Epsilon Archive for Student Projects

Abstract

Various methods are used to analyse cholesterol oxidation products (COP) due to the
unavailability of a standard method. In order to select a suitable method for the
enrichment of COP, three methods of saponication (A – C),and transesterication (D)
of tallow with three levels (5,10 and 20 µg) of spiked COP, were evaluated. Further
enrichment of COP was done by solid phase extraction, quantied by GC, and
confirmed by GC–MS. The in-house method A, and method D, showed the best
results among the four methods evaluated. The recoveries at all levels of spiked COP
were generally higher than 60% in method A. The recoveries of all spiked COP at 5
µg level were consistently lower in method D compared with method A. From the
results of this study it can be concluded that method A may be more suitable for the
analysis of very low levels of COP in foods.

Ghee (clarified butter oil), a major ingredient in Indian sweets, is an important source
of saturated fatty acids, cholesterol and COP that are considered as risk factors for
atherosclerosis. The high frequency of atherosclerotic complications reported among
the Indian immigrants in England prompted determination of lipids and lipid
oxidation status of a ghee sample and fifteen Indian sweets that are available in
London supermarkets. The fatty acid profile of the samples shows saturated fats
(about 73%), mainly composed of myristic, palmitic and stearic acids, except in two
samples, which had levels of oleic acid in excess of 60%. TBARS values ranging
from 19 to 260 µg/100 g might be due to the different oxidative status of different
sweets samples. Cholesterol (approximately 0.22%) was the main sterol in all
samples, except two where unspecified oils were used instead. Variation of total
COP was from 0.94 to 38.41 µg/g sample. Some of these sweets may be a source of
considerable amounts of saturated fatty acids, cholesterol and COP in the diet that
possibly contribute to atherosclerosis.