Polyvinyl alcohol inclusion can optimize the sol-gel, mechanical and hydrophobic features of agar/konjac glucomannan system

Dongling Qiao; Wenjuan Shi; Man Luo; Fatang Jiang; Binjia Zhang

doi:10.1016/j.carbpol.2021.118879

Polyvinyl alcohol inclusion can optimize the sol-gel, mechanical and hydrophobic features of agar/konjac glucomannan system

Carbohydr Polym. 2022 Feb 1:277:118879. doi: 10.1016/j.carbpol.2021.118879. Epub 2021 Nov 10.

Authors

Dongling Qiao¹, Wenjuan Shi¹, Man Luo¹, Fatang Jiang¹, Binjia Zhang²

Affiliations

¹ Glyn O. Phillips Hydrocolloid Research Centre at HBUT, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, School of Food and Biological Engineering, Hubei University of Technology, Wuhan 430068, China.
² Group for Cereals and Oils Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: zhangbj@mail.hzau.edu.cn.

PMID: 34893282
DOI: 10.1016/j.carbpol.2021.118879

Abstract

The practical features (e.g., sol-gel, mechanical and hydrophobic) of biopolymer systems are crucial for their materials applications. This work reveals how polyvinyl alcohol (PVA) inclusion affects the practical features of agar/konjac glucomannan (KGM) system. From rheological analysis, incorporating PVA (especially 6%) enhanced the chain entanglements of resulted ternary solution (A₇₀K₂₄P₆) with stabilized sol-gel transition point. Such effect not only increased the zero-shear viscosity (ca. 1.5 times that of agar/KGM counterpart) and structural recovery degree of A₇₀K₂₄P₆ solution, but also caused reduced crystallites and simultaneously increased tensile strength, elongation at break and hydrophobicity for A₇₀K₂₄P₆ film from solution dehydration. This ternary film exhibited a tensile strength of ca. 105 MPa, an elongation at break of ca. 20%, and a water contact angle of ca. 97.6°. Additionally, incorporating PVA almost unaffected the morphology of film fracture surface. These results are valuable for the design of agar/KGM systems with improved practical features.

Keywords: Agar; Agar (Compound CID: 71571511); Konjac glucomannan; Konjac gluocomannan (Compound SID: 135312923); Polyvinyl alcohol; Polyvinyl alcohol (PubChem CID: 11199); Practical features.