Browsing by Author "Machado, A.V."
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- Active Food Packaging with Antioxidant Properties: Incorporation of Plant Extracts in Polymeric Matrices to Extend Food Shelf-lifePublication . Sanches-Silva, A.; Carvalho-Costa, D.; Reis, A.R.; Albuquerque, T.G.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Costa, H.S.Antioxidants (AOs) play an important role in biological processes because they prevent the effect of reactive oxygen species, protecting against cancer, inflammatory processes, cardiovascular diseases and aging, and consequently the degenerative diseases associated with it. In foods, AOs prevent oxidation which causes their deterioration and limits their shelf lives. Synthetic antioxidants are very effective against lipid oxidation, however some of them have been associated to toxic effects, which have increased the interest of food industry for natural substances also effective against this phenomenon. One of the main roles of food packaging is to retard the natural processes that lead to food deterioration. AOs can be incorporated into food packaging and be released by a controlled mechanism of diffusion. The use of AOs in food packaging may delay both lipid oxidation and protein denaturation. Packaging designed to foster desirable interactions with its content has been called active packaging. This innovative food packaging concept can extend the shelf life of food through the release of AOs by a controlled mechanism of diffusion from the packaging to the food surface and dissolution in it or in the inner atmosphere of the product or by the scavenging of free radicals. The release mechanism provides a continuous replenishment of AOs to foods and therefore, can reduce the direct addition of chemicals to the food. Rosemary (Rosmarinus officinalis L.) is a widely consumed aromatic herb that belongs to the Lamiaceae family. It is a xeromorphic species that grows spontaneously on sand, cliffs and stony places near the sea in many parts of the world. The fresh and dried leaves are frequently used as a food preservative and in traditional Mediterranean cuisine as a flavouring agent, being used with meat, fish, baked potatoes and sauces. Due to the influence of different factors such as growing conditions on the content of natural antioxidants, different rosemary commercial brands were compared. Antioxidant activity (radical 2,2-diphenyl-1-picrylhidrazyl (DPPH) scavenging activity), total phenolics and total flavonoids were evaluated. Moreover, their content on natural antioxidants, carnosic acid, carnosol and rosmarinic acid was quantified by an Ultra High Performance Liquid Chromatographic method coupled with a diode array detector (UHPLC-DAD) which has been validated in our laboratory. Finally, carotenoids and vitamin E were also evaluated following another UHPLC-DAD optimized in our laboratory. Rosemary extract has been approved as food additive (Directives 2010/67/EU and 2010/69/EU). In line with this, rosemary was also used to obtain a rosemary extract with high antioxidant activity. In fact, different solvents were tested in order to evaluate which originated higher antioxidant activity. Those with higher antioxidant activity and individual antioxidants content were used to produce active food packaging. Due to environmental motivation there is an increasing interest in the use of biodegradable/compostable packaging and/or edible materials. This tendency increases when materials come from industrial waste or renewable resources. Although rosemary extract has already been used in non-biodegradable matrices, to our knowledge, it is the first time that it has been used to produce biodegradable active packaging. Therefore, different polymeric matrices were evaluated, biodegradable and non-biodegradable. Migration tests were carried with food simulants at standard conditions. Promising results were found until now, and the new packaging material will also be tested in contact with foods in order to check their capacity to inhibit lipid oxidation, allowing to preserve the quality of foodstuffs and to increase their shelf-life. Our research group of the Department of Food and Nutrition from the National Institute of Health Dr. Ricardo Jorge (INSA) has great experience in the development of analytical methods for the determination of bioactive compounds (namely antioxidants) in foodstuffs and food byproducts as well as in food-packaging interactions and mathematical modelling of migration. Moreover it has a large number of peer-review publications in this field as well as national and international collaborations with other researcher groups that work in the same or complementary fields. Some of the groups that work in close collaboration with ours include the research group of Prof. Jaime López Cervantes from the Technological Institute of Sonora (México) and the research groups of Prof. Perfecto Paseiro and Prof. José Manuel Cruz from the Universities of Santiago de Compostela and Vigo, respectively. In the future, this research group intends to extend the research to other aromatic herbs and food by-products in order to search for new and interesting extracts that can be used to produce antioxidant active food packaging, with special interest in biodegradable matrices. The final aim is to be able to extend food shelf life reducing the direct additives of antioxidants to foods with positive health implications, at long term, for the consumers.
