Comparison of antioxidant capacities and antioxidant components of commercial bitter melon (Momordica charantia L.) products

Authors: ESİN AKYÜZ, SERCAN TÜRKOĞLU, KEVSER SÖZGEN BAŞKAN, ESMA TÜTEM, MUSTAFA REŞAT APAK

Abstract: In this study, the total phenolic contents and total antioxidant capacities of some commercial bitter melon products (powder, packaged powder, capsule, paste in olive oil), and of unripe and ripe fruits were determined by spectrophotometric and chromatographic methods. The total antioxidant capacities of unripe and ripe bitter melon samples, determined by using the CUPRAC (cupric reducing antioxidant capacity assay) and ABTS (2,2'-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid)/HRP (horseradish peroxidase) methods, were 42.5 and 36.3 μmol TRE (Trolox equivalent) g^-1, and 8.7 and 7.0 μmol TRE g^-1, respectively. The TAC (total antioxidant capacity) order of the studied samples using the same 2 methods were determined as follows: capsule (CUPRAC value, 140.8; ABTS/HRP value, 143.6 μmol TRE g^-1) > packaged powder (129.6; 126.1) > powder (52.3; 64.3) > unripe fruit (42.5; 36.3) > paste in olive oil (17.6; 14.4) > ripe fruit (8.7; 7.0). The order of phenolic content was found as follows: unripe fruit (193.2 μmol GAE (gallic acid equivalent) g^-1) > capsule (162.0) > packaged powder (160.6) > powder (83.6) > paste in olive oil (38.3) > ripe fruit (14.6).

Keywords: Momordica charantia, bitter melon, total antioxidant capacity, total phenolic content, CUPRAC, ABTS, HPLC

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