Strengthening effect of nanofibrillated cellulose is dependent on enzymatically oxidized polysaccharide gel matrices

Ghafar, Abdul; Parikka, Kirsti; Sontag‐Strohm, Tuula; Österberg, Monika; Tenkanen, Maija; Mikkonen, Kirsi S.

doi:10.1016/j.eurpolymj.2015.07.046

Cited by 21 publications

(31 citation statements)

References 53 publications

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“…Resilience is a measure of the ability of the sample to recover its original shape. Cohesiveness, springiness, and resilience were lower with EOLFG, consistent with the inverse relationship between these parameters and the compressive modulus and maximum force, in accordance with what described by Ghafar et al (2015) on GaO-oxidized guar gum. Overall, these results would further support that enzymatic oxidation of fenugreek gum, followed by lyophilization, causes formation of a stable network of FG polymer, less prone to be deformed and more able to absorb an applied stress.…”

Section: Mechanical Propertiessupporting

confidence: 71%

“…We believe that the underlying mechanism involves generation of carbonyl groups by the chemo-enzymatic reaction, that are able to form hemiacetalic bonds with adjacent free OH's, thus causing internal cross-linking of the polymer and its "structuring" to yield a compact, highly elastic gel, as a prerequisite to aerogel formation by lyophilization. This is, to our knowledge, the first description of an aerogel from chemo-enzymatically oxidized FG, whose general features appear to resemble the material obtained by others with guar gum oxidized by GaO (Ghafar et al, 2015;Mikkonen et al, 2014).…”

Section: Discussionmentioning

confidence: 89%

“…Each compression cycle accounted for a maximum deformation of the sample of 2 mm, at a crosshead speed of 2 mm s −1 . Both stress-strain and force-time profiles were recorded and the following parameters were elaborated by software (TestXpert V10.11 Master): compressive modulus (i.e., E-mod, expressed in kPa, as the slope of the initial rising part of the first stress-strain curve), determined according to a secant method; maximum compressive force (i.e., F max , expressed in N, as the peak force of the first compression cycle); cohesiveness (i.e., the ratio of the area of the second cycle to the area of the first cycle); springiness (i.e., the area of compression of the second cycle divided by the area of compression of the first cycle); resilience (i.e., the ratio of the area of decompression to the area of the compression of the first cycle) (Ghafar et al, 2015). All tests were carried out at 23 ± 0.5 • C and 40 ± 2.5% relative humidity (RH).…”

Section: Mechanical Featuresmentioning

confidence: 99%

“…: depolymerization with carbohydrolases or lyases (Cheroni, Formantici, & Galante, 2010;Delattre et al, 2015;Tavernier et al, 2008), debranching with ␣-glycosidase, oxidation with oxidases (i.e., laccase, peroxidase, galactose oxidase), but also for the "elimination" of insoluble proteins with proteases (Baldaro et al, 2012). Enzymatic oxidation of guar GM has been described using either a wild type galactose oxidase (GaO), followed by reductive amination (Hall & Yalpani, 1980) or by halogen oxidation (Frollini, Reed, Milas, & Rinaudo, 1995), or with a highly engineered GaO by Parikka and co-workers (Delagrave et al, 2001(Delagrave et al, , 2002Ghafar et al, 2015;Leppanen et al, 2010;Mikkonen et al, 2014;Parikka & Tenkanen, 2009;Parikka et al, 2010Parikka et al, , 2012Parikka, Master, & Tenkanen, 2015). More generally, oxidation of polysaccharides with the enzyme laccase can generate reactive groups (e.g., carbonyls, carboxyls) on cellulose , on starch (Viikari, Niku-Paavola, et al, 1999), on pullulan (Jetten et al, 2000), and on guar galactomannan (Lavazza et al, 2011).…”

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confidence: 99%

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

Rossi

Campia

Merlini

et al. 2016

Carbohydrate Polymers

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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.

