Comparative proximate composition and bioactive compounds in flesh and rind of mini watermelon

Abstract

Importance of the work: In accordance with the changing lifestyle and consumption patterns, watermelon production has shifted from large-sized to small-sized fruits having desirable quality attributes. Hence, analyses of fruit quality traits are crucial to develop improved mini watermelon cultivars.
Objectives: To appraise promising mini watermelon genotypes with enhanced nutritional compositions and bioactive compounds.
Materials & Methods: Fruit physical attributes, proximate compositions and bioactive compounds were evaluated of the flesh and rind of five mini watermelon genotypes: BARI watermelon-1 (W₁), BARI watermelon-2 (W₂), L-32468 (W₃), L-32236 (W₄) and L-32394 (W₅).
Results: There was wide genotypic diversity for fruit morphological aspects and significant variability regarding nutritional attributes and bioactive compounds. Among the studied genotypes, W₁ stood out with the highest total soluble solids (10.79°Brix), rind vitamin C (29.70 mg/100 g) and total phenolic content (89.74 mg gallic acid equivalent (GAE)/100 g) accompanied by higher fruit weight (3.19 kg). In addition, the flesh of the W₃ genotype had the highest β carotene (0.17 mg/100 g), total phenolic content (107.08 mg GAE/100 g) and total flavonoid content (18.37 mg quercetin equivalent (QE)/100 g). However, the rind of the W₅ genotype had the maximum sugar and total flavonoid contents (17.17 mg QE/100 g).
Main findings: BARI watermelon-1 and L-32468 could be exploited for table purposes and used in a breeding program to develop mini watermelon cultivars with more attractive fruit in terms of quality acceptance and nutritional value. Furthermore, the rind of BARI watermelon-1 and L-32394 enriched with bioactive compounds could be utilized as dietary supplements in relevant food industries to develop functional food products which would decrease the solid waste in the environment.