Assessing the Impact of Different Drying Techniques on the Quality of Sorghum bicolor Microgreens

Introduction

Microgreens are becoming increasingly popular because of their unique nutritional profile, diverse phytochemical composition, and intense flavor. Given their highly perishable nature, considering futuristic applications, this study explored the scope of using different drying techniques to retain the quality of fresh Sorghum bicolor microgreens.

Materials

This study investigates the drying behavior of microgreens using three different drying techniques: oven drying (OD) at 60 °C, conductive hydro drying (CHD) at 60 °C, and freeze drying. In addition, a drying kinetics analysis was conducted to understand the moisture removal pattern and optimize the drying process. The impact of the physical characteristics and phytochemical composition of the microgreens was evaluated to assess the quality retention.

Result and Conclusion:

In determining drying kinetics, the higher R² value observed in OD indicates the faster moisture removal and higher drying efficiency in OD of ⁓40% than in CHD. The time taken for each drying method is FD > CHD > OD. The phytochemical analysis revealed that the microgreens are rich in phenols and flavonoids (although ⁓20% and ⁓13% contents, respectively, were lost). Among the drying techniques, CHD preserved the quality of microgreens most effectively, showing comparable results to FD. More greatly enhanced powder flow properties (CI<15) were observed in CHD than in OD and FD. Furthermore, the application of appropriate drying techniques addresses the challenges related to the shelf life of microgreens and highlights the strategies for drying microgreens to enhance shelf-life and consumer acceptance, for market expansion.