Antioxidant substances

In animals it is clear that both endogenous and exogenous ROS can produce acute injury to pulmonary cells in vitro and in vivo, and that a variety of antioxidant substances can reduce such damage. However, although... 

Figure 22 Meaning of technological variants for the gain of antioxidant substances in red wine. A, Heating of the mash for 2 h at 60°C B, immediately pressed different duration of mash storage C, 2 days D, 3 days E, 7 days F, 10 days.

Anti-foaming agent Antioxidant Substance which prevents or reduces foaming Substance which prolongs the shelf life of foodstuffs by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes... 

Antioxidant. Substances that retard or inhibit autoxidation at moderate temperatures and pressures. Commonly Icnown, commercial antioxidants are aromatic amines, alkylated phenols, cresols, and hydroquinones. 

The provision of fat-soluble vitamins and lipids is difficult, if not impossible, in various diseases. This is especially true for diseases that are accompanied by a lot of oxidative stress, for example, mucoviscidosis. The requirements of fat-soluble antioxidative substances are certainly high in these cases and can barely be covered by intramuscular injections because fat-soluble vitamins can hardly, if at all, be absorbed from oily preparations. Alternatively, the vitamins can administered via the buccal mucosa the fat-soluble substances have to be packaged in such a way that they can be transported in a watery compartment and are thus able to largely dissolve in the saliva. When they have an adequate size, they can then penetrate the buccal mucosa. One approach is the development of the so-called nanocolloids, that is, particles with a polar nucleus, in which the fat-soluble vitamin is dissolved, and an apolar wrapping (monolayer). This structure makes an oral application of fat-soluble substances possible. First tests demonstrated that vitamin A palmitate, a-tocopherol, as well as coenzyme Qio are thus able to enter the systemic circulation via the buccal mucosa. 

Phenolic and antioxidant substances have usually studied in red wines, however, recently, interest has increased in the study of bioactive phenolics in white wines Frega et al. [374] isolated and measured concentration of ethyl caffeoate in Verdicchio white wine by HPLC-tandem-mass spectrometry (HPLC-ESI-MS/MS) and they also determined its effects on hepatic stellate cells and intracellular peroxidation. The resnlts were interesting in the light of other studies demonstrating the relationship between reactive oxygen species, chronic liver injury, and hepatic fibrosis. 

Peptides derived from fish proteins have shown the ability of exerting potent antioxidative activities (Table 15.1) in different oxidative systems (Rajapakse et ah, 2005). Currently, an increasing interest exists to explore natural antioxidative substances without side effects and the identified antioxidative activities have potential to develop safe and nonhazardous natural antioxidants for the complications arose from oxidation of biomolecules. Je et ah (2007) purified an antioxidative peptide from tuna backbone protein and identified as VKAGFAWTANQQLS (1519Da) which was very important regarding the functional foods. It was reported that the derived peptides were good radical scavengers and antioxidant. 

LDL becomes oxidized in vivo. There is evidence that LDL is protected against oxidation in plasma by water-soluble antioxidative substances, such as ascorbic acid, uric acid, or bilirubin. Thus, it is likely that the majority of oxidative modification of LDL occurs in the artery wall, where LDL is largely isolated from the plasmatic antioxidants. Recent evidence suggests that metal ions (copper or iron) and the enzymes myeloperoxidase and lipoxygenase play major parts in the modification of LDL [161]. 

Recently, Maruta et al. [112] have found that methanol extracts of roots of burdock show a significant antioxidant activity in an in vitro lipid peroxidation assay, and have isolated five caffeoylquinic acid derivatives (CQAs) from the roots of burdock (Arctium lappa L ), an edible plant in Japan. Antioxidant activities of DCQAs and related compounds have been investigated by measuring the hydroperoxidation of methyl linolate via radical chain reaction. This study indicates that in this particular system caffeic acid and CQAs are more effective than a-tocopherol. These results approximately agree with our findings [38], Additionally, CQAs as the principle antioxidative substance in burdock root have been characterized. 

Uses Aniline is an oily liquid used in the manufacture of dyestuffs, intermediates for dyestuffs, and manufacture of rubber accelerators and antioxidant substances. Aniline has been extensively used as an intermediate in the manufacture of plastics, pharmaceuticals, pesticides, isocyanates, and hydroquinones. Occupational exposure to aniline is extensive and as diverse as its industrial uses. Workers associated with the manufacturing of acetanalide bromide, coal tar, colors and dyes, leather, disinfectants, nitraniline, perfumes, rubber, and photographic materials become victims of adverse effects from aniline. 

