Color Characteristics of Carrots: Effect of Drying and Rehydration

Abstract

The aim of this study was to observe a change in color and a degradation of total carotenoids and β-carotene in carrots subjected to spout-fluidized bed drying at 60, 70, 80, and 90°C. Additionally, the color of carrots rehydrated at 95°C (10 min) was measured in order to estimate the reversibility of color changes caused by drying. Significant changes in a*, b*, ΔE*, and ΔC* were observed during drying and rehydration of carrots. The total difference in color and saturation ranged from 23.67 to 30.28, and from 22.97 to 29.90, depending on drying air temperature. The rate of deterioration of total carotenoids and β-carotene content influenced the color parameters of carrots. The first-order kinetic model adequately described evolution of a*, b*, ΔE*, and ΔC* derived for carrots during drying at 60, 70, 80, and 90°C. It was found that the spout-fluidized bed drying followed by rehydration changed the color of carrots irreversibly.

Keywords:

• Carrots
• Blanching
• Drying
• Rehydration
• Color characteristic
• Modeling

ACKNOWLEDGMENT

The study was financially supported by the Polish Ministry of Science and Higher Education through the program entitled “Supporting International Mobility of Researchers.”