Antioxidant release

Later studies from Japan showed beneficial effect of antioxidants-releasing BiodivYsio stent. Carvedilole and prombucole were induced in porcine coronary arteries. 

Other additives to be used in food packaging include ethylene scavengers (e.g., potassium permanganate) on silica, CO2 scavenger (e.g., calcium hydroxide reacting to calcium carbonate), and CO2- generating additives (e.g., ferrous carbonate). Further additives to be used for content protection incorporated in plastics provide antimicrobial effects, for example, silver or ethanol release, antioxidant release, flavor release, flavor absorption, and moisture control [66]. 

Hazardous Decomp. Prods. Heated to decomp., emits acrid smoke and irritating fumes Uses Crystallization inhibitor, sequestrant, antioxidant, release agent in foods defoamer for beet sugar and yeast processing in paper/paperboard in contact with aq./fatty foods... 

Extruded PLA films containing flavonoids like catechin and epicatechin were prepared as a vehicle for the antioxidant release into food. The release kinetics into ethanol 95% was estimated at 20, 30, 40 and 50 °C, displaying Fickian behaviour with diffusion coefficients in the 10 cm s range. The antioxidant activity of the films was also measured, after extraction with... 

Antioxidant release. Although permitted antioxidants such as BHA and BHT are normally added directly to the food, the packaging material, such as wax-coated paper, has sometimes been used as a reservoir for delivery by the vapour phase in the US cereal industry (Labuza and Breene, 1989). 

Antioxidant releasing BHA/BHT, TBHQ, vitamin C or E. Cellulose acetate films... 

Applications. These materials are stiU in developmental infancy. Current production is limited to one commercial process in Europe and a demonstration-scale process in North America. The lignins produced in these processes have potential appHcation in wood adhesives, as flame retardants (qv), as slow-release agents for agricultural and pharmaceutical products, as surfactants (qv), as antioxidants (qv), as asphalt extenders, and as a raw material source for lignin-derived chemicals. 

The effects of release additives on bulk properties must also be carefully considered, particularly with integral additives to plastics. Eor example, partial solubiHty usually confers some plastici2ing effect. This may improve impact strength but could reduce the heat distortion temperature. Some release additives such as metallic soaps have secondary antioxidant and heat-stabiH2er benefits. Such effects are exploited in multipurpose formulations. 

Meat Products. Citric acid is used in cured meat products to increase the effectiveness of the antioxidant preservatives, as a processing aid, and a texture modifier. It is often encapsulated and released at a specific temperature from a controlled release matrix. 

Gene regulation by tocopherols has mainly been associated with PKC because of its deactivation by a-tocopherol and its contribution in the regulation of a number of transcription factors (NF-kappaB, API). A direct participation of the pregnane X receptor (PXR)/ retinoid X receptor (RXR) has been also shown. The antioxidant-responsive element (ARE) and the TGF-beta-responsive element appear in some cases to be implicated as well. The obser ved immunmodulatory function of a-tocopherol may also be attributed to the fact that the release of the proinflammatory cytokine interlukin-l 3 can be inhibited by a-tocopherol via... 

Figure 45-6. Interaction and synergism between antioxidant systems operating in the lipid phase (membranes) of the cell and the aqueous phase (cytosol). (R-,free radical PUFA-00-, peroxyl free radical of polyunsaturated fatty acid in membrane phospholipid PUFA-OOH, hydroperoxy polyunsaturated fatty acid in membrane phospholipid released as hydroperoxy free fatty acid into cytosol by the action of phospholipase Aj PUFA-OH, hydroxy polyunsaturated fatty acid TocOH, vitamin E (a-tocopherol) TocO, free radical of a-tocopherol Se, selenium GSH, reduced glutathione GS-SG, oxidized glutathione, which is returned to the reduced state after reaction with NADPH catalyzed by glutathione reductase PUFA-H, polyunsaturated fatty acid.)...

Fig. 2.2 Simplified scheme of oxidant/antioxidant regulation ofNF-KB activation. Different stimuli, leading to an increase of ROS generation inside the ceU, activate the phosphorylation of IkB inhibitory protein and the subsequent proteolysis. Thioredoxin (Trx) may reduce activated NF-kB proteins facilitating nuclear translocation.Qnce released from IkB, the NF-kB complex translocates into the nucleus and the binding to DNA domain in the promoters and enhancers of genes such as TNF-a, IL-1, proliferation and chemotactic factors, adhesion molecule. Some of these genes, in turn, may further induce NF-kB activation, leading to a vicious circle if the regulatory cellular system escapes from...

Meat products have to be stabilised in some cases, as meat lipids contain no natural antioxidants or only traces of tocopherols. Most muscle foods contain, however, an efficient multi-component antioxidant defence system based on enzymes, but the balance changes adversely on storage. The denaturation of muscle proteins is the main cause of the inbalance as iron may be released from its complexes, catalysing the lipid oxidation. Salting contributes to the negative effects of storage, as it enhances oxidation. Using encapsulated salt eliminates the deleterious effect of sodium chloride. 

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