Characterization of physical properties of red beet pigments

This work aimed to extract betalain pigments from red beet (Beta vulgaris L.) by different extraction methods: water and citric acid (2%) solvents to select the optimal method for extraction. In addition, the study determined total betalains, and effect of pH, time and temperature on betalains stability. The results showed that, pH, temperature and time of extraction did not have effect on the stability of Vulgaxanthin-1 pigment extracted using water and citric acid solvents. The concentration of betalain pigments extracted by water was higher than pigments extracted by citric acid solvent. Water extract of betanin pigments was more stable at temperatures between 25-60 °C, with maximum concentration of betanin pigment at 50°C extracted for 5 to15 minutes. Also, the pigment was stable at pH ranged between 2 to 6. The highest concentration was in pH 6 with water extract, while, the highest concentration of betanin pigment was in pH 2 with citric acid extract. Therefore, water is the optimal method for extraction of pigments from red beet.