Heat-induced geometrical isomerization of α-linolenic acid: Effect of temperature and heating time on the appearance of individual isomers

1993 ◽  
Vol 70 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Robert L. Wolff
Keyword(s):  
Linolenic Acid ◽  
Heating Time ◽  
Effect Of Temperature ◽  
Geometrical Isomerization ◽  
Acid Effect

scholarly journals Synthesis, Characterization and Process Optimization of Bone Whitlockite

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1856 ◽  
Author(s):  
Sadaf Batool ◽  
Usman Liaqat ◽  
Zakir Hussain ◽  
Manzar Sohail
Keyword(s):  
Raman Spectroscopy ◽  
Feed Rate ◽  
Secondary Phase ◽  
Heating Time ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Subsequent Aging ◽  
Subtle Change ◽  
Living Bone ◽  
Ph Range

Whitlockite, being the second most abundant bio-mineral in living bone, finds huge applications in tissue regeneration and implants and its synthesis into its pure form has remained a challenge. Although precipitation of whitlockite phase has been reported recently in many publications, effects of various parameters to control such phase as well as conditions for the bulk preparation of this extremely important bio-mineral have not been investigated so far. In this work, we report the precipitation of pure whitlockite phase using common precursors. As reported in the literature, whitlockite is stable in a narrow pH range, therefore; optimization of pH for the stabilization of whitlockite phase has been investigated. Additionally, in order to narrow down the optimum conditions for the whitlockite precipitation, effect of temperature and heating conditions has also been studied. The obtained solids were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). From PXRD analysis, it was observed that heating the precursor’s mixture at 100 °C with subsequent aging at the optimized pH resulted in the precipitation of pure whitlockite phase. These results were further confirmed by TGA, SEM and Raman spectroscopy analysis and it was confirmed that the conditions reported here favor whitlockite precipitation without formation of any secondary phase. These reaction conditions were further confirmed by changing all the parameters like aging, heating time, feed rate of precursors one by one. From PXRD analysis of these samples, it was concluded that not only pH but temperature, heating time, aging time and feed rate effect simultaneously on the precipitation of pure whitlockite phase and a subtle change in any of these parameters could lead to the formation of undesired stable secondary calcium phosphate phases.

scholarly journals The Effect of Temperature and Heating Time of Roselle Extract (Hibiscus Sabdariffa L) Powder Solution on Growth Inhibition of Staphylococcus aureus ATCC 25923

2021 ◽  
Vol 8 (2) ◽  
pp. 55
Author(s):  
Hana Sofiana Maghfira ◽  
Isnaeni Isnaeni ◽  
Asri Darmawati
Keyword(s):  
Staphylococcus Aureus ◽  
Block Design ◽  
Heating Time ◽  
Bacterial Activity ◽  
Effect Of Temperature ◽  
Diffusion Method ◽  
Hibiscus Sabdariffa ◽  
Control Block ◽  
Significant Difference ◽  
Inhibition Zones

The main ingredients of roselle (Hibiscus sabdariffa L.) which have antioxidant and antibacterial effect were anthocyanins, and flavonoids. Flavonoid compounds were unstable at high temperatures. Meanwhile, the processing of roselle extract powder into ready-to drink or food preparations generally requires the thermal processes. The aims of this study were to determine the effect of temperature and heating time of roselle extract powder solution on the inhibition of microbial growth of Staphylococcus aureus ATCC 25923. The method of this study uses a ready-to- process roselle powder extract sample. The roselle extract powder solution in a screw cap tube was heated at a temperature of 40°C, 50°C, 60°C, 70°C, 80°C, and 90°C on a waterbath, with heating times at each temperature were 15 minutes and 30 minutes. Anti bacterial activity of the sample solution was measured based on the ability to inhibit the growth of Staphylococcus aureus ATCC 25923 by the agar-well diffusion method. The inhibition zone of the sample was measured by caliper. The result of this study showed that inhibition zones caused by the sample that had been heated at those temperature for 15 minutes were 9.55±0.70 mm, 9.53 ±0.04 mm, 9.70±0.14 mm, 9.68±0.24 mm, 10.10±0.14 mm, and 10.25±0.21 mm. Meanwhile, after heating for 30 minutes the inhibition zones were 10.08±0.25 mm, 10.20±0.28 mm, 10.43±0.18 mm, 10.08±0.18 mm, 10.78±0.04 mm, 9.70±0.14 mm. Two ways statistical test ANOVA Randomized Control Block Design with 95% confidence level was used to prove that there was a significant difference berween the mean inhibition zones of each sample. The conclution of this research was, the temperature in the range of 40 -90 oC has no effect on the anti-bacterial activity of the sample. However, the heating time of the sample affected the antibacterial activity of the roselle extract powder solution against Staphylococcus aureus ATCC 25923.

