Quantificação de compostos antioxidantes em frutos in natura e polpa congelada / Quantification of antioxidant compounds in fresh and frozen fruits pulp

Objetivo ­ O presente estudo teve como objetivo a dosagem de vitamina C, fenólicos totais e antocianinas, em frutas, para a verificação e possíveis perdas em frutas in-natura e polpa congelada. A ingestão diária de frutos e frutas assegura uma dieta rica em compostos bioativos, no entanto, as concentrações destes alimentos podem apresentar-se diferentes depois do processamento, no caso o congelamento, comparando-o com o fruto in natura. Métodos ­ Frutas obtidas no comercio local, nas variedades: ameixa, caqui, goiaba, maçã, pêra, uvas verde e vermelha foram utilizadas para as dosagens in natura e depois de 8 semanas de congelamento. Foram dosadas vitamina C, fenólicos totais, e antocianinas, sendo que foram feitas em triplicata. Os dados foram analisados por teste t considerando significativo p<0,05. Resultados ­ Foi observada diminuição significativa em quantidades de vitamina C, compostos fenólicos e antocianinas em todas as frutas analisadas. A pêra mostrou-se a fruta mais afetada pelo processo de congelamento, apresentando a maior perda em todas as dosagens dos antioxidantes, diminuindo 50,9% em vitamina C, 96,2% em antocianinas e 60,2% em fenólicos totais. Já a goiaba foi a fruta que se mostrou mais resistente ao congelamento, apresentando a menor diminuição em todas as dosagens de antioxidantes, com perda de 9,5% de vitamina C, 9,7 de fenólicos totais, e 25,7% de antocianinas. Em concentrações de vitamina C, maçã teve diminuição de 36,6%, ameixa de 42,9%, caqui 26,9%, uva verde 22,6%, uva vermelha 47% e sementes de goiaba 27,6%. Já nas concentrações de fenólicos totais maçã teve diminuição de 11,2%, ameixa de 24,7%, caqui 26,9%, uva verde 48,5%, uva vermelha 46,6%% e sementes de goiaba 30,1%. Quanto as antocianinas maçã apresentou diminuição de 91,9%, ameixa de 81,1%, caqui 35,8%, uva verde 51,4%, uva vermelha 57,1%% e sementes de goiaba 32,4%. Conclusões ­ Desta maneira fica evidente a perda, diferenciada entre as frutas, de compostos antioxidantes com o processamento

Objetivo ­ O presente estudo teve como objetivo a dosagem de vitamina C, fenólicos totais e antocianinas, em frutas, para a verificação e possíveis perdas em frutas in-natura e polpa congelada. A ingestão diária de frutos e frutas assegura uma dieta rica em compostos bioativos, no entanto, as concentrações destes alimentos podem apresentar-se diferentes depois do processamento, no caso o congelamento, comparando-o com o fruto in natura. Métodos ­ Frutas obtidas no comercio local, nas variedades: ameixa, caqui, goiaba, maçã, pêra, uvas verde e vermelha foram utilizadas para as dosagens in natura e depois de 8 semanas de congelamento. Foram dosadas vitamina C, fenólicos totais, e antocianinas, sendo que foram feitas em triplicata. Os dados foram analisados por teste t considerando significativo p<0,05. Resultados ­ Foi observada diminuição significativa em quantidades de vitamina C, compostos fenólicos e antocianinas em todas as frutas analisadas. A pêra mostrou-se a fruta mais afetada pelo processo de congelamento, apresentando a maior perda em todas as dosagens dos antioxidantes, diminuindo 50,9% em vitamina C, 96,2% em antocianinas e 60,2% em fenólicos totais. Já a goiaba foi a fruta que se mostrou mais resistente ao congelamento, apresentando a menor diminuição em todas as dosagens de antioxidantes, com perda de 9,5% de vitamina C, 9,7 de fenólicos totais, e 25,7% de antocianinas. Em concentrações de vitamina C, maçã teve diminuição de 36,6%, ameixa de 42,9%, caqui 26,9%, uva verde 22,6%, uva vermelha 47% e sementes de goiaba 27,6%. Já nas concentrações de fenólicos totais maçã teve diminuição de 11,2%, ameixa de 24,7%, caqui 26,9%, uva verde 48,5%, uva vermelha 46,6%% e sementes de goiaba 30,1%. Quanto as antocianinas maçã apresentou diminuição de 91,9%, ameixa de 81,1%, caqui 35,8%, uva verde 51,4%, uva vermelha 57,1%% e sementes de goiaba 32,4%. Conclusões ­ Desta maneira fica evidente a perda, diferenciada entre as frutas, de compostos antioxidantes com o processamento

