HomeFAQBleaching earth has been the best known method for bleaching the colour of palm oil. Are there any new developments in the bleaching of oils?
Bleaching earth has been the best known method for bleaching the colour of palm oil. Are there any new developments in the bleaching of oils?
FAQ / Chat on line / Give me a price / Date: November 19, 2014
The use of activated bleaching earth (clay) in the processing of oils and fats has a long and successful history.
Bleaching earths have gradually and steadily improved in quality so that with reasonably good crude palm oil, addition of about 1% enables the desired final colour limit of 3 RED (5.25 inch Lovibond cell) to be reached every time.But the performance of a bleaching earth cannot be assessed on colour considerations alone because the removal of phosphatides and trace metals is also very important in ensuring maximum stability to oxidation and resistance to flavour deterioration.
Now new materials are challenging the position of bleaching earth e.g. the development of silica hydrogel which, when used to replace part of the bleaching earth, lead to equally good colour values in the finished oil, and also much better removal of phosphatides.
Thus, 0.3% hydrogel plus 0.6% bleaching earth gives better removal of trace metals and gums than 1.3% bleaching earth alone.
Bleaching earths have gradually and steadily improved in quality so that with reasonably good crude palm oil, addition of about 1% enables the desired final colour limit of 3 RED (5.25 inch Lovibond cell) to be reached every time.But the performance of a bleaching earth cannot be assessed on colour considerations alone because the removal of phosphatides and trace metals is also very important in ensuring maximum stability to oxidation and resistance to flavour deterioration.
Now new materials are challenging the position of bleaching earth e.g. the development of silica hydrogel which, when used to replace part of the bleaching earth, lead to equally good colour values in the finished oil, and also much better removal of phosphatides.
Thus, 0.3% hydrogel plus 0.6% bleaching earth gives better removal of trace metals and gums than 1.3% bleaching earth alone.
