Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Preparation and in vitro digestibility of corn starch phosphodiester

Guanglei Li , Fei Li, Jie Zeng, Junliang Sun

School of Food Science, Henan Institute of Science and Technology, Xinxiang, 453003, China;

For correspondence:- Guanglei Li Email: lgl70_hist@163.com Tel:+86 373 3693693

Received: 8 January 2015 Accepted: 27 February 2015 Published: 31 March 2015

Citation: Li G, Li F, Zeng J, Sun J. Preparation and in vitro digestibility of corn starch phosphodiester. Trop J Pharm Res 2015; 14(3):355-362 doi: 10.4314/tjpr.v14i3.1

© 2015 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To optimize the process conditions and analyze in vitro digestibility of corn starch phosphodiester prepared by sodium trimetaphosphate (STMP).

Methods: By using response surface method, the effects of STMP concentration, pH, esterification temperature, and urea addition on digestion resistance of corn starch phosphodiester were investigated and optimal conditions were determined. Corn starch phosphodiester was identified by Fourier transform infrared spectroscopy (FT-IR) and an in vitro digestibility method was applied to investigate starch digestion performances of corn starch phosphodiester.

Results: The optimum conditions for the preparation of corn starch phosphodiester were as follows: STMP, 3.3 %; pH 9.07; esterification temperature, 42 °C; and urea, 2.3 %. Under these conditions, corn starch phosphodiester with a digestion resistance of 66.02 % ± 1.63 % was obtained. Compared with corn starch, the digestible starch content of corn starch phosphodiester decreased sharply (from 86.6 to 10.9 %), while digestion-resistance starch content increased significantly from 1.9 to 66.0 % (p < 0.05), and its digestibility was reduced. FTIR spectrum showed new absorption peaks at 1028 cm-1 indicating that an esterification cross-linking reaction occurred between corn starch and sodium trimetaphosphate.

Conclusion: The corn starch phosphodiester obtained has a lower digestbility and therefore, can potentially be used as a medium glycemic index food for diabetic patients.

Keywords: Corn starch phosphodiester, Digestion resistance, Sodium trimetaphosophate, In vitro digestibility, Glycemic index