A thermoanalytic and kinetic study of sunflower oil

Souza, A. G.; Santos, José Carlos Oliveira; Conceição, Marta Maria da; Silva, M. C. Dantas; Prasad, Shiva

doi:10.1590/s0104-66322004000200017

Cited by 124 publications

(67 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other than DSC, TGA has been widely applied in the monitoring of oxidative stability, thermal behavior, kinetic parameters and activation energy in various oil samples [13][14][15][16][17] . It can also be used to determine fraction volatile components by monitoring the weight change as the sample is heated.…”

Section: Introductionmentioning

confidence: 99%

Comparative Study on Oxidative Decomposition Behavior of Vegetable Oils and Its Correlation with Iodine Value Using Thermogravimetric Analysis

2008

View full text Add to dashboard Cite

A comparative study of oxidative decomposition behavior of a wide range of vegetable oils and its correlation to iodine value (IV) using thermogravimetric analysis (TGA) was described. The oxidative decomposition of saturated fatty acids shows weight loss before 385 while oxidative decomposition of unsaturated fatty acids shows lower rate of weight loss (dWt/dt) compared to saturated fatty acids due to the oxidation process ('up taking' of oxygen) involving breaking down of double bond to form primary and secondary oxidation products, which leads to some weight gain in the sample before being decomposed. The relative differences in the dWt/dt (%/min) of the both fatty acids give different decomposition steps in TGA thermogram, enabling IV to be determined through the percentage weight loss of saturated fatty acids per 100% of total sample weight (excluding weight loss from moisture and volatile compounds). Therefore, TGA method can be used as an alternative method for IV determination with no sample predilution and solvent consumption. Using the TGA methods, good correlation (r = 0.9889) with standard AOCS method was achieved.

show abstract

Section: Introductionmentioning

confidence: 99%

Comparative Study on Oxidative Decomposition Behavior of Vegetable Oils and Its Correlation with Iodine Value Using Thermogravimetric Analysis

2008

View full text Add to dashboard Cite

show abstract

“…the edible oil they are derived from, and the presence of the ligand. T h e increase in activation energy in relation to the steps in thermal decomposition of the systems studied, occurred due to the possible break in the molecular bonds of unsaturated fatty acids, which are less stable than the molecular bonds of stable saturated fatty acids requiring higher activation energy for degradation [1]. Also the thermal stability as well as the energy of activation is the highest for Urea complexes and least for the soaps.…”

Section: Resultsmentioning

confidence: 97%

“…decomposition of hydroxides and peroxides take place in low molecular weight acids and aldehydes [1,2]. TGA / DTA curves are analysed in order to evaluate the kinetic parameters and the oxidative induction period [3,4].…”

Section: Introductionmentioning

confidence: 99%

Thermal Behaviour and Kinetics of Copper (II) Soaps and Complexes Derived from Mustard and Soyabean Oil

Tank

Sharma

2017

JAPLR

View full text Add to dashboard Cite

TGA technique has been applied to Copper (II) soaps derived from Mustard and Soyabean oils and their complexes, with N and S containing ligands, for their thermal analysis and evaluation of energy of activation. Of the six systems studied, three (CM, CMU and CMB) are derived from Mustard oil, and three (CS, CSU and CSB) are derived from Soyabean oil. The results of thermogravimetric analysis reveal that all the referred systems undergo stepwise thermal degradation in three steps corresponding to the decomposition of polyunsaturated, monounsaturated and unsaturated fatty acid components of their corresponding edible oil in the temperature range of 473K-823K (2000C-5500C). The energy of activation 'E' has been evaluated for thermal degradation of each of the three steps for all our referred systems, using various equations like Coats -Redfern, Horowitz -Metzger and Broido equation. It has been observed that for all the equations applied, the stepwise energy of activation follow the order -Step III > Step II > Step I. The general order of activation energies can be represented as -Copper Mustard and Soyabean soap-Urea complex > Copper Mustard and Soyabean soap-2-amino,6-chloro Benzothiazole complex > Copper Mustard Soap > Copper Soyabean Soap.

