The stability of vegetable oils IV. Flavor reversion in soybean oil

1941 ◽  
Vol 18 (5) ◽  
pp. 95-98 ◽  
Author(s):  
W. G. Bickford
2018 ◽  
Vol 69 (9) ◽  
pp. 2366-2371
Author(s):  
Andrei Cucos ◽  
Petru Budrugeac ◽  
Iosif Lingvay ◽  
Adriana Mariana Bors ◽  
Andreea Voina

Thermal TG/DTG/DTA analysis coupled with FTIR spectroscopy was applied to some sorts of mineral and vegetable oils used in electrical equipment. On heating in inert atmosphere, it was observed that the mineral oils vaporize, while the vegetable oils undergo hydrolysis, yielding fatty acids as main volatiles, as indicated by FTIR. In synthetic air, the FTIR spectra of gaseous products confirm the presence of similar oxidation products, both for mineral and vegetable oils. The TG results indicated that the vegetable-based oils exhibit a substantially higher thermal stability than the mineral oils. The presence or absence of anti-oxidant inhibitors in these oils greatly influences the onset of the oxidation process in air environment factor, as results from the DTA results.


Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1637
Author(s):  
Yunjiao Zhao ◽  
Rui Liu ◽  
Cuiping Qi ◽  
Wen Li ◽  
Mohamed Rifky ◽  
...  

The active components in garlic essential oil are easily degradable, which limits its application in the food industry. Vegetable oils (VOs) were used to improve the stability of garlic essential oil (GEO) emulsion. The volatile compounds of GEO and its mixtures with vegetable oils (VOs), including corn oil (CO), soybean oil (SO), and olive oil (OO) indicated that GEO-VO mixtures had a higher percentage of Diallyl disulfide and Diallyl trisulfide than pure GEO. Adding an appropriate amount of VOs promoted the GEO emulsion (whey protein concentrate and inulin as the wall materials) stability in order of CO > SO > OO. Evaluation of the encapsulation efficiency, controlled release, and antimicrobial activity of GEO-VO microcapsules showed that the GEO was successfully entrapped and slowly released with active antibacterial activities on both E. coli and S. aureus. Collectively, these results implied that VOs, especially for 20% CO, improved the stability of GEO emulsions and the encapsulation efficiency of GEO microcapsules. The mechanism might be related to (1) the regulating effect of density difference between oil and water phases on prevention to gravitational separation, (2) the promotion to the compatibility of GEO and VOs to inhibit the phase separation caused by Ostwald ripening.


