kamal; Barreira, João C.M.; Ferreira, Isabel C.F.R.Punica granatum L. (pomegranate), is a fruit that has been widely studied due to its composition in specific phenolic compounds, having also been described as displaying excellent bioactive properties (antioxidant, antimicrobial, and anti-inflammatory activity), with preventive action against some diseases [1,2]. Given that the inedible part of this fruit can represent up to about 50% of the total weight, this bio-waste has high potential as a source of bioactive compounds of interest [3]. Thus, this study compared different types of solvents in the extraction of phenolic compounds from the exocarp, mesocarp and pericarp of two pomegranate varieties: Mollar de Elche (yellow pomegranate) and Purple Queen (red pomegranate). Chemical characterization was performed by HPLC-DAD-ESI/MS and revealed the presence of fourteen phenolic compounds in the Mollar de Elche, highlighting punicalagin and galloyl-HHDP-glucose as the major compounds. The extracts of pomegranate Purple Queen showed the same 14 phenolic compounds, despite being present in lower amounts, but this cultivar revealed also three anthocyanins, which may justify the characteristic reddish color of its bark. Additionally, the antioxidant activity (inhibition of thiobarbituric acid reactive species formation in brain homogenates and inhibition of oxidative hemolysis, OxHLIA), antibacterial (against a panel of 5 Gram-positive bacteria and 3 Gram-negative bacteria, using the microdilution method), anti-inflammatory activity (rat macrophage cells), and cytotoxic potential (in human tumor cell lines by the sulforhodamine B method). Mollar de Elche stood out for its higher antioxidant and antibacterial activity, and cytotoxicity. In general, the different extracts obtained from the by-products of both pomegranate varieties represent a source of phenolic compounds that allow it to exhibit excellent bioactive properties with potential application in the food industry as a natural ingredient, which will allow valuing these bio-residues.
- Recovery of bioactive anthocyanin pigments from Ficus carica L. peel by heat, microwave, and ultrasound based extraction techniquesPublication . Backes, Emanueli; Pereira, Carla; Barros, Lillian; Prieto Lage, Miguel A.; Genena, Aziza Kamal; Barreiro, M.F.; Ferreira, Isabel C.F.R.Due to its coloration, the fig (Ficus carica L.) peel, a by-product of fruit processing and/or consumption, is a potential source of anthocyanin compounds. In the present study different extraction techniques (heat, ultrasound, and microwave) were compared aiming to recover the anthocyanin pigments and optimize its extraction conditions. A response surface methodology tool with three factors and five levels for each factor was used according to a circumscribed central composite design. The variables tested for the heat and microwave extraction methods were time, temperature, and solvent proportion (ethanol/water ratio), meanwhile, for the ultrasound method, the variables tested were the ultrasonic power, time, and solvent proportion. The anthocyanin composition of the extract was determined by HPLC-DAD-ESI/MS, and the used criteria responses were: i) quantification of cyanidin 3-rutinoside (C) in the extracted residue (mg C/g R) and in the dried peel (mg C/g P dw), and the extraction yield of the obtained residue (g R/g P dw). Ultrasound extraction was the most effective method, yielding 3.82 mg C/g R at the optimal global extraction conditions (21 min, 310 W, and 100% of ethanol). Additionally, the solid-to-liquid ratio effect was studied at the optimal conditions, using a dose-response format, in view of its plausible transference to industrial level. For the ultrasound method, an increased non-linear relationship was observed for concentrations in the range 5 to 200 g/L, being the optimal solution close to 150 g/L. In brief, the obtained results show the potential of fig peels as a source of anthocyanin pigments, with potential uses in various industrial fields, such as food, pharmaceutical, and cosmetic.
- Use of water-soluble curcumin in TPS/PBAT packaging material: interference on reactive extrusion and oxidative stability of chia oilPublication . Mücke, Naiara; Silva, Tamires Barlati Vieira; Oliveira, Anielle; Moreira, Thaysa Fernandes Moya; Venancio, Camila da Silva; Marques, Leila Larisa Medeiros; Valderrama, Patrícia; Gonçalves, Odinei Hess; Silva-Buzanello, Rosana; Yamashita, Fabio; Shirai, Marianne Ayumi; Genena, Aziza Kamal; Leimann, Fernanda VitóriaThe reactive extrusion technique is efficient in the incorporation of bioactive compounds for active packaging development. The application of curcumin, a strong antioxidant in its pure, isolated form to obtain active packaging has already been investigated; however, the use of water-soluble curcumin (WSC) in thermoplastic starch/poly(butylene adipate-co-terephthalate) (TPS/PBAT) films has not yet been investigated. It is important to determine how WSC would affect starch esterification reaction during reactive extrusion (REx). The use of WSC at 0.5%wt led to an increase in tensile strength, elongation at break, and Young’s modulus. A reduction in starch esterification was observed; however, an improvement in TPS/PBAT compatibility was detected by infrared spectroscopy, X-ray diffraction, and scanning electron microscopy images. It is worth noting that WSC addition resulted in an increase in the film’s solubility and water vapor permeability, due to the hydrophilic character of the WSC. The films were used to package chia oil, and the oxidative stability data were evaluated by UV-Vis spectroscopy coupled with principal component analysis. The addition of WSC (0.5%wt) in the films led to the improvement of the oil oxidative stability, suggesting that using water-soluble curcumin may be a promising alternative to active packaging in the case of reactive extruded films.