Optimization of Total Phenolic and Flavonoid Contents of Defatted Pitaya (Hylocereus polyrhizus) Seed Extract and Its Antioxidant Properties

Abstract

The present study was conducted to optimize extraction process for defatted pitaya seed extract (DPSE) adopting response surface methodology (RSM). A five-level central composite design was used to optimize total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 2,2′-azino-bis (3-ethylbenzothizoline-6-sulfonic acid (ABTS) activities. The independent variables included extraction time (30–60 min), extraction temperature (40–80 °C) and ethanol concentration (60%–80%). Results showed that the quadratic polynomial equations for all models were significant at (p < 0.05), with non-significant lack of fit at p > 0.05 and R2 of more than 0.90. The optimized extraction parameters were established as follows: extraction time of 45 min, extraction temperature of 70 °C and ethanol concentration of 80%. Under these conditions, the recovery of TPC, TFC, and antioxidant activity based on FRAP and ABTS were 128.58 ± 1.61 mg gallic acid equivalent (GAE)/g sample, 9.805 ± 0.69 mg quercetin equivalent (QE)/g sample, 1.23 ± 0.03 mM Fe2+/g sample, and 91.62% ± 0.15, respectively. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) analysis identified seven chemical compounds with flavonoids constituting major composition of the DPSE.

Assessment of Physicochemical Quality, Antioxidant Content and Activity, and Inhibition of Cholinesterase between Unripe and Ripe Blueberry Fruit

“…Total flavonoid content was measured by colorimetric analysis [ 22 , 23 ]. To a 15-mL test tube containing 4 mL of distilled water and 1 mL of blueberry extract, we added 0.3 mL of 5% NaNO 2 .…”

“…Total phenolic content was measured using the Folin–Ciocalteu colorimetric method [ 22 , 24 ]. After adding 0.2 mL of blueberry extract to a 15-mL test tube containing 2.6 mL of deionized water, 0.2 mL of Folin–Ciocalteu reagent was added and the mixture was vortexed and left at room temperature for 6 min.…”

Optimizing Conditions for Microwave-Assisted Extraction of Polyphenolic Content and Antioxidant Activity of Barleria lupulina Lindl.

“…RSM has been widely used in several fields, such as industrial crops and products [ 36 ], food chemistry [ 29 ], and renewable energy [ 37 , 38 ]. Previous studies have shown that RSM was useful in establishing optimal conditions for the extraction of antioxidant compounds and their activities [ 39 , 40 , 41 ].…”

Exploring the Potential Use of Hylocereus polyrhizus Peels as a Source of Cosmeceutical Sunscreen Agent for Its Antioxidant and Photoprotective Properties

“…In another research that was conducted to optimize extraction conditions for higher total phenolic flavonoids recovery and to determine in vitro antioxidant activities of defatted H. polyrhizus seed extract (DPSE) using response surface methodology, UPLC-QTOF/ MS analysis revealed the presence of rutin at the retention time 8.38 and m/z peak 609.14 which is in a good agreement with the findings of this study. Besides, sinapic acid and flavonoid compounds with core moieties of kaempferol as well as isorhamnetin were also detected in DPSE [53]. e phytochemical composition of HPPE revealed in this study also justifies the good results obtained for its total phenolic content (172.01 mg gallic acid equivalent (GAE)/g) and total flavonoid content (7.45 mg quercetin equivalents (QE)/g) that were conducted in our previous work which focused on optimizing the extraction conditions for phenolic and flavonoid compounds from H. polyrhizus peels using a statistical approach [28].…”