Conductive hydro drying of beetroot (Beta vulgaris L) pulp: Insights for natural food colorant applications

Abstract

AbstractNatural food colorants are often unstable and undergo rapid degradation reactions. These are significant at higher temperatures, as in the case of drying of food powders. In this research, conductive hydro drying (CHD), a variant of the refractance window drying technology was used to prepare flakes from beetroot pulp. Three different temperatures (40, 50, and 60°C) were used and the results were compared against tray dried counterparts. Significant differences in moisture content, water activity, color, powder characteristics, reconstitution behavior, total phenolic content, antioxidant property, and betalain content (both betaxanthin and betacyanin) were observed between the drying methods. With significantly lower drying time, CHD can be conveniently used for commercial applications requiring the drying of natural pigment‐rich foods.Practical applications CHD is an effective alternative method for drying of natural colorant rich foods “Non‐thermal” drying approach showed significant retention of betalains, phenolics, and antioxidant activity as compared with tray drying CHD is commercially viable and can be conveniently scaled up This novel drying approach shows significant savings in cost, energy, and time