Effects Of Extraction And Spray-Drying Conditions On Antioxidant Capacity And Amylase Inhibitory Potentials Of Bioactive Compounds Extracted From Bitter Melon (Momordica Charantia)

Abstract

The aim of this study is to determine the optimum condition for extracting the highest phenolic contents of Momordica charantia and the effect of spray-drying on bioactive compounds as well as antioxidant capacity and enzyme inhibitory capacity of the extracts. The highest phenolic content was obtained (14.71 ± 0.04 mg FAE/g) under the optimal extraction conditions using 50% ethanol as the best solvent at the ratio of sample:solvent of 1:50, and shaking at 30oC for 20 min. The extract also contained the low flavonoid contents (0.99 ± 0.03 mg RE/g) with medium antioxidant capacity, alpha-amylase and alpha – glucosidase inhibitory potential (24.72 ± 0.315%, 11.57 ± 2.99% and 7.13 ± 0.726%, respectively). After spray-drying, the powder contained the much lower phenolic contents (1.74 ± 0.188 mg FAE/g spray-dried powder) and flavonoid contents (0.11 ± 0.008 mg RE/g spray-dried powder) compared to the sample before spray-drying. Similarly, the antioxidant capacity, alpha-amylase and alpha – glucosidase inhibitory potential of spray-dried powder were also lower than the extract (14.79 ± 1.278%, 5.03 ± 0.629% and 1.52 ± 0.134%, respectively). Keywords: Momordica charantia, spray-drying, antioxidant capacity, alpha-glucosidase inhibitory, alpha-amylase inhibitory, total phenolic contents (TPC), total flavonoid contents (TFC).