Improved deodorization technology for the production of high quality food oils

The quality of a refined oil is usually evaluated by traditional quality parameters such as a low residual free fatty acid (FFA) content, a high oxidative stability, a light colour and a neutral odour and taste. Recently, more attention is also paid to the nutritional quality of edible oils. High quality food oils should contain low trans fatty acid (TFA) levels, high amounts of natural antioxidants and vitamins and low levels of polymeric and oxidized triglycerides. These quality issues have long not been addressed in palm oil refining. Due to its relatively saturated character, palm oil is less sensitive towards formation of TFA and polymeric triglycerides. However, palm oil is also a known source of natural antioxidants (e.g. tocotrienols,...) and vitamins. Today, an increased interest is observed in the valuable minor components of edible oils because of their apparent positive nutritional aspects. Process conditions can be optimized to maximize their retention in the refined oil. On the other hand, they are sometimes removed from vegetable oils (soyabean, rapeseed, sunflower,...) during deodorization and valorized with a high added value as so-called `nutraceuticals`. In any case, improved deodorization technology is required which enables the controlled stripping and recovery of valuable minor components without affecting the general quality characteristics of the refined oil. Intensive research aiming at a bettter understanding of the deodorization process resulted in the development of the Dual Temp deodorization concept. Comparison with the more conventional packed column technology showed that this technology may also be beneficial for the refining of palm oil. The combination of a deodorization and stripping under mild conditions (lower temperature) and a further stripping at higher temperature for a shorter time enables the production of a refined palm oil with an excellent overall quality and a controlled retention of tocotrienols. In addition, it may result in the production of a distillate enriched in tocotrienols.