Optimization of anthocyanin pigment extraction from Echium Amoenum petals by soaking and solvent method

Color is one of the most important properties for consumer acceptance. Pigments (natural dye compounds) are the safest dyes for oral use. Anthocyanins are the most important group of natural pigments after chlorophyll that are non toxic, water soluble and widely present in plant cytoplasm. These flavonoid pigments are responsible for the colors of red, blue and purple in many fruits, vegetables and flowers. Echium Amoenum is one of the most important medicinal plants in the country. This plant is cultivated in many parts of the world for therapeutic purposes and uses many flowers and leaves of this plant. The general objective of this research was to optimize the conditions for extraction of anthocyanin pigment from the Echium Amoenum petals.

In order to determine the optimum conditions for the highest extraction of anthocyanin pigment from Echium Amoenum petals by solvent soaking (methanol/water) effects of three variables of temperature (60, 50 and 40 °C), time (3, 4 and 5 h) and the weight ratio of Echium Amoenum petals to the solvent (3 and 5 g). Therefore, 18 treatments were designed in accordance with a complete full factorial design. Methanol and water were mixed at 0.5 to 1.5% volumetric/volumetric ratio. Extraction conditions were considered in accordance with the design of table treatments. The amount of anthocyanin extracted from each treatment was measured by differential pH method by spectrophotometer. Using the results of the tests, the best conditions for extracting the extract from Echium Amoenum petals were predicted with the highest anthocyanin level. Statistical analyzes were done in Minitab 16 software as a full factorial design.

The linear effects of temperature, time and weight ratio of Echium Amoenum petals to the solvent on anthocyanin content were significant. Interaction and quadratic effects of temperature, time and weight ratio of Echium Amoenum petals on anthocyanin changes were not significant. The results showed that extracted anthocyanin content increased significantly with increasing temperature, time and weight ratio of Echium Amoenum petals to the solvent. Optimal conditions to extract the highest amount of anthocyanin extracts from Echium Amoenum petals (229.191 mg/l) were predicted at temperature, time and weight ratio of Echium Amoenum petals at 60 °C, 5 h and 5 g, respectively. The optimal predictive conditions for extraction of pigment from Echium Amoenum petals were performed in the laboratory. The results showed that there was no significant difference between predicted and experimental extraction conditions.

By replacing natural dyes instead of conventional synthetic dyes in foods, can take a positive step towards the health and safety of food. A full factorial design is a safe way to predict the conditions for the extraction of pigments from plants.