Thermal Degradation Kinetics of Encapsulated Palm Carotenes Using Different Combination of Wall Materials

Palm oil is known as one of the richest sources of carotenes. Carotenes concentrate could be prepared from crude palm oil and possessing potency to be used as nutraceutical materials. Due to the susceptibility of carotenes against heat, the encapsulation procedure might be applied to provide protections. The present study was aimed to learn the influence of using different combination of wall materials toward the thermal degradation kinetics of palm carotenes. Maltodextrin was used as primary wall material, being combined with various surface-active agents, i.e. Tween-80 (A), Tween-20 (B), and Arabic gum (C). The carotenes concentrate was encapsulated through emulsification steps, and the vivid yellow powder was obtained after freeze drying process. Then, encapsulated palm carotenes were stored in 200C, 350C, and 500C for several days, and the color, carotenes spectrum, as well as water content were monitored periodically. The kinetics of thermal degradation of carotenes were estimated using Arrhenius equation. The results showed that the use of different combination of wall materials exhibited distinct degradation rate. The combination of maltodextrin and Tween-80 gave preferable protection compared to the others, being half-degraded after 51 days in 200C.

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Thermal Degradation Kinetics of Carotenoids in Palm Oil

Journal of the American Oil Chemists Society ◽

10.1007/s11746-012-2156-1 ◽

2012 ◽

Vol 90 (2) ◽

pp. 191-198 ◽

Cited By ~ 22

Author(s):

Klicia A. Sampaio ◽

Jose V. Ayala ◽

Simone M. Silva ◽

Roberta Ceriani ◽

Roland Verhé ◽

...

Keyword(s):

Thermal Degradation ◽

Palm Oil ◽

Degradation Kinetics ◽

Thermal Degradation Kinetics ◽

Kinetics Of

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Thermal Degradation Kinetics and Modeling Study of Ultra High Molecular Weight Polyethylene (UHMWP)/Graphene Nanocomposite

Molecules ◽

10.3390/molecules26061597 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1597

Author(s):

Iman Jafari ◽

Mohamadreza Shakiba ◽

Fatemeh Khosravi ◽

Seeram Ramakrishna ◽

Ehsan Abasi ◽

...

Keyword(s):

Thermal Stability ◽

Molecular Weight ◽

Thermal Degradation ◽

High Molecular Weight ◽

Degradation Kinetics ◽

Graphene Nanosheets ◽

Thermal Degradation Kinetics ◽

Graphene Nanocomposites ◽

Kinetics Of ◽

Ultra High Molecular Weight

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.

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