Antioxidant activity of citron peel (Citrus medica L.) essential oil and extract on stabilization of sunflower oil

Somayeh Okhli,Seyed Ebrahim Hosseini,Habibollah Mirzaei

doi:10.1051/ocl/2020022

Abstract

Due to the unfavorable effects of synthetic antioxidants, the use of various sources of plant antioxidants to prevent foods oxidation, especially oil-based or fat-based varieties, has been recently got considerable attention. In this study, the antioxidant effect of essential oil and extract from the citron fruit (Citrus medica L.) was investigated on the thermal stability of sunflower oil. Aqueous, ethanolic, and methanolic extracts of citron peel (800 ppm), BHT synthetic antioxidant (200 ppm), and citron peel essential oil (800 ppm) were added to sunflower oil. The oil oxidation stability was evaluated during 5 days through analyzing the values of peroxide, anisidine, thiobarbituric acid, totox, and oxidative stability index (OSI). Results showed that the peroxide, anisidine, and totox value had an increasing trend over time. The effects of storage time, extract, and essential oil were statistically significant in reducing the oxidation rate of sunflower oil during storage. Ultrasonic-assisted ethanolic extract at 30 min showed the highest OSI. The results of this study demonstrated the positive effects of citron peel extract essential oil and on sunflower oil stability and its superiority over synthetic antioxidants.

Highlights

Citrus medica is a type of citrus fruits consisting of two parts including the outer layer, which is an important part of citron in international trade, and the other layer is the pulp as an edible part of the fruit and a good source of pectin (Abdul, 2014)
It was shown that peroxide values in control oil samples were higher than those of oil samples containing butylated hydroxyl toluene (BHT) and anemone plant extract, with the lowest peroxide value belonging to extract-containing samples (Agregán et al, 2017), this finding was in agreement with our findings
Ethanolic extracts were more effective in preventing oil oxidative rancidity than the other treatments, the synthetic antioxidant and the essential oil

Summary

Introduction

Citrus medica is a type of citrus fruits consisting of two parts including the outer layer, which is an important part of citron in international trade, and the other layer is the pulp as an edible part of the fruit and a good source of pectin (Abdul, 2014). C. medica has long been used for medical purposes, for example, to combat seasickness, lung problems, intestinal diseases, and other disorders. Flavored essential oils of this fruit (located in the outermost, pigmented layer of the peel) are considered as antibiotics. Terpenes, aldehydes, ketones, esters, alcohols, organic acids, etc. Limonene counteracts the effect of pathogenic microorganisms and contains terpenes, sesquiterpene aliphatic terpenes, oxygenated derivatives, bicyclic terpenes, nonterpene aliphatic components, aromatic hydrocarbons, and nitrogen-containing esters. Geraniol and other monoterpenes found in citron fruit peel extract are reported to have anticancer properties (Meena et al, 2011)

Methods

Results

Conclusion