2 2 diphenyl 1 picrylhydrazyl dpph reagent

To estimate the Carbazole derivatives' antioxidant potential, a solution of each compound (1 mM/mL) in methanol was serially diluted with methanol to obtain a concentration of 1, 2, 5, 10, 20, 50, and 100 µM/mL. Then, DPPH (2,2-diphenyl-1-picrylhydrazyl) reagent (Sigma, USA) was dissolved in 0.002% w/v methanol and mixed with the previously prepared working concentrations in a 1:1 ratio. The same procedures were repeated for Trolox (Sigma-Aldrich, Denmark), which was used as a positive control. All of the solutions were kept in the dark chamber for 30 min at an ordinary temperature. Then, their absorbance values were measured at a wavelength of 517 nm utilizing a UV–visible spectrophotometer. The DPPH inhibition potentials by Carbazole derivatives and Trolox were determined employing the following equation: $$\text{DPPH inhibition}(\text{\%})=\frac{\text{abs}(\text{blank})-\text{abs}(\text{sample})}{\text{abs}(\text{blank})}\ast 100\text{\%}$$ where abs_blank is the blank absorbance and abs_sample is the absorbance of the samples [58 (link)]. The antioxidant half-maximal inhibitory concentration (IC₅₀) of the synthesized carbazole derivatives and Trolox were assessed by using an online tool “Quest Graph™ IC50 Calculator.” AAT Bioquest, Inc., 25 May. 2023, https://www.aatbio.com/tools/ic50-calculator.

Methanol was obtained from Wako Pure Chemicals Industries, Ltd. (Osaka, Japan); acetone and sodium carbonate from Kanto Chemical Co., Inc. (Tokyo, Japan); and Folin & Ciocalteu's phenol reagent, gallic acid, (±)‐6‐hydroxy‐2,5,7,8‐tetramethyl‐chromane‐2‐carboxylic acid (Trolox), and 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) reagent from Sigma‐Aldrich (St. Louis, MO, USA). Food materials were purchased locally.

2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent, gallic acid, rutin and silychristin (silymarin II), and methanol were purchased from Sigma Aldrich (Germany). The rotary evaporator was purchased from Buchi Laboratory Instruments (Switzerland). A hot air oven was acquired from Biobase (China).

Andean blueberries (Vaccinium meridionale Swart) maturity stage 5 (100% dark purple) were obtained in Ráquira (Boyacá, Colombia) at 2150 m.a.s.l. The berries were examined previous to its use to separate fruits with physical, mechanical, or microbial damage. The fruits were washed and disinfected with a 100 mg L⁻¹ of chlorine solution.
Maltodextrin (MD) dextrose equivalent (DE) 18–22 from Tecnas S.A. (Medellín, Colombia) was used as a carrier. Folin–Ciocalteu reagent was purchased from Panreac (Barcelona, Spain) and gallic acid was purchased from Merck (Darmstadt, Germany). 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) reagent was purchased from Sigma-Aldrich (St. Louis, MO, USA). All the chemicals used were of analytical grade.

Raw milk was prepared by Dairy workshop at Faculty of Agriculture, University of Tehran (Iran). Bitter orange peel was purchased from a local market in Mazandaran (Iran), and Gaz‐angubin was supplied by a local market in Khansar (Iran). Folin–Ciocalteu reagent, 2,2‐Di Phenyl‐1‐Picryl Hydrazyl (DPPH) reagent, and monohydrated Gallic acid were purchased from Sigma Co. (USA), and PC‐AGAR culture medium and other experimental chemicals used in this research were purchased from Merck Co., Germany.

Nine phenolic standards including gallic acid (GA), syringic acid (SRA), p-coumaric acid (pCA), ferulic acid (FA), sinapic acid (SNA), cinnamic acid (CNA), protocatechuic acid (PRA), rutin (RUT) and quercetin (Q), 2,2-diphenyl-1-picrylhydrazyl (DPPH reagent), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS reagent), 4-chloro-7-nitrobenzofurazan (NBD-Cl), ammonium acetate, and neocuproine were purchased from Sigma-Aldrich (St. Louis, MO, USA). In all cases, the purity of the standards exceeded 98%. Aluminum chloride (AlCl₃) was obtained from AcrossOrganics (Morris Plains, NJ, USA) and high-performance liquid chromatography (HPLC)-grade acetonitrile (ACN) was obtained from Avantor (Central Valley, PA, USA) while the other reagents were obtained from POCh (Gliwice, Poland). The redistilled water was prepared by triple distillation of water in a Destmat^® Bi-18 system (Heraeus Quarzglas, Hanau, Germany).

Cellulose non-woven fabrics (CNWF) were purchased from Futamura Chemical Co., Ltd. (Aichi, Japan). Catechin, 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent, dimethylformamide (DMF), and polydimethylsiloxane PDMS were purchased from Sigma-Aldrich (Tokyo, Japan). Laccase derived from Myceliophthora was kindly donated by Novozymes Japan Ltd. (Chiba, Japan) Chloroform, tetrahydrofuran (THF), hydrochloric acid (HCl), sodium hydroxide (NaOH), and Oil Red O were purchased from Fujifilm Wako Pure Chemical Corporation (Tokyo, Japan). dimethylformamide (DMF) was purchased from Nacalai Tesque Inc. (Kyoto, Japan). Methylene blue was purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). Deionized water (DI water) was used for solution preparation and dilution. All reagents were of analytical grade and used as received without further purification.