Evaluation of peel, flesh and seeds of bitter gourd (Momordica charantia L.) for biologically active components, through development of powders and ethanolic extracts

Abstract

The bitter gourd (Momordica charantia L.), has been remained a well-known ethnic medicinal vegetable, used traditionally as a pharma food to obtain a plenty of pharmacological benefits. However, which fraction of fruit is most effective for provision of bioactive components, has been remained undiscovered yet. This study examined the chemical composition, phytochemicals and antioxidant activities of peel, flesh, and seeds of bitter gourd. Our results showed that fat (3.50 ± 0.03%) and protein (3.40 ± 0.06%) content were found to be significantly (P < 0.05) high in bitter gourd seed powder (BSP), whereas ash (6.26 ± 0.06%) and fiber (5.46 ± 0.10%) in bitter gourd peel powder (BPP). Microminerals including Fe, Zn, Cu and Mn were found significantly (P < 0.05) high in BSP, with values 3.95 ± 0.05, 4.92 ± 0.04, 2.44 ± 0.04 and 1.32 ± 0.20 mg/100 g, respectively, whereas, macrominerals, Ca (74.90 ± 0.60 mg/100 g) and Mg (52.59 ± 0.20 mg/100 g), in bitter gourd flesh powder (BFP). Total phenolic content (27.78 ± 0.95 mg GAE/100 g), total flavonoid content (12.18 ± 0.08 mg QE/100 g) and total antioxidant activity (16.87 ± 0.11 mg trolox/100 g) was highest in BSP. However, BFP exhibited the greatest total carotenoid content (93.45 ± 0.40 mg/100 g) and β–carotene content (41.72 ± 0.15 mg/100 g). HPLC analysis revealed that all fractions of bitter gourd were loaded with bioactives, as naringenin and catechin were highest in BFP, epicatechin, ferulic acid, kaempferol and p-coumaric acid were highest in BPP, whereas, chlorogenic acid, caffeic acid, gallic acid and apigenin were highest in BSP. As compared to BFP and BPP, BSP exhibited the high concentration of important bioactive components, therefore instead of discarding these waste by-products of bitter gourd could be utilized as source of bioactives.