Bioactive compounds, antioxidant capacity and nutritional composition of fruit flesh and seed oil content of selected Momordica varieties

Abstract

Momordica fruits and seeds are widely used in traditional Sri Lankan medicine and local diets due to their antiviral, anti-inflammatory, anticancer and anti-diabetic properties, which help manage chronic diseases and promote health. However, limited scientific data exist on the functional properties, nutritional composition, and seed oil content of different Momordica cultivars. This study aimed to evaluate the bioactive compounds, antioxidant capacity, proximate composition, and seed oil content of nine Momordica cultivars grown in Sri Lanka. The varieties included four improved types (Thinnaweli White, MC 43, Matale Green and a hybrid), two traditional types (Kalu Karawila and Batu Karawila) and three wild types (Uru Karawila, Geta Karawila, and Thumba Karawila). Eight belong to Momordica charantia, while Thumba Karawila represents Momordica dioica. All analyses were conducted using three replicates per variety. Fruit samples for nutritional analysis were collected at the harvesting stage, while seeds from fully ripened pods were used for oil extraction. Laboratory analyses included the Ferric Ion Reducing Antioxidant Power (FRAP) assay for total antioxidant capacity (TAC), the aluminum chloride (AlCl₃) colorimetric method for total flavonoid content (TFC), and the Folin-Ciocalteu reagent method for total phenolic content (TPC). Proximate composition was determined using AOAC methods, and seed oil content by Soxhlet extraction. Data were statistically analyzed using ANOVA and Tukey’s test in SAS. Significant differences (p < 0.05) were observed among varieties. MC43 showed the highest TPC (4.28 ± 0.11 mg GAE/g DW) and TAC (3.81 ± 0.26 mg TE/g DW). Wild types like Uru Karawila and Thumba Karawila had high bioactive and protein content. Thinnaweli White showed the highest seed count (28 ± 2) and oil content (12.03 ± 0.85%). These findings highlight the potential of Momordica varieties for agricultural and pharmaceutical use. Promoting their cultivation could enhance health and support Sri Lanka’s economy.