show abstract

“…This result indicates the increased oxidation sensitivity of oils after ozone treatment either due to the partial hydrolysis of triglycerides or by the destruction of compounds having high antioxidant activity. In a prior work, it was determined that the activation energy for the oxidation of sunflower oil was higher as the amount of artificial antioxidants were increased (Souza et al, 2004). The lower activation energy means less energy required for oxidation products to form.…”

Section: Dsc Kineticsmentioning

confidence: 99%

Oxidation kinetics of hazelnut oil treated with ozone

Uzun

İbanoğlu

2018

Grasas y Aceites

View full text Add to dashboard Cite

SUMMARY:The present study investigates the oxidation kinetics of hazelnut oil ozonated in different treatment periods (1, 5, 60 and 180 min). The kinetic rate constant (k) was taken as the inverse of oxidation onset time (T o ) observing a linear relationship from the plot of lnT o to isothermal temperatures (373, 383, 393, and 403 K) carried out at differential scanning calorimetry. Kinetic parameters, activation energy (E a ), activation enthalpy (ΔH ‡ ) and entropy (ΔS ‡ ) were calculated based on the Arrhenius equation and activated complex theory. k values showed an exponential rise with the increase of ozone treatment time. The increase in k correlated well with the increase in the peroxide and free fatty acid values of all samples. E a and ΔH ‡ of the ozone treated oils showed a reducing trend and reflected an increased oxidation sensitivity after ozone treatment. Consistently, an increase in ΔS ‡ indicated a faster oxidation reaction with an increase in ozone exposure time. However, no significant difference was observed in k, E a , ΔH ‡ , ΔS ‡ (p < 0.05) as a function of storage period, after the hazelnut oil was treated with ozone for 1 min. KEYWORDS: DSC; Hazelnut oil; Kinetics of oxidation; OzoneRESUMEN: Cinética de oxidación del aceite de avellana tratado con ozono. El presente estudio investiga la ciné-tica de oxidación del aceite de avellana ozonizado durante diferentes períodos (1, 5, 60 y 180 min). La constante de velocidad cinética (k) se tomó como la inversa del tiempo de inicio de la oxidación (To) observando una relación lineal cuando se representa el lnTo con las temperaturas isotérmicas (373, 383, 393 y 403 K) llevadas a cabo en calorimetría de barrido diferencial. Los parámetros cinéticos, energía de activación (Ea), entalpía de activación (ΔH ‡ ) y entropía (ΔS ‡ ) se calcularon sobre la base de la ecuación de Arrhenius y de la teoría compleja activada. Los valores de k mostraron un aumento exponencial con el aumento del tiempo de tratamiento de ozono. El aumento de k se correlacionó bien con el aumento de peróxidos y de los ácidos grasos libres de todas las muestras. Ea y ΔH ‡ de los aceites tratados con ozono mostraron una tendencia reductora que refleja una mayor sensibilidad a la oxidación de los aceites después del tratamiento con ozono. Consistentemente, un aumento de ΔS ‡ indicó una reacción de oxidación más rápida con un aumento del tiempo de exposición al ozono. Sin embargo, no se observó diferencia significativa en k, Ea, ΔH ‡ , ΔS ‡ (p <0.05) en función del período de almacenamiento, después de que el aceite de avellana fue tratado con ozono durante 1 min.

show abstract

A thermoanalytic and kinetic study of sunflower oil

Cited by 124 publications

References 9 publications

Comparative Study on Oxidative Decomposition Behavior of Vegetable Oils and Its Correlation with Iodine Value Using Thermogravimetric Analysis

Comparative Study on Oxidative Decomposition Behavior of Vegetable Oils and Its Correlation with Iodine Value Using Thermogravimetric Analysis

Thermal Behaviour and Kinetics of Copper (II) Soaps and Complexes Derived from Mustard and Soyabean Oil

Oxidation kinetics of hazelnut oil treated with ozone

Contact Info

Product

Resources

About