Desenvolvimento de um aditivo natural à base de catequina: otimização da extração e estabilização a partir de frutos de Arbutus unedo L.

The common Mediterranean ornamental strawberry-tree (Arbutus unedo L.) produces an edible reddish sweet berry that is found to be bland and tasteless unless it is consumed overripe, otherwise it is discarded or used as basic agricultural sub residue. The bioactive properties of this fruit have been reported and related with phenolic compounds, mainly flavan-3-ols, such as catechin and procyanidins, which has opened the opportunity to exploit their extraction from alternative sources.The common Mediterranean ornamental strawberry-tree (Arbutus unedo L.) produces an edible reddish sweet berry that is found to be bland and tasteless unless it is consumed overripe, otherwise it is discarded or used as basic agricultural sub residue. The bioactive properties of this fruit have been reported and related with phenolic compounds, mainly flavan-3-ols, such as catechin and procyanidins, which has opened the opportunity to exploit their extraction from alternative sources. This study compares and optimizes the maceration, microwave and ultrasound extraction techniques in the recovery of a catechin extract from Arbutus unedo L. fruits and evaluate the stability of flavan-3-ols during storage and application processes. To obtain conditions that maximize the catechin extraction yield, a response surface methodology was used. Maceration and microwave extractions were found to be the most effective methods, capable of yielding 1.38±0.1 and 1.70±0.3 mg of catechin/g dry weight (dw) in the corresponding optimal extraction conditions. The optimal conditions for maceration were 93.2±3.7 min, 79.6±5.2 ºC and 23.1±3.7 % of ethanol, while for the microwave extraction were 42.2±4.1 min, 137.1±8.1 ºC and 12.1±1.1 % of ethanol. The microwave system was a quicker solution, conducting to slightly higher yields of catechin than maceration, but this one needed lower temperatures to reach similar yields. The ultrasound method was the least effective solution in terms of catechin yield extraction (0.71±0.1 mg/g at 42.4±3.6 min, 314.9±21.2 W and 40.3±3.8 %. ethanol). The stability was tested with of the catechin-enriched extract (60% flavan-3-ols and 22% catechin), obtained under the best maceration conditions, was tested. Therefore, catechin-enriched extracts were submitted to physical and chemical stability studies, considering the main affecting variables (time, temperature and pH): i) a stability study of the extracts during storage as powder system; and ii) a stability study of the extracts in simulated food environment (aqueous solution system). The measured responses were the flavan-3-ols and catechin contents, determined by HPLC-DAD, and the antioxidant activity of the extracts evaluated by hydrophilic assays. Mechanistic and phenomenological equations were used to describe the responses, and the optimal conditions for flavan-3-ols (including catechin) stability as powder extract during a month were pH= 5.4 and T= -20ºC; while its stability in aqueous solution remained during the 24 h of application at pH<4 and T<30ºC. This study compares and optimizes the maceration, microwave and ultrasound extraction techniques in the recovery of a catechin extract from Arbutus unedo L. fruits and evaluate the stability of flavan-3-ols during storage and application processes. To obtain conditions that maximize the catechin extraction yield, a response surface methodology was used. Maceration and microwave extractions were found to be the most effective methods, capable of yielding 1.38±0.1 and 1.70±0.3 mg of catechin/g dry weight (dw) in the corresponding optimal extraction conditions. The optimal conditions for maceration were 93.2±3.7 min, 79.6±5.2 ºC and 23.1±3.7 % of ethanol, while for the microwave extraction were 42.2±4.1 min, 137.1±8.1 ºC and 12.1±1.1 % of ethanol. The microwave system was a quicker solution, conducting to slightly higher yields of catechin than maceration, but this one needed lower temperatures to reach similar yields. The ultrasound method was the least effective solution in terms of catechin yield extraction (0.71±0.1 mg/g at 42.4±3.6 min, 314.9±21.2 W and 40.3±3.8 %. ethanol). The stability was tested with of the catechin-enriched extract (60% flavan-3-ols and 22% catechin), obtained under the best maceration conditions, was tested. Therefore, catechin-enriched extracts were submitted to physical and chemical stability studies, considering the main affecting variables (time, temperature and pH): i) a stability study of the extracts during storage as powder system; and ii) a stability study of the extracts in simulated food environment (aqueous solution system). The measured responses were the flavan-3-ols and catechin contents, determined by HPLC-DAD, and the antioxidant activity of the extracts evaluated by hydrophilic assays. Mechanistic and phenomenological equations were used to describe the responses, and the optimal conditions for flavan-3-ols (including catechin) stability as powder extract during a month were pH= 5.4 and T= -20ºC; while its stability in aqueous solution remained during the 24 h of application at pH<4 and T<30ºC.

O desenvolvimento do turismo desportivo: o caso das provas da meia maratona e da maratona do Porto

O turismo tem sido e prevê-se que continuará a ser um dos fenómenos que mais contribui para a economia de uma nação. Também, o desporto ao longo dos anos tem tido um papel importante na sociedade que se manifesta em diferentes perspetivas, ao nível cultural, económico e social. Nesta linha e como catalisador de sinergias entre o turismo e o desporto surge o turismo desportivo, como sendo um único fenómeno social, económico e cultural que decorre da interação das atividades, pessoas e locais. O turismo desportivo, nos últimos anos, tem tido o seu reconhecimento como uma fonte que gera riqueza dando suporte ao desenvolvimento económico dos locais, regiões e até mesmo dos países onde se realizam os eventos desportivos. De salientar que o Turismo Desportivo tem sido visto como uma oportunidade que permite combater a sazonalidade e os impactos negativos do turismo em massa. Neste sentido, com o presente trabalho pretendeu-se analisar a importância das provas da meia maratona e maratona, realizadas na cidade do Porto em 2015, para o desenvolvimento turístico, na perspetiva dos visitantes desportistas, uma vez que os eventos desportivos têm sido considerados uma forma de assegurar o desenvolvimento sustentável de uma região/local. Tendo por base a informação recolhida e os resultados obtidos, quanto ao perfil dos inquiridos que participaram, em ambas as provas, pode dizer-se que são do sexo masculino, o grupo etário com idades compreendidas entre os 41 e 51 anos tem a maior percentagem de participantes, a maioria são casados e portugueses e maioritariamente residem no Grande Porto. Apurou-se ainda a estimativa do gasto médio por inscritos atendendo às provas e nacionalidade. No que diz respeito aos portugueses, estes fazem mais despesas no decurso da prova da Meia Maratona gastando cerca de 530 mil euros e os estrangeiros na prova da Maratona despendendo um valor estimado de 634 mil euros. Globalmente, atendendo às provas principais e associadas, são os portugueses que apresentam um gasto estimado mais elevado cerca de 1.755.570,65€, e os estrangeiros 1.436.159,14€. No global o valor estimado despendido, para o total das provas, para os participantes desportistas, ascende a 3.191.730€. Os valores apresentados não incluem as despesas com a inscrição dos participantes nas provas. Os valores indiciaram, também, para a existência de impactos económicos positivos decorrentes da organização e realização das provas e demonstraram que estas podem constituir uma ferramenta para impulsionar a economia local e regional. Também se concluiu que as provas da Meia Maratona e Maratona foram consideradas importantes para o desenvolvimento turístico da Região do Grande Porto, os inquiridos encontram-se globalmente satisfeitos com as provas e pretendem regressar em próximas edições, existe uma relação forte, positiva e direta entre a satisfação global e a intenção de participar em edições futuras das provas.