Chemical changes in β‐Lactoglobulin structure during ageing of protein‐stabilized emulsions

Leaver, J. D.; Law, Andrew J. R.; Brechany, Elizabeth Y.; McCrae, Catharina H.

doi:10.1046/j.1365-2621.1999.00308.x

Cited by 14 publications

(11 citation statements)

References 2 publications

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“…Though purified olive oil, free from oxidation products, was used for emulsion production, fresh emulsions contained about 1.6 mM hydroperoxides. This confirms the pro-oxidative effect of the emulsification process, which induces the oxidation of unsaturated fatty acids and the release of volatiles [ 22 , 23 , 24 , 25 ]. In the first stage of the oxidation test, hydroperoxides underwent a decrease, while the second phase of oxidation was characterized by an increase of hydroperoxides.…”

Section: Resultssupporting

confidence: 64%

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Radical Scavenging Activity of Olive Oil Phenolic Antioxidants in Oil or Water Phase during the Oxidation of O/W Emulsions: An Oxidomics Approach

et al. 2020

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Omics approaches are recently being applied also in food lipid oxidation, to increase knowledge of oxidation and antioxidation mechanisms. The so-called oxidomics throws a wider spot of light on the complex patterns of reactions taking place in food lipids, especially in dispersed systems. This research aimed to investigate the radical scavenging activity of olive oil phenolic antioxidants (OPAs) in O/W emulsions, as affected by the phase in which they were added. This allowed one to assess whether different behaviors could be expected from antioxidants originally present in phenolic-rich olive oils compared to natural antioxidants added in the water phase during emulsion production. Hydroperoxide decomposition kinetics and the analysis of volatile pattern provided an outline of antioxidation mechanisms. Though being effective in slowing down oxidation when added both in the oil and water phase, OPAs interfered in different ways with oxidation pathways, based on the phase in which they were added. OPAs added to the water phase were more effective in slowing down hydroperoxide decomposition due to the hydrophilic radical initiator. On the other hand, OPAs present in the oil were more effective in preventing radical propagation, with relevant consequences on the volatile pattern.

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Section: Resultssupporting

confidence: 64%

“…Proteins in emulsions, and specifically BLG, have been reported to interact with aldehydes. Covalent interactions have been demonstrated to involve a,b-monounsaturated aldehydes [ 22 , 34 ]. Covalent binding of saturated aldehydes is controversial and was reported in aqueous systems and high aldehyde concentrations [ 22 , 34 ].…”

Section: Resultsmentioning

confidence: 99%

Radical Scavenging Activity of Olive Oil Phenolic Antioxidants in Oil or Water Phase during the Oxidation of O/W Emulsions: An Oxidomics Approach

et al. 2020

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“…Differences observed between CD value and hydroperoxides measured by xylenol orange method (results not shown) provide arguments in favor of this explanation. Second, oxygen could be involved in reactions other than CD formation such as oxidation of the protein at the interface induced by lipid free radicals (9,18,19). Finally, one may note that CD value is the result of both CD produced and CD converted into secondary products of oxidation.…”

Section: Resultsmentioning

confidence: 99%

Effect of droplet size on lipid oxidation rates of oil‐in‐water emulsions stabilized by protein

