In Situ Observation of Taurine Crystallization via Single Droplet Drying

Abstract

Taurine, an amino acid that provides physiological benefits for the human body, naturally crystallizes as needles. To be able to manipulate the size and shape of spray-dried taurine particles is desirable to improve fluidity. In this study, a single droplet drying technique was used to obtain an in situ observation of crystallization behavior by elucidating nucleation time, perimeter-based fractal dimension, and onset of oversaturation within the taurine droplet. The range of drying temperature observed (70–110°C) had little impact on their crystallinity, indicating that crystalline particles can potentially be produced via spray drying even at a lower temperature.

[Supplemental materials are available for this article. Go to the publisher's online edition of Drying Technology for the following free supplemental resource: Supplementary figures.]

Keywords:

• Crystallization
• Fractal analysis
• Single droplet drying
• Supersaturation
• Taurine

ACKNOWLEDGMENTS

R. Lin thanks the Guangzhou Elite Project and Guangzhou Ling Nan Intel Enterprise Group Co., Ltd., for the Ph.D. scholarship. Assistance from Jiahan Chew on the single droplet drying experiments is greatly appreciated. We also acknowledge the financial support from Xiamen University (China), “Research and Development of Spray Drying Equipment,” 863 Project, Natural Science Foundation of China (2011AA100801-3).