Integrated Downstream Processing involving Biocompatible methods for Extraction, Purification and Concentration of Anthocyanin, a Natural Colourant

The thesis mainly covers the extraction, separation, purification and
concentration of natural food colorant from Garcinia indica Choisy. The response
surface methodology was employed to optimize the ultrasound-assisted
extraction conditions. Characterization of anthocyanin using HPLC, mass and
NMR spectroscopy analysis confirmed that the pigment essentially contains two
anthocyanins namely, cyanidin-3-glucoside and cyanidin-3-sambubioside. Major
emphasis was given to develop alternative/newer approaches involving
membranes for the concentration of natural food colorant. Mechanism of water
transport from feed to osmotic agent side during forward osmosis has been
elucidated. In a large-scale experiment, the anthocyanin extract was
concentrated from 49 mg/l to 2.69 g/l (54-fold). The purification and concentration
of anthocyanin by integrating conventional purification processes such as
ultrafiltration with forward osmosis process was carried out. A comparison of
thermally concentrated sample with the sample produced by integrated
membrane process indicated that the integrated membrane process has several
advantages over the thermal concentration in terms of higher stability, lower
browning index and less conversion of (-)-hydroxy citric acid to its lactone form.
Microencapsulation using spray drying was found to be an effective method for
production of microencapsulated anthocyanin. The present study resulted in the
characterization as well as development of improved processes for the
purification and concentration of anthocyanin.