Antioxidant characterization of cinnamon, Citrus aurantium and green tea leaves

Abstract

<strong>Background and objective: </strong>Plants are full of phenolic compounds and naturalantioxidants able to scavenge free radicals in foods and human body. They are more popular than synthetic antioxidants because of lower concern about their mutagenicity and carcinogenicity in human. This study tried to examine the antioxidant properties of water extracts of cinnamon and green tea, and methanolic extract of<em> Citrusaurantium</em> compared to butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) as synthetic antioxidants. <strong>Materials and methods:</strong> Cinnamon, <em>Citrus aurantium</em>, and green tea leaves were prepared from local markets in Iran and their antioxidant properties were examined individually and in combination. The extracts were analyzed by gas chromatograph coupled with mass spectrometer. Total phenol content and antioxidant potency against synthetic antioxidants of BHT and BHA were respectively determined by Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. <strong>Results and conclusion:</strong> E. cinnamaldehyde (32.41%), linalool (65.08%), and kaempferol-3-O-glucoside (84%) were the most important components of cinnamon<em>, Citrus aurantium</em>, and green tea leaves extracts, respectively. According to the results, the treatments with a higher percentage of green tea leavesand cinnamon extracts had the highest phenolic content (28.98 ±0.12 µg/g GA) and those with the highest amount of <em>Citrus aurantium</em> had the lowest phenolic content (15.56 ±0.06 g/g GA). DPPH test revealed that the lowest IC₅₀ was related to the mixture of three extracts (307.62 µg/ml) where the highest belonged to <em>Citrus aurantium</em> extract treatment (2100.3 µg/ml). In comparison, for BHT and BHA in 200 mg/l concentration, radical scavenging capacities were 50.7% and 64%, respectively. The three extracts had significant radical scavenging capacity. However, their activity was lower than the synthetic antioxidants of BHT and BHA currently used in food industry.