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|Type:||Artigo de periódico|
|Title:||Effect Of Type Of Bleaching Earth On The Final Color Of Refined Palm Oil|
De Greyt W.
|Abstract:||Although studies indicate chemical changes during bleaching such as carotene and unsaturated fatty acids oxidation, which are probably responsible for the color fixation of palm oil, this process is not very clear. The objective of this study was to investigate the effect of type and amount of bleaching earth (BE) on the final quality of refined palm oils, especially on the oxidative state and color. Two types of bleaching earth were tested, one natural (NBE) and one acid-activated (ABE) (0.5-3.0% w/w). Crude palm oils were bleached at 105°C, during 30min at 50mmHg pressure. Afterwards, a deodorization step was performed at 260°C, 3mbar, 1.5% steam during 60min. These refining procedures were evaluated after each step by measuring β-carotene, color, peroxide (PV) and p-anisidine (pAV) values. It was observed that both BE can decompose peroxides. However, a maximum pAV followed by a decrease was observed for ABE while the pAV remains approximately constant at a maximum for NBE, suggesting only ABE catalytically decomposes secondary oxidation products. The color after deodorization was inversely proportional to pAV when bleaching was performed with ABE, even though the oil has a lighter color after deodorization. © 2014 Elsevier Ltd.|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
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