Debittering of bitter gourd juice using β-cyclodextrin: Mechanism and effect on antidiabetic potential

Abstract

Triterpene glycosides namely momordicoside K and momordicoside L causes bitterness in bitter-gourd thereby reducing its consumer acceptance. Reducing bitterness of the juice by addition of β-cyclodextrin (0.25-2%) was attempted and its effect on sensory quality, total phenolic content, antioxidant activity and antidiabetic potential was evaluated. Juice with 1.5% β-cyclodextrin demonstrated highest score (7.7 ± 0.3) for sensory acceptability compared to the control (3.8 ± 0.7). A significantly (p < 0.05) higher total phenolic content and antioxidant activity was observed. A marginal (10%) but significant (p < 0.05) reduction in α-glucosidase inhibition activity without affecting α-amylase activity was noted. Results from NMR, ROESY and FTIR studies indicated formation of an inclusion complex by interaction of hydrophobic triterpenoidal region of momordicosides with β-cyclodextrin.

Keywords: Momordica charantia; Momordicoside K; Momordicoside L; NMR; β-Cyclodextrin.