Phospholipids in foods: prooxidants or antioxidants? Cui, Leqi; Decker, Eric A
Journal of the Science of Food and Agriculture/Journal of the science of food and agriculture,
15 January 2016, Letnik:
96, Številka:
1
Journal Article
Overly high intake of saturated fat is an international problem contributing to global health issues. Low-moisture snacks account for a nutritionally significant proportion of the saturated fat in ...the diet, making these foods a key target for improving consumers' health. However, it is not currently feasible to maintain the same oxidative shelf life when replacing saturated fats with unsaturated fats, which are generally perceived to be more heart-healthy. This article summarizes current theories and available research on lipid oxidation in low-moisture foods in order to lay the groundwork for new lipid oxidation rate-reduction strategies. Research deficits needing attention and new methods for assessing lipid oxidation in low-moisture foods are also discussed.
Plant lipids are stored as emulsified lipid droplets also called lipid bodies, spherosomes, oleosomes or oil bodies. Oil bodies are found in many seeds such as cereals, legumes, or in microorganisms ...such as microalgae, bacteria or yeast. Oil Bodies are unique subcellular organelles with sizes ranging from 0.2 to 2.5 μm and are made of a triacylglycerols hydrophobic core that is surrounded by a unique monolayer membrane made of phospholipids and anchored proteins. Due to their unique properties, in particular their resistance to coalescence and aggregation, oil bodies have an interest in food formulations as they can constitute natural emulsified systems that does not need the addition of external emulsifier. This manuscript focuses on how extraction processes and other factors impact the oxidative stability of isolated oil bodies. The potential role of oil bodies in the oxidative stability of intact foods is also discussed. In particular, we discuss how constitutive components of oil bodies membranes are associated in a strong network that may have an antioxidant effect either by physical phenomenon or by chemical reactivities. Moreover, the importance of the selected process to extract oil bodies is discussed in terms of oxidative stability of the recovered oil bodies.
Mechanisms of lipid oxidation in food dispersions Waraho, Thaddao; McClements, D. Julian; Decker, Eric A.
Trends in food science & technology,
2011, 2011-01-00, 20110101, Letnik:
22, Številka:
1
Journal Article
Recenzirano
As the continues to improve the nutritional content of their products, challenges in prevention of rancidity have increased due to the presence of more polyunsaturated fatty acids. In addition, ...consumer demand for all natural foods has limited the use of traditional methods to control lipid oxidation such as synthetic antioxidants and hydrogenation. To overcome these challenges a better understand the mechanisms of lipid oxidation are needed so that novel antioxidant technologies can be developed. Lipids in foods often exist as dispersions stabilized by emulsifiers that provide physical stability. Food emulsions contain an oil-water interface that has major impact on the lipid oxidation pathways by influencing the location and reactivity of prooxidative transition metals, lipid hydroperoxides, minor lipid components, free radical scavengers and metal chelators. Understanding how the physical properties of the lipid–water or lipid–air interface in food dispersions impacts oxidation chemistry has lead to new strategies to create lipid structures that slow down the development of rancidity by decreasing interaction between lipids in the emulsion droplet core with prooxidants and oxygen as well as increasing antioxidant concentrations at the site of oxidation.
Lipid oxidation is a major cause of quality deterioration in food products. In these foods, lipids are often present in a bulk or in emulsified forms. In both systems, the rate, extent and pathway of ...oxidation are highly dependent on the presence of colloidal structures and interfaces because these are the locations where oxidation normally occurs. In bulk oils, reverse micelles (association colloids) are present and are believed to play a crucial role on lipid oxidation. Conversely, in emulsions, surfactant micelles are present that also play a major role in lipid oxidation pathways. After a brief description of lipid oxidation and antioxidants mechanisms, this review discusses the current understanding of the influence of micellar structures on lipid oxidation. In particular, is discussed the major impact of the presence of micelles in emulsions, or reverse micelles (association colloids) in bulk oil on the oxidative stability of both systems. Indeed, both micelles in emulsions and associate colloids in bulk oils are discussed in this review as nanoscale structures that can serve as reservoirs of antioxidants and pro-oxidants and are involved in their transport within the concerned system. Their role as nanoreactors where lipid oxidation reactions occur is also commented.
