Optimization of Virgin Olive Oil Yield and Quality Applying Nonthermal Processing

The objective of this work was to optimize and comparatively evaluate the potential benefit of pulsed electric fields (PEF) and high pressure processing (HPP) processes on the yield, quality, and oxidative stability of olive oil. Olive paste was subjected to various PEF (0.5-2.0 kV/cm, 0-2500 pulses) or HPP (100-600 MPa, 0-30 min) pretreatments, followed by malaxation (15-30 degrees C, 0-60 min). The effect on olive oil yield and phenolic content was studied as a function of the malaxation temperature and time and HPP and PEF pretreatment conditions. The response surface methodology was applied for selecting optimum PEF- and HPP-assisted malaxation conditions. Quality, bioactive compounds, oxidative stability, and sensory evaluation of olive oils produced at optimal conditions (PEF: 1.5 kV/cm, 100 pulses; HPP: 600 MPa, 5 min; malaxation at 26 degrees C, 35 min) were compared to ones obtained conventionally (no pretreatment malaxation: 30 degrees C, 45 min). PEF and HPP pretreatments led to an increase in olive oil yield by 10.6 and 9.3%, respectively, compared to control. Pretreated olive oils had increased oxidative stability attributed to enhanced extraction of polyphenols and a-tocopherols. The combination of each pretreatment with low malaxation temperature led to improved sensorial characteristic of the olive oil.

Automated summary

The objective of this study was to optimize and compare the potential benefits of pulsed electric fields (PEF) and high pressure processing (HPP) on the yield, quality, and oxidative stability of olive oil. Various PEF and HPP pretreatments and different malaxation conditions were studied, and the results showed that PEF and HPP pretreatments increased the olive oil yield and oxidative stability. The combination of pretreatment with low malaxation temperature also improved the sensory characteristics of the olive oil.