Cold storage of olive fruit has been the subject of study for over more than 50 years. From the 1990s on, an increasing amount of knowledge is build-up about the impact of the conservation on the physiological response of the fruit as well as on the quality of the extracted oil therefrom. This review offers a comprehensive synopsis of this research, discusses the most important influential factors and summarizes the results on the influence of the studied parameters on both the fruit and the oil. Currently, changing climatic conditions, new harvesting techniques and a more demanding consumer market are triggering the need to broaden this strict focus on conservation. A more dynamic view on the effects of temperature from the moment the fruit is harvested up to the oil extraction process, reveals the necessity to manage this crucial influential factor more diversely. An overview of how this management can take form is structured through a focus on the different phases of the postharvest processing and the widely different harvesting scales. Future prospects of research are presented based on the actual state of the art of cold storage research as well as on the necessities that come forward from a broader fruit temperature management perspective.

Evaluation of a manual olive fruit harvester for small producers | Eddy Plasquy, Rafael R. Sola-Guiraldo, Carmen Florido, José M. García, Gregorio Blanco-Roldán | Agricultural Journals

Background: Secondary metabolites in stevia leaves offer important therapeutic benefits. The germination problems of stevia seeds and the high heterogeneity of the resulting populations make micropropagation the preferred tool for obtaining a large number of plants in a short time. Until now, studies have focused on optimizing the action of growth regulators for the improvement of stevia micropropagated plantlets. In this project, we study alternative mineral nutrients in the substrate and two culture systems on micropropagated stevia plantlets to obtain proper amounts of enhanced plantlets. Methods: Criolla and Morita varieties; MS, MSM, and G substrates, and temporary immersion (TIS) and agar-medium systems were used. Biometric variables and damage to the cell membrane of the resulting plantlets were tested. Results: More productivity in the Criolla plantlets growing in MS solid medium and TIS. The Morita plantlets presented higher productivity in the solid MS, MSM, and G substrates and TIS. The explants growing in MS and MSM presented the highest productivity. The solid substrate was generally better than TIS. No damage to the cell membrane was found. Conclusions: The micropropagation efficiency of stevia plantlets of the two varieties has been enhanced without negative effects on their physiological condition. Consequently, any of the culture systems used, including bioreactors, can be of industrial application on a large scale.