Uv line 9400

The 2,2′-azino-di-3-ethylbenthiazolinesulfonate (ABTS) assay was performed using ABTS cation radical decolourisation (20 (link)). The ABTS aqueous solution (7 mM) was mixed with potassium persulphate (140 mM) (Sigma-Aldrich, USA) and left to stand at room temperature for 16 h. The mixture was diluted with methanol until it reached the absorbance value of 0.70 (SD = 0.02) at 734 nm. The jelly extract (20 μL) was mixed with 100 μL of ABTS working solution and incubated in the dark for 6 min before the measurement. The readings were measured in triplicates at 734 nm against the blank using a UV/VIS-spectrophotometer (Schott UVLine 9400, USA). A standard calibration curve was plotted using 0.625 μg/mL–10 μg/mL of Trolox (r²= 0.7513). The result was expressed in mg of Trolox equivalence per 100 g of MTJ (mg TEQ/100g).

An HPLC chromatograph (Agilent 1100) with sample loop 20 μl was used with column Lichrospher 100-NH2, 250 × 4 mm i.d., 5 μm (Merck 1.50834), precolumn Lichrospher 100-NH2, 5 μm (Merck 50958), and refractive index detector (Shodex RI-71, Japan).
All spectrophotometric measurements were made with a UV-visible diode array spectrophotometer (UvLine9400, Schott Instruments, USA).
A Conductivity Pocket Meter (Cond330i WTW, Germany) with cell (TetraCon 325/S, WTW, Germany), an AR 200 Automatic Digital Refractometer (Leica, Germany), and a Honey Color Photometer (HI 96785, Hanna Instruments, USA) were also used.

To measure the extracts effect on the DPPH radical, the optimized method of Brand-Williams, Cuvelier & Berset (1995) (link) was estimated. The DPPH solution (25 ppm in methanol 80% v/v) was prepared, and 3.9 mL of this solution was mixed with 0.1 mL methanolic extract (each sample). Absorbance was measured at 515 nm after 45 min of incubation with DPPH solution in the dark by a spectrophotometer (Schott UV line 9400). The antioxidant Trolox was used as standard, and the results were expressed as micromoles of Trolox equivalents in each 100 g of fresh weight (µmol TE·100 g⁻¹ fw).

All chlorophylls were determined using an adapted method proposed by Hansmann (1973) . The crushed aerial parts of each plant were suspended in acetone extraction solution (80% v/v), then they were stirred and filtered to avoid turbidity, and the volume was completed with the same extraction solution. Absorbance was measured at 645, 653 and 663 nm (Schott UV line 9400) immediately. The wavelengths corresponded to chlorophylls a, b and total respectively. The results were expressed as micrograms of grams of fresh weight (μg·g⁻¹ fw).

The optical properties of the composite films were determined by measuring the absorption of light at 190–1100 nm, at the optical resolution of 4 nm, using a UV-Vis spectrophotometer (UV line 9400, Schott Instruments, Mainz, Germany).