Adriano do Nascimento Simões

Armazenamento de melão amarelo, híbrido RX 20094, sob temperatura ambiente

ABSTRACT Yellow melon, RX 20094 hybrid, stored at room temperature The postharvest shelflife of yellow melon RX20094 hybrid wasobtained through visual, physical, and physical-chemical evaluationsin two experiments carried out at Escola Superior de Agricultura deMossoro, Rio Grande do Norte State, Brasil. A completelyrandomized design with six treatments, consisting of storage days(0; 5; 10; 15; 20; and 25) and five replications, with 2 fruits per plot,was utilized. The fruits were kept at the temperature of 30±1oC and50±5% of relative humidity. Evaluations were made at five-dayintervals with the determination of flesh firmness, weight loss,external and internal appearances and soluble solids content (SS).The storage days had effect on all characteristics. Yellow melonsRX20094 hybrid maintained good quality characteristics for up to astorage period of 25 days at room temperature. Keywords: Cucumis melo L . , postharvest, quality, shelf life. (Recebido para publicacao em 17 de dezembro de 2002 e aceito em 02 de novembro de 2003)

Mudanças metabólicas após recondicionamento a 15ºC de tubérculos de batata armazenados a baixa temperatura

Potato tubers of cultivars Atlantic, Eliza and Perola were firstl stored at 2oC for 10 days and then reconditioned at 15oC for 10 or 20 days, in order to verify if these treatments could reduce the cold-sweetening. The reconditioning was associated to reduced tuber sucrose levels in all cultivars analyzed, and was followed by a clear reduction in the activity of sucrose-phosphate syntase, UDP-glucose pyrophosphorylase, and sucrose synthase. The decrease in invertase activity was only transient, and limited to some genotypes. These treatments also reduced linearly the glucose levels in Perola and Atlantic tubers, which in turn suggest that stronger reductions could be observed under longer reconditioning periods. Starch contents were not changed in reconditioned tubers, although a transient decrease in the activity of starch phosphorylase and total amidolitic activity was observed in some genotypes. These data indicate that reconditioning, even under short time periods (20 days) and mild temperatures (15°C), result in a strong and heterogeneous effect on tuber carbohydrate metabolism. More importantly, these results indicate that the reconditioning could reduce cold-sweetening in the cultivars Perola and Atlantic.

Endogenous levels of polyamines during cold storage of bird-ofparadise treated with biocides

This study aimed to analyse the endogenous levels of free polyamines putrescine (Put), spermidine (spd) and spermine (spm) under the effect of 8-HQC (8-hydroxyquinoline citrate) and chlorine during cold storage of bird-of-paradise floral scapes. Flowers were selected, labelled and randomly distributed in recipients for postharvest trials. The base of flower scapes was immersed with pulsing treatments (Control, 100 chlorine, 250 or 500 mg L-1 8-HQC) for 48 h, thereafter, stored at 10.5 °C and 90% relative humidity for a period of 12 days. Flower parts were sampled for polyamines analysis at day 0, 4, 8 and 12 days during storage. All samples had higher Put levels than the control. Treatment with 500 mg L-1 8-HQC showed the highest Spd levels in bracts, while chlorine treatment had the highest Spm levels in stems.