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Abstract

Coatings of rice flour (RF), reinforced or not with rosemary essential oil (ROS), were used to evaluate changes in the internal quality of quail eggs stored at room temperature. Quality parameters [egg weight loss (EWL, %), Haugh unit (HU), yolk index (YI), albumen and yolk pH], microbiological (counts of total aerobic mesophilic bacteria and Enterobacteriaceae) and sensory (colour, aroma, odour, texture, taste, and general acceptability) parameters were evaluated during the experiment. Compared to the number of total aerobic mesophilic bacteria on the shell of uncoated eggs (2.02 ± 0.49; 1.78 ± 0.20 log10 CFU mL−1), RF/ROS exhibited significant inhibition effects for these bacteria on 0. (1.16 ± 0.25 log10 CFU mL−1) and 21. (0.84 ± 0.11 log10 CFU mL−1) days of storage at room temperature. On days 7, 14, and 21, RF had no effect on HU (P > 0.05), but eggs coated with RF/ROS had significantly higher HU (P < 0.05) than uncoated eggs from day 14, maintaining grade AA (73.88 ± 2.67) on day 21, while uncoated eggs had grade A (68.90 ± 1.55) at that time. The RF coating reinforced with ROS was a bioactive, efficient, and safe formulation for application based on internal quality, microbiological and sensorial aspects of quail eggs.

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Acta Alimentaria
Authors:
P.G.d.S. Pires
,
C. Bavaresco
,
G.d.S. Oliveira
,
C. McManus
,
V. Machado dos Santos
, and
I. Andretta

Abstract

This study aimed to compare and evaluate the effects of different protein coatings on maintaining the quality of eggs stored for six weeks at 20 °C. 308 brown table eggs from ISA Brown hens were used for four treatments: uncoated eggs, coated with rice protein concentrate – RPC, soy protein concentrate – SPC, and whey protein concentrate – WPC. Eggs started with Haugh Units (HU) of 82.01 and reduced in proportions of 28.75% (control), 12.82% (RPC), 12.90% (SPC), and 10.54% (WPC) on the last day of storage. Coated eggs showed smaller reductions (P < 0.0001) in this response. Protein coatings can effectively maintain the quality of eggs stored for six weeks at 20 °C. However, the WPC coating maintained the highest egg rate and the best yolk index for eggs stored for six weeks at 20 °C.

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Journal of Thermal Analysis and Calorimetry
Authors:
F. T. G. Vieira
,
A. L. M. Oliveira
,
D. S. Melo
,
S. J. G. Lima
,
E. Longo
,
A. S. Maia
,
A. G. Souza
, and
I. M. G. Santos

Abstract

Alkaline earth stannates have recently become important materials in ceramic technology due to its application as humidity sensor. In this work, alkaline earth stannates doped with Fe3+ were synthesized by the polymeric precursor method, with calcination at 300 °C/7 h and between 400 and 1100 °C/4 h. The powder precursors were characterized by TG/DTA after partial elimination of carbon. Characterization after the second calcination step was done by X-ray diffraction, infrared spectroscopy, and UV–vis spectroscopy. Results confirmed the formation of the SrSnO3:Fe with orthorhombic perovskite structure, besides SrCO3 as secondary phase. Crystallization occurred at 600 °C, being much lower than the crystallization temperature of perovskites synthesized by solid state reaction. The analysis of TG curves indicated that the phase crystallization was preceded by two thermal decomposition steps. Carbonate elimination occurred at two different temperatures, around 800 °C and above 1000 °C.

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Journal of Thermal Analysis and Calorimetry
Authors:
Y. A. Ribeiro
,
J. D. S. de Oliveira
,
M. I. G. Leles
,
S. A. Juiz
, and
M. Ionashiro

Thermogravimetry, derivative thermogravimetry (TG, DTG) and differential scanning calorimetry (DSC), were used to study the thermal behaviour of mefenamic acid, ibuprofen, acetaminophen, sodium diclofenac, phenylbutazone, dipyrone and salicylamide. The results led to thermal stability data and also to the interpretation concerning the thermal decomposition.

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Journal of Thermal Analysis and Calorimetry
Authors:
J. Maul
,
A. S. Brito
,
A. L. M. de Oliveira
,
S. J. G. Lima
,
M. A. M. A. Maurera
,
D. Keyson
,
A. G. Souza
, and
I. M. G. Santos

Abstract

Copper monoxide (CuO) was successfully obtained by microwave-assisted hydrothermal method, using different conditions—in a solution without base, in a solution alkalinized with NaOH or with NH4OH. The powders were analyzed by thermal analysis (TG/DTA), X-ray diffraction (XRD), infrared spectroscopy, UV–Visible spectroscopy, and scanning electronic microscopy. XRD results showed that CuO was obtained with monoclinic structure and without secondary phases. Thermal analysis and infrared spectra indicated the presence of acetate groups on the powder surface. TG curves also showed a mass gain assigned to the Cu(I) oxidation indicating that a reduction possibly occurred during synthesis. The high and broad absorption band in the UV–Vis spectroscopy from 250 to 750 nm indicated the coexistence of Cu(II) and Cu(I), confirming the Cu(II) reduction, inside the CuO lattice. It was also possible to confirm the Cu(II) reduction by a displacement of the Me–O vibration bands observed in the IR spectra at around 500 cm−1.

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