- Advances in phenolic compounds analysis of aromatic herbs and their potential applications.Publication . Carvalho-Costa, D.; Costa, H.S.; Reis, A.R.; Albuquerque, T.G.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.; PhenolicIntroduction: Herbs can be considered important sources of antioxidants and have a long history of medicinal and culinary applications. The use of plants as sources of antioxidants for nutritional and preservation purposes in the food industry is currently growing. Materials and Methods: An extensive bibliographic review on the methods for analysis of phenolic compounds present in herbs was carried out. Results, Discussion and Conclusion: Plant derived phenolic compounds can be divided in four groups: phenolic acids, phenolic diterpenes, flavonoids and volatile compounds. Considering the first three groups, the identification and quantification of the compounds in the literature is accomplished using High Performance Liquid Chromatography while for volatile compounds, the identification and quantification is accomplished with Gas Chromatography. Several herbs, such as sage (Salvia officinalis), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), oregano (Origanum majorana), dandelion (Taraxacum officinale), peppermint (Mentha piperita) and basil (Ocimum basilicum) were analyzed in different studies regarding their phenolic compounds. The major phenolic acids found in herbs were ferulic, caffeic, neochlorogenic and rosmarinic. In terms of phenolic diterpenes, carnosol, rosmanol and carnosic acid were the most reported. Regarding flavonoids, luteolin, quercetin and apigenin were predominant. Concerning volatile compounds, thymol, carvacrol and eugenol were the most common. The herbs with more antioxidant potential regarding their composition on phenolic compounds were compared and the potential of utilisation of these food matrices for newer applications such as active packaging was discussed.
- Aromatic herbs: determination of phenolic compounds by ultra-high performance liquid chromatography with diode array detectionPublication . Reis, A.R.; Costa, H.S.; Carvalho-Costa, D.; Albuquerque, T.G.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.Aromatic herbs contain phenolic compounds which have attracted scientific interest and consumers because of their health-promoting effects as antioxidants. Seven plants, Origanum majorana L. (marjoram), Ocimum basilicum L. (basil), Thymus vulgaris (thyme), Artemisia dracunculus L. (tarragon), Origanum vulgare L. (oregano), Mentha piperita L. (peppermint) and Rosmarinus officinalis L. (rosemary), have been examined in order to determine their phenolic composition. Ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD) method was developed for the identification and quantification of phenolic compounds in the aforementioned plants. All samples were extracted with methanol. Chromatographic separation was performed with an Acquity UPLC® BEH Shield guard-column (5 mm, 2.1 mm I.D., 1.7 µm particle size) and an Acquity UPLC® BEH Shield RP18 (100 mm, 2.1 mm I.D., 1.7 µm particle size). Mobile phases were (A) water: acetic acid 0.1 % (v/v); (B) acetonitrile: acetic acid 0.1 % (v/v). Total phenolic content of the plants was also determined spectrophotometrically applying the Folin-Ciocalteu method. The major phenolic acids found in herbs were ferulic, caffeic and rosmarinic. In terms of volatile compounds thymol, carvacrol and eugenol were determined. The selected aromatic herbs are good sources of phenolic compounds which extend their potential of application to the cosmetics, pharmaceutical and food packaging industries besides the food industry.
