RBD palm oil process means Refined Bleached Deodorised Palm Oil (RBD Palm Oil) process.
In the past three decades the chemical refining process scheme has gradually been superceded by the more cost-effective and more environmentally-friendly Physical refining processing scheme. In physical refining the process of caustic refining is eliminated, and the vacuum deodorization has been replaced by a higher temperature Steam stripping and deodorization processes that enables the Free Fatty Acids and other impurities to be removed without the use of caustic soda. The term in the Physical Refining indicates that chemicals have not be used to remove the fatty acids. Although caustic soda is no longer utilized in Physical refining, the term RBD is still in use to describe the fully-refined palm oil.
The refining process consists of 3 major steps :
Degumming : To condition gums (phosphatides) and oxidative trace metals ( such as copper and iron ) with food grade phosphoric acid, citric acid, EDTA etc, for later removal with the spent earth after the bleaching stage
Bleeching : To remove pigments, oxidation products, residual trace metals and phosphatides, and soaps
Steam refining/deodorization : To remove fatty acids, pigments (e.g. carotenoids)
In order to increase the oxidative stability and improve the nutritional properties of crude palm oil it is necessary to treat the oil by a series of processes, that are collectively known as refining. The first stage of the processing is primarily to remove the gums and pro-oxidative trace metals, and is called the degumming stage. Historically, the next stage of the process involved neutralization of the Free Fatty Acids by caustic soda, to remove them in the form of soaps. This process was known as Caustic Refining (and represents the “R” in “RBD”). The next stage utilized bleaching earth to remove pigments, oxidation products, soaps and traces of gums and heavy metals. This is called the Bleaching stage, and is represented by the “B” in “RBD”.
The final stage being a high-temperature vacuum deodorization mainly to remove residual pigments, and oxidation products etc, which would otherwise adversely affect the flavour, odour and rate at which the oil would turn rancid. T he Deodorization stage represents the “D” in “RBD”. The fully refined oil was then termed Refined, Bleached and Deodorized Oil, or more commonly as RBD palm oil.