Poliana Cristina Spricigo

Effects of antibrowning solution and chitosan-based edible coating on the quality of fresh-cut apple

Fresh-cut apples were treated with an antibrowning solution and with a chitosan-based edible coating associated to antibrowning agents and the effects on the deterioration at low temperature were studied. The combined effect of ascorbic acid (AA), citric acid (CA) and chitosan was also evaluated. Control, coated and uncoated apples were packed in polyethylene terephthalate trays and the changes in headspace atmosphere, colour, firmness and microbial growth measured along ten days of storage at 5°C. The samples coated with 1% AA + 2% CA + chitosan maintained a good colouration until day 6, similar to those treated with 1% AA + 2% CA without chitosan. Afterwards, the fruits became darker and similar to the control. A slight reduction in the rates of CO2 production was observed in all samples. Ethylene increased continuously during storage although gas production was extremely low. Texture did not change for all treatments; showing values around 9.0 to 10.0 N. Growth of Salmonella, and total and fecal coliforms were not detected. The chitosan coating treatment was the most effective in inhibiting growth of moulds and yeasts, with count of 1.7 CFU g–1. Chitosan coating could be an alternative for preserving quality of fresh-cut ‘Gala’ apples. Results from this study suggest that.

Turgescência de crisântemos após a colheita utilizando o equipamento Wiltmeter

The main goal of this research was to determine the quality by measuring turgor in flowers stems of chrysanthemums stored in tap water and on distilled water, using the method of relative water content (RWC) and the equipment Wiltmeter®. The flower stems were harvested in a commercial field and placed randomly into unitary containers containing distilled water or tap water. In order to monitor the water status of the stems the follow analyses were done: variation of fresh mass, water absorption rate, water transpiration rate, relative water content and turgor pressure. Data were subjected to analysis of variance by F test, means were compared through the days of vase life, using Tukey test at 5% significance level. For comparison of the RWC and the turgor pressure the Pearson correlation coefficient was calculated. Flower stems kept in tap water maintained turgor significantly better than the ones maintained on distilled water. There is a correlation between turgor pressure and relative water content, which remain higher as the plant tissues are new and well hydrated. The estimate of the turgor pressure was effective and sensitive in evaluating the water status of the tissues of the stems of cut chrysanthemums.

Soluções de manutenção na pós-colheita de Chrysanthemum morifolium cv. Dragon

The development and use of techniques that extend the life vase of the flowers, maintaining the quality of the product, is essential for reducing postharvest losses. The objective of this work was to evaluate different solutions for maintenance, associated or not to sucrose, in maintaining the postharvest quality of chrysanthemum stems. The treatments used distilled water, 8-HQC to 100 mg L-1, 8-HQC to 100 mg L-1 + sucrose 50 g L-1, 8-HQC to 200 mg L-1, 8-HQC to 200 mg L-1 + sucrose 50 g L-1. Physical assessments were made: color, fresh mass and relative water content; chemical evaluations: reducing sugars and pigments, and qualitative assessments: turgidity, color of the flowers, and number of buttons, open flowers and partially open flowers. The combination of 8-HQC 200 mg L-1 + sucrose 50 g L-1 was the best performance that made for maintaining the quality of flower stems, favoring the opening of buttons and turgidity of petals. Sucrose contributed to better maintenance of the reserve substances in the shaft, which had increased the flower vase life.

Inibidor da ação do etileno na conservação pós-colheita de Chrysanthemum morifolium Ramat cv. Dragon

A durabilidade e a qualidade pos-colheita de flores de corte sao atributos fundamentais na sua valoracao ao longo da cadeia produtiva e na satisfacao dos consumidores. Objetivou-se, nesta pesquisa, verificar o efeito do tiossulfato de prata, associado ou nao a sacarose, na manutencao da qualidade pos-colheita de hastes de crisântemos (Chrysanthemum morifolium Ramat cv. Dragon) . O experimento foi conduzido sob delineamento inteiramente casualizado, em esquema fatorial testando solucoes de manutencao com tiossulfato de prata (STS), sob cinco niveis (Agua destilada; STS a 0,2 mM; STS a 0,2 mM + sacarose a 50 g L-1; STS a 0,4 mM; STS a 0,4 mM + sacarose a 50 g L-1); e data de amostragem, por tres niveis (0; 3; 6 dias). Utilizaram-se tres repeticoes com duas hastes florais em cada tratamento. Foram feitas avaliacoes fisicas: coloracao, massa fresca e conteudo relativo de agua (CRA); avaliacoes quimicas: acucares redutores e pigmentos; e avaliacoes qualitativas: turgescencia, cor das flores, e numero de botoes, flores entreabertas e abertas. O tratamento com 0,2 mM de STS possibilitou melhor manutencao da massa fresca das hastes. A concentracao de pigmentos e carboidratos redutores foi maior naqueles tratamentos em que a sacarose foi associada. A coloracao e o conteudo relativo de agua foram favorecidos nos tratamentos STS a 0,2 e 0,4mM. A concentracao de 0,2 mM de STS foi a que obteve os melhores resultados, prolongando a vida de vaso das hastes. A qualidade das hastes foi superior, tendo as melhores avaliacoes de conteudo de agua, cor e turgescencia.