Reuse of discarded deactivated bleaching earth in the bleaching of oils

Authors

  • Adel Y. Girgis Agricultural Research Centre, Food Technology Res. Institute, Oils and Fats Res. Dept

DOI:

https://doi.org/10.3989/gya.2005.v56.i1.132

Keywords:

Activation of spent bleaching earth, Discarded deactivated bleaching earth, Recycling of deactivated bleaching earth

Abstract


Discarded bleaching earth was used after its reactivation for the bleaching of sunflower, soybean and corn oils. The efficiency of reactivated bleaching earth was compared to the efficiency of virgin activated bleaching earth. Acid reactivated earth (pH 2.5-3) had a slightly higher content in silicone than virgin activated or neutralized reactivated earths. The best results in the color of sunflower and corn oils were obtained when neutralized earth (pH 6–7) was used at 1 and 2 % levels. Acid reactivated earth used at 2 % achieved a higher reduction in soybean oil color than virgin earth (pH 3) at the same dosage. Both reactivated earths reduced peroxide value, iron, conjugated dienes and soap, while they increased acidity and conjugated trienes. Furthermore, these reactivated earths determined higher decrements in the oil induction period than virgin earth. Reactivated earth could be used for 5 cycles for the bleaching of soybean or corn oils and for more than 6 cycles for sunflower oil.

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Published

2005-03-30

How to Cite

1.
Girgis AY. Reuse of discarded deactivated bleaching earth in the bleaching of oils. grasasaceites [Internet]. 2005Mar.30 [cited 2022Dec.6];56(1):34-45. Available from: https://grasasyaceites.revistas.csic.es/index.php/grasasyaceites/article/view/132

Issue

Section

Research