Synthesis and characterisation of starch cuprate

• Published in: Food chemistry Vol. 129; no. 3; pp. 1217 - 1223
• Main Author: Staroszczyk, Hanna
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2011; Elsevier
• Subjects: anions; Biological and medical sciences; chlorides; Cupration; differential scanning calorimetry; esterification; Food industries; Fundamental and applied biological sciences. Psychology; heat treatment; irradiation; Microwave-assisted reactions; Potato starch; starch; Starch and starchy product industries; thermal stability; X-radiation; Microwave-assisted reactions; Cupration; Potato starch; Microwave; Synthesis; Polysaccharide
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2011.05.114

► Starch was esterified with ammonium tetrachlorocuprate(II) in the microwave-assisted and the convectional heating process. ► In the reaction the ligand exchange occurred. ► In the microwave-assisted process, a cuprate anion introduced into starch additionally coordinated water molecules. ► The microwave-assisted reaction significantly accelerated cupration. ► The deterioration of starch crystallinity influenced the cupration. The cupration of granular potato starch with ammonium tetrachlorocuprate(II) was performed by a 20min lasting microwave-assisted process and by 40min convectional heating. In both cases the degree of esterification (DE) did not exceed 6.4×10−3. A higher dose of cuprate had a positive effect on DE, regardless of whether the microwave irradiation or the convectional heating was applied, and on the thermal stability of the starch cuprate produced in the microwave-assisted way. As a result of cupration, the hydroxyl ligand of the starch d-glucose units was replaced by the chloride ligand of the tetrachlorocuprate(II) anion. In the starch cuprate formed in the microwave-assisted process, the cuprate anion additionally coordinated water molecules. The cupration reduced starch crystallinity, as indicated by X-ray diffractometry and differential scanning calorimetry.