Determination of antioxidant activity and phenolic compounds of Muntingia calabura Linn. peel by HPLC‐DAD and UPLC‐ESI‐MS/MS

Abstract

Summary Antioxidant activity in Muntingia calabura Linn. peel was evaluated by DPPH radical, ORAC, ABTS cation radical, FRAP assays and total phenolic contents by different extraction conditions. In addition, a method for determination of phenolic compounds in calabura peel samples harvested in Brazil using methanol:water and magnetic stirring as the extraction method, HPLC‐DAD and UPLC‐ESI‐MS/MS analysis were developed. Calabura peel showed antioxidant activity for all extraction conditions and assays evaluated, the most polar solvents being more effective. The developed HPLC‐DAD method allowed the accurate determination of phenolic compounds, with recoveries in the range of 72–107% and precision values ≤4%, with exception for chlorogenic acid. Gallic acid was determined at the highest concentration levels, followed by myricetin, ferulic acid and vanillic acid. However, all the five proposed phenolic compounds were identified in calabura peel samples by UPLC‐ESI‐MS/MS. Thus, calabura peel, an uncommon edible fruit part, can be appointed as a rich source of phenolic compounds.

Determination of Phenolic Compounds in Red Sweet Pepper (Capsicum annuum L.) using a Modified QuEChERS Method and UHPLC-MS/MS Analysis and Its Relation to Antioxidant Activity

“…However, for individual identification and quantification, chromatographic techniques based on liquid chromatography coupled to ultraviolet-visible spectrophotometry (UV-Vis) and mass spectrometry detectors have been widely used. 25,[30][31][32] The extraction step also plays a crucial role in the individual identification and quantification of phenolic compounds. Currently, there is a trend in the use of sample preparation techniques that are easier to perform, faster, inexpensive and that promote clean-up of the sample extract.…”

Content of phenolic compounds in fruit processing residues by mass spectrometry

“…The mobile phase was composed of solvent A (water acidified with 0.1% formic acid) and solvent B (methanol). The following gradient was used and the organic solvent (B) percentage was changed linearly as follows: 0 min, 30; 0.33 min, 60; 1 min, 60; 1.33 min, 50; 2.33 min, 50; 2.67 min, 30; and 4 min, 30% (Rotta, Haminiuk, Maldaner, & Visentainer, 2017) The ESI Xevo Acquity ® (Waters, Milford, MA) source parameters were as follows: 3.0 kV capillary voltage, 50 L hour -1 cone gas flow, 700 L h -1 desolvation gas flow, 550°C desolvation temperature, and 130°C source temperature. The mass spectrometer was operated in MS/MS mode using multiple reaction monitoring (MRM) and a 30 ms dwell time.…”

Physical–chemical characterization and antioxidant properties of extruded products made from mixtures composed of corn grits and red potato flour (Oxalis tuberosa)

“…The results were expressed as a percentage inhibition. The ABTS test was carried out according to the technique described by Rotta, Haminiuk, Maldaner, and Visentainer (2017), with some modifications: 50 μL of extract was diluted with 1450 μL of ABTS, 30 min after was measured the absorbance to 732 nm.…”