Resumen
- Oregano plants produce secondary metabolites, which they are utilized by the plant for growth and reproduction, but they are useful as functional additives in animal feeding systems because their intrinsic bioactivities properties. Oregano antioxidant property is attributed to thymol and carvacrol that react with lipid and hydroxyl radicals converting them into stable products. The aim of this study was to evaluate the effect of oregano essential oils (OEO) on lipid oxidation of n-3 PUFA-enriched fresh eggs and storage at 4 ºC y −10 ºC during six months. A total of 160 laying hens 40 wk old were placed in 80 cages and were randomly assigned to one of the 8 experimental diets: palm oil and fish oil (n-3 PUFA source), with and without supplementation of OEO at 4 qualitative thymol levels. Results showed that lipid oxidation was greater in eggs storage at 4ºC (3.09 mg MDA/g). In n-3 PUFA-enriched fresh eggs the lowest lipid oxidation was shown by the group supplemented with OEO low thymol (1.27 mg MDA/g). Lipid oxidation increased in n-3 PUFA-enriched eggs stored at 4ºC and −10ºC compared to fresh eggs (P<0.001). At 4ºC greater lipid oxidation was shown in enriched eggs without OEO (5.6 mg MDA/g), but OEO supplementation lowered lipid oxidation around 48%. In the present study, dietary OEO supplementation positively influenced by retarding lipid oxidation in eggs enriched with dietary omega-3 fatty acids during storage.