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Section: Mechanical Propertiessupporting

confidence: 71%

Section: Discussionmentioning

confidence: 89%

Section: Mechanical Featuresmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

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

Rossi

Campia

Merlini

et al. 2016

Carbohydrate Polymers

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“…AG showed the highest and CMC showed the lowest value of this parameter. This behavior and the highest strain stiffening of AG among different hydrocolloids at all the nonlinear strain in LAOS test could be attributed to the higher nonlinear stretchability, looser consistency and finite extensibility of the network strands connecting network junctions of AG in comparison to the other hydrocolloids (Creton, Hu, Deplace, Morgret, & Shull, ; Ghafar et al, ). These factors resulted in the greatest resistance of AG gel network to the nonlinear strain and large deformation.…”

Section: Resultsmentioning

confidence: 94%

Classification of hydrocolloids based on small amplitude oscillatory shear, large amplitude oscillatory shear, and textural properties

Alghooneh

Razavi

Kasapis

2019

Journal of Texture Studies

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Dynamic rheological and mechanical properties of seven commercial (xanthan [XG], guar [GG], high methoxylated pectin [HMP], κ‐carrageenan [κ‐Car], agar [AG], alginate [ALG], and carboxymethylcellulose [CMC]) and four emerging hydrocolloids (basil seed gum [BSG], sage seed gum [SSG], Balangu‐Shirazi seed gum [BSSG], and cress seed gum [CSG]) were investigated and the classification of the hydrocolloids were carried out based on them. AG belonged to the first class with 0.81 membership function (MF), κ‐Car and HMP grouped in the second class with 0.68 and 0.71 MFs, respectively, XG, BSG, and SSG were depended to the third class with 0.61–0.70 MFs, finally, CMC, GG, BSSG, ALG, and CSG related to the fourth class, as the most populated class, with MF > 0.61. The first class contained the highest amount of hardness parameter (43.40 ± 2.76 g), the second class included the highest pseudoplasticity parameter (shear‐thinning ratio = −0.54 ± 0.03) and relaxation time (66.25 ± 2.61 s) and the fourth cluster comprised the highest frequency dependency of viscous modulus (exponent of power‐law model for viscous modulus vs. frequency = 0.30 ± 0.05). In addition, the results of this study showed that there was a distinct relationship between nonlinear harmonics in the stress wave and fundamental characteristics of hydrogel networks. The investigation of the rheo‐mechanical properties of biopolymers in large deformation under shear and normal forces can have an important role in the prediction of the behavior of the material in real processes and application conditions, especially in the food industry. Due to the inconvenience of large deformation mechanical tests, such as Weissenberg effect, the complication of the results analyzing and sampling difficulty of semi‐dilute samples; herein, we determined the correlation between large deformation (LAOS and texture analysis) and small deformation (SAOS) tests properties. The studied rheo‐mechanical parameters showed high correlation with the four mentioned network parameters (more than 65% similarity index). Using these results, other scientists could rationally design the experiments and avoid experiments with similar parameters.

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Aerogel from chemo-enzymatically oxidized fenugreek gum: an innovative delivery system of isothiazolinones biocides

Silvetti

Merlini

Brasca

et al. 2018

Appl Microbiol Biotechnol

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Aerogels of chemo-enzymatically oxidized, lyophilized fenugreek gum (EOLFG) were evaluated as "delivery system" (DS) of the microbiocide mix 5-chloro-2-methyl-4-isothiazolin-3-one (CIT) and 2-methyl-4-isothiazolin-3-one (MIT). These biocides have a broad activity spectrum and a low MIC (minimal inhibitory concentration) in the ppm range. They are approved under the EU Biocidal Product Directive for various applications, including cosmetics, are classified as skin sensitizers, and are under increasing scrutiny to limit or eliminate their use.We demonstrate that CIT/MIT can be uptaken into EOLFG aerogel corks by immersion into aqueous solutions of microbiocides, followed by blotting and re-lyophilization to generate "loaded" EOLFG aerogels. Incubation of "loaded" corks in water brings about a slow and almost complete release of the absorbed actives having the same MIC of free biocides against selected bacterial pathogens.This new biomaterial could represent an innovative DS of microbiocides and other actives for a variety of industrial, food, cosmetic, and biomedical applications.

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Strengthening effect of nanofibrillated cellulose is dependent on enzymatically oxidized polysaccharide gel matrices

Cited by 21 publications

References 53 publications

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

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

Classification of hydrocolloids based on small amplitude oscillatory shear, large amplitude oscillatory shear, and textural properties

Aerogel from chemo-enzymatically oxidized fenugreek gum: an innovative delivery system of isothiazolinones biocides

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