Machining effects of different mechanical crushers on pit particle size and oil drop distribution in olive paste

The purpose of this study is to evaluate the effects of the mechanical components of the crushers on pits and oil droplet fractionation. The olive pastes obtained using four different crushing systems were compared. Analyses of the pit particle size distribution and oil drop aggregation were performed. The analysis of the experimental data shows that different crushing machines produce different pit and oil drop fragmentation, and the trends confirm that increased pit fragmentation corresponds to increased droplet fragmentation. Therefore, the results confirm that the partial de-pitter and hammer crusher yielded the greatest enhancement in emulsification of oil droplets, and the stone mill and disc crusher yielded the greatest aggregation of oil droplets. Practical applications: The practical application of this work includes understanding the effects of four different crushers on oil drops and pit fragmentation. The experimental data could be useful to define the best malaxation time and to gain a better understanding of the minor components distribution in olive oil. The results obtained could be used to construct a guideline for the design and sizing of crushing machines. Different crushing machines produce different pit and oil drop fragmentation, and the trends confirm that increased pit fragmentation corresponds to increased droplet fragmentation. The data expressed in this research could be used to construct a guideline for the design and sizing of crushing machines with the goal of achieving a balance between pulp fragmentation, pit breakage and oil drop fragmentation.