The anthocyanins of Siahe Sardasht variety (Vitis vinifera L. var. S.S.) were extracted from freezed samples and were purified by adsorption on cationexchange resin column. Individual pigments were separated by TLC on cellulose plates. Monomeric anthocyanin content that was determined by pH-differential, was 1740.11±3.58 mgL-1 (based on malvidin 3-glucose). Five major pigments were identified by 1H-NMR, IR and UV-Visible spectroscopies. All pigments were acylated with acetyl groups and three of them were acylated with malonyl groups.

This study uses a chemically modified electrode (CME) based on carbon nanomaterials to demonstrate the electrochemical redox behaviour of crude fresh purple cabbage extract. Here, the redox properties of purple cabbage juice were examined using a three electrode cyclic voltammetry (CV) technique as a model system. PGE/GMC@e-cab, a purple cabbage-graphitized mesoporous carbon modified, pencil graphite electrode (PGE) was put through CV in a 10 mL pH 2 HCl/KCl solution using Ag/AgCl electrode and bare PGE as the reference and counter electrodes, respectively. A significant redox peak was observed at a potential of approximately -0.45 V vs Ag/AgCl in a potential window of -0.2 to 0.9 V on the CV of the modified PGE plausibly due to anthocyanin phytochemical dye pigment. This implies a direct passage of electrons between PGE/GMC and the anthocyanin components. FT-IR, Raman, and UV-Vis were utilized to characterize the patterned PGE. Additionally, the impacts of potential scan rate, pH, and concentration were thoroughly investigated. The obtained redox peak was further adjusted for the detection of cysteine (Cys) in order to examine the electrocatalytic activity. This first attempt paves the path for the electrochemical assessment of food crop quality and acts as a prototype study for the electro-active component in natural products.

In this study, optimum conditions of anthocyanins (Acys) extraction from petals of saffron flower (Crocus sativus) were determined by acidified ethanol solvent. The independent factors were solvent to sample ratio (20- 80 ml/g), percent of ethanol (25 -75%), temperature (25-45oC) and extraction time (8-24h). Response surface methodology (RSM) was used to determine optimum conditions of extraction of anthocyanins with the highest extraction rate of cyanindin-3-glucoside. The experiments were designed according to Box Behnken Design with four independent factors. Obtained coefficients of variance showed that the effect of temperature was more markedly than others (p<0.05). Optimum extraction conditions were a ratio of 20 ml solvent/g sample, ethanol percent 25.02 %, temperature 25.8oϹ and extraction time 24h. Under these optimum conditions, 1609 11mg/l Acys was produced. A quadratic reduced second-order regression equation described the effects of independent process variables on extraction Acys from Saffron flower.