Download or read book PRO AND ANTIOXIDANT EFFECTS OF PHOSPHOLIPIDS ON LIPID OXIDATION IN BULK OIL written by Leqi Cui and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this thesis is to explore how phospholipids at concentrations similar as in refined vegetable oils impact bulk oil lipid oxidation. The possible formation of association colloids and synergism with primary antioxidants are considered. The results provided a better understanding of the pro- and antioxidant activities of phospholipids. Lipid oxidation leads to quality deterioration by generating off-flavor, nutrient loss, color alteration, texture changes, and even generation of potential toxic products. Phospholipids are important minor components in edible oil that play a role in lipid oxidation. Surface active phospholipids have an intermediate hydrophilicdoubledashlipophilic balance value, which allows them to form association colloids such as reverse micelles in bulk oil. These association colloids can influence lipid oxidation since they create lipiddoubledashwater interfaces where prooxidants and antioxidants can interact with triacylglycerols. In this study, we examined the formation of reverse micelles in a stripped oil system by dioleoyl phosphoethanolamine (DOPE) and the effect of these physical structures on lipidoxidation kinetics. The critical micelle concentration (CMC) of DOPE was approximately 200 [mu]mol/kg oil at 45 °C. Oxidation kinetics studies showed that DOPE was prooxidative when it was above its CMC (400 and 1,000 [mu]M), reducing the lag phase from 14 days (control) to 8 days. The addition of combinations of DOPE and dioleoyl phosphocholine (DOPC) resulted in formation of mixed micelles with a CMC of 80 [mu]mol/kg oil at 45 °C. These mixed micelles were also prooxidative when concentrations (100 and 500 [mu]M) were above the CMC, decreasing the lag phase from 14 to 8 days. DOPC and DOPE reverse micelles were examined on their impacts on the activity of primary antioxidants such as the nonpolar [alpha]-tocopherol and the polar trolox in stripped and commercial soybean oils. The results showed that DOPC reverse micelles decreased the activity of 100 [mu]M [alpha]-tocopherol or trolox. On the other hand, DOPE increased the antioxidant activity of both [alpha]-tocopherol and trolox. The polar trolox exhibited better antioxidant activity than the nonpolar [alpha]- tocopherol in the presence of both DOPC and DOPE reverse micelles because trolox partitioned more at the water-lipid interface, which was confirmed by a fluorescence steady state spectroscopy. Different ratios of DOPE to DOPC were added to oil containing 100 [mu]M [alpha]-tocopherol, and antioxidant activity increased with increasing DOPE/DOPC ratio. Addition of DOPE to commercial oil inhibited lipid oxidation, where as DOPC was ineffective. HPLC showed that DOPE regenerated [alpha]-tocopherol. Overall, these findings provide a better understanding of the role of phospholipids reverse micelles in lipid oxidation in edible oil and indicating that the antioxidant activity of tocopherols could be improved by utilizing phosphatidylethanolamine (PE) to engineer the properties of reverse micelles in bulk oil.
Download or read book Lipid Oxidation written by Edwin N. Frankel and published by Elsevier. This book was released on 2014-01-23 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this second edition, Edwin Frankel has updated and extended his now well-known book Lipid oxidation which has come to be regarded as the standard work on the subject since the publication of the first edition seven years previously. His main objective is to develop the background necessary for a better understanding of what factors should be considered, and what methods and lipid systems should be employed, to achieve suitable evaluation and control of lipid oxidation in complex foods and biological systems. The oxidation of unsaturated fatty acids is one of the most fundamental reactions in lipid chemistry. When unsaturated lipids are exposed to air, the complex, volatile oxidation compounds that are formed cause rancidity. This decreases the quality of foods that contain natural lipid components as well as foods in which oils are used as ingredients. Furthermore, products of lipid oxidation have been implicated in many vital biological reactions, and evidence has accumulated to show that free radicals and reactive oxygen species participate in tissue injuries and in degenerative disease. Although there have been many significant advances in this challenging field, many important problems remain unsolved. This second edition of Lipid oxidation follows the example of the first edition in offering a summary of the many unsolved problems that need further research. The need to understand lipid oxidation is greater than ever with the increased interest in long-chain polyunsaturated fatty acids, the reformulation of oils to avoid hydrogenation and trans fatty acids, and the enormous attention given to natural phenolic antioxidants, including flavonoids and other phytochemicals.
