Optimization of operating conditions for lampante olive oil deacidification by short path molecular distillation: Waste valorization approach

Abstract

Short path molecular distillation (SPMD) is an advanced distillation eco-friendly technique performed under high vacuum with vast applications in food processing, including vegetable oils physical refining. In this research, lampante olive oil, as a low-grade byproduct of olive oil producing companies, with high free fatty acids (FFA) content of 10.11 (wt % as oleic acid) was deacidified using SPMD. Optimization of SPMD was carried out using Box-Behnken response surface methodology (RSM-BB). Three important operating factors including evaporation temperature (150–200 °C), feed flow rate (0.50–3.00 mL/min), and feed temperature (50–100 °C) were selected to evaluate the SPMD process. At the best separation conditions of 195 °C, 0.5 mL/min, and 50 °C, the FFA content, deacidification efficiency (DE) and polar compounds (PC) were determined as 1.42 wt %, 85.95 % and 8.2 wt % respectively. Furthermore, SPMD efficiency was compared to some conventional methods including fractional distillation (FD), steam stripping distillation (SSD) and alkali neutralization (AN). In addition, the impact of FFA content on SPMD process was examined. It was concluded that SPMD could effectively and sustainably deacidify lampante olive oil to a reasonable extent and could facilitate the physical refining as a valorization process.