title: Starch-based xerogels: Effect of acetylation on Physicochemical and rheological properties.
abstract: This study was aimed at evaluating the physicochemical and rheological properties of starch-based xerogels. The starch from the shoots of Borassus aethiopium was physically modified by xerogelization, and chemically by acetylation, and combination of acetylation and xerogelization. The solubility, swelling and syneresis of the starches were determined by gravimetric techniques. Evaluation of the native starch and derivatives was done using microscopy, Fourier transform infra-red (FTIR), x-ray diffractometry (XRD), and1H NMR spectroscopy. Rheological evaluation was done on 10%w/v dispersions using a Bohlin Gemini rheometer (fitted with a 55mm and 2° cone and plate geometry with gap of 70). The diffractograms displayed three peaks, centered on 2θ=15.3, 17.2 and 23.1° for the native and the starch acetate while the xerogel and the starch acetate xerogel were amorphous. The1H NMR and FTIR confirmed the presence of acetyl groups at about 2.05ppm and 1720cm-1, respectively. Acetylation of the native starch resulted in improvement of solubility. The starch acetate-xerogel sample formed viscoelastic gels without the need for heating. Acetylation and/or xerogelization of the native starch inhibited syneresis. Starch acetate-xerogels, may find application as stabilizer or suspending agent in liquid food and pharmaceutical formulations.
authors.affiliation: Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, PMB 2084, Jos, 930001, Nigeria.
authors.forename: Chinwe U
authors.initials: CU
authors.lastname: Kemas
authors.affiliation: Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, PMB 2084, Jos, 930001, Nigeria.
authors.forename: Ndidi C
authors.initials: NC
authors.lastname: Ngwuluka
authors.affiliation: Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, PMB 2084, Jos, 930001, Nigeria.
authors.forename: Nelson A
authors.initials: NA
authors.lastname: Ochekpe
authors.affiliation: Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, PMB 2084, Jos, 930001, Nigeria. Electronic address: irmiyan@unijos.edu.ng.
authors.forename: Elijah I
authors.initials: EI
authors.lastname: Nep
mesh_terms: D000107:Acetylation; D028023:Arecaceae / Q000737:chemistry; D055598:Chemical Phenomena; D055119:Elastic Modulus; D005782:Gels; D018520:Plant Shoots / Q000737:chemistry; D012212:Rheology; D012995:Solubility; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D014783:Viscosity
chemical_list: D005782:Gels; D013213:Starch
keywords: Borassus aethiopium; Rheology; Starch acetate xerogel