A Study on Anthocyanins

A Study on Anthocyanins

Author Name : Dr. Janaki Subramanyan, Dr. Saloni Bahri, Dr. Somdutta Sinha Roy, Pragati, Aditi Soni, Anu Middha, Sakshi Rathor, Shreya Bhardwaj, Bhawana, Madhu

DOI: https://doi.org/10.56025/IJARESM.2022.101022933

ABSTRACT

Anthocyanins are water-soluble pigmentspresent in the vacuole of cells of the skin and pulp of fruits, and petals of flowers. The pigments have a wide range of colours and attract insects and birds, thus aiding in pollination and seed dispersal. Anthocyanins have medicinal values and are important components of the food we consume. Eight experimental materials that were easily available during the summer-five species for fruits and three species for flowers-were chosen for the study. Anthocyanins have been   localized in the cells using microscopy, separated by paper and thin layer chromatography, the absorption spectra of the extracts have been plotted, and the effect of pH on the colour of anthocyanin extracts has been studied. In the peel mounts of fruit skinsand flower petals prepared in water, the epidermal cells appear coloured because of anthocyanins contained in the expanded vacuoles. The ethanolic extracts of anthocyanin were found to be of bright  deep colours. In order to determine the colour shade, standard colour charts were used as a reference.The technique of paper and thin layer chromatography using different solvents enabled us to understand that each material containsone to several anthocyanins; in paper chromatograms one to four different anthocyanins could be detected under visible light, and two to six different anthocyanins under UV light. In thin layer chromatograms observed under visible light all materials studied showed the presence of at least two anthocyanins. Absorption spectra of anthocyanin extracts recorded at a wavelength ranging from 400nm to 700 nm showed that the peak absorbance for all extracts was at 500 nm. It was also observed that the colour of anthocyanins is sensitive to pH changes. Further studies are required to identify the anthocyanins present in the experimental materials used.

Keywords: anthocyanins, paper chromatography, thin layer chromatography, absorption spectra, pH