Lipid oxidation vitamins, control

Control of Lipid Oxidation Vitamins as Natural Antioxidants.391... 

CONTROL OF LIPID OXIDATION VITAMINS AS NATURAL ANTIOXIDANTS... 

Muscle tissues contain a multi-component antioxidant system consisting of lipid-soluble compounds (a-tocopherol, ubiquinone), water-soluble compounds (ascorbate, histidine-dipeptides) and enzymes (superoxide dismutase, catalase, glutathione peroxidase). Lipid oxidation in meats can be effectively controlled by the use of various phenolic compounds derived from spice extracts, by vitamin E supplementation of animal diets, and by processing of cured meat with sodium nitrite. Various natural antioxidant formulations containing mixtures of tocopherols, ascorbyl palmitate and citric acid show synergistic effects in stabilizing cooked and frozen meat. Synthetic antioxidants, BHA, TBHQ, propyl gallate (see Chapter 9) and combinations with citric acid, ascorbic acid or phosphates are also effective formulations used to retard lipid oxidation in... 

Several factors can be manipulated to control and reduce flavor deterioration in meat due to lipid oxidation. Factors related to raw material include vitamin E content and age, while factors related to processing include addition of antioxidants, heat treatment and packaging. Oxidation in meat and other muscle foods is promoted by any processing that disrupts the natural cellular compartmental separation that controls oxidation. Heating and grinding raw meat thus accelerate lipid oxidation. It is therefore important to maintain the integrity of heated meat products to retard flavor deterioration from lipid oxidation. 

Figure 8.1 Metmyoglobin accumulation (a) and lipid oxidation (b) in fresh-ground sirloin beef patties from control and vitamin-E supplemented Holstein steers n = 11 for each group standard error bars are indicated (after Faustman et al. (1989b) with permission).

Ellis et al. [72] recently studied the effects of short- and long-term vitamin C therapy in the patients with chronic heart failure (CHF). It was found that oxygen radical production and TBAR product formation were higher in patients with CHF than in control subjects. Both short-term (intravenous) and long-term (oral) vitamin C therapy exhibited favorable effects on the parameters of oxidative stress in patients the treatments decreased oxygen radical formation and the level of lipid peroxidation and improved flow-mediated dilation in brachial artery. However, there was no correlation between changes in endothelial function and oxidative stress. 

Cystic fibrosis is the most common lethal autosomal-recessive disease, in which oxidative stress takes place at the airway surface [274]. This disease is characterized by chronic infection and inflammation. Enhanced free radical formation in cystic fibrosis has been shown as early as 1989 [275] and was confirmed in many following studies (see references in Ref. [274]). Contemporary studies also confirm the importance of oxidative stress in the development of cystic fibrosis. Ciabattoni et al. [276] demonstrated the enhanced in vivo lipid peroxidation and platelet activation in this disease. These authors found that urinary excretion of the products of nonenzymatic lipid peroxidation PGF2 and TXB2 was significantly higher in cystic fibrotic patients than in control subjects. It is of importance that vitamin E supplementation resulted in the reduction of the levels of these products of peroxidation. Exhaled ethane, a noninvasive marker of oxidative stress, has also been shown to increase in cystic fibrosis patients [277]. 

Moderately thermally oxidized soybean oil (130°C, air flow-through) of peroxide value (PV) = 75 mEq 02/kg diet (compared with the control of 9.5 Eq 02/kg diet) was fed to rats for 40 days (Eder and Kirchgessner, 1999). The study showed no adverse effects on liver, heart, kidney, or adipose tissue FA composition, and even a reduction in the osmotic fragility of erythrocytes and hepatic lipogenesis. However, the moderately oxidized oil slightly reduced the vitamin E status in the tissues. A slightly increased susceptibility of LDL to lipid peroxidation, and an increased concentration of thiobarbituric acid reactive substances (TEARS) in LDL, were also observed. 

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