VIABILITY OF USING A ONE-DIMENSIONAL LOVIBOND SCALE FOR COLOUR MEASUREMENT OF PALM OIL AND PALM OIL PRODUCTS

摘要

A one-dimensional Lovibond scale for measuring colour required fixing the yellow numeral in some functional relation to the red. The colour of a sufficiently large number of palm oil and palm oil products was measured using the conventional Lovibond scale. The colour of the same samples was then measured by fixing the yellow units at pre-determined values but varying the red values to get the closest colour match. The fixed yellow unit for each type of palm oil and palm oil products was determined by reading the colour of the oils at fixed yellow units of 25, 30, 35 and 40 with independent variation of the red units. Four analysts from two different laboratories were involved in the colour measurements. The readings obtained were then analysed to determine the yellow value that gave the best colour match. Statistical evaluation showed that the colour values obtained using the one-dimensional Lovibond colour scale did not differ from the results using the conventional scale. Nevertheless, the investigation indicated that the results of palm oil and palm olein colour obtained by analysts from different laboratories using the former method were more comparable than that of the latter. As this was not observed in measurements for palm stearin, the recommendation is therefore for the retention of the conventional method of colour measurement.