ABSTRACT ‘Frangi’ papaya is a F1 hybrid cultivar produced by Malaysian Agrifood Corporation Bhd in 2006. Since then, ‘Frangi’ papaya is a new hybrid and its physiology may differ from another cultivars. Several importer countries, such as Japan and China, have made the vapour heat treatment (VHT) an export requirement for disinfestation of fruit flies in Malaysia. The exporting country is also required to carry out ripening treatments with ethylene before export. Therefore, the objective of this work was to determine the effects of maturity stages (4, 5 and 6) and ethylene treatments on ripening characteristics of vapour heat treated papaya during storage at 25 °C. Papaya fruits were treated with VHT systems. After VHT, the fruits were exposed with 100 µL.L–1 ethylene gas at 20 °C for 24 h. Non-ethylene treated fruits (control) were kept separately at 20 °C for 24 h. After 24 h, the fruits were removed from the ripening rooms, and stored at 25 °C. The ripening characteristics of fruits that reached maturity stages 4, 5, and 6 were recorded. Results showed that the fruits ripened normally at 25 °C with or without ethylene following VHT with respect to peel and pulp color, edible firmness and soluble solids concentration (SSC). Fruits at maturity stage 5 were considered at the edible stage by taking into account the firmness, SSC, titratable acidity, and ascorbic acid contents. It is recommended that no ethylene treatment is needed to ripen vapour heat treated fruits, since the ethylene treatment did not affect the ripening process of the fruits.

AbstractOrchids possess a very special place amongst ornamental plants. But high ethylene sensitivity and early flower senescence of orchid result in a short vase life and rapid quality deterioration which is of great concern for the growers, traders and consumers. An attempt was made to study the influence of 1-methylcyclopropene (1-MCP) (0 and 300 nL L–1) and аquеous ozone (0 and 5.2 nL L–1) in prolonging vase life and maintaining quality of two cut orchid hybrids Dendrobium 'Darren Glory' (DDG) and Mokara “Calypso Jumbo” (MCJ). Results showed that orchid hybrids exhibited differences in their ethylene sensitivity, vase life, 1-aminocyclopropane-1-carboxylic acid (ACC) content and ACC oxidase activities. Pre-treatment with 1-MCP resulted in reduced ethylene production, vase life, ACC content and ACC oxidase activities, but increased bud opening %. Pre-treatment with аquеous ozone failed to influence all those parameters except bud opening %. Interaction effects of hybrid and 1-MCP were significant for ethylene production, hybrid and ozone for vas life, 1-MCP and ozone for bud opening %, and hybrid, 1-MCP and ozone for ethylene production and vase life. Aqueous ozone markedly contributed to the inhibition of microbial growth in vase solution. Pre-treatment of the cut orchid flowers with 300 nL L–11-MCP, followed by using 5.2 mg L–1 aqueous ozone as the vase solution could be recommended to maintain quality and extend vase life of both the DDG and MCJ orchid hybrids.

Leafy vegetables such as lettuce grown under different production systems may accumulate different concentrations of nitrate which may reach to the levels potentially toxic to humans. Moreover, nitrate accumulation varies in various plant parts and physiological age of the plant. Therefore, to determine the effect of production system and harvesting stage on nitrate accumulation and quality of butterhead lettuce, a study was conducted considering two lettuce production systems namely hydroponic and organic, and four different harvesting stages such as 35, 38, 41 and 44 days after transplanting (DAT). The experimental design was complete randomized design (CRD) with four replications. Hydroponic and organic systems performed similar in terms of yield, quality and nitrate content of butterhead lettuce. Delaying harvesting can not only increase yield but also can minimize nitrate accumulation and health hazard risk as well. Delay in harvesting stage may result in quality deterioration of lettuce and increased production cost. Thus, a compromise is necessary to consider 41 DAT as the optimum stage to harvest butterhead lettuce with significantly higher reduction of nitrate content in both outer adult leaf blades and young leaves of hydroponic lettuce. Fresh weight, firmness and color of butterhead lettuce at this stage were still acceptable.