Oleh: Ratnawati L Djanis, Hanafi (Akademi Kimia Analisis Bogor)
Antioxidant activity of guava fruit (Psidium guajava L) during ripening process was studied using DPPH (2,2-diphenyl-1-picrylhidrazyl) test. Concentration of ascorbic acid and water content in the flesh and seed of guava fruits were also analyzed in this study. The result was examined using correlation test between ascorbic acid concentration and antioxidant activity. This study showed that the highest antioxidant activities of red guava flesh (IC-50) was 314,96 ppm and of white guava (IC-50) was 318,53 ppm. The highest ascorbic acid concentration of white guava flesh was reached on the second day while of red guava flesh was on the first day. The maximum ascorbic acid concentration for white and red guava flesh were 179,80 mg/100 g and 60 mg/100 g, respectively. The correlation test revealed that ascorbic acid was the dominant active compound that produced antioxidant activity. The water content of red guava is higher than that of white guava with range of 66,4% – 84,91%.
Key words : antioxidant, guava, ascorbic acid, flesh