Juice components and antioxidant capacity of four Tunisian Citrus varieties.

摘要

Background: Juices from four Citrus species of Tunisia were investigated mainly for quality parameters and antioxidant capacity. Results: Citrus reticulata (mandarin) juice had the highest content of total flavonoids (85.33 mg CE L--1). The latter also occurred in high quantity (82.01 mg CE L--1) in Citrus lemon (lemon) juice which was also marked by its richness in total aroma (70.16 mug mL--1) and in total fatty acids (48.10 mug mL--1). Mandarin and lemon juices had the highest antioxidant activity, as determined b the beta-carotene bleaching assay (26.67% and 22.67%, respectively). Citrus aurantium (bitter orange) juice was characterised by the highest content of total polyphenols (784.67 mg GAE L--1) and by the greatest inhibition of DPPH (96.10%). Citrus sinensis (blood orange) juice was only marked by the high quantity of ascorbic acid (36.90 mg mL--1). GC/MS analysis of juice aroma showed the predominance of limonene (48.85-69.59%) in mandarin and in bitter and blood oranges, but of camphene (89.05%) in lemon. GC analysis of juice fatty acids revealed their richness in oleic acid (23.13-39.52%). HPLC analysis of juice phenolics indicated the predominance of phenolic acids (73.13-86.40%). Conclusion: The Citrus species used in this study were considered valuable varieties from the point of view of antioxidant capacity and nutrition.