Objective ­ The present study had the objective of the dosage of vitamin C, total phenolics and anthocyanins, in fruits, for the verification and possible losses in in natura fruits and frozen pulp. The daily intake of fruits and fruits ensures a diet rich in elements that contribute to the antioxidant capacity. However, the concentrations of these foods may be different after processing, in this case the freezing, comparing it with the in natura fruit. Methods ­ Fruits obtained in the local commerce, in the varieties: plum, kaki, guava, apple, pear, green and red grapes were used for the in natura dosages and after 8 weeks of freezing. The laboratorial determinations were Vitamin C, total phenolics and anthocyanins. All dosages were standardized in triplicate. Data were analyzed by t-test considering significant p <0.05. Results ­ Significant decrease was observed in amounts of vitamin C, phenolic compounds and anthocyanins in all fruits analyzed. The pear was the fruit most affected by the freezing process, presenting the highest loss in all antioxidant dosages, decreasing 50.9% in vitamin C, 96.2% in anthocyanins and 60.2% in total phenolics. The guava fruit was the most resistant to freezing, presenting the lowest decrease in all antioxidant dosages, with loss of 9.5% of vitamin C, 9.7 of total phenolics, and 25.7% of anthocyanins. In vitamin C concentrations, apple had a decrease of 36.6%, plum of 42.9%, persimmon 26.9%, green grape 22.6%, red grape 47% and guava seeds 27.6%. In the total phenolic concentrations, apple had a decrease of 11.2%, plum of 24.7%, persimmon 26.9%, green grape 48.5%, red grape 46.6 %% and guava seeds 30.1%. As for the anthocyanins apple showed a decrease of 91.9%, plum of 81.1%, persimmon 35.8%, green grape 51.4%, red grape 57.1 %% and guava seeds 32.4%. Conclusions ­ In this way the loss, differentiated between fruits, of antioxidant compounds with the processing

α-Linolenic acid prevents hepatic steatosis and improves glucose tolerance in mice fed a high-fat diet.

OBJECTIVES: Dietary omega-3 fatty acids have been efficacious in decreasing serum cholesterol levels and reducing the risk of cardiovascular disease. However, the metabolic and molecular changes induced by the omega-3 fatty acid α-linolenic acid (ALA), which is found in linseed oil, are not fully understood. In this study, we showed a correlation between ALA and insulin resistance, inflammation and endoplasmic reticulum stress (ERS). METHODS: We studied 40 male mice (C57/BL6) divided into 4 groups: a control (C) group, a control + omega-3/ALA (CA) group, a high-fat diet (HFD) (H) group and a high-fat diet + omega-3/ALA (HA) group. For 8 weeks, the animals in the H and HA groups were fed a high-fat (60%) diet, while the animals in the C and CA groups received regular chow. The diets of the CA and HA groups were supplemented with 10% lyophilized ALA. RESULTS: ALA supplementation improved glucose tolerance and reduced insulin resistance, as measured by intraperitoneal glucose tolerance tests and the homeostasis model assessment for insulin resistance, respectively. In addition, ALA reduced hepatic steatosis and modified the standard fat concentration in the liver of animals fed an HFD. Dietary ALA supplementation reduced the serum levels of interleukin 6 (IL-6), interleukin 1 beta (IL-1ß) and monocyte chemoattractant protein-1 (MCP-1), increased the expression of important chaperones such as binding immunoglobulin protein (BIP) and heat shock protein 70 (HSP70) and reduced the expression of C/EBP-homologous protein (CHOP) and X-box binding protein 1 (XBP1) in hepatic tissues, suggesting an ERS adaptation in response to ALA supplementation. CONCLUSIONS: Dietary ALA supplementation is effective in preventing hepatic steatosis; is associated with a reduction in insulin resistance, inflammation and ERS; and represents an alternative for improving liver function and obtaining metabolic benefits.

α-Linolenic acid prevents hepatic steatosis and improves glucose tolerance in mice fed a high-fat diet

OBJECTIVES: Dietary omega-3 fatty acids have been efficacious in decreasing serum cholesterol levels and reducing the risk of cardiovascular disease. However, the metabolic and molecular changes induced by the omega-3 fatty acid α-linolenic acid (ALA), which is found in linseed oil, are not fully understood. In this study, we showed a correlation between ALA and insulin resistance, inflammation and endoplasmic reticulum stress (ERS). METHODS: We studied 40 male mice (C57/BL6) divided into 4 groups: a control (C) group, a control + omega-3/ALA (CA) group, a high-fat diet (HFD) (H) group and a high-fat diet + omega-3/ALA (HA) group. For 8 weeks, the animals in the H and HA groups were fed a high-fat (60%) diet, while the animals in the C and CA groups received regular chow. The diets of the CA and HA groups were supplemented with 10% lyophilized ALA. RESULTS: ALA supplementation improved glucose tolerance and reduced insulin resistance, as measured by intraperitoneal glucose tolerance tests and the homeostasis model assessment for insulin resistance, respectively. In addition, ALA reduced hepatic steatosis and modified the standard fat concentration in the liver of animals fed an HFD. Dietary ALA supplementation reduced the serum levels of interleukin 6 (IL-6), interleukin 1 beta (IL-1β) and monocyte chemoattractant protein-1 (MCP-1), increased the expression of important chaperones such as binding immunoglobulin protein (BIP) and heat shock protein 70 (HSP70) and reduced the expression of C/EBP-homologous protein (CHOP) and X-box binding protein 1 (XBP1) in hepatic tissues, suggesting an ERS adaptation in response to ALA supplementation. CONCLUSIONS: Dietary ALA supplementation is effective in preventing hepatic steatosis; is associated with a reduction in insulin resistance, inflammation and ERS; and represents an alternative for improving liver function and obtaining metabolic benefits.