Lethuaut

Métro

Génot

2002

J Americ Oil Chem Soc

165

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In emulsions lipid oxidation is mainly influenced by the properties of the interface. The aim of this work was to investigate the effects of droplet size and interfacial area on lipid oxidation in protein-stabilized emulsions. Emulsions, made of stripped sunflower oil (30% vol/vol) and stabilized by BSA were characterized by surface area values equal to 0.7, 5.1, and 16.3 m 2 ·cm −3 oil. The kinetics of O 2 consumption and conjugated diene (CD) formation, performed on emulsions and nonemulsified controls, showed that emulsification prompted oxidation at an early stage. On condition that oxygen concentration was not limiting, the rates of O 2 consumption and CD formation were higher when the interfacial area was larger. Protein adsorbed at the interface probably restrained this pro-oxidant effect. Once most of the O 2 in the system was consumed (6-8 h), CD remained steady at a level depending directly on the ratio between oxidizable substrate and total amount of oxygen. At this stage of aging, the amounts of primary oxidation products were similar whatever the droplet size of the emulsion. Hexanal and pentane could be detected in the headspace of emulsions only at this stage. They were subsequently produced at rates not depending on oil droplet size and interfacial area.Paper no. J10026 in JAOCS 79, 425-430 (May 2002).KEY WORDS: Conjugated dienes, droplet size, interfacial area, lipid oxidation in emulsions, oxygen, protein, volatile compounds.Many foods are oil-in-water emulsions stabilized by protein and lipid surfactants in a protein or polysaccharide matrix. In these systems, oxidation of unsaturated FA leads to the formation of volatile compounds, which are major contributors to the aroma or to undesirable off-odors and off-flavors (1). Oxidation in bulk and emulsified oils is influenced by several common factors, but additional factors are important in emulsions (2). These include the structure of the emulsions and the physicochemical properties of the aqueous phase and of the droplet membrane. The size of the oil droplets is often claimed as an important factor. On one hand, small droplet size signifies a large surface area, implying a high potential of contact between diffusing oxygen, water-soluble free radicals and antioxidants, and the interface. It also implies a high ratio of oxidizable FA located near the interface to FA embedded in the hydrophobic core of the droplets (3). Decreasing the size of the oil droplets is therefore expected to favor development of oxidation. On the other hand, when the droplet size decreases, the number of lipid molecules per droplet diminishes and the amount of surface-active compounds adsorbed at the interface is increased. This could limit initiation and propagation, as surface-active compounds may act as a barrier to the penetration and diffusion of pro-oxidants or even interfere with oxidation. For instance, homogenization is reported to protect milk fat from oxidation catalyzed by metal complexes (4) because casein, which adsorbs to the droplet surface, is an efficie...

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“…Finally, as previously mentioned, adsorbed proteins undergo extensive oxidative modifications upon aging of an emulsion (Leaver and others ; Rampon and others ; Hidalgo and Zamora ; Dalsgaard and others ; Mestdagh and others ). Protein modifications may even precede lipid oxidation (Østdal and others ; Salminen and others ; Berton and others ).…”

Section: Interfacial Properties Affecting Lipid Oxidation In Emulsionsmentioning

confidence: 89%

Lipid Oxidation in Oil‐in‐Water Emulsions: Involvement of the Interfacial Layer

Berton‐Carabin

Ropers

Génot

2014

Comp Rev Food Sci Food Safe

473

372

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More polyunsaturated fats in processed foods and fewer additives are a huge demand of public health agencies and consumers. Consequently, although foods have an enhanced tendency to oxidize, the usage of antioxidants, especially synthetic antioxidants, is restrained. An alternate solution is to better control the localization of reactants inside the food matrix to limit oxidation. This review establishes the state-of-the-art on lipid oxidation in oil-in-water (O/W) emulsions, with an emphasis on the role of the interfacial region, a critical area in the system in that respect. We first provide a summary on the essential basic knowledge regarding (i) the structure of O/W emulsions and interfaces and (ii) the general mechanisms of lipid oxidation. Then, we discuss the factors involved in the development of lipid oxidation in O/W emulsions with a special focus on the role played by the interfacial region. The multiple effects that can be attributed to emulsifiers according to their chemical structure and their location, and the interrelationships between the parameters that define the physicochemistry and structure of emulsions are highlighted. This work sheds new light on the interpretation of reported results that are sometimes ambiguous or contradictory.

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Chemical changes in β‐Lactoglobulin structure during ageing of protein‐stabilized emulsions

Cited by 14 publications

References 2 publications

Radical Scavenging Activity of Olive Oil Phenolic Antioxidants in Oil or Water Phase during the Oxidation of O/W Emulsions: An Oxidomics Approach

Radical Scavenging Activity of Olive Oil Phenolic Antioxidants in Oil or Water Phase during the Oxidation of O/W Emulsions: An Oxidomics Approach

Effect of droplet size on lipid oxidation rates of oil‐in‐water emulsions stabilized by protein

Lipid Oxidation in Oil‐in‐Water Emulsions: Involvement of the Interfacial Layer

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