Oxidants and Antioxidants
P. K. Shah in Risk Factors in Coronary Artery Disease, 2006
As the process of atherosclerosis continues, fatty streaks develop into fibromuscular plaques. The initial step in this transition is the phenotypic modulation of contractile smooth muscle cells of the media into synthetically active repair cells. The mechanisms involved in activation of this modulation remain to be fully understood, but they appear to involve degradation of the extracellular matrix surrounding the smooth muscle cells by proteases released from inflammatory cells. Accordingly, inflammation has a key role in activation of the vascular fibroproliferative process. This is not surprising since inflammation is the general signal for repair after any tissue injury. Again, lipid oxidation may influence this process primarily by causing injury and inflammation.
Antibacterial Activity of Seaweeds and their Extracts
Leonel Pereira in Therapeutic and Nutritional Uses of Algae, 2018
Moroney et al. (2015) reported an enhancement of pork quality in meat from pigs fed extracts of Laminaria digitata containing laminarin and fucoidan for three weeks prior to slaughter. Animals were fed either 450 mg or 900 mg laminarin and fucoidan per kg feed. In both cases, pork meat was found to have an improved fatty acid profile without loss of lipid stability. Saturated fatty acid content was significantly lowered and lipid oxidation was reduced. Aquaculture food products can be a source of food-borne pathogenic and spoilage bacteria. Vibrio genera are a common source of food-borne illness in fish products. Seaweeds have been shown to have antibacterial properties against many species that infect farmed fish, which in turn reduces the occurrence of pathogenic bacteria in the final food product (Vatsos and Rebours 2015).
Processing of Native Plant Foods and Ingredients
Yasmina Sultanbawa, Fazal Sultanbawa in Australian Native Plants, 2017
The value of natural additives in the food and beverage industry is estimated to increase to 45 USD billions in the global market; this figure includes vitamins, minerals and functional food ingredients according to Leatherhead’s Global Food Additives Market report, 2014. A certain growth percentage of this industry is attributed to consumer’s concerns of possible toxic effects from synthetic additives such as antioxidants, chemical preservatives and colouring agents. As an example: alternative methods to retard lipid oxidation in foods have increased the need for natural antioxidants. Sources of these natural antioxidants include the use of herbs, spices, fruits, vegetables and by-products from the food industry. It is well known that the additive and synergistic effects of the complex phytochemical mix present in these plant sources are responsible for their enhanced antioxidant activity (Neacsu et al., 2015). Recent publications (Konczak et al., 2009, 2010b; Sakulnarmrat and Konczak, 2012) have reported about the high antioxidant capacities of commercially grown Australian native plant foods which are far greater than those previously reported for blue berries, well known for its high antioxidant levels. The enhanced antioxidant capacity of native plant foods such as Kakadu plum is mainly attributed to the high levels of vitamin C and phenolic compounds (Konczak et al., 2009).
Production of rice bran oil (Oryza sativa L.) microparticles by spray drying taking advantage of the technological properties of cereal co-products
Published in Journal of Microencapsulation, 2022
Nathan H. Noguera, Dyana C. Lima, José Claudio Klier Monteiro Filho, Rodney A. F. Rodrigues
There are several reactional mechanisms of lipid oxidation, generally divided into initiation, propagation, and termination phases. Thus, one of the linoleic acid oxidation pathways can be described as follows: a hydrogen is abstracted from the pentadiene system of linoleic acid, producing the alkyl radical (L •), which combines with oxygen (O2) to form the pexoryl radical (LOO •); then, the peroxyl radical is attacked by another hydrogen, producing 13-hydroperoxide (LOOH), which has its O–OH bond fissioned, resulting in the alkoxyl radical (LO •); finally, β-cleavage occurs at the acid terminal of the alkoxyl radical, producing the hexanal as the main final product (Damodaran and Parkin 2017). Hexanal is considered one of the most volatile and the easiest to detect by gas chromatography/headspace. In advance, unlike most authors, our results indicated that particles with higher surface oil content were the ones that presented the best stability.
Antioxidant and antihyperlipidemic activities of catechol derivatives and biflavonoid isolated from Semecarpus anacardium seeds
Published in Toxicology Mechanisms and Methods, 2022
Ramalingam Sundaram, Karuppiah Muthu, Palanivelu Shanthi, Panchanatham Sachdanandam
In healthy individuals, there is an equilibrium between the natural antioxidative defence system and the reactive oxygen species (ROS), generated from both living organisms and exogenous sources. When the equilibrium is disrupted the ROS can induce oxidative damage to various biomolecules, including; protein, lipid, DNA and RNA in the human body associated with lipid and protein peroxidation, cell structural damage, tissue injury or gene mutation (Velazquez et al. 2005). This oxidative damage is considered to play a causative role in aging, as well as several degenerative diseases, such as heart disease, hypertension and cancer (Halliwell and Gutteridge 1984). On the other hand, lipid oxidation initiated by free radicals is one of the major factors for food deterioration during processing and storage (Thitilertdecha et al. 2008). In order to protect foods and human beings against oxidative damage caused by free radicals, synthetic antioxidants such as butylated hydroxyl anisole (BHA) and butylated hydroxyl toluene (BHT) were created because of demand (Moure et al. 2001). However, consumers’ concern has come to focus on the toxicity and potential health hazards of synthetic antioxidants.
Oxidative stress tolerance and antioxidant capacity of lactic acid bacteria as probiotic: a systematic review
Published in Gut Microbes, 2020
Lipid peroxidation is the best-studied biologically relevant free-radical chain reaction. Although lipid peroxidation generally occurs late in the oxidative damage process, after damage of proteins and DNA,182 lipid peroxidation detection is among the assays the most commonly used to assess the dynamics of isolated redox processes.162 The extent of lipid oxidation can be determined by measuring the loss of unsaturated fatty acids or the amount of peroxidation products.182 Several assays are available to measure lipid peroxidation; however, as with other free-radical assays, no single method can accurately account for the entire process. Thiobarbituric acid (TBA) and diene-conjugate assays are relatively simple, but nonspecific assays. In probiotic research, the TBA assay is one of the methods the most commonly used to evaluate antioxidant capacity. The suppression of lipid peroxidation by several L. acidophilus and B. longum strains was measured using the TBA method, and the result was confirmed by detecting the lipid peroxidation product-scavenging ability.183 Noureen and colleagues measured the levels of lipid peroxidation inhibition of 16 LAB strains from different sources using the TBA assay to compare their antioxidant potential.72 They found that intact cells (47–82.38%) and culture supernatants (41–74.34%) showed higher lipid peroxidation inhibition activity than did cell lysates (10–48.92%).72
Related Knowledge Centers
- Fatty Acid
- Hydroxyl Radical
- Reactive Oxygen Species
- Cell Membrane
- Lipid
- Redox
- Radical
- Polyunsaturated Fat
- Methylene Bridge
- Hydrogen