Development and process optimization of red radish concentrate extract as potential natural red colorant

Rodriguez-Saona, L.; Giusti, M.; Durst, R.; Wrolstad, R.

doi:10.1111/j.1745-4549.2001.tb00452.x

Red radish concentrate extracts produced from two radish cultivars, red-skinned cv. Fuego and red-fleshed cv. Chinese Red Meat, were evaluated as potential sources of natural colorants. Unit operations were developed and optimized. Anthocyanins were extracted using a modified abrasive peeler or a hammermill for cultivars Fuego and Red Meat, respectively. The anthocyanin extract was further purified by standard juice processing operations and concentrated by conventional evaporative technology and/or direct osmosis. Anthocyanin recoveries of 80-90% as compared to solvent/resin purification were obtained. Anthocyanins extracted from epidermal tissue resulted in juices with fairly low initial degrees Brix (1.3 degrees), which facilitated juice concentration to levels of 17 degrees Brix containing 400 mg anthocyanin/100 mL concentrate. Radish concentrate provided color similar to FD&C Red #40. Sensory analysis showed that the combined use of conventional evaporation and direct osmosis improved aroma attributes. Radish concentrate extracts represent a promising natural alternative to the use of FD&C Red #40.