Cholesterol removal by selected metal-organic frameworks as adsorbents

The aim of this study was to investigate the cholesterol removal capacity of seven metal-organic frameworks (MOF) and to compare with active carbon as adsorbents, and with aqueous β-cyclodextrine complexation removal technique. There were slight color differences in the oil samples after the treatments. The lowest free fatty acidities (0.13% and 0.13% linoleic acid) and peroxide values (21.07 and 23.50 meqO₂/kg) were measured in aluminum-MOF (Al-MOF) and titanium-MOF (Ti-MOF) treated samples when compared to control sample (0.15%, and 27.62 meqO₂/kg). Cholesterol reduction ratios of the Al-MOF treated sample (27.45%) and Ti-MOF treated sample (26.27%) were higher among all adsorbent treatments, but lower than that of the β-cyclodextrine aqueous complexation technique (33.07%). Further experiments with Al-MOF and Ti-MOF showed that when adsorbent addition level increased to 3.0%, removed cholesterol content increased. Likewise, when treatment times extended to 180 min, more cholesterol was removed. But, the removed cholesterol contents at 100 °C and 30 °C treatment temperatures were lower than that of at 50 °C treatment temperature. Further experiments with butter and sheep tail tallow showed that Al-MOF was quite effective as an adsorbent to remove cholesterol. This study proves the great potential of MOF to remove cholesterol selectively from oil/fat by adsorption principle.