Optimizing parameters on the antioxidant capacity of watermelon pulp using conventional orbital shaker and ultrasound‐assisted extraction methods
Beverly Tan Mei Chin, Asgar Ali, Hina Kamal, Maysoun A. Mustafa, Ghulam Khaliq, Yasmeen Siddiqui
Abstract
The current work had two objectives: to compare the total phenolic content (TPC) and antioxidant activity via two different extraction methods ultrasound-assisted extraction (UAE) and conventional orbital shaker (COS) extraction. Second, parameters (solvent concentration, acidity, and sample-to-solvent ratio) influence the extraction of phenolic compounds. For each respective solvent, the sample-to-solvent ratio compared were 1:5, 1:10, and 1:20. The TPC of the pulp was extracted most effectively by UAE (38.69 mg). Total mean of extraction yield across all parameters showed that UAE (561.7 mg) was statistically more effective in DPPH radical scavenging activity than the COS extraction (499.8 mg). However, the COS results from FRAP and ABTS yielded higher antioxidant activity. For all the tested assays, it was observed that the absolute methanol solvent and solvent-to-sample ratio of 1:20 were the most effective for extracting bioactive compounds from watermelon while solvent acidity had negligible effect. Novelty Impact Statement Current work demonstrated how individual extraction characteristics (concentration, acidity, sample-to-solvent ratio, and method used for extraction) of watermelon “New Dragon A-117” variety is located in the phenolics and antioxidant characteristic map. Thus, providing information that can practically assist future product developers for their product formulation as a nutraceutical in a more sustainable and environment friendly manner.