137 research outputs found

    Physicochemical parameters, phytochemical composition and antioxidant activity of the algarvian avocado (Persea americana Mill.)

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    The physical, chemical and nutritional properties of Persea americana fruits variety ‘Hass’ produced in the Algarve region were studied. Edible and non-edible parts of the fruits (pulp, seeds and peel) were compared considering their possible contribution to improve the sustainability of the food and pharmaceutical industries. The nutritional contents evaluated were moisture, ash, proteins, fat, total soluble solids and acidity. It were also evaluated the contents of bioactive compounds (phenolics, flavonoids, carotenoids, ascorbic acid and vitamin E) and their influence in the antioxidant activity exhibited by the fruit material. The results of the analysis demonstrated that the Algarvian avocado has physical and chemical characteristics comparable or superior to avocados from other growing regions around the world namely, Mexico and California. With regard to the contents of bioactive compounds, the pulp of the Algarvian avocado proved to be rich in carotenoids (0.815±0.201 mg/100g), phenolic compounds (410.2±69.0 mg/100g) and flavonoids (21.9±1.0 mg/100g). The skin was superior to the pulp in the contents of all these compounds with 2.585±0.117 mg/100g of carotenoids, 679.0±117.0 mg/100g of total phenolics and 44.3±3.1 mg/100g of flavonoids. The seed, in turn, was the part of the fruit with the highest total phenolic content (704.0±130.0 mg/100g) and flavonoids (47.97±2.69 mg/100g). Regarding the concentration of vitamins C and E, the highest values were found in the pulp (5.36±1.77 mg/100g of vitamin E) and skin (4.1±2.7 mg/100g of vitamin C). The extracts obtained from the seeds demonstrated higher in vitro DPPH· assay antioxidant activity (43%) than those obtained from the skin (35%) and the fruit pulp (23%). The contents of carotenoids, phenolic compounds and flavonoids found in the non-edible parts of the Algarvian avocado demonstrated that these byproducts could be an interesting inexpensive raw material for the food and cosmetic industries.info:eu-repo/semantics/publishedVersio

    Comparison between the phytochemical and antioxidant properties of plants used in plant infusions for medicinal purposes

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    It has already been acknowledged among the medical community that plant based treatments represent an interesting contribution to modern therapeutics due to the presence in their composition of molecules with pharmacological and antioxidant action. The aim of this study was to evaluate the contents of total phenolics, flavonoids, and caffeine in six plants used traditionally by healers in Portugal and usually consumed as tea or infusion namely: Camellia sinensis, Melissa officinalis, Lippia citriodora, Cymbopogon citratus, Matricaria chamomilla, and Tilia cordata. Total phenolics ranged from 32.05 mg GAE/100g for aqueous extracts obtained from leaves of L. citriodora to 145.28 mg GAE/100g for aqueous extracts of C. sinensis. Significant variations in the flavonoid content were also found among analyzed plants and depending on the nature of the extract, with C. sinensis standing out again with the highest values (78.31 mg CE/100g) and the ethanolic extract obtained from the flowers of T. cordata exhibiting the lowest content (25.15 mg CE/100g). The concentration of caffeine was also very diverse and followed the sequence M. officinalis < T. cordata < C. citratus < M. chamomilla < L. citriodora < C. sinensis. The antioxidant activity of each plant was evaluated in vitro using a standard model system, the DPPH assay, and was found to vary according to C. citratus (90.9%) > C. sinensis (87.8%) > M. officinalis (50.7%) > M. chamomilla (45.3%) > T. cordata (32.2%) > L. citriodora (28.0%). The aqueous extracts presented lower antioxidant activity than the corresponding ethanolic ones.info:eu-repo/semantics/publishedVersio

    Recent advances regarding the phytochemical and therapeutic benefits of diospyros kaki fruit

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    Lately, several studies have demonstrated the health benefits associated with natural compounds consumption. Fruit phenolics, lycopene and ascorbic acid, have strong antioxidant, anti-inflammatory, antimugenic and anticarcinogenic activities. In the present study parameters related to fruit quality and climacteric conditions, such as color, moisture, pH, water activity, total phenolic compounds, ascorbic acid and lycopene content were analyzed. Diospyros kaki cv. chocolate fruits were extracted with different solvents, such as methanol, ethanol and water. Total polyphenolics of each extract determined by Folin-Ciocalteu method were found to be higher in methanolic extract and lower in ethanol considering Diospyros fruits with peel. Significant variations were found in the levels of these parameters according to different geographic regions. Results support the importance of Diospyros kaki cv. chocolate fruits, Portuguese cultivar, as a functional food with high antioxidant potential that may have beneficial effects against oxidative human damage.info:eu-repo/semantics/publishedVersio

