Estresse oxidativo em banana "Prata"; minimamente processada tratada com anti-oxidantes e avaliado em camundongo Apo-E-/-

• Autor(a) principal: Melo, Anderson Adriano Martins
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/981
• topic: Processamento mínimo; Capacidade antioxidante; Estresse oxidativo; Aterosclerose; Minimal processing; Antioxidant capacity; Oxidative stress; Atherosclerosis; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::FISIOLOGIA VEGETAL

Fresh-cut banana is highly perishable, due to enzymatic browning and oxidative stress, which can cause degradation of membranes of plant tissue. Immersion of banana slices in chemical treatments can increase its shelf-life, and turning it a healthier product with a higher antioxidant capacity, as well as preventing the development of degenerative diseases. The objectives of this work were to evaluate the effects of dipping banana slices in mixtures of antioxidants on physical, physiological and biochemical parameters related to visual quality, and associate them to changes in antioxidant and oxidative stress in plant tissue. It was also intended to evaluate the effect of fresh-cut banana on reducing the development of atherosclerosis in mice susceptible to this disease. To assess the effects on plant tissue, bananas from cultivar Prata at ripening stage 6 (fully yellow peel) were immersed in solutions containing ascorbic acid, calcium chloride and cysteine and citric acid during processing. We evaluated the effect of immersion in solutions with and without pH control on the enzymatic browning and the effect of cutting and chemical treatment on oxidative stress and antioxidant potential during storage. In plant tissue, immersion in the mixture containing cysteine at pH 2.0 promoted the decrease in the the activity of polyphenoloxidase, maintained the highest concentration of soluble phenolics, and remained the highest antioxidant capacity, but induced higher lipid peroxidation. The antioxidant capacity of control (non-immersed) fresh-cut banana was reduced by 80%, while those immersed was decreased to 50%. The reduction of the antioxidant potential in banana pulp showed associated with a reduction in the concentration of soluble phenolics (r = 0.96), while lipid peroxidation was correlated with the activity of catalase and superoxide dismutase. Treatment with antioxidants promoted greater reduction of catalase activity with increased concentrations of malondialdehyde in the tissue. To assess the effects on animal tissues, fresh-cut banana slices were immersed in ascorbic acid and calcium chloride solution and supplied to the animals during 10 weeks, in a daily supplemental feeding for Apo-E-/- mice. The development of atherosclerotic lesions in arteries and oxidative stress in the liver were evaluated. Dietary supplementation with fresh-cut banana prevented the development of atherosclerotic lesions in aortas. Lipid peroxidation in the liver tissue revealed that treatment with ascorbic acid and calcium chloride in the solution promoted increased oxidative stress, reflecting in lower antioxidant capacity. The treatment of fresh-cut banana with calcium chloride 1% (w/v) ascorbic acid + 1% (w/v) + cysteine 1% (w/v) was beneficial for the maintenance of product quality, however it might speed up degenerative processes related to oxidative stress in the tissue. Daily intake of minimally processed untreated banana seemed to promote a positive effect on the control of the development of atherosclerosis in Apo-E-/- mice.