Joseana Severo

Destanização e conservação de frutos de jambolão

Alternative methods were investigated for the reduction of astringency (detannization) and conservation of Jambolan fruit (Syzygium cumini, L.). In the first experiment, fruits were harvested at an intermediate ripening stage, maintained at room temperature and subjected to the following treatments: control (normal atmosphere), 98kPa CO2, 20kPa CO2, 98kPa N2, ethylene (100ppm), 1-MCP (1ppm) followed by treatment with ethylene (100ppm) and 3,85mL absolute ethanol L-1. Acetaldehyde, soluble tannin, fruit firmness and astringency were evaluated. In the second experiment, fruits were harvested ripe and stored under passive modified atmosphere at room temperature (PMART, 23±1°C) and passive modified atmosphere under cold storage (PMACS, 4±1°C) for 5, 10 and 15 days. Fruits treated with N2, ethylene and ethanol showed the best detannization results, with increased acetaldehyde content, reduction of soluble tannins and astringency. However ethylene and ethanol treatments induced excessive softening of the fruit. Storage under PMAR kept the purple-blue color of fruits and, besides preventing fungal incidence, it aided the maintenance of the total phenolic content, ascorbic acid and antioxidant activity of fruits.

Preharvest UV-C radiation influences physiological, biochemical, and transcriptional changes in strawberry cv. Camarosa

Ultraviolet C (UV-C) radiation is known for preventing fungal decay and enhancing phytochemical content in fruit when applied postharvest. However, limited knowledge is available regarding fruit responses to preharvest application of UV-C radiation. Thus, the effects of UV-C radiation on photosynthetic efficiency, dry matter accumulation and partitioning, fruit yield and decay, phytochemical content, and relative transcript accumulation of genes associated with these metabolic pathways were monitored in strawberry (Fragaria x ananassa Duch.) cv. Camarosa. A reduction in photosynthetic efficiency was followed by a decrease in light harvesting complex LhcIIb-1 mRNA accumulation as well as a decrease in yield per plant. Phenylalanine ammonia lyase activity, phenolic, anthocyanin, and L-ascorbic acid contents were higher in UV-C treated fruit. In addition, preharvest UV-C treatment reduced microorganism incidence in the greenhouse and on the fruit surface, increased the accumulation of β-1,3-Gluc and PR-1 mRNA, and prevented fruit decay.

Qualidade pós-colheita de Physalis sob temperatura ambiente e refrigeração

A physalis (Physalis peruviana) e um pequeno fruto cujo cultivo vem se expandindo no Brasil. No entanto, informacoes a respeito do seu armazenamento ainda sao escassas. Por isso, o objetivo deste trabalho foi avaliar a qualidade de physalis durante o armazenamento, sob temperaturas ambiente e refrigerada. A colheita foi realizada quando o calice dos frutos apresentava coloracao amarelo-esverdeada, sendo os frutos submetidos aos seguintes tratamentos: 1- armazenamento a temperatura de 20°C (± 0,5°C) e 2- armazenamento a temperatura de 4°C (± 0,5°C). Foram avaliados os teores de SS, AT, SS/AT, o pH, a firmeza, a cor e a perda de massa dos frutos, a cada dois dias, durante oito dias. Foi possivel observar que o emprego da refrigeracao promoveu a manutencao da firmeza, auxiliando tambem na prevencao da perda de massa fresca, do fruto e do calice. O teor de solidos soluveis (SS) reduziu-se significativamente, independentemente da temperatura de armazenamento dos frutos. Frutos armazenados sob refrigeracao apresentaram teores superiores de acidez titulavel (AT) e, consequentemente, menor relacao SS/AT. Os resultados, obtidos neste estudo, permitiram concluir que as modificacoes que ocorrem em parâmetros considerados importantes para a qualidade de physalis, como pH, AT, SS/AT, firmeza e cor, durante o periodo de armazenamento de frutos, podem ser minimizados com o uso da refrigeracao (4 °C).