Study of the Antioxidant Power of the Waste Oil from Palm Oil Bleaching Clay

Abstract

Palm oil is one of the most consumed oils, one of whose refining steps is the removal of pigments and other substances using bleaching clay as adsorbent. Worldwide production of this oil was 70 million tons in 2017, requiring 1 t of clay to produce 1000 t of refined oil. The residual bleaching clay, having an oil fraction (12.70%) rich in phenolics, carotenoids and tocopherols, was extracted in this study with ethanol to obtain an antioxidant-rich palm oil bleaching extract (POBE), with the aim of using it as a natural antioxidant source. The POBE antioxidant capacity determined by the DPPH method corresponded to a 20.29% inhibition of radical formation. The POBE was also tested for its potential to enhance oxidative stability of passion fruit, pracaxi and Brazil nut oils used as reference oils, and compared to common synthetic antioxidants (tert-butylhydroquinone and propyl gallate), either separately as controls or in mixtures with them. Besides the increased oxidative stability of these oils induced by the POBE, a positive synergistic effect between it and the synthetic antioxidants was observed. These results taken together suggest that the exploitation of the waste oil from bleaching clay as an additive to improve the oxidative stability of biofuels or lubricating oils is feasible.

A Comparative Analysis of Activated Carbons from African Teak (IROKO) Wood and Coconut Shell in Palm Oil Bleaching

“…Palm oil is a vegetable oil extracted from the mesocarp of the fruits of the Oil Palm tree (Elaeis guineensis) [1]. It is very important because it finds application in the food, energy, biofuels, cosmetics and general manufacturing industries [2]. Palm oil is one of the cheapest and most abundant vegetable oil in the world [3].…”

“…Palm oil is different from Palm kernel oil (PKO), in that Palm kernel oil (PKO) is gotten from the kernels of the oil Palm fruit. The tree from which both oils are obtained, the Oil Palm tree (Elaeis guineensis), is currently grown in over 11 million hectares of land worldwide [2]. Due to its abundance in nature, it can meet the demand for vegetable oils in the world market.…”