- Atividade antioxidante do alecrim (Rosmarinus officinalis L.): efeito do solvente de extraçãoPublication . Costa, D.; Costa, H.S.; Albuquerque, T.G.; Ramos, F.; Castilho, M.C.; Machado, A.V.; Sanches-Silva, A.O alecrim (Rosmarinus officinalis L.) é um subarbusto densamente ramoso e foliado e pertence à família Lamiaceae. É utilizado como erva aromática e foi recentemente aprovado como aditivo alimentar (Directivas 2010/67/UE e 2010/69/UE). As propriedades antioxidantes do alecrim tornam-no muito importante como conservante dos alimentos, e estas propriedades devem-se principalmente aos seus compostos fenólicos: ácidos fenólicos, diterpenos fenólicos, flavonóides e óleos voláteis. Neste estudo, o alecrim foi extraído com diferentes solventes e a sua actividade antioxidante foi testada através de três métodos: ensaio do DPPH● (2,2-difenil-1-picril-hidrazilo), determinação dos compostos fenólicos totais e determinação dos flavonóides totais. O alecrim foi extraído com acetona, metanol, etanol e hexano/etanol. No ensaio do DPPH● adicionou-se uma alíquota de extrato (50 μL) a 2 mL de solução metanólica de DPPH● (3,6 × 10-5 M) e agitou-se. Após 30 min, mediu-se a absorvência a 515 nm. Para a determinação dos compostos fenólicos totais adicionou-se uma alíquota de 1 mL da solução teste, a 7,5 mL de reagente Folin–Ciocalteu. Deixou-se à temperatura ambiente durante 5 min e adicionou-se 7,5 mL de solução aquosa de Na2CO3 (60 mg/mL). Mediu-se a absorvência a 725 nm, após 2 h. Para a determinação dos flavonóides totais a uma alíquota de 1 mL da solução, adicionou-se água até perfazer 5 mL. De seguida adicionou-se 0,3 mL de NaNO3 (5%, p/v) e homogeneizou-se. Após 5 minutos, juntou-se 0,6 mL de AlCl3 (10%, p/v) e homogeneizou-se novamente. Ao fim de 6 min, adicionou-se 2 mL de NaOH 1 M e 2,1 mL de água. A absorvência foi medida a 510 nm. No ensaio do DPPH●, para os extratos em metanol, etanol, hexano/etanol e acetona, os valores de EC50 (concentração de extrato que produz uma inibição de 50% do DPPH•) obtidos foram 1,66 ± 0,04; 2,90 ± 0,05; 2,97 ± 0,03; e 3,04 ± 0,02 mg/mL, respectivamente. No segundo ensaio, os resultados obtidos, em mg GAE (equivalentes de ácido gálico)/g de extrato, foram 82,4 ± 2,43; 24,7 ± 0,74; 26,4 ± 1,46; e 24,8 ± 1,58, respectivamente. Relativamente ao terceiro ensaio, os resultados obtidos, em mg ECE (equivalentes de epicatequina)/g de extrato, foram 74,5 ± 5,24; 18,72 ± 1,40; 36,5 ± 17,71; e 13,9 ± 5,55, respectivamente. Verificou-se que o melhor solvente, entre os testados, foi o metanol, sendo as diferenças obtidas estatisticamente significativas (P <0,05).
- Carotenoids and α-tocopherol content of some aromatic herbs by ultra-high performance liquid chromatography with diode array detectionPublication . Carvalho-Costa, D.; Albuquerque, T.G.; Costa, H.S.; Reis, A.R.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.Carotenoids are colorful plant pigments with antioxidant properties that can prevent some forms of cancer and heart disease as well as enhance immune response to infections. Several aromatic herbs, such as Origanum majorana L. (marjoram), Ocimum basilicum L. (basil), Thymus vulgaris (thyme), Artemisia dracunculus L. (tarragon), Origanum vulgare L. (oregano), Mentha piperita L. (peppermint) and Rosmarinus officinalis L. (rosemary) have been examined in order to determine their carotenoids and vitamin E composition. Carotenoids were extracted from aromatic herbs with a mixture of hexane/ethanol, 4:3 (v/v). All samples were subjected to a procedure with and without saponification step. Separation and quantification was performed by Ultra-High Performance Liquid Chromatography with diode array detection (UHPLC-DAD). Chromatographic separation was performed with Acquity UPLC® BEH C18 analytical column (50 mm, 2.1 mm I.D., 1.7 µm particle size) and an Acquity UPLC® BEH C18 guard column (5.0 mm, 2.1 mm I.D., 1.7 µm particle size). Mobile phases were (A) ultrapure water; (B) acetonitrile/methanol (containing 0.05 M ammonium acetate)/dichloromethane (75:20:5, v/v/v). The flow-rate was 0.5 mL/min. In the case of rosemary, lutein, zeaxanthin, α-carotene and α-tocopherol were quantified and saponification decreased the amount of these carotenoids. The analysed aromatic herbs can be considered good sources of carotenoids, although a great variability was found among their content. Due to the putative health benefits of these compounds, their consumption shall be encouraged and promoted.
