Browsing by Author "Vasconcelos, Marta W."
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- Cold storage demand for Rocha pear ripening: A comparison between a shorter and a longer cold periodPublication . Dias, Cindy; Ribeiro, Tânia; Rodrigues, Ana Cristina; Ferrante, António; Vasconcelos, Marta W.; Pintado, Manuela'Rocha' pear is a cultivar that when harvested at the recommended maturity stage (physiological condition that allows resisting to prolong cold storage), requires chilling exposure after harvest, to induce an autonomously ripening appreciated by the consumer. Fruit were stored immediately after harvest, for 6 d (batch 1) or 26 d (batch 2), in normal cold atmosphere storage, to further our understanding of 'Rocha' pear ripening under different short cold storage durations. The ripening events were then monitored at 0, 3, 7, and 10 d of shelf-life at room temperature (± 20 °C) through physicochemical and biochemical changes, including firmness, soluble sugars, malic acid, esters profile, and ethylene metabolism (1-aminocyclopropane-1-carboxylic acid (ACC) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO)). We found that ripening behaviour upon rewarming from both cold storage periods was similar, with fruit ripening with a typical pattern of ethylene production and respiration rates concomitant with a higher ACO activity. Soluble sugar and esters emission were not influenced by cold storage duration, but interestingly butyl acetate levels were significantly higher on pear, which was cold stored for 26 d Our data provide more novel information about Rocha' pear's ripening physiology, indicating for the first time that approximately one week of chilling temperature is enough to promote ripening rate processes. Such knowledge could be an asset to the efficient management of 'Rocha' pear storage.
- Improving the ripening process after 1-MCP application: Implications and strategiesPublication . Dias, Cindy; Ribeiro, Tânia; Rodrigues, Ana Cristina; Ferrante, António; Vasconcelos, Marta W.; Pintado, ManuelaBackground: Consumers’ lifestyles demand high-quality products, requesting adequate fruit storage. Management of ethylene production is of paramount importance when planning postharvest storage, since this phytohormone is the key molecule behind the ripening and senescence process. Cold storage combined with 1-MCP has been one of the most applied postharvest treatments to extend the shelf-life of several fruit. However, 1-MCP is a potent inhibitor of ethylene action, leading frequently to the blockage of ripening denominated as ‘evergreen’ effect. Scope and approach: Ethylene biosynthesis and perception pathway are described, as well as a critical review on 1-MCP inhibitory mechanisms. Technologies used to induce postharvest ripening after 1-MCP application are described with special attention to the latest and most significant published works. The most relevant 1-MCP reversion strategies are discussed, aiming to develop more innovative and effective approaches for stimulating ripening. Finally, the importance of tailoring treatments to specific cultivars is discussed, using pear as a case study. Key findings and conclusions: Optimizing temperature and applying exogenous ethylene have been the main methods to reverse the effect of 1-MCP. Also, treatment with other phytohormones has shown promising results. However, the strategies effectiveness is dependent on the cultivar, time of application, and concentration of the applied compound. Also, since 1-MCP binds irreversibly to the ethylene receptor, the biosynthesis of new receptors may reverse the ‘evergreen’ behaviour. Therefore, attempts should be made to develop strategies according to each cultivar and their capacity to stimulate the expression of ethylene genes both related to its biosynthesis and perception.
- Relationship between minerals and physicochemical parameters with fruit quality in ‘Rocha’ pear orchardsPublication . Dias, Cindy; Ribeiro, Tânia; Rodrigues, Ana Cristina; Vasconcelos, Marta W.; Ferrante, António; Pintado, ManuelaAt the same location, variability among orchards may be high, which is reflected in fruit quality, and it may be associated mainly with growers’ practices. This study aimed to identify physicochemical variability within pears (Pyrus communis L. cv 'Rocha') from three orchards from the same location and under the same climate conditions and correlate it with mineral composition.