Download or read book Lipid Oxidation written by Amy S. Logan and published by Elsevier. This book was released on 2015-08-15 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lipid oxidation in food systems is one of the most important factors which affect food quality, nutrition, safety, color and consumers’ acceptance. The control of lipid oxidation remains an ongoing challenge as most foods constitute very complex matrices. Lipids are mostly incorporated as emulsions, and chemical reactions occur at various interfaces throughout the food matrix. Recently, incorporation of healthy lipids into food systems to deliver the desired nutrients is becoming more popular in the food industry. Many food ingredients contain a vast array of components, many of them unknown or constituting diverse or undefined molecular structures making the need in the food industry to develop effective approaches to mitigate lipid oxidation in food systems. This book provides recent perspectives aimed at a better understanding of lipid oxidation mechanisms and strategies to improve the oxidative stability of food systems. Five chapters on naturally-derived antioxidants that focus on applications within food systems Contributors include an international group of leading researchers from academic, industrial, and governmental entities Discusses the oxidative stability of enzymatically produced oils and fats Provides overviews on the complexities of lipid oxidation mechanisms, and emulsion systems most suseptible to rapid lipid oxidation
Download or read book Minor Components and Their Roles on Lipid Oxidation in Bulk Oil that Contains Association Colloids written by Bingcan Chen and published by . This book was released on 2012 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combination of water and surface active compounds found naturally in commercially refined vegetable oils have been postulated to form physical structures known as association colloids. This research studied the ability of 1,2-dioleoyl-sn-glycerol-3-phosphocholine (DOPC) and water to form physical structures in stripped soybean oil. Interfacial tension and fluorescence spectrometry results showed the critical micelle concentration (CMC) of DOPC in stripped soybean oil was 650 and 950 microM, respectively. Light scattering attenuation results indicated that the structure formed by DOPC was reverse micelles. The physical properties of DOPC reverse micelles were determined using small-angle X-ray scattering (SAXS) and fluorescence probes. These studies showed that increasing the water concentration altered the size and shape of the reverse micelles formed by DOPC. The impact of DOPC reverse micelles on the lipid oxidation of stripped soybean oil was investigated by following the formation of primary and secondary lipid oxidation products. DOPC reverse micelles had a prooxidant effect, shortening the oxidation lag phase of SSO at 55 °C. It also was not able to change the lipid oxidation of stripped soybean oil compared with DOPC reverse micelles at same concemtration (i.e., 950 microM). 1,2-dibutyl-sn-glycerol-3-phosphocholine (DC4PC) which has the shorter fatty acid than DOPC was not able to form association colloids and did not impact lipid oxidation rates. This indicated that the choline group of the phospholipid was not responsible for the increased oxidation rates and suggested that the physical structure formed by DOPC was responsible for the prooxidant effect. The impact of the DOPC reverse micelles on the effectiveness and physical location of the antioxidants, alpha-tocopherol and Trolox was also studied. Both non-polar (alpha-tocopherol) and polar (Trolox) were able to inhibit lipid oxidation in stripped soybean oil in the presence of DOPC reverse micelles. Trolox was a more effective antioxidant than alpha-tocopherol. Fluorescence steady state and lifetime decay studies suggested that both alpha-tocopherol and Trolox were associated with DOPC reverse micelle in bulk oil. Trolox primarily concentrated in the water pool of reverse micelle since it quenched NBD-PE fluorescence intensity with increasing concentrations. A portion of alpha-tocopherol