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The productivity of virgin olive oil depends not only on agronomic factors but also on the technological factors of the extraction process. The ‘Arbequina’ variety has extractability problems, which is a challenge for master millers anywhere. This work aims to evaluate the behavior of different decanters and seeks to modulate the effect of some processing parameters and their interactions with oil extraction efficiency in the case of ‘Arbequina.’ Fruit characteristics, processing parameters, and extractability were collected over 10 years from 38 decanters that belong to five different brands. The results have shown that fruit moisture is the most relevant factor for oil extractability, especially over 52%. Furthermore, extractability is positively correlated with malaxing temperature, addition of water, and total fat content in the fruit. However, the results show that before applying a regulation, the type of decanter must be considered. The model used in this study has allowed us to optimize the regulations for each type of decanter to reduce oil losses within the pomace, achieving an extraction efficiency within the range of 78%–91.5%. In fact, the best extraction efficiency results (91.5%) were obtained by processing at temperatures >26°C and water injection of 5%.

“Negret” is the most widely planted hazelnut cultivar in Northeastern Spain, where it is highly appreciated by the local kernel marked for its favorable nut traits. Its main disadvantages are the high suckers emission, causing large maintenance costs every year, and its medium-to-low vigor and susceptibility to iron chlorosis. In 2000, a trial to select new vigorous and non-suckering rootstocks for hazelnut was established at IRTA Mas Bové (Spain). The “Negret N-9” selection was grafted onto four clonal rootstocks (“Dundee” and “Newberg” two selections of open-pollinated Corylus colurna seedlings, the low suckering cultivar “Tonda Bianca” and the local selection “IRTA MB-69”) and compared to the self-rooted “Negret N-9” as a control. The trial was designed as a randomized complete block with 10 replications and one tree per plot (10 trees per treatment). Plant vigor, suckers emission, yield, and nut and kernel traits have been evaluated over 10 years (2003–2012). During the 2006 to 2010 growing seasons, the qualitative traits of kernels, such as kernel skin color, oil content, and fatty acid profiles, were added to the characterization. Physiological data, such as steam water potential, stomatal conductance, and leaf chlorophyll content, were also evaluated during the 2015 growing season. The results showed that clonal rootstocks had a strong influence on vigor and yield of “Negret N-9.” The “Dundee,” “Newberg,” and “IRTA MB-69” rootstocks showed the highest vegetative growth and the lower suckers emission. The yield was highest in trees grafted on “Dundee” rootstock. In terms of the qualitative traits of kernel which are important to the hazelnut industry, rootstocks increased the oil stability and induced a brown light color in the kernel pellicle versus the brown dark color observed in nuts collected from self-rooted “Negret N-9.” The fatty acids profile was also influenced by the grafting combination. Finally, physiological traits indicated a higher overall performances for “Dundee” rootstock, which was generally found to be the best rootstock for “Negret N-9” in the experimental environment.

Olive (Olea europaea L.) growing has outstanding economic relevance in Spain, the main olive oil producer and exporter in the world. Fruit skin properties are very relevant for fruit and oil quality, water loss, and susceptibility to mechanical damage, rots, and infestations, but limited research focus has been placed on the cuticle of intact olive fruit. In this work, fruit samples from nine olive cultivars (“Arbequina,” “Argudell,” “Empeltre,” “Farga,” “Manzanilla,” “Marfil,” “Morrut,” “Picual,” and “Sevillenca”) were harvested from an experimental orchard at three different ripening stages (green, turning, and ripe), and cuticular membranes were enzymatically isolated from fruit skin. The total contents of cuticular wax and cutin significantly differed among cultivars both in absolute and in relative terms. The wax to cutin ratio generally decreased along fruit maturation, with the exception of “Marfil” and “Picual.” In contrast, increased water permeance values in ripe fruit were observed uniquely for “Argudell,” “Morrut,” and “Marfil” fruit. The toluidine blue test revealed surface discontinuities on green samples of “Argudell,” “Empeltre,” “Manzanilla,” “Marfil,” and “Sevillenca” fruit, but not on “Arbequina,” “Farga,” “Morrut,” or “Picual.” No apparent relationship was found between water permeability and total wax coverage or the results of the toluidine blue test. The composition of cuticular waxes and cutin monomers was analyzed in detail, and sections of fruit pericarp were stained in Sudan IV for microscopy observations. Skin surface topography was also studied by means of fringe projection, showing large differences in surface roughness among the cultivars, “Farga” and “Morrut” fruits displaying the most irregular surfaces. Cultivar-related differences in cuticle and surface features of fruit are presented and discussed.