Filtration and filter system for treated frying oil

Used canola oil was treated with commercially available adsorbents (HB 600, Magnasol, and Frypowder) and a UGA blend for flow rate study and oil quality improvement. Viscosity measurements of fresh and used oil indicated that the oil temperature > 140C was best suited for active filtration. One percent adsorbent gave better flow rates than 2% except for Frypowder, which showed no difference in flow rates. All the adsorbents significantly improved the oil quality. Most significant improvement was observed in FFA values (15-20% and 24-35% for 1% and 2% adsorbent level, respectively) except for Frypowder, which resulted in least improvement (4 to 7%). Neither increasing the duration of treatment, prior to filtration, from 3 to 6 min, with 3% UGA blend, nor the multipass filtration treatment showed any significant improvement in oil quality. Pressure system was more promising for active filtration than vacuum and gravity systems.