was also associated with the aqueous phase of the DOPC reverse micelles but this was likely at the oil-water interface since alpha-tocopherol is not water soluble. The addition of ferric chelator, deferoxamine (DFO) to stripped soybean oil significantly prevented the lipid oxidation caused by DOPC reverse micelles as the lag phase was extended from 2 to 7 days. DFO was also found to increase the antioxidant activity of both Trolox and alpha-tocopherol. Trolox and alpha-tocopherol were found to be rapidly decomposed by high-valence Fe(III) while low-valence-state (Fe (II) was much less reactive. Fe(III) was also consumed by both hydrophilic Trolox and lipophilic alpha-tocopherol presumably though reduction to Fe (II). DOPC reverse micelles were able to decrease antioxidants-iron interactions as evidence by a decrease in antioxidant depletion by iron and a decrease in iron reduction by the antioxidants. These results suggested that the ability of DFO to increase the antioxidant activity of alpha-tocopherol and Trolox was due to its ability to decrease free radical production and not its ability to decrease direct iron-antioxidant interactions. Overall, the results presented in this dissertation show phospholipids and water can form reverse micelles in edible oils. These reverse micelles increase lipid oxidation rates by increasing the prooxidant activity of iron. Free radical scavenging antioxidants can inhibit oxidation promoted by the reverse micelles with polar Trolox being more effective than non-polar alpha-tocopherol presumably because Trolox is more highly associated with the reverse micelle. The reverse micelles produced by DOPC protected alpha-tocopherol and Trolox from direct degradation by iron. The knowledge gained from this study will improve our understanding of the mechanism of lipid oxidation in bulk oils which will hopefully provide new technologies to improve the oxidation stability of edible oils. For example, it may be able to use oil refining technologies to remove prooxidative minor components that for physical structure in bulk oils.
Download or read book Utilization of Modified Lecithin to Control Lipid Oxidation in Bulk Oils written by Anuj Shanbhag and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lipid oxidation is a major challenge faced by the food industry since it causes loss of quality in lipid containing foods which results in a decrease of shelf life. In order to delay the oxidation in lipids, food industries make use of antioxidants such as EDTA (ethylene diamine tetraacetic acid), BHA (tbutyl-4-hydroxyanisole), BHT (t-butyl-4-hydroxytoluene), and TBHQ (tert-butyl-hydroxyquinone). However, these antioxidants are chemically synthesized and consumers desire simpler and cleaner labels without artificially synthesized antioxidants. Also, artificially synthesized antioxidants such as t-butyl-4-hydroxyanisole (BHA) can cause cancer in humans. Previous studies have shown that phospholipids such as phosphatidylethanolamine (PE) and phosphatidylcholine (PC) affect the activity of nonpolar antioxidants such as [alpha]-tocopherol in bulk oils. PE when added to stripped soybean oil containing 100 [mu]M of [alpha]-tocopherol was able to improve oxidative stability of the oil. However, PC decreased the activity of [alpha]-tocopherol or had no effect. HPLC demonstrated that tocopherols were regenerated by PE which explains its synergism with [alpha]- tocopherol. This study evaluated the effect of [alpha]-tocopherol with varying levels of PE in stripped soybean oil. vi Additionally, antioxidant activity of [alpha]-tocopherol has been shown to increase with increasing PE/PC ratio in lecithin. This study also examined the possibility of converting PC to PE in egg lecithin which will can be further used with [alpha]-tocopherol. The enzyme phospholipase D was used for the conversion since it has been shown to have transphosphatidylation activity with phospholipids. The synergism of the modified lecithin with [alpha]-tocopherol was analyzed in stripped soybean oil as well as in commercially refined oils. KEYWORDS: phospholipid, antioxidant, lipid oxidation, tocopherols, lecithin.
