Oxidation Changes of Vegetable Oils during Microwave Heating

Lukešová, D.; Dostálová, Jana; Mahmoud, E. Abd El-Moneim; Svárovská, M.

doi:10.17221/929-cjfs

Cited by 28 publications

(24 citation statements)

References 7 publications

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“…Thus, corn oil reached the peroxide value 10 mmol 0.5 O 2 kg −1 after 8‐min heating, while sunflower oil reached the same number 2 min earlier. In concord with other authors we found that microwave heating of corn oil for periods of 6, 8, and 10 min led to 3‐, 5‐ and 8‐times increase in its peroxide value, respectively, compared to that in fresh oil. The rise in conjugated dienes content in heated corn oil was very similar, too.…”

Section: Resultssupporting

confidence: 88%

Chemical changes in microwave heated vegetable oils

Kreps

Vrbiková

Schmidt

et al. 2014

Euro J Lipid Sci & Tech

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The aim of this study was to investigate the influence of microwave heating on sunflower and corn oil in two types of microwave oven. The microwave ovens had the same output power and varied mainly in time of dissipation. The oil samples were heated for 90% and 70% of the total heating time by the two types of ovens, named as the first and the second oven, respectively, and the remaining time was dissipation pause. It was observed that greater dissipation pause in second microwave caused degradation of oil almost two times lower than did heating in the first microwave oil. In microwave heated oils the focus was on analysis of primary and secondary oxidation products, the fatty acids content, the tocopherol content and tocopherol degradation kinetics. The rate of tocopherol degradation in oils heated in the first oven was on average 2-times higher than in the second oven. Oils heated for 10 min in the second oven were found to contain twice the tocopherol content, three times lower peroxide value, three times lower conjugated dienes and aldehydes compared with oils heated in the first type of oven. This is the first report about gentle microwave heating of oils and its dependence on time of heating and dissipation time.Practical applications: In order to dissipate heat during heating, microwave ovens are designed with different default magnetron pause. It was proved that in oils heated by microwave oven with longer dissipation pause there was less degradation of oils and their antioxidants. For the manufacturer it is important to conveniently select the lengths of heating a heat dissipation periods. By judicious selection of these two time characteristics healthier microwave heated food with lower degradation of lipids and their antioxidants can be obtained, since overheating is largely avoided.

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Section: Resultssupporting

confidence: 88%

Chemical changes in microwave heated vegetable oils

Kreps

Vrbiková

Schmidt

et al. 2014

Euro J Lipid Sci & Tech

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“…The values of CD and CT of BKSO increased significantly (p < 0.05) over time ( Table 2) but only a small difference was found in the CD and CT of MKSO stored at 65 °C. CD was produced at a higher level than the CT, which corresponded with results reported by Lukešová et al [28]. Increased CD and CT are associated with oxygen uptake and formation of peroxides during the early stages of oxidation as well as with the degradation of polyunsaturated fatty acids [27].…”

Section: Evaluation Of Oxidative Stabilitysupporting

confidence: 89%

Oxidative Stability of Microencapsulated Kenaf Seed Oil Using Co‐extrusion Technology

Chew

Nyam

2016

J Americ Oil Chem Soc

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This study investigates the effect of microencapsulation (via co-extrusion technology using high methoxyl pectin-enhanced alginate as a shell formulation) on the storage stability and antioxidant properties of kenaf seed oil. Microencapsulated kenaf seed oil (MKSO) and unencapsulated oil were stored at 25 °C for 28 days and at 65 °C for 24 days. The oils were then subjected to stability and quality evaluation based on peroxide, p-anisidine, and total oxidation values, conjugated diene and triene levels, thiobarbituric acid reactive substances, free fatty acids, total phenolic content, and the radical scavenging activity assays of 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid). The results showed that there was a significant increase (p < 0.05) in oxidation and a significant decrease (p < 0.05) of antioxidant activity in the unencapsulated oil while oxidation changes generally occurred more slowly in MKSO. It was demonstrated that the current microencapsulation method is a feasible approach to enhance oxidative stability of kenaf seed oil.

