Development of carrot top powders using foam mat drying

Abstract

Carrot tops are under-exploited greens despite having high nutritional value. The effect of ovalbumin and Emustab® concentration and whipping time on foam characteristics was evaluated, and 10% (w/w) of Emustab® and 10 min of whipping was selected for use. Foam mat drying was performed at 50–70°C, and effects of temperature on physicochemical properties, morphology, and centesimal composition of the powders were investigated. Midilli and Kucuk’s model best represented the drying kinetics (R2 = 0.994). Increasing temperature reduced drying time by more than three-fold and significantly (p < .05) affected the moisture content (6.15–11.82% d.b.), hygroscopicity (1.27–2.57%), rehydration ratio (3.30–3.77), and total color difference (14.07 < ΔE < 16.77) of the carrot tops’ powders. Powder at 50°C showed higher moisture content, lower hygroscopicity, and better rehydration rate. Drying at 70°C produced powders with lower ΔE and higher protein content. For all drying conditions, however, fresh carrot tops yielded stable and porous powders, promising for use in ready-to-cook foods.

Practical applications: carrot tops are one of the most underutilized greens of appreciable nutritive value. The foam mat drying proved to be promising for the dehydration of these materials, being the carrot top powders extensively characterized to know its properties and variations caused by drying. The results obtained will benefit both researchers and industry professionals to design better drying processes and innovative products based on carrot tops.