Temperature effects on the deacidification of mixtures of sunflower oil and oleic acid

Although it is well known that oil temperature is an essential factor for determining the deacidification mass rate and the final free fatty acids content, the influence of the temperature of the gas distillates above the liquid phase in the deodorizer on the oil temperature is much less understood. An extensive study of the effect of the temperature of the oil and of the gas distillates was undertaken in a continuous deodorizer, comparing the results with those obtained using a batch process. Variations in temperature from the temperature obtained without additional heating of the gases to a higher temperature than that of the oil were assayed for the gas distillates at the head of the deodorizer. It was possible to obtain low outlet free fatty acid contents at lower oil temperatures by controlling the overheating of the distillates, even for very high initial free fatty acids content, indicating that this is an essential variable to consider in distillation. However, increasing the temperature of the gas distillates above that of the oil sometimes produces a negative effect in deacidification.