Extraction, Identification and Thermal Stability of Anthocyanins from Eggplant Peel as a Natural Colorant

In the present study, various mixtures of aqueous ethanol and acetone solutions were utilized to extract anthocyanins from eggplant peel by a discontinuous process to obtain a natural red-purple colorant. First, the most appropriate combination for extraction solvent was selected as ethanol 70 wt in water acidified with acetic acid 3 wt, which was determined by analysis of extraction yields and total anthocyanins content of extracts utilizing UV-Visible spectrophotometer. Then, the extracted anthocyanins were recognized and quantified by high performance liquid chromatography with diode array detector HPLC-DAD and characterized by high performance liquid chromatography equipped with tree-dimensional mass spectrometry HPLC-MS3 measurements. According to HPLC-DAD and HPLC-MS3 analyses the major anthocyanin in eggplant skin was delphinidin-3-rutinoside 91.43. Eventually, the thermal stability of extracted anthocyanins was estimated along 15 days using varied temperature values. Results demonstrated th