Alternatively, unroasted sesame seeds are pressed once followed by solvent extraction to recover the oil from residue. The oxidative stability of sesame oil was found to be dependent on the extraction method and seed pretreatment (64). Extraction of the sesame seeds after effective seed crushing with polar solvent, heptane-isopropanol (3 1, v/v), would yield a more stable oil from whole sesame seeds because more antioxidative substances and phospholipids could be extracted. Phospholipids may act as synergists to antioxidants (81). 

In many cases, the described health effect is antioxidative. Antioxidative properties of a food ingredient can influence different health-related effects in the body. The energy metabolism in our body cells is based on oxidation, which can also lead to the formation of unwanted substances, e.g. free radicals. Antioxidants protect the cells from such damage. The health effect of antioxidative substances varies, among others, from cardiovascular protection to cancer prevention and strengthening of the immune system. 

The opposite must be said in the case of alcoholic beverages. Experimental results did not indicate that they might play a role in the potentiation of cancer risk. This notion was somehow supported by the epidemiological studies carried out in France, which lead to the discovery of the so-called French paradox. Contrary to the common belief among this country s population, despite high alcohol intake, the frequency of heart failures and possibly also tumor incidence is lower than that in other states. Currently, it is postulated that antioxidant substances present in colored alcoholic beverages and particularly abundant in red wine (Figure 14.1) offer such protection. 

The free-radical-scavenging activity of compounds was evaluated in the TEAC and CL assays. The first measures the relative abiUty of antioxidant substances to scavenge the radical cation 2,2 -azinobis(3-ethylbenzothiozoline-6-sulfonate) (ABTS" ) as compared to a standard amount of the synthetic antioxidant Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid). The CL assay measures the inhibition of iodophenol-enhanced chemiluminescence by a horseradish peroxidase/perborate/luminol system. Trolox was used as the reference antioxidant. The results showed that xanthones exhibited free-radical-scavenging activity at potency levels comparable to those of reference antioxidant compounds quercetin and rutin, while the benzophenone and phloroglucinol type compoimds had more moderate activities [87]. 

Although the term lipoprotein can describe any protein that is covalently linked to lipid groups (e.g., fatty acids or prenyl groups), it is most often used for a group of molecular complexes found in the blood plasma of mammals (especially humans). Plasma lipoproteins transport lipid molecules (triacylglycerols, phospholipids, and cholesterol) through the bloodstream from one organ to another. Lipoproteins also contain several types of lipid-soluble antioxidant molecules (e.g., a-tocopherol and several carotenoids). (The function of antioxidants, substances that protect biomolecules from free radicals, is described in Chapter 10.) The protein components of lipoproteins are called apolipoproteins or apoproteins. 

Many of the therapeutic effects of curcumin are attributed to its strong antioxidant property. Most natural antioxidative compounds can be classified into two types phenolic compounds and 3-diketone compounds [17]. Sesaminol from sesame belongs to the former type, and n-tritriacontan-16,18-dione from the leaf wax of Eucalyptus belongs to the latter type. However, few antioxidative substances possess both phenolic hydroxy and /3-diketone groups in one molecule, and curcumin has both features. 

Antioxidant Substance that slows or stops oxidation. In herbalism, specifically one that slows the formation of free-radicals. 

CFR allowed the use of malic acid in foodstuffs as an acidifier, aroma enhancer, and pH regulator. Malic acid also contributes to the non-browning of fruits and acts synergistically with antioxidant substances. ... 

The approval of an antioxidant for food use requires extended toxicological studies that consist of studies for possible transformation, carcinogenic, and teratogenic effects. Finally, there are some antioxidant substances that have been recognized as safe (GRAS). 

Antioxidants Substances that at low concentrations than those of an oxidizable biochemical substrate markedly delay or prevent oxidation of this substrate [67]. Their behavior could be ascribed to scavenging reactive radicals and chelation of redox-active metals, particularly iron and copper. The most active and evaluated dietary antioxidants belong to the family of phenolic and polyphenolic compounds. 

Basically, the active packaging is able to interact with the inner atmosphere of the package. The declared aim is the modification of packaged products and related headspaces by means of antimicrobial and/or antioxidant substances. This alteration tends to improve the shelf life and other important features (colour, smell, texture). 

A mixture of emulsifiers can improve the stability of colloid food systems by strengthening the film membrane and by interaction between emulsifiers at the interface. Combinations of oil-soluble and water-soluble surfactants (Spans and Tweens) are often used in food formulations to produce more stable oil-inwater emulsions. Mixtures of phospholipids and proteins in foods undergo complex interactions during various thermal processing that can either promote or retard oxidation. At elevated temperatures phospholipids can produce antioxidant substances by the browning reaction, and proteins can denature to release reducing sulfhydryl groups that increase the oxidative stability of heated foods (e.g. evaporated milk). 

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