- Carotenoids and α-tocopherol determination in common aromatic herbsPublication . Sanches-Silva, A.; Carvalho-Costa, D.; Albuquerque, T.G.; Reis, A.R.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Costa, H.S.Aromatic herbs have long been recognised for their pleasant flavour and therapeutic properties. Nowadays there is an increasing interest on their study, especially in what concerns to their bioactive compounds with potential health benefits. The objective of this study was to analyse seven aromatic herbs regarding their content on carotenoids (zeaxanthin, lutein, β-cryptoxanthin, lycopene, α-carotene and β-carotene) and α-tocopherol. Samples were acquired in supermarkets of Lisbon in the dried form. The following aromatic herbs were selected for the study: basil (Ocimum basilicum L.), marjoram (Origanum majorana L.), oregano (Origanum vulgare L.), peppermint (Mentha piperita L.), rosemary (Rosmarinus officinalis L.), tarragon (Artemisia dracunculus L.) and thyme (Thymus vulgaris). Carotenoids were extracted from samples with hexane/ethanol, 4:3 (v/v). In the case of peppermint, thyme, basil and tarragon, two sample preparation procedures were compared, with and without saponification with methanolic KOH (10%, w/v) during 4 h. Ultra-High Performance Liquid Chromatography with diode array detection (UHPLC-DAD) was used for quantification. An Acquity UPLC® BEH C18 guard column (5.0 mm x 2.1 mm I.D., 1.7 µm particle size) and an Acquity UPLC® BEH C18 analytical column (50 mm x 2.1 mm I.D., 1.7 µm particle size) were selected for the separation. The mobile phase was a gradient of solvent (A) ultrapure water and solvent B [acetonitrile/methanol (containing 0.05 M ammonium acetate)/dichloromethane (75:20:5, v/v/v)]. The run time was 22 min and the flow-rate was 0.5 mL/min. Saponification is a common step for the determination of carotenoids in foods from plant origin because it allows the hydrolysis of carotenoid esters and carotenol esters, and eliminates chlorophylls and other interfering substances like unwanted lipids. However in the analysis of peppermint, thyme, basil and tarragon, saponification degraded carotenoids. Lutein was found in all the studied aromatic herbs (from 389 to 20739 µg/100 g of sample, for tarragon and thyme, respectively) and zeaxanthin in all except one. Remarkable amounts of lutein were found in thyme, indicating this particular herb as an excellent source of this carotenoid. The highest content of β-carotene was found for peppermint (1149 µg/100 g of sample) followed by marjoram (359 µg/100 g of sample). The quantification of β-carotene in rosemary, peppermint, marjoram and oregano indicates that these aromatic herbs present provitamin A activity. α- tocopherol was quantified in rosemary (9.3 mg/100 g of sample) and oregano (8.1 mg/100 g of sample). Comparing all the analysed herbs, rosemary presented the highest concentrations of α-tocopherol and zeaxanthin, and considerable concentrations of lutein. The intake of aromatic herbs may contribute for the total daily intake of antioxidants, which have positive health benefits, like prevention of cardiovascular disease and cancer, and may help to reduce the addition of sugar and salt to foods; therefore their consumption shall be encouraged and promoted.
- Current state of the Rose4Pack workplanPublication . Sanches-Silva, A.; Carvalho-Costa, D.; Reis, A.R.; Albuquerque, T.G.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Costa, H.S.