Download or read book Lipid Oxidation in Health and Disease written by Corinne M. Spickett and published by CRC Press. This book was released on 2015-03-03 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oxidative modification of lipids and phospholipids-including radical damage, halogenation, and nitration-result in significant changes to the chemical properties of the molecules, which in turn have a major effect on their biochemical functions. Lipid oxidation has long been regarded as a deleterious process responsible for lipid rancidity, loss of
Download or read book Lipid Oxidation Pathways written by Afaf Kamal-Eldin and published by AOCS Publishing. This book was released on 2003-08-30 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autoxidation of unsaturated lipids has received much attention because it has many applications in the rancidity of foods and stability of lipids in biological tissues and compartments. This book reviews state-of-the-art developments in the understanding of the oxidation of lipids and its connection with the oxidation of other biological molecules such as proteins and starch. The various chapters illustrate the special features associated with different lipids, antioxidants, reaction conditions, and lipids environments. The material in this book provides a better understanding of lipid oxidation pathways.
Download or read book Lipid Peroxidation written by Angel Catalá and published by Nova Science Publishers. This book was released on 2017 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of lipid peroxidation: inhibition, effects and mechanisms. The topics analyzed, cover a broad spectrum of functions played by lipid peroxidation and presents new information in this area of research. The topics analyzed include: progress in the knowledge of lipid peroxidation, from the first evidences issued by Nicolas Theodore de Saussure in Paris 1804; fighting against lipid peroxidation: the unique story of docosahexaenoic acid in the brain; protective effects of melatonin and structurally-related molecules in reducing membrane rigidity due to lipid peroxidation; synergistic effects of antioxidant compositions during inhibited lipid autoxidation; lipid peroxidation and animal longevity; free radicals in health and disease; lipid peroxidation in autoimmune diseases; aldehydes derived from lipid peroxidation in cancer and autoimmunity; the role of reactive oxygen species and lipid peroxidation in the neurodegenerative process after spinal cord injury; kinetics and mechanisms of inhibited lipid autoxidation in presence of 4-substituted-coumarins; hypoxia and oxidative stress: cell signaling mechanisms and protective role of vitamin C and cilnidipine; characterization of oxidative stress and antioxidant potency; paying attention to time and location; lipid peroxidation in aquatic organisms: ontogenetic, phylogenetic and ecological aspects; chemistry of lipid oxidation in edible oils; and menopause progression and oxidative stress: associated mechanisms and the importance of physical exercise.
Download or read book Frying of Food written by Dimitrios Boskou and published by CRC Press. This book was released on 2016-04-19 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frying of Food is the first reference to examine frying of food from the point of view of changes occurring to biologically-active constituents and the effects of such changes on the stability, performance and nutritive value of frying oil. It focuses on the nature of the frying media and discusses changes to non-glyceride components, especially nu
Download or read book Membrane Lipid Oxidation written by Carmen Vigo-Pelfrey and published by CRC-Press. This book was released on 1990-11-26 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume text compiles the efforts of distinguished scientists nd focuses on the formation of free radicals, toxic effects of lipoperoxides, biological antioxidant protection against lipid peroxidation damage, and pathological implications of lipid peroxidation. This review also addresses vitamin E deficiency, carbon tetrachloride and ethanol poisoning, radiation damage, hyperbaric effects, tumors, aging, diabetes, liver degeneration, DNA damage, lipoprotein modification and artherosclerosis, multiple sclerosis, angiopathy, Parkinson's disease, lupus, and many other degenerative diseases. It is an excellent resource for biological chemist, cell biologists, and all who are interested in the pharmaceutical sciences.
Download or read book Autoxidation of Unsaturated Lipids written by H. W.-S. Chan and published by . This book was released on 1987 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lipid Peroxidation in Biological Systems written by Alex Sevanian and published by The American Oil Chemists Society. This book was released on 1988 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lipid Oxidation in Food and Biological Systems written by Carlos Bravo-Diaz and published by Springer Nature. This book was released on 2022-02-06 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a new physical chemistry perspective on the control of lipid oxidation reactions by antioxidants, and it further explores the application of several oxidation inhibition strategies on food and biological systems. Divided in 3 parts, the book reviews the latest methods to control lipid oxidation, it examines lipid oxidation and inhibition in different food systems, and it finishes with an overview of the biological, health and nutritional effects of lipid oxidation. Chapters from expert contributors cover topics such as the use of magnetic methods to monitor lipid and protein oxidation, the kinetics and mechanisms of lipid oxidation and antioxidant inhibition reactions, interfacial chemistry, oxidative stress and its impact in human health, nutritional, sensory and physiological aspects of lipid oxidation, and new applications of plant and marine antioxidants. While focused on lipid peroxidation in food and biological systems, the chemistry elucidated in this book is applicable also to toxicology, medicine, plant physiology and pathology, and cosmetic industry. The book will therefore appeal to researchers in the lipid oxidation field covering food, biological and medical areas.
