Efficiency of dietary vegetable oils in preserving the quality of shell eggs under ambient tropical conditions



The study evaluates the efficacy of three common market-grade culinary vegetable oils—groundnut oil, cottonseed oil and coconut oil—in preserving the internal quality of freshly laid eggs coated with them and stored under tropical room conditions of 25–32°C and 40–85% r.h. for 36 days. All three vegetable oils significantly (P<0.01) limited diurnal weight losses of the eggs to 0.013–0.016 g as against 0.186 ± 0.013 g for the untreated eggs over 36 days storage. Liquefaction of the yolk and albumen was also significantly reduced (P<0.05) such that the albumen pH of the oiled eggs increased from 7.65 to only 8.35–8.65 after 36 days when the untreated eggs had an albumen pH of 9.80. Subsequently, the yolk index of oiled eggs dropped by only 0.10–0.13 after 36 days and remained significantly superior (P<0.001) to that of the untreated eggs which had dropped from an initial value of 0.47 to 0.11. These preservative effects of the vegetable oils may be attributable to their fatty acid component, rather than their glycerol which showed no significant (P>0.05) improvement over untreated eggs.