- Embalagens - veículo de informação alimentar: conhecimento dos hábitos de reciclagem dos consumidores portuguesesPublication . Carvalho-Costa, D.; Costa, H.S.; Albuquerque, T.G.; Reis, A.R.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.Atualmente há uma grande variedade de embalagens, tanto no que se refere ao tipo de materiais, como às propriedades desses mesmos materiais (resistência, permeabilidade ao oxigénio ou ao vapor de água, entre outras). A forma como são utilizadas as embalagens, respeitando ou não as indicações do fabricante, poderá ter um grande impacto na segurança e na saúde dos consumidores. Deste modo, é relevante que se obtenham dados acerca do conhecimento dos consumidores tanto em relação à identificação dos materiais das embalagens, como em relação à utilização das mesmas. Considerando que a grande maioria dos alimentos são comercializados embalados, o impacto ambiental das embalagens quando não é feita a sua reciclagem, poderá ser significativo. Assim, é de grande importância obter informação sobre os hábitos de reciclagem da população portuguesa. Foi realizado um estudo baseado num questionário para avaliar o grau de conhecimento dos consumidores sobre as embalagens, principalmente as plásticas, incidindo em temas como a preocupação em reciclar as mesmas ou de utilizar as mesmas só nas condições indicadas pelo fabricante. O estudo foi aplicado a 179 indivíduos, na sua maioria jovens adultos. Verificou-se que cerca de 60% dos inquiridos considera que o tipo de embalagem é relevante para a escolha dos produtos. Aproximadamente 89% dos inquiridos consideram que o plástico é o tipo de material mais frequentemente utilizado para embalar os produtos alimentares que adquirem. Cerca de 26% dos inquiridos afirma nunca ou raramente reciclar as embalagens plásticas de uso alimentar, enquanto 43% afirma reciclar sempre. Aproximadamente 12% refere procurar e cumprir as indicações do fabricante (adequado para lavar na máquina, material aprovado para uso alimentar, reciclável, adequado para micro-ondas), apesar de desconhecer os riscos de uma inadequada utilização, enquanto 26% não procura as indicações nas embalagens e cerca de 6% não se encontra familiarizado com os símbolos das embalagens plásticas. Os resultados indicam a necessidade de consciencializar a população para os perigos relacionados com o uso indevido das embalagens, bem como para a importância da reciclagem.
- Estudo para avaliar o grau de conhecimento dos consumidores sobre embalagens plásticasPublication . Carvalho-Costa, D.; Costa, H.S.; Reis, A.R.; Albuquerque, T.G.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.Actualmente, a grande maioria dos alimentos disponíveis nos supermercados encontram-se embalados. As embalagens podem ser muito variadas, quer no que respeita à permeabilidade ao oxigénio ou ao vapor de água, ao tipo de material/materiais, como à resistência. A escolha das mesmas deve ser sempre realizada de acordo com o tipo de alimento a que se destina. Foi realizado um estudo baseado num inquérito por questionário para avaliar o grau de conhecimento dos consumidores sobre as embalagens, principalmente as plásticas, incidindo em temas como a preocupação com a reciclagem ou a utilização das embalagens de acordo com as indicações do fabricante Dado o interesse crescente nos novos tipos de embalagens como as embalagens ativas, que interagem com o alimento embalado com o objetivo de prolongar o tempo de conservação ou de manter/melhorar o estado do alimento embalado, e as embalagens inteligentes que monitorizam o estado de conservação dos alimentos ou do ambiente que os envolve, estas também foram incluídas no estudo. O estudo foi aplicado a cerca de 200 indivíduos, na sua maioria jovens adultos. Verificou-se que cerca de 60% dos inquiridos não tinha conhecimento da existência de embalagens activas nem de embalagens inteligentes, mas aproximadamente 90% dos mesmos estaria disposto a adquirir alimentos nestas embalagens. Cerca de 55% dos inquiridos afirma cumprir as indicações do fabricante aquando da utilização de recipientes de plástico, conhecendo os riscos derivados da má utilização deste tipo de materiais. Aproximadamente 40% dos inquiridos recicla sempre as embalagens de plástico, enquanto cerca de 20% raramente o faz. A análise dos resultados teve em linha de conta a faixa etária e o nível de escolaridade dos inquiridos. Os resultados indicam a necessidade de consciencializar a população para os perigos relacionados com o uso indevido das embalagens, a importância da reciclagem bem como para os benefícios/riscos dos novos tipos de embalagens.
- Folheto do Projeto Rose4PackPublication . Silva, A. Sanches; Costa, H.S.; Ramos, F.; Castilho, M.C.; Machado, A.V.; Nóbrega, J.M.; Carneiro, O.S.; Albuquerque, T.G.; Cunha, E.