Original Article

Green preparation of citric acid cross-linked starch for improvement of physico-chemical properties of Cyperus starch


  • Bunmi Olayemi
  • Christianah Yetunde Isimi
  • Kokonne Ekere
  • Ajeh Johnson Isaac
  • Judith Eloyi Okoh
  • Martins Emeje

Received Date: 13.09.2019 Accepted Date: 05.12.2019 Turk J Pharm Sci 0;0(0):0-0 [e-Pub]


This study was undertaken to assess the properties of Cyperus esculentus tuber starch cross-linked with citric acid from liquid substrates of orange peel derived via the natural solid-state fermentation process; a green-approach.


The flow properties of the prepared starches were evaluated using standard methods. Water holding capacity, swelling capacity, moisture sorption capacity, gelatinization temperature using Differential Scanning Calorimetry (DSC), morphology, Fourier Infrared Spectroscopy and pH of the starches were evaluated.


According to the results the pH of the cross-linked starches were lower (3.39 - 4.07) than that of the native starch (5.25) and flow profile was found to improve. Water holding capacity (90.67 – 96.69 %) of the cross-linked starches were higher while emulsion capacity (15.33) was similar to that of the native starch (15.33). No change was observed in the morphology of the granules of the cross-linked starches. The infrared spectra of the native and cross-linked starches showed identical peaks; the enthalpy of gelatinization (ΔHgel) of the crosslinked products were found to differ from that of the native starch. The modified starches show propensity of being exploited as binding agents in food and pharmaceutical industries.


The green process of modification has proved to be value addition to the processes of starch modification available.

Keywords: Cyperus esculentus tuber starch, cross-linking, citric acid, orange peel, cross-linked starch