Thermal behaviour of TEGMMA copolymers obtained by photopolymerization using iron complexes

Rigoli, Isabel C.; Cavalheiro, Carla Cristina Schmitt; Ramos, Luiz Antônio; Neumann, Miguel G.; Cavalheiro, Éder Tadeu Gomes

doi:10.1590/s0100-46702007000300006

Cited by 1 publication

(1 citation statement)

References 13 publications

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“…Differential scanning calorimetry (DSC) curves were obtained in a differential scanning calorimetric module DSC 910 (TA Instruments, Waters, New Castle, DE, USA) (heat flow type) coupled to a TA2000 (TA Instruments, Waters) thermal analyzer, using aluminum sample support under air and nitrogen atmosphere. To demonstrate the influence of the parameters, 3 mg of heated sample were used under a dynamic atmosphere of synthetic air (100 mL/min) and increasing heating (2.5, 5, 10, 15, 20 and 40 °C/min) for each sample ( 19 ).…”

Section: Methodsmentioning

confidence: 99%

Nutritional, Physicochemical and Structural Parameters of Mauritia flexuosa Fruits and By-Products for Biotechnological Exploration of Sustainable Goods

Pereira-Freire

Aquino

Campos

et al. 2022

Food Technol. Biotechnol. (Online)

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Research background. Commercialization of Mauritia flexuosa fruits in Brazil is embryonic and handmade. Herein, we evaluated the nutritional value of pulp, peel and endocarp samples from M. flexuosa fruits, performed macroscopic and microscopic evaluations and analyzed physicochemical properties. Experimental approach. Samples were analyzed in relation to size and weight, pH, °Brix, protein content, soluble/insoluble fibers, total titratable acidity and energy value. Mineral profiling was performed by energy dispersive X-ray fluorescence spectrometry, and fatty acids and phytosterols were determined by gas chromatography-mass spectrometry using an Rxi-5HT capillary column. Samples were also submitted to differential scanning calorimetry coupled to a thermal analyzer, and microstructure, morphology, surface and viscosity evaluations were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) with copper radiation and rheological behavior. Results and conclusions. Lyophilized pulp showed higher nutritional contents of ash, proteins, carbohydrates, and energy than in natura pulp. Lyophilized pulp and its by-products showed suitable yields (>17.31 %) and low aw, potassium, manganese, and monounsaturated fatty acids. Peels showed elevated percentages of saturated and polyunsaturated fatty acids, endothermic event and single by-products presenting phytosterols (β-sitosterol and stigmasterol). The lyophilization process did not alter mineral contents, but the reduction ranged from 18.5 to 22.7 % for calcium, magnesium and manganese. Drying processes generated semi-crystalline powders. Peels and endocarps demonstrated higher amounts of insoluble fibers and lower contents of sugars. This composition was reproduced by comparable microscopic morphology and similar thermograms and XRD outcomes. Pulps and endocarps exhibited pseudoplastic non-Newtonian behavior, and flow behavior index values were lower than 1, while peels presented dilatant comportment. Then, physicochemical and nutritional characterization of pulp and by-products, such as peels and endocarp, are essential to support scientific research and exploration of new sustainable products. Novelty and scientific contribution. Processing and conservation techniques, as lyophilization of buriti whole fruits, maintain the good quality of nutritional contents and bioactive compounds, and it can be used to extend their shelf life, preserve alimentary characteristics and provide wider purposes and availability. Such parameters may generate income and food security for local and regional communities.

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Section: Methodsmentioning

confidence: 99%