Kinetics of oxidation of 30% TBP solutions in С13 diluent with nitric acid: Effect of temperature and γ-irradiation

2016 ◽  
Vol 58 (4) ◽  
pp. 426-430 ◽  
Author(s):  
E. V. Belova ◽  
Z. V. Dzhivanova ◽  
G. P. Tkhorzhnitskii ◽  
S. V. Stefanovsky ◽  
B. F. Myasoedov
Keyword(s):  
Nitric Acid ◽  
Effect Of Temperature ◽  
Γ Irradiation ◽  
Kinetics Of Oxidation ◽  
Acid Effect ◽  
Kinetics Of

EFFECT OF TEMPERATURE AND HEATING TIME ON THE DETECTION OF OFF-FLAVOR IN AVOCADO PASTE

1975 ◽  
Vol 40 (1) ◽  
pp. 200-200 ◽  
Author(s):  
RICARDO GARCÍA ◽  
JULIO ANDRADE ◽  
CARLOS ROLZ
Keyword(s):  
Heating Time ◽  
Effect Of Temperature

scholarly journals Pengaruh Suhu dan Lama Pemanasan terhadap Karakteristik Ikan Tongkol Olahan yang Direndam Dalam Larutan Asap Cair Batang Bambu Tabah (Gigantochloa nigrociliata BUSE-KURZ)

2019 ◽  
Vol 8 (1) ◽  
pp. 158
Author(s):  
Luber Turnip ◽  
I Wayan Widia ◽  
Pande Ketut Diah Kencana
Keyword(s):  
Water Content ◽  
Heating Temperature ◽  
High Water ◽  
Heating Time ◽  
Effect Of Temperature ◽  
High Water Content ◽  
Color Test ◽  
Liquid Smoke ◽  
Organoleptic Characteristics ◽  
Randomized Design

Tuna has a high protein and water content, and has solid meat. But tuna is also very easy to damage. The cause of damage fish is a high water content which can cause microorganisms to multiply easily. Fumigation with  liquid smoke is safer and more practical than conventional fumigation, because liquid smoke contains phenol, carbonyl and organic acids which are useful for providing a distinctive taste and as preservatives in fish. The liquid smoke comes from stem of tabah bamboo (Gigantochloa nigrociliata Buse-Kurz). The purpose of this study was to determine the effect of temperature and heating time on the characteristics of processed tuna which soaked in liquid smoke stem of tabah bamboo and to find out the temperature and heating time of the best organoleptic characteristics of processed tuna which soaked in a solution of liquid smoke stem of tabah bamboo. The method used is Factorial Completely Randomized Design with two factors. The first factor is the treatment of heating temperature which consists of three levels, and the second factor is the treatment of heating time which consists of three levels. Each treatment was repeated twice. The best combination of treatments is the heating temperature of 100?C, heating for 4 hours produce pH 5.5, water content 58.06%, ash content 1.69%, protein content 18.29%, hedonic color test 3.94, aroma test hedonic 4.28, hedonic texture test 4.72, hedonic taste test 4.5, texture scoring test 4.83, and the overall acceptance scoring test is 4.39. Keywoard : smoked tuna, liquid smoke, tabah bamboo.

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