Adsorption isotherms and thermal behavior of hybrids based on quercetin and inorganic fillers

Milia, Azzurra; Bruno, Maurizio; Cavallaro, Giuseppe; Lazzara, Giuseppe; Milioto, Stefana

doi:10.1007/s10973-019-08257-x

Cited by 13 publications

(7 citation statements)

References 47 publications

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“…The incorporation of CNC and quercetin did not affect Tonset and Td,max compared to the PLA/ZN control values (see Table 3). A reduction of the volatile release rate was observed with the incorporation of ZN.Q.CNC layer, showing weight losses between 44 and 47 wt %, as well as a slight increase in the Tonset and Td with TGA thermograms of Q and CNC were also analyzed and the maximum degradation rate of the quercetin and cellulose nanocrystals occurred at the typical temperatures of these components, 355 and 292 • C, respectively [42,43]. Two degradation stages were observed for anhydrous quercetin, while CNC analysis evidenced a degradation attributed to the removal of hydroxyl and -CH 2 -OH groups starting from 289 • C and the decomposition of cellulose chains at higher temperatures (see Figure 3A) [43][44][45].…”

Section: Thermogravimetric Analysismentioning

confidence: 99%

Development of Bilayer Biodegradable Composites Containing Cellulose Nanocrystals with Antioxidant Properties

et al. 2019

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The interest in the development of novel biodegradable composites has increased over last years, and multilayer composites allow the design of materials with functionality and improved properties. In this work, bilayer structures based on a coated zein layer containing quercetin and cellulose nanocrystals (CNC) over an extruded poly(lactic acid) (PLA) layer were developed and characterized. Bilayer composites were successfully obtained and presented a total thickness of approx. 90 µm. The coated zein layer and quercetin gave a yellowish tone to the composites. The incorporation of the zein layer containing CNC decreased the volatile release rate during thermal degradation. Regarding to mechanical properties, bilayer composites presented lower brittleness and greater ductility evidenced by a lower Young’s modulus and higher elongation values. Water permeability values of bilayer composites greatly increased with humidity and the zein coated layer containing quercetin increased this effect. Experimental data of quercetin release kinetics from bilayer structures indicated a higher release for an alcoholic food system, and the incorporation of cellulose nanocrystals did not influence the quercetin diffusion process.

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Section: Thermogravimetric Analysismentioning

confidence: 99%

Development of Bilayer Biodegradable Composites Containing Cellulose Nanocrystals with Antioxidant Properties

et al. 2019

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“…Furthermore, stabilized pigments obtained by transforming an organic dye (based on anthocyanins) into an inorganic one, can be used in the field of restoration in the form of pictorial retouching [ 42 ]. As reported in our previous article [ 43 ], the adsorption capacity of inorganic fillers for functional organic molecules can be correlated to the thermal behavior of the corresponding composite materials. In this regard, it should be noted that thermogravimetric analysis represents a powerful technique to investigate the thermal characteristics of inorganic–organic hybrids, which include polymeric nanocomposites [ 44 , 45 , 46 , 47 ], nanocarriers [ 48 , 49 , 50 ] and catalytic supports [ 51 , 52 ].…”

Section: Introductionmentioning

confidence: 77%

Conversion of Organic Dyes into Pigments: Extraction of Flavonoids from Blackberries (Rubus ulmifolius) and Stabilization

et al. 2021

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The blackberry’s color is composed mainly of natural dyes called anthocyanins. Their color is red–purple, and they can be used as a natural colorant. Anthocyanins are flavonoids, which are products of plants, and their colors range from orange and red to various shades of blue, purple and green, according to pH. In this study, the chemical composition of an extract obtained from blackberries was defined by LC-ESI/LTQOrbitrap/MS in positive and negative ionization mode. Furthermore, we investigated the adsorption process of blackberry extract using several inorganic fillers, such as metakaolin, silica, Lipari pumice, white pozzolan and alumina. The pigments exhibit different colors as a function of their interactions with the fillers. The analysis of the absorption data allowed the estimation of the maximum adsorbing capacity of each individual filler tested. Through thermogravimetric measurements (TGA), the thermal stability and the real adsorption of the organic extract were determined.

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“…However, the incorporation of Q and CNC reduced the T onset of bi- and trilayer films due to their decomposition at T d.max lower than PLA. T d of Q has been reported around 350 °C attributed to the degradation of the aromatic rings, lower than T d,max of PLA (364.3 °C) [ 29 , 47 , 48 ]. Q has also presented a mass loss of 10 wt% approximately up to 160 °C attributed to the elimination of water molecules [ 47 , 48 ].…”

Section: Resultsmentioning

confidence: 99%

“…T d of Q has been reported around 350 °C attributed to the degradation of the aromatic rings, lower than T d,max of PLA (364.3 °C) [ 29 , 47 , 48 ]. Q has also presented a mass loss of 10 wt% approximately up to 160 °C attributed to the elimination of water molecules [ 47 , 48 ]. Despite of lipophilicity of Q, hydroxyl groups of this polyphenolic compound in the solid-state form intermolecular hydrogen bond with water molecules [ 49 ].…”

Section: Resultsmentioning

confidence: 99%

Designing Biodegradable and Active Multilayer System by Assembling an Electrospun Polycaprolactone Mat Containing Quercetin and Nanocellulose between Polylactic Acid Films

et al. 2021

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The design of multilayer systems is an innovative strategy to improve physical properties of biodegradable polymers and introduce functionality to the materials through the incorporation of an active compound into some of these layers. In this work, a trilayer film based on a sandwich of electrospun polycaprolactone (PCL) fibers (PCLé) containing quercetin (Q) and cellulose nanocrystals (CNC) between extruded polylactic acid (PLA) films was designed with the purpose of improving thermal and barrier properties and affording antioxidant activity to packaged foods. PCLé was successfully electrospun onto 70 µm-thick extruded PLA film followed by the assembling of a third 25 µm-thick commercial PLA film through hot pressing. Optical, morphological, thermal, and barrier properties were evaluated in order to study the effect of PCL layer and the addition of Q and CNC. Bilayer systems obtained after the electrospinning process of PCL onto PLA film were also evaluated. The release of quercetin from bi- and trilayer films to food simulants was also analyzed. Results evidenced that thermal treatment during thermo-compression melted PCL polymer and resulted in trilayer systems with barrier properties similar to single PLA film. Quercetin release from bi- and trilayer films followed a similar profile, but achieved highest value through the addition of CNC.

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Adsorption isotherms and thermal behavior of hybrids based on quercetin and inorganic fillers

Cited by 13 publications

References 47 publications

Development of Bilayer Biodegradable Composites Containing Cellulose Nanocrystals with Antioxidant Properties

Development of Bilayer Biodegradable Composites Containing Cellulose Nanocrystals with Antioxidant Properties

Conversion of Organic Dyes into Pigments: Extraction of Flavonoids from Blackberries (Rubus ulmifolius) and Stabilization

Designing Biodegradable and Active Multilayer System by Assembling an Electrospun Polycaprolactone Mat Containing Quercetin and Nanocellulose between Polylactic Acid Films

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