An aerogel obtained from chemo-enzymatically oxidized fenugreek galactomannans as a versatile delivery system

Abstract

a b s t r a c tWe describe a new aerogel obtained from laccase-oxidized galactomannans of the leguminous plant fenugreek (Trigonella foenum-graecum) and suggest its potential practical use.Laccase/TEMPO oxidation of fenugreek in aqueous solution caused a viscosity increase of over 15-fold. A structured, elastic, stable hydrogel was generated, due to formation of carbonyl groups from primary OH of galactose side units and subsequent establishment of hemiacetalic bonds with available free hydroxyl groups.Upon lyophilization of this hydrogel, a water-insoluble aerogel was obtained (EOLFG), capable of uptaking aqueous or organic solvents over 20 times its own weight. The material was characterized by scanning electron microscopy, FT-IR, elemental analysis and 13 C CP-MAS NMR spectroscopy and its mechanical properties were investigated.To test the EOLFG as a delivery system, the anti-microbial enzyme lysozyme was used as model active principle. Lysozyme was added before or after formation of the aerogel, entrapped or absorbed in the gel, retained and released in active form, as proven by its hydrolytic glycosidase activity on lyophilized Micrococcus lysodeikticus cells wall peptidoglycans.This new biomaterial, composed of a chemo-enzymatically modified plant polysaccharide, might represent a versatile, biocompatible "delivery system" of active principles in food and non-food products.

Laccase/TEMPO oxidation in the production of mechanically strong arabinoxylan and glucomannan aerogels

“…The densities of the aerogel products were quite similar to those described earlier for polysaccharide aerogels [Mikkonen et al, 2014, Rossi et al, 2016. The 2 % (w/v) solution of AXox affected the density increasing it roughly up to ca.…”

“…It was clear that the ice crystal templated freezing technique was superior to the conventional freezing, if high hardness and mechanical stiffness was pursued. Conventional freezing and lyophilization were utilized in a recent study in the preparation of fenugreek galactomannan aerogel by similar oxidation with laccase/TEMPO -system [Rossi et al, 2016]. Some of the physical properties of the product were determined, and the compressive modulus was very low, only ca.…”

“…The use of laccase as the secondary oxidant in the regeneration of TEMPO has previously been studied in the oxidation of cellulose [Viikari, 1999;Jausovec, 2015], pullulan [Jetten 2000], and certain galactomannans [Lavazza et al, 2011;Merlini et al, 2015;Rossi et al, 2016]. Laccase itself has a wide range of substrates, such as, substituted mono-and polyphenols, aromatic amines and thiol compounds [Madhavi and Lele, 2009].…”

Biopolymer‐Aerogele und ‐Schäume: Chemie, Eigenschaften und Anwendungen

“…In den letzten Jahren sind mehrere Biopolymer‐Aerogelsysteme entwickelt worden, die für Anwendungen in Lebensmitteln vorgeschlagen wurde. Guar‐ und Bockshornklee‐Galactomannan‐Aerogele sowie Tamarindsamen‐Galactoxyloclucan‐Aerogele wurden als Zusätze und Verpackungsmaterialien für Lebensmittel vorgeschlagen. κ‐Carrageen‐Aerogele und Aerogele aus Molkeprotein, gemischt mit kristallinen Cellulosepartikeln, wurden mit Sonnenblumen‐ bzw.…”

LYG1 exerts antitumor function through promoting the activation, proliferation, and function of CD4+ T cells

“…To evaluate the bacteriolytic ability of LYG1, an enzymatic assay that lysed bacteria was performed using M. lysodeikticus, which is a typical enzymatic substrate for lysozyme and is generally used to detect bactericidal activity. [24][25][26][27] As shown in Fig. S2, rhLYG1 could not lyse M. lysodeikticus, while human lysozyme (positive control) exhibited high bacteriolytic activities.…”