Evaluation of data for ice formed from pure water and analysis of ice crystal structures in crystallized fructose aqueous solutions

X-ray diffraction (XRD) patterns of hexagonal ice (Ih) and/or stacking-disordered ice (Isd) have been observed for ice formed in various aqueous systems.Ice Ih and ice Isd exhibit a diffraction peak at XRD angle of 2 40 deg, but Ih uniquely shows additional peaks at 2 34 deg and 44 deg, which are absent in ice Isd.We consider that the XRD peak areas at 34, 40, and 44 deg in crystallized aqueous solution can be utilized to estimate the fraction of ice Ih and ice Isd in crystallized aqueous solutions.To analyze the crystal structure of ice in aqueous solutions, X-ray diffraction measurements of ice formed from pure water as a reference of ice Ih were conducted at 213 K and 188 K at various cooling rates in a range of 0.67 -150 K/min.Assuming that the ice from pure water is the ice Ih, and variation of the peak areas at 2 34, 40, and 44 deg were evaluated.X-ray diffraction measurements were conducted on crystallized fructose aqueous solutions with fructose concentrations of 20 and 40 wt.%.Based on the results of pure water ice, ice in the fructose aqueous solutions up to 40 wt.% of fructose were identified as ice Ih.