Usability of mangrove plant leaves as tea materials: A comparison study on phenolic content and antioxidant capacities with commercial teas

Hinokidani, Ko; Aoki, Ryota; Inoue, Tomoko; Irie, Mami; Nakanishi, Yasuhiro

doi:10.1016/j.bcab.2022.102307

Cited by 1 publication

(1 citation statement)

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“…The antioxidant capacity of teas using the DPPH method is carried out by spectrophotometric techniques, − and the results can be expressed in EC 50 , which is defined as the efficient concentration of the antioxidant required to reduce the initial DPPH concentration by 50%. , The assessment of antioxidant capacity using a spectrophotometer involves monitoring the decrease in absorbance (at 517 nm) of the DPPH solution, which initially appears purple and turns yellow as the sample (composed of phenolic compounds) scavenges the DPPH radical. , Since the reactions of phenolic antioxidants with radical species involve electron transfer, electrochemical techniques can be an alternative in evaluating the antioxidant capacity of teas. Based on electrochemical sensors, these techniques can be used to monitor the decrease in DPPH’s signal due to its reaction with antioxidant species.…”

Section: Introductionmentioning

confidence: 99%

Rapid Quantification of Antioxidant Capacity in Tea Using Laser-Induced Graphene Electrodes

Inoque,

Araújo,

de Lima

et al. 2024

ACS Food Sci. Technol.

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This paper describes a new analytical method based on laser-induced graphene (LIG) electrodes for evaluating antioxidant capacity in tea by quantifying the consumption of the 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical. The LIG electrodes were produced by pyrolysis using a CO 2 infrared laser source (10 electrodes were produced in 5 min). The LIG sensor was coupled to a three-dimensional (3D)-printed batch-injection analysis cell to amperometrically detect the remaining DPPH. The sensing properties included a linear range from 2 to 900 μmol L −1 (R 2 > 0.99), adequate limit of detection (LOD = 0.6 μmol L −1 ), fast responses (∼10 s), and good precision relative standard deviation (RSD < 4.0%). The efficient concentration of tea samples necessary to reduce the initial DPPH concentration by 50% (EC 50 ) was determined after incubation with DPPH radicals for 30 min. The results of EC 50 showed good agreement with the conventional spectrophotometric results. Therefore, LIG electrodes are a powerful analytical tool for applications in teas.

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