COMPARATIVE PERFORMANCE OF STEAM AND NITROGEN AS STRIPPING GAS IN PHYSICAL REFINING OF EDIBLE OILS

Olive, sunflower, and soybean oils were physically refined in a discon tinuous laboratory system with either nitrogen or steam as stripping g as during the deodorization step. Comparative assays were also carried out on olive oil in a 10-MT discontinuous industrial plant. Vaporizat ion efficiency of free fatty acids was calculated, and quality of refi ned oils and composition of deodorizer distillates were analyzed. Resu lts indicated that, in all assays, the efficiency of free fatty acid d istillation was higher when nitrogen was used. The amount of nitrogen needed was much lower than that of steam for refined oils of similar h igh quality. The results also suggested that the amount of stripping g as had a clear influence on the composition of deodorizer distillates because lower quantities of triglycerides and unsaponifiable matter we re round when nitrogen was employed.