Rheological Properties of Polysaccharides from Longan (Dimocarpus longanLour.) Fruit

Xingxun Liu,Sumei Zhou,Lei Zhao,Yongyue Luo,Chunjie Zha,Liya Liu

doi:10.1155/2015/168064

Abstract

Longan polysaccharide (LP) was extracted from longan (Dimocarpus longanLour.) pulp. The composition and rheological properties were determined by chemical analysis and dynamic shear rheometer. The flow behavior and viscoelastic behavior of longan polysaccharide (LP) solution were investigated by steady shear and small amplitude oscillatory shear (SAOS) experiments, respectively. The result shows that the solution is a pseudoplastic flow in a range of shear rate (1–100 s−1). The rheological behavior of LP was influenced by cations such as Na+and Ca2+. With an increase of apparent viscosity,G′andG′′were accompanied by addition of Na+and Ca2+.

Highlights

Polysaccharides have attracted much attention due to their broad spectra of therapeutic properties and relatively low toxicity [1,2,3]
The longan polysaccharide (LP) was determined to contain 80.72% of polysaccharides, 5.27% of uronic acids, and 13.10% of proteins, which is similar to previous report [22]
The apparent viscosity of each concentration solution obviously decreased with the increase of shear rate, showing a shear-thinning behavior, which means that this kind of crude longan polysaccharide solution belongs to non-Newtonian fluid

Summary

Introduction

Polysaccharides have attracted much attention due to their broad spectra of therapeutic properties and relatively low toxicity [1,2,3]. Polysaccharides can be divided into animal polysaccharides, plant polysaccharides, and microbial polysaccharides according to their different sources. Plant polysaccharides are widely distributed and are of higher content among all polysaccharides. Plant polysaccharides show some bioactivities, such as antioxidation, immunomodulation, antitumor, and hypoglycemic activities, in development of therapeutic drugs and high value healthy food in modern science [4]. Logan pulp and pericarp contain polysaccharides, which have a variety of bioactivities, such as antioxidation [9] and antitumor activities [10] and the activity of antiglycation and antityrosinase [11]

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Conclusion