Metabolismo de carboidratos e de fenóis no armazenamento refrigerado de cenoura

• Ano de defesa: 2009
• Autor(a) principal: Chaves, Daniela Vieira
• Orientador(a): Finger, Fernando Luiz
• Banca de defesa: Moreira, Marialva Alvarenga , Moura, Marcelo Amaral de , Puiatti, Mário
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fisiologia Vegetal
• Departamento: Controle da maturação e senescência em órgãos perecíveis; Fisiologia molecular de plantas superiores
• País: BR
• Palavras-chave em Português: Processamento mínimo; Atividade enzimática; Carboidratos; Fenóis
• Palavras-chave em Inglês: Minimal processing; Enzymatic activity; Carbohydrates; Phenols
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::FISIOLOGIA VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/986

When subjected to processing, the carrot roots suffer several types of cuts that promote physical, chemical and physiological changes in the tissue. So, the first experiment was conducted in order to evaluate the carbohydrate contents and the enzymatic activity in either whole carrots and pieces stored at 4oC. A second experiment was carried out to evaluate the contents of the carotenoids and phenols as well as the activity of the enzymatic enzymes in whole carrots and Cenouretes® stored at 5oC under light and darkness conditions. The carrots were harvested, washed, selected, separated and processed according to the experiment. In the first experiment, the cultivars Alvorada, Brasília and Esplanada were separated in either whole carrots or 6cm-long pieces, maintaining the periderm of the roots. Following, they were conditioned in plastic boxes and stored at 4°C temperature during 14 days. At 2-day intervals, samples of the roots were removed for analyses of the mass loss, starch, total, reducer and non-reducer sugars, acid invertase, peroxidase and polyphenoloxidase. In the second experiment, the cultivars Esplanada and Sugarsnax 54 were divided into whole roots and minicarrots and were wrapped in polyethylene low-density bags. Then, they were stored at 5°C for 17 days under light and darkness conditions. At 2, 5, 8, 11, 14 and 17 days, some carrot samples were removed for the analyses of carotenoids, phenolic compounds, peroxidase and polyphenoxidase. In the first experiment and independently from processing, those three cultivars lost some mass during the refrigerated storage. The percentage of total soluble sugars increased during storage, except for the whole roots Alvorada that decreased. The starch contents decreased in the roots during storage. The reducing sugars increased in the cultivars Alvorada and Esplanada, whereas a reduction occurred in the Brasília cv. The cultivar Brasília and whole roots Esplanada showed increase in contents of the non-reducing sugars, different from Alvorada where the reduction occurred. The activity of the acid invertase was highest at the eighth day under storage in those three cultivars and in both roots. The activity of the peroxidase increased during storage; however, the activity was stable only in the cut roots Brasília. The polyphenoloxidase showed activity peaks during storage, as varying according to cultivar and root type. In the second experiment, the light and darkness conditions showed similar values during storage of the roots. The total carotenoid contents reduced during storage of the carrot Sugarsnax 54, and showed low variations in Esplanada cv. The content of total phenols reduced with the storage time, except for the whole carrots Sugarsnax 54 that was stable. The activity of peroxidases were reduced in roots of the Sugarsnax 54 cv., but high activity occurred in the whole roots of the Esplanada cv. at the beginning of the storage. In Esplanada cv., the polyphenoloxidase showed high activity at the beginning of the storage, whereas a reduction occurred in the whole roots Sugarsnax 54 . Thus, in the first experiment, significant differences occurred in relation to the attributes between the whole carrots and the cut ones as well as among the cultivars during the storage under refrigeration. Despite no differences were found between storage under light and dark conditions in the second experiment, they really occurred either between cultivars and the types of roots.