Efeito de diferentes tempos de exposição à luz Led vermelha em compostos bioativos de flores de capuchinha (Tropaeolum majus L.)
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Data
2019-02-19
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Universidade Federal de Viçosa
Resumo
As flores comestíveis têm ganhado espaço na dieta humana com o intuito de obter sabores, aromas e cores diferenciadas e com benefícios para saúde. Desta forma, o presente estudo teve como objetivo investigar o efeito do tempo de exposição à lâmpadas de LED vermelho sob a produção de compostos bioativos em flores amarelas, alaranjadas e vermelhas de capuchinha. As plantas foram cultivadas em estufa com exposição à luz natural durante o dia e diferentes tempos de suplementação com lâmpadas de LED vermelho (2, 4 e 6 horas) durante a noite, além do controle sem exposição à luz LED. As flores foram coletadas, separadas em pétalas e sépalas e secas para obtenção do extrato hidroalcóolico e do extrato de carotenoides. As amostras foram avaliadas quanto à capacidade antioxidante, carotenoides totais, fenólicos totais, antocianinas, flavonoides, parâmetros de cor (L*, C* e h*) e teor de luteína em HPLC. Os resultados mostraram que para as pétalas amarelas, os pontos de máxima capacidade antioxidante foram encontrados em 3,03 horas para DPPH e 3,23 horas para ABTS. Pela técnica ABTS observou-se um aumento de 68,91% no conteúdo de antioxidante quanto comparado ao controle. O tempo para se obter a maior concentração de carotenoides em pétala amarela foi de 4,73 horas com teor máximo de 79,34 mg.g -1 . O valor obtido é mais que o dobro do teor de carotenoide encontrado nas pétalas da flor controle. Para as sépalas amarelas, as maiores capacidades antioxidantes foram encontradas nos tempos de 4,53 horas para DPPH e 3,69 horas para o método ABTS. As análises de capacidade antioxidante demonstraram que em pétala alaranjadas, essa variável não sofreu o efeito dos diferentes tempos de exposição (p>0,05). O ponto de máximo para fenólicos totais em pétalas alaranjadas foi de 128,13 mg AGE·100g -1 encontrado no tempo de 2,71 horas, um aumento em torno de 14% quando comparado a pétala alaranjada controle. Quanto ao teor de carotenoides o maior tempo estudado (6 horas) foi o mais eficiente para obter maior teor de carotenoides em pétalas e sépalas alaranjadas. Para pétalas foi possível observar um aumento de 16,15% no teor de carotenoides totais, já para sépala o valor foi de aproximadamente 100%. Em pétalas vermelhas foi possível observar, que o máximo de capacidade antioxidante (222,16 μmol de Trolox.g -1 ) foi obtida no tempo de 3,14 horas e é 37,13 % maior que a amostra controle. Para pétalas vermelhas destaca-se o elevado teor de antocianinas encontrado, desde a pétala controle (1389,92±8,86 mg.100g -1 ) até o ponto máximo (1973,10 mg.100g -1 ), com um aumento de 41,95% alcançado em 4,17 horas. Sépala vermelha foi a única amostra no qual se pode estabelecer um modelo matemático para a variável luteína analisada em HPLC, sendo que o maior teor (4,56 mg LUT.g -1 ) foi obtido no tratamento de maior tempo (6 horas), com um aumento significativo de 56,70%. Em relação aos parâmetros de cor, o tempo de exposição ao LED não apresentou efeito significativo, para pétalas e sépalas de nenhuma das cores analisadas. Os resultados demonstram o grande potencial de utilização da luz LED no estímulo da produção de fitoquímicos em flor de capuchinha.