The antioxidant interactions between α-tocopherol and myricetin in stripped soybean oil-in-water emulsions at pH 4.0 and pH 7.0 were analyzed. At pH 7.0, α-tocopherol (α-TOC):myricetin (MYR) ratios ...of 2:1 and 1:1 yielded interaction indices of 3.00 and 3.63 for lipid hydroperoxides and 2.44 and 3.00 for hexanal formation, indicating synergism. Myricetin’s ability to regenerate oxidized α-tocopherol and slow its degradation was identified as the synergism mechanism. Antagonism was observed at pH 4.0 due to high ferric-reducing activity of myricetin in acidic environment. The interaction between α-tocopherol and taxifolin (TAX) was also investigated due to structural similarities of myricetin and taxifolin. α-Tocopherol and taxifolin combinations exhibited antagonism at both pH 4.0 and pH 7.0. This was associated with taxifolin’s inability to recycle α-tocopherol while still increasing the prooxidant activity of iron. The combination of α-tocopherol and myricetin was found to be an excellent antioxidant strategy for oil-in-water emulsions at pH values near neutrality.
Biological Implications of Lipid Oxidation Products Vieira, Samantha A.; Zhang, Guodong; Decker, Eric A.
JAOCS, Journal of the American Oil Chemists' Society,
March 2017, Letnik:
94, Številka:
3
Journal Article, Book Review
Recenzirano
Essentially all fat-containing foods have the potential to undergo lipid oxidation even where unsaturated fatty acid compositions are low. Therefore, consumption of lipid oxidation products is ...potentially common with risk of consuming lipid oxidation products increasing in foods with high amounts of unsaturation (e.g. foods with omega-3 fatty acids), foods subjected to extensive thermal processing (e.g. fried foods), or food high in pro-oxidants (e.g. meats). Lipid oxidation generates potentially toxic products that have shown correlation with inflammatory diseases, as well as cancer, atherosclerosis, aging, etc. These potentially toxic products can enter the body through the diet and can develop
in vivo
during the digestion of lipids. Oxidation products can be absorbed into the blood and in some cases transported to tissues. The aim of this manuscript is to review how potentially toxic lipid oxidation products are formed and evaluate their potential to impact health. While lipid oxidation produces literally hundreds of oxidation products, this review focused on acrolein, 4-hydroxy-
trans
-nonenal, 4-hydroxy-
trans
-hexanal, crotonaldehyde, malondialdehyde, and cholesterol as they are the most reactive oxidation products and also the most studied.
The susceptibility of food oil to quality loss is largely determined by the presence of oxygen. This article reviews the current understanding concerning the effect of oxygen types, location, and ...concentration on the oxidative stability of foods. It also discusses the major factors that influence the interaction between oxygen and lipids such as antioxidants, prooxidants, reactive oxygen species (ROS), environmental conditions, and oxygen scavengers. Research has shown that the amount of oxygen needed to cause oxidation is generally very small and that by reducing oxygen concentration in containers to less than 2%, oxidative stability can be greatly enhanced. However, very few studies have systematically examined the oxygen levels needed to reduce, or inhibit, lipid oxidation processes. Thus, a more comprehensive understanding of the relationship between oxygen levels and lipid oxidation is necessary for the development of innovative antioxidant solutions and package designs that prolong the quality of foods containing lipids.
Antioxidant Activity of Proteins and Peptides Elias, Ryan J; Kellerby, Sarah S; Decker, Eric A
Critical reviews in food science and nutrition,
05/2008, Letnik:
48, Številka:
5
Journal Article
Recenzirano
Proteins can inhibit lipid oxidation by biologically designed mechanisms (e.g. antioxidant enzymes and iron-binding proteins) or by nonspecific mechanisms. Both of these types of antioxidative ...proteins contribute to the endogenous antioxidant capacity of foods. Proteins also have excellent potential as antioxidant additives in foods because they can inhibit lipid oxidation through multiple pathways including inactivation of reactive oxygen species, scavenging free radicals, chelation of prooxidative transition metals, reduction of hydroperoxides, and alteration of the physical properties of food systems. A protein's overall antioxidant activity can be increased by disruption of its tertiary structure to increase the solvent accessibility of amino acid residues that can scavenge free radicals and chelate prooxidative metals. The production of peptides through hydrolytic reactions seems to be the most promising technique to form proteinaceous antioxidants since peptides have substantially higher antioxidant activity than intact proteins. While proteins and peptides have excellent potential as food antioxidants, issues such as allergenicity and bitter off-flavors as well as their ability to alter food texture and color need to be addressed.
