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Having a short postharvest life, cucumber undergoes rapid loss of quality. In this research, the effects of temperature, oxygen, and postharvest storage time on the respiration rate of Royal cucumbers were investigated. To design a Modified Atmosphere Packaging (MAP) for cucumber in order to extend its shelf-life, a mathematical model using Michaelis–Menten’s equation, with the model constants described by means of an Arrhenius-type relationship, was applied to predict respiration rate at various temperatures (4, 10, and 20ºC) and O2 concentrations. Results revealed that all three factors affected respiration rate of the cucumbers, but the influence of temperature was most pronounced. The model was validated in a commercial passive and active MAP. The model could well predict the O2 change in the package but the modeling of CO2 change, mainly at 20ºC, was not satisfactory, which might be due to occurrence of anaerobic condition. The mathematical model was verified as long as the O2 concentration did not reach anaerobic levels at 20°C. Applying the corresponding respiration, the model will also be applicable for other variety of cucumbers with similar metabolic and respiratory behavior to design the optimal MAP conditions.

Sliced tomatoes soften rapidly as well as becoming translucent. To develop a physiologically-based mechanism to describe softening the firmness of two cultivars, as a function of time, storage temperature, type of compression (repeated on the same spot or single measurements on consecutive spots on the equator of the pericarp) and initial maturity was measured using tomato slices. The proposed mechanism assumes that the softening of slices is radically different from that of whole tomatoes and depends on the stage of ripening at slicing. The mechanism is also based on the assumption that the pericarp solubility will quickly increase because of exposure to, amongst others, vacuolar contents with a low pH. This exposure will have a more serious effect on the firmness behaviour of ripe tomatoes because the pericarp tissue will have been exposed longer to a lower pH environment that will affect pectin solubility. A kinetic model that describes the individual firmness behaviour over time was developed. This model described trends well despite the high variability of the raw data. It was found that firmness loss induced by wounding occurs within 12 h. The effect of the initial maturity on the final firmness of the slices was large. The model indicates that consumer acceptance of sliced tomatoes is greatly affected by selection of cultivars with sufficient final (structural) firmness combined with a thorough assessment of the maturity at the time of slice preparation.

Pot plant production in green house is most of the time under high relative humidity and frequent irrigation. While, during shipping and retailing plants may be exposed to high temperature and infrequent irrigation. These unfavorable conditions often cause water loss, desiccation of plants and short shelf life. To reduce the deteriorating effect of water loss, application of anti-transpirants is one of the integral measures to implement. In the first experiment we evaluated the anti-transpirant effect of two physiologically gaseous active compounds Ethylene and 1-MCP (1-methylcyclopropane) and their interaction with the successful active compound ABA (Abscisic acid). In the second experiment, hoping to discover a more potent anti-transpirant we evaluated the efficacy of an active compound-film forming blend. Excised leaves of Spathiphyllum sweet checo were sprayed with different formulations. Weight loss of leaves as gram of water per gram of initial leaf weight and stomatal conductance were measured. On the first experiment, 10 ppm Ethylene and 500 ppb 1-MCP found to reduce water loss conspicuously and negatively interacted with 1.5 mM ABA. On the second experiment, a potent mixture of active compound-film anti-transpirants: ABA 1.5 mM+Leaf shine 1:20 followed by SA (Salicylic acid) 5 mM+Leaf shine 1:20 and SNP (Sodium nitroprusside) 200 µM+Leaf shine 1:20 were discovered. On both experiments significant positive correlations were found between weight loss and stomatal conductance (R=0.975, 0.987, P

Pot plant production in green house is most of the time under high relative humidity and frequent irrigation. While, during shipping and retailing plants may be exposed to high temperature and infrequent irrigation. These unfavorable conditions often cause water loss, desiccation of plants and short shelf life. To reduce the deteriorating effect of water loss, application of anti-transpirants is one of the integral options to implement. In this study we evaluated several physiologically active stomata closing compounds. Spathiphyllum sweet checo and Calathea rufibarba were sprayed with different active compound formulations. Weight loss of leaves as gram of water per gram of initial leaf weight and gram of water per centimeter square leaf area and stomatal conductance were measured. On both plant species most physiologically active compound treatments reduce weight loss and stomatal conductance significantly. 1.5 mM Abscisic acid (ABA), 5 mM Salicylic acid (SA) and 200 µM Sodium nitroprusside (SNP) on Spathiphyllum sweet checo and 1.5 mM ABA ,200 µM SNP and 200 µM Pyrabactin on Calathea rufibarba were the three most effective active compound treatments. Significant positive correlation were found between weight loss and stomatal conductance on both plant species (R=0.888, P

Over the last decades, ethylene detection in plant physiological studies is mainly done through enclosing of the plant material under study for a period of time in a closed flask or container and analyzing the accumulated ethylene in the headspace using a gas chromatography equipped with a flame ionization detector. In most of the studies, this will give a reasonable measure of the in vivo ethylene production. However, especially the changing composition of the atmosphere may influence plant behavior and subsequently its ethylene production. Also, if such measurements are mostly done on excised plant parts, the induced wounding also may affect the total ethylene production. Therefore, there is clearly a need for more sensitive equipment to measure ethylene of whole plant or plant parts (in planta) in a flow-through situation. One direction is to further optimize standard GC equipment. This can be done, e.g., by using a more sensitive photoionization detector or through improved sampling and preconcentration devices. Another route is provided by other techniques including the laser-based detection or mass spectrometry that are inherently more sensitive and fast for ethylene measurement. This chapter discusses several of the available techniques for ethylene detection as well as the gas sampling approaches. Guidelines for proper selection and use of the described methods are provided together with examples of applications of monitoring ethylene production from various biological samples.

To protect themselves from disease, plants have evolved sophisticated defense mechanisms in which the signal molecules salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) often play crucial role (Pieterse and Van Loon, 1999). Elucidation of signaling pathways controlling disease resistance is a major objective in research on plant–pathogen interactions. The capacity of a plant to develop a broad-spectrum, systemic acquired resistance (SAR) after primary infection with a necrotizing pathogen is well known and its signal transduction pathway extensively studied (Durrant and Dong, 2004).