Effect of drying air temperature on drying kinetics, color, carotenoid content, antioxidant capacity and oxidation of fat for lotus pollen

Abstract

Hot air drying of lotus pollen at temperatures ranging from 40 to 70 °C was investigated experimentally. Results indicated that the whole drying process occurred in the falling rate period. Color analysis showed that lotus pollen suffered color deterioration. The antioxidant capacity decreased and the fat oxidation activity increased following drying. The carotenoid content exhibited significant loss when dried at 70 °C (p < .05). Zero-order, first-order, and fractional conversion models were employed to fit the experimental data for color profile, antioxidant capacity, and fat oxidation. The first-order fraction model can precisely describe the color change and the antioxidant capacity deterioration, while the kinetics of thiobarbituric acid reactive substances followed the linear model. There is a correlation between color, antioxidant activity, and fat oxidation.

Keywords:

• Drying kinetics
• lotus pollen
• quality evolution
• color
• antioxidant capacity
• modeling

Additional information

Funding

This research is supported by the National Natural Science Foundation of China (No. 31871861, 31501548), the National Modern Agriculture (Bee) Industry and Technology System Construction Projects (NCYTI-43-KXJ17), and the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences (CAAS-ASTIP-2015-IAR).