Spectral analysis and physical properties of benzylated starch

• Published in: Die Stärke 2012-06, Vol.64 (6), p.481-488
• Main Authors: Šárka, Evžen, Koláček, Jaroslav, Synytsya, Andriy, Hrušková, Kateřina, Maixner, Jaroslav, Štětina, Jiří
• Format: Article
• Language: English
• Subjects: Benzylated starch; Biological and medical sciences; Cereal and baking product industries; Food industries; Fundamental and applied biological sciences. Psychology; IR spectra; loss modulus; nuclear magnetic resonance spectroscopy; potato starch; Rheological properties; rheology; spectral analysis; starch; Starch and starchy product industries; storage modulus; XRD patterns
• ISSN: 0038-9056; 1521-379X
• DOI: 10.1002/star.201100174

A‐ and B‐wheat starch (in native or acetylated form) and potato starch (slightly acetylated) were subjected to benzylation with benzylchloride in various reaction conditions and at various reaction times (40–100°C, 1–90 h). Modified and original starches were characterized by elemental analysis and spectroscopic methods (FT‐IR and 1H NMR). The semicrystalline or amorphous character was indicated by X‐ray powder (XRD) patterns. Rheological properties of benzyl starch of DS ∼ 1 were measured by small amplitude oscillation shear rheology (SAOS) using the rheometer Haake Rheostress RS 80. The results indicated predominantly elastic behavior because the storage modulus was higher than the loss modulus over the whole frequency range; it corresponded to a true gel. The storage and loss moduli increased with increasing frequency while the tangent of phase did not change and was approximately δ = 40°.