Pyrodextrins from waxy and normal tapioca starches: Molecular structure and in vitro digestibility

Carbohydr Polym. 2021 Jan 15:252:117140. doi: 10.1016/j.carbpol.2020.117140. Epub 2020 Sep 28.

Abstract

Pyrodextrins were prepared from acidified waxy and normal tapioca starches (pH∼3) at 3 temperatures (130, 150 and 170 °C) and 3 times (1, 2 and 4 h) to determine their in vitro digestibility and molecular structure. Pyrodextrin from waxy tapioca starch produced at 170 °C/4 h had 5% higher total indigestible carbohydrate than pyrodextrin from normal tapioca starch (45.2 % and 40.4 %, respectively) as determined by a modified AOAC Method 2011.25. The low-molecular weight indigestible carbohydrate content at this condition was also higher for waxy tapioca starch than normal tapioca starch (40.6 % and 34.9 %, respectively). Gel permeation chromatography and nuclear magnetic resonance spectroscopy were used to study changes in molecular structure and correlate with digestibility of the pyrodextrins. Molecular size distribution indicated that waxy tapioca starch underwent thermal modification more readily than normal tapioca starch. Non α-1,4/α-1,6 glucosidic linkages were increased in the pyrodextrins with increasing in indigestible carbohydrate content.

Keywords: In vitro digestibility; Indigestible carbohydrate; Nuclear magnetic resonance; Pyrodextrins; Waxy tapioca starch.

MeSH terms

  • Dextrins / chemistry*
  • Manihot / chemistry*
  • Molecular Structure
  • Molecular Weight
  • Solubility
  • Starch / chemistry*
  • Temperature
  • Waxes / chemistry*

Substances

  • Dextrins
  • Waxes
  • Starch