Philippine E-Journals

Comparative Analysis of the Antioxidant Activities of Leaf Extracts from Two Varieties of Coffea liberica Bull. ex Hiern

Ernelea Cao | Alysa Estopace | Clarence Aira Diaz | Ruel Mojica

 

Abstract:

The leaves of coffee have been reported to produce secondary metabolites that have bioactivities including antioxidant, antimicrobial and geno-protective activities. In this study, two varieties of the lesser studied Coffea liberica Bull. ex Hiern, namely, Liberica and Excelsa were evaluated for their antioxidant activities. Immature and mature leaves were collected from the Bureau of Plant Industry in Baguio City, Benguet and the National Coffee Research, Development and Extension Center of Cavite State University, Indang, Cavite. The leaves were subjected to methanolic and aqueous extraction procedures and tested for their antioxidant activities, using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay. Antioxidant activity of methanolic extracts like the Liberica Benguet mature methanolic extract (LBMM) and Excelsa Cavite mature methanolic extract (ECMM) were comparable with that of the positive control, ascorbic acid, at 400 ?g/mL. Furthermore, the antioxidant activity of Excelsa Cavite mature methanolic extract (ECMM) at 400 ?g/mL to 100 ?g/mL were also not significantly different from the positive control (Tukey-HSD, p>.05) and at lower concentrations, ECMM activity was even significantly higher than the positive control (Tukey-HSD, p<.05). In contrast, aqueous extracts have significantly lower antioxidant activity as compared with the positive control at concentrations of 50 ?g/mL and higher. Mature or older leaves have significantly higher antioxidant activity than immature leaves. Samples from Benguet have also significantly higher activity than samples from Cavite, and activity of Excelsa extracts were significantly higher activity than Liberica extracts.