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“…There was no significant difference between heating methods although the K270 values for each sample significantly changed during heating (data not shown). Lukesova et al, (2009) reported that the PV, K232 and K270 in rapeseed, corn, soybean and sunflower oils increased due to microwave heating. They also noted that K232 were formed at higher levels compared to K270.…”

Section: Conjugated Dienes (K232) and Trienes (K270)mentioning

confidence: 99%

“…They also noted that K232 were formed at higher levels compared to K270. Vieira and Regitano-D'arce (1998) and Lukesova et al, (2009) noted that K232 was a good index for measuring oil deterioration after microwave heating.…”

Section: Conjugated Dienes (K232) and Trienes (K270)mentioning

confidence: 99%

Effects of microwave and conventional heating on the oxidative stability of corn oil enriched with different antioxidants

Baştürk

2019

Grasas y Aceites

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Four different corn oil samples including stripped (SCO, Control), refined (RCO), stripped corn oil enriched with rosemary extract (SCO+ROS) and ascorbyl palmitate (SCO+AP) were exposed to microwave (MWH) and conventional heating (CVH). For both heating methods, peroxide value (PV) and conjugated dienes increased at up to 230 °C, at which temperature hexanal (HEX) and conjugated trienes started to increase instead. Kinetic analysis revealed that PV and HEX formation were first ordered and the reaction rate among the samples was as follows: Control > SCO+ROS > RCO > SCO+AP for PV and SCO+ROS > RCO > SCO+AP > Control for HEX. The unsaturated fatty acid contents of CVH and MWH treated samples showed 9.5 and 12.9% reduction in SCO, while they were 2.9 and 7.7% in RCO, 3.6 and 6.1% in SCO+ROS, and finally 4.0 and 4.8% in SCO+AP. It was concluded that MWH led to a more severe deterioration and that the antioxidant activity of ROS was superior to that of AP for both heating methods. RESUMEN:Efectos del calentamiento mediante horno microondas y convencional sobre la estabilidad oxidativa del aceite de maíz enriquecido con diferentes antioxidantes. Cuatro muestras diferentes de aceites de maíz que incluyen aceites de maíz crudo (SCO, Control), refinados (RCO) y crudo enriquecido con extracto de romero (SCO + ROS) y palmitato de ascorbilo (SCO + AP) se expusieron a microondas (MWH) y calentamiento convencional (CVH). Para ambos métodos de calentamiento, el índice de peróxido (PV) y los dienos conjugados aumentaron hasta 230 °C, a partir de donde hexanal (HEX) y trienos conjugados comenzaron a aumentar. El análisis cinético reveló que la formación de PV y HEX es de primer orden y la velocidad de reacción entre las muestras fue la siguiente: Control > SCO+ROS>RCO> SCO+AP para PV y SCO+ROS>RCO> SCO+AP>Control para HEX. El contenido de ácidos grasos insaturados de las muestras tratadas con CVH y MWH mostró una reducción de 9,5 y 12,9% en SCO, mientras que fueron de 2,9 y 7,7% en RCO, 3,6 y 6,1% en SCO+ROS, y finalmente 4,0 y 4,8% en SCO+AP, respectivamente. Se concluye que el MWH condujo a un deterioro más severo y la actividad antioxidante de ROS fue superior en comparación con la de AP para ambos métodos de calentamiento. PALABRAS CLAVE: Aceite de maíz; Cinética; Hexanal; Microonda; Oxidación palmitato de ascorbilo ORCID ID: Baştürk A https://orcid.org/0000-0001-7701-9306 Citation/Cómo citar este artículo: Baştürk A. 2019. Effects of microwave and conventional heating on the oxidative stability of corn oil enriched with different antioxidants. Grasas y Aceites 70 (4), e326. https://doi.

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Oxidation Changes of Vegetable Oils during Microwave Heating

Cited by 28 publications

References 7 publications

Chemical changes in microwave heated vegetable oils

Chemical changes in microwave heated vegetable oils

Oxidative Stability of Microencapsulated Kenaf Seed Oil Using Co‐extrusion Technology

Effects of microwave and conventional heating on the oxidative stability of corn oil enriched with different antioxidants

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