Extra virgin olive oil is the typical sources of fat in the Mediterranean diet. It has exceptional nutritional value and positive impact on human health due to its bioactive composition (Lu et al., 2024). Nowadays this is especially important because antioxidants help eliminate free radicals that cause oxidative stress (López-Miranda at al 2010). The quality of oil depends primarily on the transfer of desirable chemical substances from the olive fruit to the oil. Two factors are important for the transfer of these compounds to the oil, namely the quality of the olive fruit and the production processes of virgin olive oil (VOO). Hence, a significant amount of research in VOO production technology focuses at clarifying and solving the issue of oil extraction while optimizing the production process without compromising nutritional and sensory quality.

The conclusion is almost always that there is an interaction between the olive variety and the processing conditions (Clodoveo et al., 2014; Lechhab et al., 2022). One of the possible reasons for this is that, to date, there is no characteristic(s) of the fruit that could serve as an indicator for establishing process parameters that maximize the amount of high-quality extracted oil. The question that arises and to which we would like to obtain an answer is: do all varieties with the same fruit characteristics (in this case texture characteristics) behave in the same way during the processing process, regardless of the change in the conditions for processing the fruit in the VOO, and can this knowledge improve the optimization of the processing process and the quality of the VOO?

The olive fruit is highly variable in terms of size, shape and chemical composition. Its chemical composition influences its nutritional value, its sensory and health properties, but also its mechanical properties, especially its texture. The mesocarp represents 90% of the fruit weight and is composed of water (40-70%), oil (6-25%), and 25-35 % other carbohydrates (Koprivnjak, 2006; Clodoveo et al., 2014), while lipids predominate in the exocarp (González-Cabrera et al., 2018). Primary mesocarp cell wall is composed of pectin, cellulose, and hemicellulose substances, while in the intercellular space a thin central lamella of pectin connects the adjacent cells into a tissue and influences the hardness of the fruit. The cells of the mesocarp are characterized by the accumulation of oil in vacuoles, by membranes separated from the rest of the aqueous content of the cytoplasm. Sugars play an important role in olive fruit as important components of the cell wall related to structural properties, they are precursors of olive oil biosynthesis, and they provide energy for metabolic changes. Phenolic compounds are minor constituents of olive fruit but play a crucial role in the sensory properties of VOO (Andrewes et al., 2003), the stability of the oil (Carrasco-Pancorbo et al., 2005; Servili et al., 2013), and the beneficial health effects (Bendini et al., 2007; Rallo et al., 2018). About 5% of biophenol in the pulp has the function of cross bridges between the polysaccharide chains that form the cell walls, contributing to the structural properties of the tissue, referring primarily to the textural properties (Koprivnjak, 2006).