Author(s):  
В.И. МАРТОВЩУК ◽  
С.А. КАЛМАНОВИЧ ◽  
А.А. ЛОБАНОВ ◽  
Е.В. МАРТОВЩУК

Исследовано влияние механохимической активации на гидратируемость фосфолипидов растительных масел. Для эксперимента использовали механохимический активатор, обеспечивающий высокие локальные давления, сдвиговые деформации и кавитационный эффект, при следующих параметрах работы: давление на контактирующих поверхностях 70 МПа, частота 180 Гц, скорость сдвига 10200 с–1, размер капли эмульсии 1–2 мкм. Обработку образцов подсолнечного масла осуществляли в течение от 0 до 80 с при температурах 50, 60 и 70°С. Активность фосфолипидов оценивали по величине их адсорбции на границе с полярной поверхностью (водой) в оптимальном температурном режиме при обработке в механохимическом активаторе и без нее. Установлено, что механохимическая активация способствует снижению энергии активации с 6,4 до 4,7 кДж/моль за счет химических и структурных изменений фосфолипидов. В жирнокислотном составе фосфолипидов на 10–12% увеличилось содержание олеиновой кислоты при соответствующем уменьшении линолевой; в фосфатидилэтаноламинах и фосфатидилсеринах отмечено увеличение до 3% содержания пальмитиновой кислоты и незначительно – стеариновой кислоты. Эти изменения жирнокислотного состава и физических свойств фосфолипидов способствуют повышению их гидратируемости и уменьшению доли полиненасыщенных жирных кислот, что должно обеспечить стабильность обработанных в механохимическом активаторе масел к окислению при хранении. The effect of mechanochemical activation on the hydration of phospholipids of vegetable oils has been studied. A mechanochemical activator providing high local pressures, shear deformations and cavitation effect was used for the experiment with the following operating parameters: pressure on the contact surfaces of 70 MPa, frequency of 180 Hz, shear rate of 10200 s–1, the size of the emulsion drop of 1–2 microns. Processing of sunflower oil samples was carried out during 0 to 80 s at temperatures of 50, 60 and 70°C. The activity of phospholipids was estimated by the amount of their adsorption at the border with the polar surface (water) in the optimal temperature mode when processed in a mechanochemical activator and without it. It was found that mechanochemical activation contributes to a decrease in the activation energy from 6,4 to 4,7 kJ/mol due to chemical and structural changes in phospholipids. In the fatty acid composition of phospholipids, the content of oleic acid increased by 10–12% with a corresponding decrease in linoleic acid; in phosphatidylethanolamines and phosphatidylserines, the increase in the content of palmitic acid was noted to 3%, and stearic acid – slightly. These changes in the fatty acid composition and physical properties of phospholipids contribute to increasing their hydration and reducing the proportion of polyunsaturated fatty acids, which should ensure the stability of the oils processed in the mechanochemical activator to oxidation during storage.


1991 ◽  
Vol 68 (10) ◽  
pp. 769-771 ◽  
Author(s):  
Yasushi Endo ◽  
Hiromi Endo ◽  
Kenshiro Fujimoto ◽  
Takashi Kaneda

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S185-S187 ◽  
Author(s):  
Z. Réblová ◽  
D. Tichovská ◽  
M. Doležal

Relationship between polymerised triacylglycerols formation and tocopherols degradation was studied during heating of four commercially accessible vegetable oils (rapeseed oil, classical sunflower oil, soybean oil and olive oil) on the heating plate with temperature 180°C. The content of polymerised triacylglycerols 6% (i.e. half of maximum acceptable content) was achieved after 5.3, 4.2, 4.1, and 2.6 hours of heating for olive oil, soybean oil, rapeseed oil and sunflower oil, respectively, while decrease in content of total tocopherols to 50% of the original content was achieved after 3.4, 1.6, 1.3, and 0.5 hours of heating for soybean oil, rapeseed oil, sunflower oil and olive oil, respectively. Because of the high degradation rate of tocopherols, decrease in content of total tocopherols to 50% of the original content was achieved at content of polymerised triacylglycerols 0.6%, 1.9%, 2.8% and 4.9% for olive oil, rapeseed oil, sunflower oil and soybean oil, respectively, i.e. markedly previous to the frying oil should be replaced.


1940 ◽  
Vol 17 (7) ◽  
pp. 138-143 ◽  
Author(s):  
W. G. Bickford ◽  
Scott Anderson ◽  
K. S. Markley
Keyword(s):  

2020 ◽  
Vol 10 (5) ◽  
pp. 1624
Author(s):  
Ekaterina Borovinskaya ◽  
Eva Ritter ◽  
Wladimir Reschetilowski

The base-catalyzed ethanolysis of soybean oil and waste cooking oil (WCO) was investigated in two types of continuous reactors (microreactor and T-mixer) and in a batch reactor. Flow rate, ethanol/oil ratio and concentration of catalyst were varied according to the design of experiments in continuous reaction systems. Regression analysis was carried out concerning the obtained product yields. Based on this analysis optimal conditions in different reactors types with soybean oil, fresh and WCO were determined. While the increased flow rate was unfavorable in the MX-mixer, it contributed to a great positive impact in the T-mixer system at flow rates higher than 2.2 mL/min. The soybean oil provides a slightly lower yield maximum (96.7%) than the fresh cooking oil (97.9%) and the waste cooking oil (97.5%). Therefore, the mix of vegetable oils in the cooking oil is more suitable for ethanolysis reaction than the soybean oil.


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