Structural Characteristics and In Vitro Digestibility of Malic Acid-Treated Corn Starch with Different pH Conditions.

Chang Joo Lee,Jun-Young Park,Jong Hee Na,Pahn-Shick Chang

doi:10.3390/molecules24101900

Chang Joo Lee, Jun-Young Park + Show 2 more

Open Access

https://doi.org/10.3390/molecules24101900

Copy DOI

Abstract

The objective of this study was to investigate the influence of pH value on the in vitro digestibility of malic acid-treated corn starch in relation to its structural properties. Varying pH values (1.5–8.5) of 2 M malic acid solution were combined with corn starch in a forced-air oven at 130 °C for 12 h. Using Fourier-transform infrared spectroscopy (FT-IR), carbonyl groups were detected in malic acid-treated corn starch, indicating cross-linking through esterification. As the pH value of malic acid-treated corn starch decreased from 8.5 to 1.5, the resistant starch content increased from 18.2 to 74.8%. This was the result of an increased degree of substitution and was maintained after gelatinization. The granular structure of malic acid-treated corn starches was not destroyed, and the starches maintained birefringence. This malic acid-treated corn starch could be utilized in heat processed foods such as bread and cookies as well as in products with reduced calories.

Highlights

Consumer’s changing dietary preferences are increasing demand for low-calorie but high-satiety foods [1,2]
Starch granules treated with 2.0 M malic acid were not destroyed [18]
Granule shape of malic acid-treated starch was not destroyed by any concentration of malic acid

Summary

Introduction

Consumer’s changing dietary preferences are increasing demand for low-calorie but high-satiety foods [1,2]. Low-calorie processed foods manufactured using RS have better textures than those manufactured with dietary fiber [5]. Foods manufactured with RS have similar total cholesterol content to those manufactured with dietary fiber; RS consumption has been shown to increase HDL cholesterol [6]. These various RSs are classified into the following four categories based on resistance to digestion: RS1 is physically inaccessible to digestion due to entrapment in a non-digestible matrix; RS2 is ungelatinized starch; RS3 is retrograded starch; and RS4 is chemically modified starch [4]

Objectives

Methods

Results

Conclusion