Comparative study of phytochemical profile and antioxidant activity of flavedo from two Iranian citron fruit (Citrus medica L.)

The citrus fruit peel essential oils (EO) can be considered a valuable by-product of citrus production and processing and the main product of some specific citrus cultivars. The EO contents of two citron fruits including Citrus medica L. var. ‘ medica ’ Proper. (small citron) and C. medica L. var. ‘ macrocarpa ’ Risso. (big citron), as well as their constituents and antioxidant activity (IC 50 ), were analyzed by GC/MS. Some biochemical properties of flavedo extract (total flavonoide and total phenol) and polyphenol compounds (HPLC methods) including rutin, quersetin, hesperidin, hesperetin and trans-ferrulic acid are determined. The EO percentage and yield were 0.71% (v/w) and 0.09 ml/fruit in the big citron while 1.86% and 0.20 ml/fruit in the small citron, respectively. The main constituent of EO in macrocarpa variety was limonene (89.39%). While in medica variety, limonene (48.59%), linalool (22.98%) and linalyl acetate (8.21%) were detected as the major components. The antioxidant activity of the EO in the big citron was higher than that in the small citron. All polyphenol compounds, with the exception of rutin, have a higher value in big citron as compare with small citron. In general, limonene was identified as the main compound in both citron trees. These varieties are seemingly divided into two chemotypes: limonene chemotype ( macrocarpa variety) and limonene-linalool chemotype ( medica variety).