The effect of filter aids used in winterization on oil loss and quality of vegetable oil

In this research, it was aimed to determine the effect of filter aids used in winterization on oil loss and quality of vegetable oils. When national and international researches are taken into account, to our knowledge, there is still no research done to determine the effect of filter aids on oil loss amount and quality of vegetable oils. Perlite used in winterization is a domestic good whereas kieselguhr is imported from foreign countries. Turkey is particularly rich in perlite mineral. Determination the effects of these compounds produced domestically on oil quality and losses for the first time is important. For this purpose, within the framework of the plan phase of this study, this research is thought to shed light on the removal of waxes (winterization) in edible vegetable oil plants.Waxes and other compounds having high melting points are undesired to be found in oils for high quality should be removed from oils by winterization with the least possible oil loss amounts. At this point of view, a laboratory-scale winterization unit was established and a study was planned for industry by making several actions to change the parameters used in process. In this study, the effect of using different amounts (0.3% or 0.6%) of filter aids (perlite or kieselguhr) for the winterization of different vegetable oils (sunflower oil or corn oil) at different mixing times (6h, 12h or 24h) on oil quality and loss amounts. Mixing speed, cooling temperature and cooling rate parameters were kept constant.In order to determine the effectiveness of filter aids on winterization process, performing the analysis of wax content, turbidity, triglyceride composition and oil loss amount (process effectiveness) are particularly important. At the same time, as supporting analysis in order to determine the oil quality, color, iodine value, free acidity, peroxide value, conjugated dien value, p-anisidine value, Fe, Cu and Ni analyses were done.As a result of this study, turbidity ? one of the important physical parameters ? generally decreased in filter aid added oils during winterization when compared to control sample, whereas because of the transition of filter aids from filter into oil during filtration, turbidity increased in some samples at 12th hour but then decreased at the end of the 24th hour when compared to control sample.Filter aids used in research had no effect on color values of the samples. Only the effect of filtration process on color was observed. Some of the color pigments were filtered by filtration.When the effect of winterization on oil loss was investigated, it was concluded that filter aids increased the oil loss amount during process. In applications (0.6% kieselguhr and 0.6% perlite) in which the majority of waxes were removed, oil loss amounts were higher.Several quality control analyses were carried out to determine the oxidation in oils, and it was determined that peroxide, conjugated dien and p-anisidine values of the samples increased during winterization process. Limited increases in free acidities of the samples were not significantly important. Free acidity did not change significantly during winterization.It was observed that Fe, Cu and Ni contents of the oil samples increased during winterization. Increase in Fe and Cu which are known as trace elements was higher than Ni content. This shows us that transition of metals from tanks into oils was realized during process.During the winterization of sunflower and corn oils by using different filter aids, no significantly important changes were occurred in proportionally amounts of fatty acids and triglyceride compositions. Winterization had a significant effect on the changes in wax amounts of the samples. Iodine values of the samples increased in terms of the removal of the waxes. Iodine values of the samples increased with the increasing proportion of unsaturated fatty acids.As a result of the analyses, although too much difference was not observed during winterization of oils by using perlit or kieselguhr, it was concluded that the most effective winterization process was the one in which 0.6% kieselguhr was used as filter aid. Majority of waxes were removed in winterization process by using 0.6% kieselguhr as filter aid for both corn and sunflower oil. Since waxes could not be removed in control sample (without using filter aid) adequately, filter aid materials should be used in winterization process in order to remove the wxes. Oil loss amounts recorded in process without using filter aids were lower than the process in which filter aid materials were used. Oil loss amounts in winterization processes in which kieselguhr was used were higher than the oil loss amounts in process in which perlite was used as filter aid. Oil loss amount increased with the increasing amounts of removed waxes. Th most effective winterization period was determined as 24 hours.