    Subprodutos e desperdícios da produção vinícola para a obtenção de nutracêuticos

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    Atualmente, a União Europeia encoraja o uso de subprodutos agro-alimentares como forma de obtenção de nutracêuticos, tais como proteínas, fibras, polissacarídeos, fitoquímicos, entre outros. A reutilização destes subprodutos pode passar pela produção de ingredientes funcionais, com aplicação na indústria alimentar, farmacêutica e cosmética. Os polifenóis apresentam diferentes propriedades fisiológicas associadas aos diferentes grupos de compostos bioativos, tais como antioxidante, cardioprotetora, anticarcinogénica, anti-inflamatória, antimicrobiana. O benefício do consumo de vinho tinto é já reconhecido, sendo este associado à presença de certos compostos polifenólicos, tais como resveratrol, quercetina e catequina; no entanto, estes não são suficientes para caracterizar o vinho como alimento funcional. Por esse motivo, o interesse por ingredientes funcionais com base em extratos de vinho de uva e de videira (subprodutos e desperdícios da produção vinícola), tem vindo a aumentar, fomentando o conceito de sustentabilidade.info:eu-repo/semantics/publishedVersio

    Propriedades biológicas das sementes da papaia (Carica papaya L.): valorização de um resíduo alimentar

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    O interesse pelo reaproveitamento das diferentes partes dos frutos e vegetais tem vindo a aumentar, não só com o intuito de promover a sustentabilidade ambiental, como também pelas demais propriedades benéficas, que vários autores já identificaram. A concentração em compostos bioativos das sementes da papaia, que são quase sempre desperdiçadas, levou ao estudo de usos alternativos das mesmas. Neste âmbito, quantificou-se a concentração de compostos não-nutritivos das sementes da Carica papaya L., nomeadamente fenólicos e flavonoides totais, avaliando-se também a atividade antioxidante das mesmas. Os resultados obtidos permitiram concluir que a concentração em compostos bioativos é influenciada pelo tipo de solvente extrator utilizado (água ou etanol). O extrato aquoso evidenciou maior concentração de flavonoides, enquanto o extrato etanólico mostrou maior quantidade de compostos fenólicos. A atividade antioxidante foi avaliada, usando-se o ácido ascórbico como controlo. Apesar de a atividade antioxidante do ácido ascórbico ter sido superior à observada nos dois extratos, estes últimos poderão ser utilizados como antioxidantes naturais, sendo o extrato etanólico o que permite tirar maior partido da atividade antioxidante dos compostos bioativos das sementes da Carica papaya L.. Apesar das evidências de que as sementes da papaia podem ser utilizadas como antioxidantes naturais, nas indústrias alimentar e farmacêutica, torna-se necessário aprofundar a investigação no sentido de avaliar a toxicidade das mesmas.info:eu-repo/semantics/publishedVersio

    Antimicrobial natural products

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    Our ethnopharmacological studies, in several Angolan regions, showed that Cymbopogon citratus (DC) Stapf., it´s applied in folk medicine to treat several diseases In order to validate antibacterial activity several studies were performed using 12 bacterial strains. The essencial oil samples of Cymbopogon citratus, obtained by hydro-distillation, were analysed by GC and GC-MS. Constituents were identified and tested for their antimicrobial activity by the disc agar diffusion technique and the dilution technique against Staphylococcus aureus (ATCC 25923) and Staphylococcus epidermidis (ATCC 12228) and other bacterial strains. Broad spectrum antibacterial activity was exhibited by the Cymbopogon citratus essential oil against both Gram-positive and Gram-negative bacteria as well as for MRSA that exhibited more sensitive towards the test substance compared to the non-MRSA. Our work was the first to show that Cymbopogon citratus essential oil has higher antibacterial activity against MRSA strains, than commercial antibiotics. These discover opens a new hope to fight against nosocomial infection.info:eu-repo/semantics/publishedVersio

    Chemical composition and antioxidant activity of portuguese diospyrus kaki fruit by geographical origins

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    Lately, several studies have demonstrated the health benefits associated with natural compounds consumption. Fruit phenolics, lycopene and ascorbic acid, have strong antioxidant, anti-inflammatory, antimugenic and anticarcinogenic activities. In the present study parameters related to fruit quality and climacteric conditions, such as color, moisture, pH, water activity, total phenolic compounds, ascorbic acid and lycopene content were analyzed. Diospyros kaki cv. chocolate fruits were extracted with different solvents, such as methanol, ethanol and water. Total polyphenolics of each extract determined by Folin-Ciocalteu method were found to be higher in methanolic extract (106.2 mg/100g sample) and lower in ethanol (21.9 mg/100g sample) considering Diospyros fruits with peel. The antioxidant activity (AA) was evaluated by an in vitro model system trough 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity (DPPH•) assay. Significant variations were found in the levels of these parameters according to different geographic regions. It was possible to describe correlationsbetween the antioxidant compounds (polyphenolics, ascorbic acid and lycopene) and the antioxidant activity. Aqueous solvent was more effective on the extraction of antioxidant compounds from Portuguese Diospyros fruits with 52% radical scavenging activity. Results support the importance of Diospyros kaki cv. chocolate fruits,Portuguese cultivar, as a functional food with high antioxidant potential that may have beneficial effects against oxidative human damage.info:eu-repo/semantics/publishedVersio

