Development of a fluorescence sensor to monitor lipid oxidation. II. The kinetics of chitosan fluorescence formation after exposure to lipid oxidation volatiles

1992 ◽  
Vol 6 (3) ◽  
pp. 273-293 ◽  
Author(s):  
Jennifer L. Weist ◽  
Marcus Karel
1998 ◽  
Vol 4 (1) ◽  
pp. 67-73 ◽  
Author(s):  
M.D. Ortolá ◽  
C.L. Gutiérrez ◽  
A. Chiralt ◽  
P. Fito

The kinetics of lipid oxidation in ground roast Arabica coffee from Colombia stored under different conditions were studied. Rancidity was controlled by the analysis of the peroxide value at 30-day intervals. The influence of moisture content (26 and 43 g/kg), storage temperature (5, 25 and 35 °C) and packaging conditions (with non-sealed bags, under vacuum, 35 mbar, and packed under CO2 atmosphere) on the kinetics was determined. Experimental values were fitted with a kinetic model for the mechanism of lipid oxidation. Lipid oxidation is described by two steps, which implies a monomolecular and a bimolecular initiation mechanism for the first and second period respectively. The kinetic constants showed that the plastificant effect of water and CO2 lead to an important change in the reactants' mobility within the temperature range. However, the rise in moisture content seems to protect the product from formation of the peroxide. Furthermore, this effect is more important in the second step of the oxidation process.


2016 ◽  
Vol 16 ◽  
pp. 5-10 ◽  
Author(s):  
Charles Odilichukwu R. Okpala ◽  
Gioacchino Bono ◽  
Michele Luca Geraci ◽  
Giacomo Sardo ◽  
Sergio Vitale ◽  
...  

2020 ◽  
Vol 42 ◽  
pp. e53
Author(s):  
Talita Cuenca Pina Moreira Ramos ◽  
Antonio Rogerio Fiorucci ◽  
Claudia Andrea Lima Cardoso ◽  
Margarete Soares Da Silva

O óleo extraído das sementes de uva é um produto com excelentes características antioxidantes e nutricionais, que pode ser utilizado na indústria de alimentos. Devido a essas características, este óleo foi incorporado, juntamente com o óleo de gergelim, em diferentes proporções, ao óleo de girassol, mantido na proporção de 50% em todas as misturas. Os óleos puros e misturas foram avaliados quanto à estabilidade termo-oxidativa (índice de estabilidade do óleo, OSI), compostos fenólicos, DPPH, cromatografia em fase gasosa, cinética de oxidação, entalpia e entropia e prazo de validade (a 25 ° C). A equação de Arrhenius e a teoria do complexo ativado foram utilizadas para estimar as energias de ativação, entalpias e entropia de ativação, variando de 80,66 a 90,37 kJ / mol, 77,84 a 86,61 kJ / mol e -129,46 a -104,37 J / mol K, respectivamente. O óleo de uva puro e as misturas com a maior proporção destes adicionados (B1 e B2) apresentaram os melhores valores em todos os parâmetros analisados. Os valores de energia livre de ativação (ΔG), que variaram de 27,68 a 38,59 kJ / mol, unificaram e verificaram os resultados dos outros parâmetros cinéticos, que indicam uma menor taxa de oxidação lipídica para a mistura B1, com maior proporção de uvas adicionadas.


2016 ◽  
Vol 40 (3) ◽  
pp. e12423 ◽  
Author(s):  
Hamid Tavakolipour ◽  
Mohsen Mokhtarian ◽  
Ahmad Kalbasi-Ashtari

2000 ◽  
Vol 89 (5) ◽  
pp. 2057-2064 ◽  
Author(s):  
Zengkui Guo ◽  
Bartolome Burguera ◽  
Michael D. Jensen

A pulse ([14C]palmitate)-chase ([3H]palmitate) approach was used to study intramuscular triglyceride (imTG) fatty acid and plasma free fatty acid (FFA) kinetics during exercise at ∼45% peak O2 consumption in 12 adults. Vastus lateralis muscle was biopsied before and after 90 min of bicycle exercise; 3H2O production, breath14CO2 excretion and lipid oxidation (indirect calorimetry) rates were measured during exercise. Results: during exercise, 8.2 ± 1.2 and 8.4 ± 0.7 μmol · kg−1 · min−1 of imTG fatty acids and plasma FFA, respectively, were oxidized according to isotopic measurements. The sum of these two values was not different ( P = 0.6) from lipid oxidation by indirect calorimetry (15.4 ± 1.6 μmol · kg−1 · min−1); the isotopic and indirect calorimetry values were correlated ( r = 0.79, P < 0.005). During exercise, imTG turnover rate was 0.32 ± 0.07%/min (6.0 ± 2.0 μmol of imTG · kg wet muscle−1 · min−1) and plasma FFA were incorporated into imTG at a rate of 0.7 ± 0.1 μmol · kg wet muscle−1 · min−1. The imTG pool size did not change during exercise. This pulse-chase, dual tracer appears to be a reasonable approach to measure oxidation and synthesis kinetics of imTG.


1971 ◽  
Vol 2 (3) ◽  
pp. 355-405 ◽  
Author(s):  
Theodore P. Labuza ◽  
L. R. Dugan
Keyword(s):  

2020 ◽  
Vol 11 (7) ◽  
pp. 6215-6225
Author(s):  
Fabio Valoppi ◽  
Nabil Haman ◽  
Giovanna Ferrentino ◽  
Matteo Scampicchio

This study aims to evaluate the effect of vegetable waxes on the kinetics of lipid oxidation of linseed oil.


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