Native starch extracted from the tubers of Plectranthusesculentus (Family: Lamiaceae) was modified by acetylation,oxidation, carboxymethylation, xerogel formation, acetylation/xerogel formation,and acetylation/oxidation. Starch syneresis, swelling power and solubility were determined by gravimetric techniques at 10% w/v of starch dispersion. Rheological properties were determined on a Bohlin Gemini HR Nano Rotonetic drive 2rheometer while the structural properties were evaluated using Fourier transform infra-red (FTIR) spectroscopy and x-ray diffractometry (XRD). FTIR confirmed the presence of acetyl groups at 1700 cm-1 and carboxymethyl groups at 1579 cm-1. The acetylated derivatives were resistant to syneresis. XRD displayed crystallized region with three prominent peaks, centred on 2θ = 15.1, 17.2and 23.2°, for the native starch, acetylated and oxidized starches while the carboxymethylated, xerogelized, and acetylated/xerogelizedderivatives were typically amorphous. The derivatives (carboxymethylated andacetylated/xerogelyzed) were thermally stable and formed viscoelastic gel at room temperature. Conversely, dispersions of the native starch and the derivatives (acetylated, oxidized and acetylated/oxidized) exhibited thermal transitions due to gelatinization. The acetylated derivatives have potential in terms of shelf-life, stability, and diverse opportunities for multiple applications in pharmaceutical and food industries.
Starch, excipient, acetylation, Plectranthus esculentus, rheology, food additive
How to CiteKemas U. C. , Guktur R. E. , Ochekpe N. A. , Ngwuluka N. C. & Nep E. I. (2020) “Physicochemical, rheological and functional properties of modified starches from the tubers of Plectranthus esculentus”, British Journal of Pharmacy. 4(2). doi: https://doi.org/10.5920/bjpharm.684