Determination of Curcuma longa L. (Turmeric) Leaf Extraction Conditions Using Response Surface Methodology to Optimize Extraction Yield and Antioxidant Content

Abstract

Curcuma longa L. (turmeric) has been used as a functional food material, but other parts of it such as leaves are wasted as a byproduct. This work concentrated on developing turmeric leaves as a functional food material by establishing its optimal extraction condition. Response surface methodology was applied to optimize turmeric leaf extraction conditions. Turmeric leaves were pulled out with water and ethanol (10, 30, and 50%). Then, total phenolic compound content, total flavonoid content, and radical-scavenging activity of each extract were quantified to confirm the optimal extracting solvent. According to the results, water was the most efficient solvent to extract antioxidant contents such as total phenolic compounds (3.65 ± 0.02 mg GAE/g) and flavonoids (4.99 ± 0.17 mg QCE/g) content. Radical-scavenging activity was also higher in water extract compared with others such as DPPH (51.10 ± 2.29%), H2O2 (25.39 ± 2.69%), and ABTS (91.08 ± 0.15%). Central composite design was applied to confirm the effect of independent variables such as temperature (X1) and time (X2) to the yield (Y1). After conducting experiments, the extraction condition was established as 150 min with 1 : 25 ratio at 85°C with a 15.58% yield. Proximate compositions of the extract were determined to suggest background data for further research. In conclusion, this study confirmed the antioxidant property of turmeric leaves and developed the optimal extraction condition of the leaves to promote its application in food industry as a new food source.

Phytochemical Analysis and Antimicrobial/Antioxidant Activity ofCynodon dactylon(L.) Pers. Rhizome Methanolic Extract

“…is structural change is associated with reduced absorbance. Compounds with such capability are considered antioxidants [42]. Figure 3 compares the scavenging activity of different concentrations of the methanolic extract of C. dactylon rhizomes with that of 200 ppm of the synthetic antioxidant BHT measured by DPPH.…”

Antioxidant Effects of Turmeric Leaf Extract against Hydrogen Peroxide-Induced Oxidative Stress In Vitro in Vero Cells and In Vivo in Zebrafish

“…Therefore, our previous and current studies investigated the characteristics, functionality, and optimal extraction conditions of turmeric leaves for further research and application in food industry. We analyzed biochemical properties of turmeric leaves extract in the previous study [ 22 ]. According to our previous study results [ 22 ], the total flavonoids contents of TLE were shown as 4.78 ± 0.01 mg QCE and TLE were also shown to have DPPH, ABTS, and H 2 O 2 radical scavenging activities as 51.10 ± 2.29%, 91.08 ± 0.15%, and 25.39 ± 2.69%, respectively.…”

“…We analyzed biochemical properties of turmeric leaves extract in the previous study [ 22 ]. According to our previous study results [ 22 ], the total flavonoids contents of TLE were shown as 4.78 ± 0.01 mg QCE and TLE were also shown to have DPPH, ABTS, and H 2 O 2 radical scavenging activities as 51.10 ± 2.29%, 91.08 ± 0.15%, and 25.39 ± 2.69%, respectively. Flavonoids are large compounds occurring ubiquitously in food plants and found to be strong free radical scavengers and antioxidants [ 23 ].…”

Formulation and evaluation of SGLT2 inhibitory effect of a polyherbal mixture inspired from Ayurvedic system of medicine

“…33 Curcuma longa L. (Zingiberaceae) is traditionally used as a dietary spice and medicinal herb for different infections, wounds, gastrointestinal (GI) troubles and diabetes. 34 , 35 Several studies reported its multiple pharmacological properties such as anti-inflammatory, antioxidant, antitumor, antibacterial, anticoagulant and antidiabetic activities. 36 It contains curcumin, demethoxycurcumin, bisdemethoxycurcumin, turmerones, furanodiene, ferulic acid, coumaric acid, myristicin and cyclocurcumin as bioactive constituents.…”