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Valorização de recursos naturais com poder adoçante: caracterização fitoquímica e antioxidante da Stevia rebaudiana (Bert.) Bertoni
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| PPG_29532 | 1.85 MB | Adobe PDF |
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Abstract(s)
A sustentabilidade dos ecossistemas é um desafio cada vez mais presente no contexto atual. Tendo em conta a crescente necessidade de recursos alimentares, a utilização de plantas medicinais para a formulação de novos produtos tem-se revelado uma mais-valia. Por outro lado, e tendo em consideração o uso racional de plantas, os seus extratos podem contribuir com novos efeitos terapêuticos. Um exemplo é a Stevia rebaudiana (Bert.) Bertoni.
O sabor doce é um desejo do ser humano, que remonta desde há muitos séculos atrás. Antigamente o açúcar era encarado como uma especiaria ou medicamento, só mais tarde é que passou a ser visto como um complemento alimentar. Atualmente, já são utilizados substitutos do açúcar, como por exemplo os edulcorantes naturais e os sintéticos. Estas alternativas surgiram com a finalidade de diminuir os efeitos indesejáveis que o açúcar contém, mas nem todos tiveram sucesso, sem esquecer que a segurança do consumo destes substitutos por parte do ser humano foi posta várias vezes em causa.
A Stevia rebaudiana (Bert.) Bertoni, nativa da América Central e da América do Sul, das regiões tropicais e subtropicais, é um edulcorante natural. Enquadra-se na família das Asteraceae, pertencendo a uma das 300 espécies do género. Contém elevados níveis de glicosídeos de esteviol e de compostos bioativos, reconhecidos pelas suas propriedades biológicas.
O conteúdo em fenólicos totais e o teor de flavonoides totais foram avaliados, recorrendo a um extrato hidroalcoólico da folha de Stevia seca e de um edulcorante (esteviol) comercial. A atividade antioxidante também foi estudada nos mesmos extratos, recorrendo aos métodos de capacidade de inibição do radical DPPH e capacidade antioxidante de redução do ferro (FRAP). Os resultados obtidos justificam a introdução da folha de Stevia como aditivo alimentar, não só pelo seu poder edulcorante, como também pelo seu conteúdo em compostos não-nutrientes, cujas propriedades biológicas são já reconhecidas.
The ecosystems sustainability is an increasing challenge around the world. Bearing in mind the growing need of worldwide resources, the application of medicinal plants in the development of new products has increased. Also, considering the rational use of plants, or their extracts can equally contribute to discover new therapeutic effects. An example is Stevia rebaudiana (Bert.) Bertoni. The sweet taste is a human desire that dates back for many centuries ago. Formerly sugar was seen as a spice or medicine, only later that was seen as a food supplement. Currently, there are used sugar substitutes, such as the natural and synthetic sweeteners. Those alternatives have emerged in order to reduce the undesirable effects that sugar contains, but not all have succeeded, without forgetting that these substitutes are suspects with regard to their safety to human consumption. Stevia rebaudiana (Bert.) Bertoni is a natural sweetener. This species is native to Central America and South America, in tropical and subtropical regions. This plant belongs to Asteraceae family, which comprises more than 300 species of the some genus. It contains high levels of steviol glycosides and bioactive compounds with recognized biological properties. The contents of total phenolics and total flavonoids were assessed using a hydro-alcoholic extract of dried Stevia leaf and a commercial sweetener (steviol). The antioxidant activity was also evaluated in the same extracts, using the antioxidant activity by DPPH assay and the ferric reducing ability of plasma (FRAP). The results justify the introduction of Stevia leaves as a food additive, not only for its sweetening power as their content in non-nutrients compounds, whose biological properties are already recognized.
The ecosystems sustainability is an increasing challenge around the world. Bearing in mind the growing need of worldwide resources, the application of medicinal plants in the development of new products has increased. Also, considering the rational use of plants, or their extracts can equally contribute to discover new therapeutic effects. An example is Stevia rebaudiana (Bert.) Bertoni. The sweet taste is a human desire that dates back for many centuries ago. Formerly sugar was seen as a spice or medicine, only later that was seen as a food supplement. Currently, there are used sugar substitutes, such as the natural and synthetic sweeteners. Those alternatives have emerged in order to reduce the undesirable effects that sugar contains, but not all have succeeded, without forgetting that these substitutes are suspects with regard to their safety to human consumption. Stevia rebaudiana (Bert.) Bertoni is a natural sweetener. This species is native to Central America and South America, in tropical and subtropical regions. This plant belongs to Asteraceae family, which comprises more than 300 species of the some genus. It contains high levels of steviol glycosides and bioactive compounds with recognized biological properties. The contents of total phenolics and total flavonoids were assessed using a hydro-alcoholic extract of dried Stevia leaf and a commercial sweetener (steviol). The antioxidant activity was also evaluated in the same extracts, using the antioxidant activity by DPPH assay and the ferric reducing ability of plasma (FRAP). The results justify the introduction of Stevia leaves as a food additive, not only for its sweetening power as their content in non-nutrients compounds, whose biological properties are already recognized.
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Keywords
Stevia rebaudiana (Bert.) Bertoni Esteviol comercial Compostos bioativos Atividade antioxidante Commercial steviol Bioactive compounds Antioxidant activity