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The palm oil bleaching capacity of various Nigerian clay deposits
Author(s) -
OKPALA K. O.,
NWOKE M. N.
Publication year - 1989
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.1989.tb00691.x
Subject(s) - adsorption , chemistry , palm oil , pigment , mineralogy , freundlich equation , bleach , clay minerals , residual oil , nuclear chemistry , organic chemistry , food science
Summary The ability of clay deposits from six different locations in Nigeria to bleach palm oil was assessed. Each clay was analysed for gross mineral composition. Degummed and steam‐sparged palm oil was heated with different quantities of each fine clay for 30 min. The degree of bleaching was determined by comparing the absorbance of residual pigment at 452 nm with that of unbleached oil. Performance was assessed with a modified form of the Freundlich adsorption isotherm ( X/M = KC n ), where X/M is the mass of pigment adsorbed per unit weight of adsorbent, C is the equilibrium concentration of pigment, and the constant K provides an index of performance for each clay. The exponent n was 2 for all clays, and K values varied from 120 to 2950, apparently with the Fe 2 O 3 content of the clay. Clays with high iron content should be tested further, for use in bleaching palm oil.