Composition and Rheological Properties of Polysaccharide Extracted from Tamarind (<i>Tamarindus indica</i> L.) Seed

A polysaccharide was extracted in high yield from tamarind (<i>Tamarindus indica</i> L.) seed (TSP) by acidic hot water extraction and ethanol precipitation. It was composed of 86.2% neutral polysaccharide, 5.4% uronic acid and 1.3% protein. The molecular weight of TSP was estimated to b...

Full description

Bibliographic Details
Main Authors: Huimin Shao, Hui Zhang, Yanjun Tian, Zibo Song, Phoency F. H. Lai, Lianzhong Ai
Format: Article
Language:English
Published: MDPI AG 2019-03-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/24/7/1218
Description
Summary:A polysaccharide was extracted in high yield from tamarind (<i>Tamarindus indica</i> L.) seed (TSP) by acidic hot water extraction and ethanol precipitation. It was composed of 86.2% neutral polysaccharide, 5.4% uronic acid and 1.3% protein. The molecular weight of TSP was estimated to be about 1735 kDa, with glucose, xylose, and galactose in a molar ratio of 2.9:1.8:1.0 as the major monosaccharides. The steady shear and viscoelastic properties of TSP aqueous solutions were investigated by dynamic rheometry. Results revealed that TSP aqueous solution at a concentration above 0.5% (<i>w</i>/<i>v</i>) exhibited non-Newtonian shear-thinning behavior. Dynamic oscillatory analysis revealed that 10% (<i>w</i>/<i>v</i>) TSP showed as a &#8220;weak gel&#8222; structure. Apparent viscosities and viscoelastic parameters of TSP solutions decreased drastically in an alkaline solution of pH &gt; 10, but slightly influenced by acidic solution, high temperature and the presence of salt ions and sucrose. These results indicated that TSP possessed excellent pH-resistance and thermo-stability, which might be suitable for applications in acidic beverages and high-temperature processed foodstuffs.
ISSN:1420-3049