Influence of refining of vegetable oils on minor components

The traditional quality characteristics for refined vegetable oils focus on a bland taste, a light colour and a good oxidative stability. Currently, an increased interest is observed for functional minor components naturally present in oils and fats performing a beneficial nutritional effect. Refining of crude vegetable oils involving degumming, bleaching and deodorisation has a high influence on the content of functional minor components. In this study the difference of chemical versus physical refining will be studied. Especially the reduction of the tocopherol content in refined oil is mainly due to oxidation of the tocopherol. Also the content of sterols in free and esterified form is changing during the various stages of refining. As the economic value of physical deodoriser distillates is much lower compared to chemical distillates an improved deodorization technology to increase the quality of physical deodoriser distillates by condensation of the distillate in two separate fractions was developed. Free fatty acids distillated in the initial stages of the deodorization process are collected in a first distillate, followed by a condensation of tocopherols and phytosterols in a second distillate with a high economic value. The fractionated distillation of free fatty acids and tocopherols / phytosterols was achieved by optimisation of the deodorization temperature profile