Physicochemical, rheological and functional properties of modified starches from the tubers of Plectranthus esculentus


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.


Plectranthus esculentus, rheology, acetylation, food additive, Starch, excipient

How to Cite

Kemas, 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:







Ursula Chinwe Kemas (University of Jos)
Ruth E Guktur (University of Jos)
Nelson Agaba Ochekpe (University of Jos)
Ndidi C. Ngwuluka orcid logo (University of Jos)
Elijah Irmiya Nep orcid logo (University of Jos)





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