Effect of Temperature on the Deliquescence Properties of Food Ingredients and Blends

Abstract

Deliquescence is a first-order phase transformation of a crystalline solid to a saturated solution that is triggered at a defined relative humidity (RH), RH0. Previous studies demonstrated that the RH0 of an inorganic substance with a positive heat of solution (ΔH) will decrease with increases in temperature. In this study, the relationships between ΔH, solubility, and deliquescence RH for single-ingredient and multicomponent systems were investigated. The deliquescence RHs of inorganic and organic crystalline solids and their mixtures were measured at temperatures ranging from 20 to 40 °C using a water activity meter and various gravimetric moisture sorption analyzers. The deliquescence behavior as a function of temperature for organic food ingredients was thermodynamically modeled and followed similar trends to those of the previously investigated inorganic ingredients. Furthermore, the models can be used as a predictive approach to determine physical stability and deliquescence RHs of deliquescent ingredients and blends if the storage temperature and ingredient ΔH and solubility are known.

RH‐Temperature Stability Diagram of the Dihydrate, β‐Anhydrate, and α‐Anhydrate Forms of Crystalline Trehalose

“…This trend with temperature was expected since the heat of solution of T·2H 2 O is +20.7 ± 0.2 kJ/mol (Miller, de Pablo, & Corti, ), and according to the modified Clausius–Clapeyron equation in Lipasek et al. (), the RH 0 of a deliquescent compound with an endothermic heat of solution will decrease with increasing temperatures. The measured a w s of saturated T·2H 2 O solutions at 20, 25, 30, 35, and 40 °C (Figure ) were within 0.004 a w of the a w s of saturated trehalose solutions at the same temperatures reported in Galmarini, Chirife, Zamora, and Pérez ().…”

Measurement of the Raman spectra and hygroscopicity of four pharmaceutical aerosols as they travel from pressurised metered dose inhalers (pMDI) to a model lung

“…Deliquescence describes the phase change of a crystalline solid to a saturated 26 solution droplet using water collected from the surrounding air. Temperature can affect the RH level 27 required to bring about deliquescence in hygroscopic substances but the effect varies between 28 compounds (Lipasek, et al, 2013). Temperature also has a significant influence over the saturation 29 vapour pressure of air (Lawrence, 2005) temperature influences the kinetics of drug dissolution only, rather than the thermodynamic 32 behaviour of solid particles, which remain relatively unchanged, and it is not expected to significantly 33 impact hygroscopic properties.…”

Analytic Hierarchy Process Applied to the Choice of a Long-Life Tomato (Lycopersicon esculentumMill) Drying System

“…Lipasek et al [27] reported that high temperatures tend to decompose the organic components in food. According to Bosca et al, [28] many products that are sensitive to heat may become degraded when subjected to high temperatures.…”