Microencapsulation by spray drying of red cabbage anthocyanin-rich extract for the production of a natural food colorant

Food ingredients obtained from natural sources have been a constant demand from the food industry, since the consumers are avoiding the consumption of foods prepared with synthetic additives. In this study, red cabbage (Brassica oleracea L. var. capitata L. f. rubra) anthocyanin-rich extract was microencapsulated to produce a natural food colorant. For this, the microparticles were produced by spray drying using the concentrated (CE) and raw extract (RE) of red cabbage, in different concentrations of maltodextrin and arabic gum. The results obtained demonstrated that the CE presented 50.76 +/- 1.13 mg anthocyanins 100 g(-1), which means 1.6-fold higher anthocyanins than the RE. Also, the microparticles obtained from CE showed up to 85 mg anthocyanin 100 g-1. The formulations containing the highest amount of maltodextrin resulted in the highest yield, reaching 67%. The moisture content in macroparticles varied between 6.25 and 16.42% and the water activity ranged from 0.48 to 0.64, which is a positive value for future food application. The microparticles presented a uniform appearance and homogenous size distribution, with spherical shapes and smooth surfaces. The microparticles containing a high amount of arabic gum showed a tendency to degradation in the thermogravimetric analysis. Otherwise, the interaction between maltodextrin and arabic gum was beneficial to improve the thermal stability of microparticles, confirmed by the glass transition temperature between 37 and 90 C. In conclusion, the microparticles produced with red cabbage anthocyanin-rich extract can be a promising approach to use as a natural food colorant.