Determination of Water Content in inulin by Volumetric Karl Fischer Titration (CAT#: STEM-PPA-0130-YJL)

Introduction

Inulin is a natural storage carbohydrate mainly found in chicory roots, Jerusalem artichoke and dahlia tubers. It is a mixture of polysaccharides composed of fructose unit chains (linked by β-(2→1) d-fructosyl-fructose bonds) of various length, terminated generally by a single glucose unit (linked by an α-d-glucopyranosoyl bond). Its composition depends on the plant source, harvesting date but also on extraction and post extraction processes. The use of inulin and derivatives in the food industry are in constant increase, and the main benefits and nutritional interests of these products are broadly discussed in the literature.
The most stable form for commercial inulin is the powdered form, which has the advantage of facilitating manipulation, storage and transport. Stored at different relative humidities, powder products can physically changed (i.e. crystallisation), drastically modifying their characteristics, such as caking. Because of this, the monitoring of water content of inulin during storage and quality control requires appropriate analytical techniques for accurate determination in order to prevent such negative effects.