The role of culinary herbs on the thermal degradation of carotenoids in omelets prepared by different methods

Abstract

This study investigated the effects of adding basil (Ocimum basilicum L.), oregano (Origanum vulgare), and parsley (Petroselinum crispum) on the total carotenoid content of air-fried, microwaved, and pan-fried omelets. The herb extracts were first characterized for their antioxidant capacity and total phenolic and carotenoid contents. Omelets were prepared without herbs (control) and with the herbs incorporated into the egg white and yolk mixture at three levels (0.25%, 0.5%, and 0.75%). In the control samples, cooking significantly reduced carotenoid content, except for pan frying. Air frying caused the greatest reduction, decreasing carotenoids from 14.87 ± 0.09 μg/g (raw) to 10.06 ± 0.11 μg/g, representing a 32.35% degradation. Microwaving resulted in a 23.64% loss. In contrast, higher levels of carotenoids were found in samples containing the herbs, mainly when oregano was used at 0.75%. Overall, the results indicate that while some carotenoids from the herbs may degrade during cooking, their addition can effectively protect egg carotenoids from thermal degradation by acting as natural antioxidants.