The edible flowers have gained space in the human diet in order to obtain different flavors, aromas and colors, including also health benefits. Thus, the present study aimed to investigate the effect of exposure time to red LED bulbs under the production of bioactive compounds on yellow, orange and red nasturtium flowers. The plants were grown in a greenhouse with exposure to natural light during the day and different times of supplementation with red LED lamps (2, 4 and 6 hours) at night, in addition to the control without exposure to LED light. The flowers were collected, separated into petals and sepals and dried to obtain the hydroalcoholic extract and the carotenoid extract. The samples were evaluated for antioxidant capacity, total carotenoids, total phenolic, anthocyanins, flavonoids and color parameters (L *, C * and h *) and lutein content on HPLC. The results showed that for the yellow petals, the points of maximum antioxidant capacity were found in 3.03 hours for DPPH and 3.23 hours for ABTS. The ABTS technique showed a 68.91% increase in antioxidant content compared to control. The time to obtain the highest carotenoid concentration in yellow petal was 4.73 hours with a maximum content of 79.34 mg.g -1 . The value obtained is more than the double of the carotenoid content found in the petals of the control flower. For the yellow sepals, the highest antioxidant capacities were found at the time of 4.53 hours for DPPH and 3.69 hours for the ABTS method. The analysis of antioxidant capacity for orange flowers showed that for the petal, this variable does not suffer the effect of different exposure times (p> 0.05). Analyzes of antioxidant capacity showed that in orange petals, this variable did not suffer the effect of different exposure times (p> 0.05). The maximum point for total phenolic in orange petals was 128.13 mg AGE · 100g -1 found in the time of 2.71 hours, an increase around 14% when compared to the orange petal control. Regarding the carotenoid content, the highest time studied (6 hours) was the most efficient to obtain higher carotenoid content in petals and orange sepals. For petals it was possible to observe a 16.15% increase in the total carotenoid content, and for sepals the value was approximately 100%. In red petals it was possible to observe that the maximum antioxidant capacity (222.16 μmol Trolox.g -1 ) is obtained in the time of 3.14 hours and is 37.13% higher than the control sample. The high content of anthocyanins from the control petal (1389.92 ± 8.86 mg.100g -1 ) to the maximum (1973.10 mg.100g -1 ) was observed for red petals, with an increase of 41.95% achieved 4.17 hours. Red sepals were the only sample in which a mathematical model could be established for the variable lutein analyzed in HPLC. The highest content (4.56 mg LUT.g -1 ) was obtained in the treatment of a longer time (6 hours) with a significant increase of 56.70%. Regarding the color parameters, the time of exposure to LED did not show a significant effect for petals and sepals of none of the analyzed colors. The results demonstrate the great potential of LED light to stimulate nasturtium flower phytochemical production.
The edible flowers have gained space in the human diet in order to obtain different flavors, aromas and colors, including also health benefits. Thus, the present study aimed to investigate the effect of exposure time to red LED bulbs under the production of bioactive compounds on yellow, orange and red nasturtium flowers. The plants were grown in a greenhouse with exposure to natural light during the day and different times of supplementation with red LED lamps (2, 4 and 6 hours) at night, in addition to the control without exposure to LED light. The flowers were collected, separated into petals and sepals and dried to obtain the hydroalcoholic extract and the carotenoid extract. The samples were evaluated for antioxidant capacity, total carotenoids, total phenolic, anthocyanins, flavonoids and color parameters (L *, C * and h *) and lutein content on HPLC. The results showed that for the yellow petals, the points of maximum antioxidant capacity were found in 3.03 hours for DPPH and 3.23 hours for ABTS. The ABTS technique showed a 68.91% increase in antioxidant content compared to control. The time to obtain the highest carotenoid concentration in yellow petal was 4.73 hours with a maximum content of 79.34 mg.g -1 . The value obtained is more than the double of the carotenoid content found in the petals of the control flower. For the yellow sepals, the highest antioxidant capacities were found at the time of 4.53 hours for DPPH and 3.69 hours for the ABTS method. The analysis of antioxidant capacity for orange flowers showed that for the petal, this variable does not suffer the effect of different exposure times (p> 0.05). Analyzes of antioxidant capacity showed that in orange petals, this variable did not suffer the effect of different exposure times (p> 0.05). The maximum point for total phenolic in orange petals was 128.13 mg AGE · 100g -1 found in the time of 2.71 hours, an increase around 14% when compared to the orange petal control. Regarding the carotenoid content, the highest time studied (6 hours) was the most efficient to obtain higher carotenoid content in petals and orange sepals. For petals it was possible to observe a 16.15% increase in the total carotenoid content, and for sepals the value was approximately 100%. In red petals it was possible to observe that the maximum antioxidant capacity (222.16 μmol Trolox.g -1 ) is obtained in the time of 3.14 hours and is 37.13% higher than the control sample. The high content of anthocyanins from the control petal (1389.92 ± 8.86 mg.100g -1 ) to the maximum (1973.10 mg.100g -1 ) was observed for red petals, with an increase of 41.95% achieved 4.17 hours. Red sepals were the only sample in which a mathematical model could be established for the variable lutein analyzed in HPLC. The highest content (4.56 mg LUT.g -1 ) was obtained in the treatment of a longer time (6 hours) with a significant increase of 56.70%. Regarding the color parameters, the time of exposure to LED did not show a significant effect for petals and sepals of none of the analyzed colors. The results demonstrate the great potential of LED light to stimulate nasturtium flower phytochemical production.
Descrição
Palavras-chave
Tropaeolum majus, Compostos bioativos, Diodos emissores de luz, Luteína
Citação
NASCIMENTO, Amanda Lais Alves Almeida. Efeito de diferentes tempos de exposição à luz Led vermelha em compostos bioativos de flores de capuchinha (Tropaeolum majus L.). 2019. 55 f. Dissertação (Mestrado em Ciência e Tecnologia de Alimentos) - Universidade Federal de Viçosa, Viçosa. 2019.