Crystallinity of Sucrose by X‐ray Diffraction as Influenced by Absorption versus Desorption, Waxy Maize Starch Content, and Water Activity

Crystallinity of sucrose in a mixture with waxy maize starch as affected by absorption and desorption in the range 0.33 to 0.97 a w was studied by X‐ray diffraction. Ratio of sucrose to starch peak areas was linear with weight ratios as expected. Sucrose crystallinity as determined by X‐ray diffraction was found to be in excellent agreement with that calculated from sorption data. Sucrose in a mixture equilibrated by absorption to 0.33 and 0.75 a w was about 80% crystalline. On absorption to 0.84 a w , the mixture showed sucrose crystallinity reduced to 50%. However, on desorption to 0.33–0.84 a w , the sucrose crystallinity was reduced to zero regardless of sucrose content.