O objetivo deste trabalho foi avaliar a composição de carboidratos e carotenoides em rizomas mãe e filhos das variedades de mangarito (Xanthosoma riedelianum) pequeno e gigante. Amostras dos rizomas coletadas ao longo do ciclo cultural e após 90 dias de armazenamento foram avaliadas quanto aos teores de carboidratos e carotenoides totais. Os rizomas apresentaram aumento no teor de carboidratos, e o rizoma-mãe da variedade pequeno apresentou acréscimos lineares no teor de carotenoides, ao longo do cultivo. O armazenamento reduz os teores de carboidratos e de carotenoides totais em todos os rizomas.

The objective of this work was to evaluate the composition of carbohydrates and carotenoids in mother rhizomes and small cormels of the dwarf and giant mangarito (Xanthosoma riedelianum) varieties. Rhizome samples collected during the crop cycle and 90 days after storage were evaluated for carbohydrate and total carotenoid contents. Rhizomes showed an increase in the carbohydrate content, and the mother rhizome of the dwarf variety had linear increases in the carotenoid content, during cultivation. Storage reduces carbohydrate and total carotenoid contents in all rhizomes.

This work had the goal to evaluate the influence of temperature and dry storage on the postharvest longevity of Epidendrum ibaguense flowers previously treated with silver thiosulfate (STS). The flowers were harvested and pulsed for 30 minutes with 2 mM STS. Then both, the STS treated and untreated flowers were packed in perforated low density polyethylene bags, packed in cardboard boxes and stored at 5 and 10°C, where they remained for four and eight days. After this period, the flowers were kept in vase with distilled water at 25ºC, and analyzed at every 24 h. The experiment was arranged in a complete random design 2 x 2 x 2 factorial scheme, with four replicates, containing four inflorescences each, except for the determination of transpiration and water rates uptake, composed by sixteen replicates of one stem. The vase life of the flowers of the E. ibaguense was increased to 6.5 days when pulsed with 2 mM STS for 30 minutes, followed by storage at 10ºC for a maximum period of four days. The STS applied before the cold storage reduced the rate of flower abscission and improved the ratio between the transpiration and water uptake.

Folhas de taioba danificadas fisicamente tornam-se amarelas e escuras na região do dano. Assim, o objetivo deste trabalho foi avaliar o efeito do dano físico sobre o metabolismo pós-colheita de folhas de taioba. Para esse fim, avaliou-se o teor de clorofila e o acúmulo de compostos fenólicos solúveis em discos foliares de taioba que continham furos realizados com uma agulha em um dos lados da folha, simulando os danos sofridos no campo e transporte. O lado não danificado foi usado como tratamento controle. Para a avaliação da produção de etileno e CO2, discos foliares danificados e intactos foram infiltrados com ácido 1-carboxílico-1-aminociclopropano (ACC) ou com água desionizada. Houve acentuada queda de clorofila nas primeiras 24 horas após a colheita, porém, o dano físico não estimulou a degradação da clorofila ou elevação da produção de etileno. Entretanto, nos discos foliares danificados e infiltrados com ACC, houve aumento transiente na produção de etileno após 4 horas da realização do dano. Essa resposta demonstra que a enzima ACC sintase não é estimulada pelo dano e a enzima ACC oxidase tem sua atividade aumentada apenas por um curto período. Em contrapartida, as folhas danificadas tiveram maior acúmulo de compostos fenólicos e elevada taxa respiratória.

Damaged Tannia leaves present yellowing and browning. The objective of this study was to evaluate the effect of physical damage on the postharvest metabolism of tannia leaves. Chlorophyll content and the accumulation of soluble phenolic compounds were evaluated in tannia leaf discs containing holes made with a needle in one leaf side, simulating the damage in the field and transport. The undamaged side was used as control treatment. To evaluate the ethylene and CO2 production, damaged and intact leaf discs were infiltrated with 1-aminocyclopropane-1-carboxilic acid (ACC) or deionized water. Intense degradation of chlorophyll occurred within the first 24 hours after harvest, but the damage did not stimulate the degradation of chlorophyll or ethylene production. The damaged discs infiltrated with ACC had transient increase in ethylene production after 4 hours of damage. This response demonstrates that the ACC synthase enzyme is not stimulated by physical damage and ACC oxidase enzyme has its activity increased only for a short period. In contrast, the damaged leaves had a higher accumulation of phenolic compounds and higher respiratory rate than undamaged leaves.

O objetivo deste trabalho foi avaliar o efeito de soluções de vaso na longevidade pós-colheita de inflorescências de boca-de-leão. Hastes de boca-de-leão ('Potomac White'), colhidas com seis a sete flores abertas na inflorescência, foram condicionadas em: (1) água desionizada a 20°C (controle); (2) água quente a 43°C, por uma hora, seguida de água desionizada (20°C) como solução de vaso; (3) solução de Flower® a 20°C; (4) solução de vaso preparada com 200mg L-1 de 8-HQC+20g L-1 sacarose+150mg L-1 ácido cítrico a 20°C; (5) água quente (43°C) por uma hora e Flower® em solução de vaso (20°C); e (6) água quente (43°C) por uma hora e solução contendo 200mg L-1 de 8-HQC+20g L-1 sacarose+150mg L-1 ácido cítrico como solução de vaso (20°C). A vida de vaso das inflorescências de boca-de-leão variou de três a sete dias de acordo com o tratamento utilizado. A maior longevidade foi obtida com a solução contendo 8-HQC, sacarose e ácido cítrico, tratamento que não comprometeu a abertura floral. Além disso, as inflorescências condicionadas nessa solução apresentaram ganho de massa fresca superior à massa daquelas mantidas em água desionizada ou Flower®, a partir de 24 horas, atingindo 24% de aumento no quinto dia da reidratação. Assim, o uso de soluções de vaso adequadas mantém a qualidade e prolonga a longevidade das hastes cortadas de boca-de-leão.

The goal of this research was to evaluate the influence of vase solutions on the postharvest longevity of snapdragon inflorescences. Stems of snapdragon 'Potomac White' harvested with six to seven open flowers were treated as follow: (1) distilled water at 20oC (control); (2) warm water at 43oC for one hour, followed by distilled water (20°C) as vase solution; (3) solution of Flower at 20°C; (4) vase solution of 200mg L-1 8-HQC+20g L-1 sucrose+150mg L-1 citric acid at 20°C; (5) warm water (43°C) for 1 hour followed by Flower as vase solution (20°C); (6) warm water (43°C) for one hour and 200mg L-1 8-HQC+20g L-1 sucrose+150mg L-1 citric acid as vase solution (20°C). The vase life of snapdragon inflorescences varied from 3 to 7 days according to the treatment used. The longest longevity was obtained for the flowers treated with 8-HQC, sucrose and citric acid, which did not compromise the flower opening. Furthermore, the inflorescences kept in this solution had higher the fresh weight gain when compared to distilled water or Flower after 24 hours, reaching 24% increase on the fifth day of rehydration. Thus, the appropriate vase solution maintains the quality and extends the longevity of cut stems of snapdragon.