    Alimentos funcionais: uma tendência de mercado

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    A mudança dos hábitos e costumes da sociedade moderna que tem vindo a acontecer nas últimas décadas, conduziu a uma alteração dos padrões alimentares e, consequentemente, a consumidores mais exigentes e atentos aos benefícios que cada género alimentício aporta. Como resposta a esta situação, a indústria alimentar reforçou a sua política de investigação, surgindo um novo tipo de alimentos, denominados alimentos funcionais, os quais são caracterizados como alimentos comuns, integrados na dieta e capazes de produzir benefícios específicos para a saúde. As substâncias biologicamente ativas presentes nos alimentos funcionais podem ser classificadas em: probióticos e prebióticos, alimentos sulfurados e azotados, pigmentos naturais e vitaminas, compostos fenólicos, ácidos gordos polinsaturados e fibras alimentares. Este trabalho teve como objetivo realizar uma revisão bibliográfica fundamentada que sustente a importância dos alimentos funcionais como géneros alimentícios integrantes da dieta alimentar, apresentando as diferentes classes de compostos bioativos que os integram e divulgando os seus efeitos benéficos à saúde. A pesquisa de informação para a realização deste trabalho foi efetuada recorrendo aos motores de busca PubMed, Science Direct, Google Scholar e Scielo. As palavras-chave utilizadas foram, maioritariamente, alimento funcional, ingrediente funcional, componentes bioativos, prebióticos, consumo. A pesquisa bibliográfica teve por base artigos de revisão e estudos experimentais publicados, relacionados com o tema deste trabalho, limitando-se a procura a textos escritos em inglês, espanhol e português. Uma vez que esta revisão pretendeu abranger a evolução dos alimentos funcionais, desde o aparecimento do conceito dos mesmos, no Japão, na década de 80, até aos dias de hoje, a pesquisa realizada teve como limites temporais os anos de 1995 até à atualidade.info:eu-repo/semantics/publishedVersio

    Flour fortification with grape must for nutritional and health benefits

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    Currently, dietary health natural supplements have increasingly used in the prevention and treatment of chronic disorders. Moreover, deficiencies of macro and micronutrients, (vitamins and minerals), and non-nutrients (polyphenolics) have mainly cause several illnesses, especially in children and women worldwide. World organizations have focused great efforts to address these shortcomings and improve the health of the populations. Grape must, or commonly known as grape must juice, becomes a valued ingredient with nutritional and chemical qualities already recognized. Four portuguese grapevine must (Touriga Nacional; Touriga Franca; Tinta Roriz and Vinha Velha) were analysed and results of phytochemical screening revealed that Touriga Nacional grape must contains a number of medicinally active secondary metabolites, with highest total phenolic and flavonoids contents (325.2 mg GAE/L and 218.3 mg CE/L, respectively). In contrast, Tinta Roriz exhibited the lowest values (144.4 mg GAE/L and 18.3 mg CE/L, respectively). Natural pigments were also investigated, with significantly different levels of anthocyanins in all four portuguese grapevine must: Touriga Nacional (23%), Touriga Franca (63%), Tinta Roriz (70%), and Vinha Velha (19%). Apart from the sensory attributes that grape must can impart in commercial flours, the presence of non-nutrient compounds (polyphenols) is an asset in the development of new functional foods, namely in flours for infant formulations, preteens, teens, adult and athletes.info:eu-repo/semantics/publishedVersio

    Trace minerals in human health: iron, zinc, copper, manganese and fluorine

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    Trace elements exist in the environment in small amounts but play an essential part in sustaining various physiological and metabolic processes occurring within living tissues, as enzymes structure and function, bone and blood maintenance, immune responses or transmission of nerve impulses. They must be obtained from diet, being a varied and balanced diet important for obtaining a series of elements necessary for our body. The total amount of a mineral in a food that is dependent on digestion, its release from the food matrix and the absorption rate by the intestinal cells. If minerals are not supplied in adequate quantities, signs and symptoms of trace elements deficiencies appear. Beyond the nutritional aspects, trace elements have applications in the pharmaceutical industry, integrating pharmacologically active compounds. Usually, in the form of metal complexes, these metal-based drugs are used as anticancer therapeutics, antiinflammatories, antidiabetic drugs or antimicrobial agents. This evolving field is developing metal complexes with remarkable actions, and new metal-based drugs are emerging every year. This article aims to review the main effects of trace elements in human health, namely iron, zinc, copper, manganese and fluorine, focusing on the physiopathology and consequences of lack or excess of these elements. Also, it offers an overview of research information published in recent years concerning the use of these metals in compounds that show promising pharmacological activities.info:eu-repo/semantics/publishedVersio
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