Moisture sorption characteristics and quality changes during storage of the dried petals of red water lily ( Nymphaea × rubra )

Abstract

A petal of red water lily is considered a medicinal plant due to its various health benefits. However, it suffers from a short shelf life due to the high moisture content of its fresh form. So, moisture sorption isotherm is used to design drying and storage conditions for extending its shelf life. Up to now, there is no research on sorption isotherms and factors affecting the quality changes during storage of the dried petal. Therefore, this study aimed to fulfilling this research gap in designing or controlling the drying process and storage condition. The GAB model well-described sorption isotherms data and the monolayer moisture content ranged from 3.60% to 4.57% d.b. The Blahovec–Yanniotis model provided the information on water contribution to adsorption and desorption processes. Storage time and relative humidity were the main factors affecting the quality changes during storage while storage temperature served as a facilitator for these changes. Novelty impact statement The GAB model was the best model to describe the sorption isotherm of the red water lily petal and the contribution of water in both adsorption and desorption processes could be described by the Blahovec–Yanniotis model. The moisture-changing behavior at each relative humidity step could be described using the combination of reaction order kinetic and dynamic vapor sorption data. Storage time and relative humidity played a major role in quality changes (color parameters and antioxidant capacities) during storage and the correlation between color parameters and antioxidant capacities might be used as an alternative tool for a nondestructive analytical technique.