Synergistic depolymerisation of alginate and chitosan by high hydrostatic pressure (HHP) and pulsed electric fields (PEF) treatment in the presence of H<inf>2</inf>O<inf>2</inf>

Physically-induced depolymerisation procedures are often preferred for obtaining alginate and chitosan oligosaccharides as they either do not use or make minimal use of additional chemicals; therefore, separation of the final products is facile. In this work, solutions of three types of alginate with different mannuronic and guluronic acid residues ratio (M/G ratio) and molecular weights (Mw) and one type of chitosan were non-thermally processed by applying high hydrostatic pressures (HHP) up to 500 MPa (20 min) or pulsed electric fields (PEF) up to 25 kV cm−1 (4000 μm) in the absence or presence of 3 % hydrogen peroxide (H2O2). The impact on the physicochemical properties of alginate and chitosan was investigated by rheology, GPC, XRD, FTIR, and 1H NMR. In the rheological investigations, the apparent viscosities of all samples decreased with increasing shear rate, indicating a non-Newtonian shear-thinning behaviour. GPC results reported Mw reductions that ranged between 8 and 96 % for all treatments. NMR results revealed that HHP and PEF treatment predominantly reduced the M/G ratio of alginate and the degree of deacetylation (DDA) of chitosan, whilst H2O2 promoted an increase in the M/G ratio in alginate and DDA of chitosan. Overall, the present investigation has demonstrated the feasibility of HHP and PEF for rapidly producing alginate and chitosan oligosaccharides.

Bibliographic Details

Main Authors:	Rivero Ramos, Pedro, Unthank, Matthew G., Sanz Taberner, Teresa, Rodrigo, Maria Dolores, Benlloch Tinoco, Maria
Other Authors:	Agencia Estatal de Investigación (España)
Format:	artículo biblioteca
Language:	English
Published:	Elsevier 2023-05-10
Subjects:	Degree of deacetylation, High hydrostatic pressure, M/G ratio, Molecular weight, Polysaccharide modification, Pulsed electric fields,
Online Access:	http://hdl.handle.net/10261/310819 http://dx.doi.org/10.13039/501100000780 http://dx.doi.org/10.13039/501100011033 https://api.elsevier.com/content/abstract/scopus_id/85160306501
Tags:	Add Tag No Tags, Be the first to tag this record!