Volatile profiles and involvement step of moisture in bulk oils during oxidation by action of deuterium oxide (D2O)

Euro J Lipid Sci & Tech

et al. 2021

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Effects of moisture and amphiphilic compounds, including oleic acid, lecithin, and monoacylglycerols (MAGs), on the oxidative stability are evaluated in microwave‐treated corn oil. Moreover, the physical properties including critical micelle concentration (CMC) and moisture content are determined in oils treated by microwave irradiation. The CMC of lecithin and moisture content of oils decreases remarkably, whereas the temperature of the oil increases rapidly with microwave irradiation. The addition of lecithin results in increased moisture content significantly in the edible oils, whereas oleic acid and MAGs do not exhibit these effects. Primary oxidation products in all the oil samples increase, despite the type of amphiphilic compounds used. Corn oil containing oleic acid and samples with lecithin exhibits lower and higher p‐anisidine values (p‐AV), respectively. Remarkably high moisture content in corn oils containing lecithin may contribute to the formation of volatile compounds and high p‐AV. Collectively, moisture and amphiphilic compounds affect the degree of lipid oxidation in microwave‐irradiated bulk oils. Practical application: A microwave oven is an irreplaceable home appliance and is widely used in households nowadays. Effects of amphiphilic compounds and moisture on the oxidative stability are evaluated and it is found that the amphiphilic compounds in lipids affect heat transfer and oxidative stability of oils. The results of this study can provide fundamental insights into lipid oxidation in edible oils, and can provide a direction to the food industry with respect to the development of more efficient and safe methods for the preparation of microwavable foods.

Section: Resultsmentioning

confidence: 99%

Effects of Moisture and Amphiphilic Compounds on the Oxidative Stability of Microwave‐Treated Corn Oil

Choi

Euro J Lipid Sci & Tech

et al. 2021

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“…The analysis conditions of SPME for volatile compounds were modified from the methods described by Lee et al (2018). Briefly, sample vials containing 3 g of oil were placed in a multipurpose sampler (Gerstel, Mülheim, Germany) and headspace volatiles were isolated and extracted using a 50/30 µm DVB/Carboxen/PDMS StableFlex solid phase at 30 • C. Volatiles were separated and identified by gas chromatography combined with a model 5975 B mass spectrometer (Agilent Technologies).…”

Section: Analysis Of Headspace Volatiles By Solid Phase-micro Extract...mentioning

confidence: 99%

Physicochemical properties and volatile formation mechanism of medium‐chain triacylglycerols during heating

Park

Kim

Journal of Food Science

2022

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Medium-chain triacylglycerols (MCTs), including caprylic acid (C8), a mixture of caprylic acid and capric acid (C8+C10), and high-MCT coconut oil (HMCO), were heated at 180 • C. Their volatile profiles were analyzed to determine the MCT degradation mechanisms. As heating time increased to 10 h, secondary oxidation products and acid value of all samples increased continuously. Ketones, alkanes, fatty acid anions, fatty acid esters, and lactones were found in all heated MCTs. 2-Hexanone and heptane were detected in C8 after 2 h of heating, and 2-heptanone, heptanal, methyl octanoate, γ-octalactone, and δoctalactone were detected after 4 h. For the C8+C10, ketones, alkanes, and aldehydes were first observed. Hydrolysis and decarboxylation seem to occur first for ketone and alkane formation. Cracking and cyclization may occur later for fatty acid esters and lactones in heated MCTs. This result can help to understand thermal decomposition mechanisms of saturated fatty acids like MCTs. K E Y W O R D Sdegradation mechanism, medium-chain triacylglycerol, thermal treatment, volatile profile Practical Application: Medium-chain triacylglycerols (MCTs) have been used in cosmetic and fragrance industries due to their high oxidative stability, relatively high polarity, and smooth textures. In addition, MCTs have gained popularity among consumers for their health beneficial effects. MCTs could be used as major continuous phases for many food ingredients receiving high thermal energy for cooking. The results of this study can provide basic and useful information on the physicochemical properties and thermally decomposed volatile profiles from MCTs, which can help to produce stable processed products with lengthy shelf-lives in the food industry.

“…In emulsion systems, the generation of lipid hydroperoxides results in the interaction of oil molecules and water-soluble components that promote lipid oxidation, and TBARSs are formed by the decomposition of lipid hydroperoxides [4]. Transition metals play an important role in the generation and decomposition of lipid hydroperoxides, and transition metals and water play important roles in the decomposition of lipid peroxides [39,40]. Surfactants tend to move on the interfacial film of a single emulsion droplet because of the Gibbs-Marangoni effect [41], resulting in the local stretching and compression of surfactants at the droplet surface.…”

Section: Lipid Oxidation Of Brij Surfactant-stabilized Emulsionsmentioning

confidence: 99%

Influence of Blending of Nonionic Emulsifiers Having Various Hydrophilic Head Sizes on Lipid Oxidation: Investigation of Antioxidant Polarity—Interfacial Characteristics Relationship

Choi

2021

Antioxidants

The purpose of this study was to deliver insights into the effect of interfacial composition and antioxidant polarity on the lipid oxidation of emulsions. Emulsions were created using blends of nonionic ethoxylated fatty acid alcohol surfactants with different hydrophilic head sizes, and lipophilic (TBHQ) and amphiphilic (lauryl gallate) antioxidants were incorporated into the emulsions. At the same surfactant concentration, emulsion stabilized with surfactant with a smaller hydrophilic head was more susceptible to lipid oxidation than that stabilized with surfactant with a larger hydrophilic head. When surfactants with a similar hydrophilic head size were used, lipid oxidation in emulsion containing more surfactant was slightly faster than that containing less surfactant. When emulsions were created with a 1:1 molar ratio mixture of surfactants with small and large hydrophilic heads, surfactant concentration (1.00 and 2.932 mM) had little effect on lipid peroxide generation rate. However, the concentration of thiobarbituric acid-reactive substances (TBARSs) in the emulsion prepared at 1.00 mM increased faster than that prepared at 2.93 mM. Alteration of interfacial composition and surfactant concentration did not affect antioxidant ability, regardless of antioxidant polarity, to inhibit lipid peroxide generation. However, the ability of lauryl gallate and TBHQ to prevent TBARS generation was elevated by mixing surfactants with small and large hydrophilic heads and by decreasing surfactant concentration. In most emulsions, lauryl gallate showed a more effective antioxidant ability than TBHQ.