Download or read book Lipid Peroxidation written by Angel Catala and published by BoD – Books on Demand. This book was released on 2012-08-29 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to concentrate on recent developments on lipid peroxidation. The articles collected in this book are contributions by invited researchers with a long-standing experience in different research areas. We hope that the material presented here is understandable to a broad audience, not only scientists but also people with general background in many different biological sciences. This volume offers you up-to-date, expert reviews of the fast-moving field of Lipid Peroxidation. The book is divided in four mayor sections: 1-Lipid peroxidation: chemical mechanisms, antioxidants, biological implications; 2-Evaluation of lipid peroxidation processes; 3-Lipid peroxidation in vegetables, oils, plants and meats and 4-Lipid peroxidation in health and disease.
Download or read book Understanding Lipid Oxidation in Low moisture Food written by Leann M. Barden and published by . This book was released on 2014 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-moisture snacks account for much of the saturated fat in the diet, making them a key target for improving consumers' health. However, it is not currently feasible to maintain the same shelf life when replacing saturated fats with unsaturated fats in these products. The first study characterized the microstructure of a low-moisture cracker model system and determined the impact of iron, chelators, and free fatty acids (FFA) on lipid oxidation kinetics. Confocal microscopy showed that lipids form a continuous layer surrounding the small and/or minimally gelatinized starch granules. Lipid-starch, lipid-air, and starch-lipid-protein interfaces all existed. Oxidation studies showed a large difference between the rates of hydroperoxide and headspace hexanal formation in crackers. Crackers containing 10X the usual amount of reduced iron were as oxidatively stable as the control. FFA decreased hexanal lag phases only when added at concentrations greater than 1.0% (w/w) of the total lipid weight. Metal chelators (citric acid, desferoxamine, and ethylenediaminetetraacetic acid) were mildly effective at extending the headspace hexanal lag phage. These results suggested that transition metals were not as strongly prooxidative in the crackers as they are in oil-in-water emulsions and bulk oil. The second study examined antioxidant efficacy in the low-moisture cracker model system. Rosmarinic acid esters of varying polarity exhibited different partitioning behavior (viewed with confocal microscopy) and antioxidant activity. Surprisingly, the 20-carbon ester of rosmarinic acid exhibited the strongest antioxidant activity as determined by lipid hydroperoxides and headspace hexanal generation compared to oil-in-water emulsions where the 20-carbon ester is a very poor antioxidant. Degradation of the 20-carbon ester was slower than the other rosmarinic acid derivative's as determined by HPLC. The activity of the 12-carbon ester of rosmarinic acid varied as a function of how it was added to the cracker model with increased effectiveness observed when the antioxidant was added to the lipid phase prior to formation of the dough. Synthetic, commercial antioxidants followed a similar trend with the most nonpolar being the most effective. This research highlights the need to gain a better understanding of lipid oxidation in low-moisture foods so more effective antioxidant technologies can be developed.
Download or read book Lipid Oxidation in Food written by Allen J. St. Angelo and published by . This book was released on 1992 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed from a symposium at the 202nd National Meeting of the ACS, New York City, August 1991, this volume contains 20 papers in the areas of mechanisms of free-radical processes, prevention of lipid oxidation, methodologies for assessing lipid oxidation products, and processing effects on lipid oxidation. Commodities covered include beef, pork, fresh and saltwater fish, peanuts, vegetable oils, and baby foods. Annotation copyright by Book News, Inc., Portland, OR
Download or read book Lipid Oxidation written by and published by . This book was released on 1986 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
