Effect of Continuous and Discontinuous Microwave-Assisted Heating on Starch-Derived Dietary Fiber Production.

Kamila Kapusniak,Joana Lopes,Justyna Rosicka-Kaczmarek,Karolina Kluziak,Malwina Wojcik,Karolina Lubas,Volodymyr Pavlyuk,Manuel A Coimbra,Janusz Kapusniak,Idalina Gonçalves

doi:10.3390/molecules26185619

Abstract

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.

Highlights

Nowadays, there is growing interest in the correlation of nutrition with human health.Several studies have been conducted to develop functional foods that provide caloric intake and contain bioactive compounds [1]
The solubility of dextrins at 20 ◦C was affected by the microwave-assisted heating conditions, including the microwave power intensity and the processing time (Figure 1)
The dextrins obtained by the discontinuous heating showed higher solubility than dextrins prepared by the continuous heating

Summary

Introduction

There is growing interest in the correlation of nutrition with human health.Several studies have been conducted to develop functional foods that provide caloric intake and contain bioactive compounds [1]. Considering its beneficial effects on the human body, dietary fiber (DF) is considered to be part of a group of functional foods. The main sources of DF are vegetables, fruits, and whole grains. These products are still seldom consumed by populations of high-income countries. Improper habits resulting from the consumption of a Western-type diet are the cause of the aforementioned diseases of civilization [7]. For this reason, there is a need to develop new sources of DF that can be successfully added to food to obtain new health-promoting products of better quality and, above all, properties acceptable to consumers

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