Thiobarbituric acid reacting substances

Plasma total thiobarbituric acid-reacting substances (TEARS) ... 

Oleuropein 10" M delayed the fall of vitamin E and the formation of TEARS (thiobarbituric acid reacting substances, an index of lipid peroxidation), and the accumulation of lipid hydroperoxides in human LDL oxidized with CuS04 [68]. Other compounds were shown to... 

Frankfurters containing 3.3% sodium lactate were also found to have lower microbial counts for lactic acid bacteria than those of a control (Murano and Rust, 1995). Frankfurters manufactured with potassium sorbate and sodium benzoate, at 0.05% and 1.0%, were compared with those containing 3.3% sodium lactate. After addition of 3.3% sodium lactate to the sausage formulations, decreased TBARS (thiobarbituric acid reacting substances) values were found. Storage time was found to affect the product quality and resulted in decreases in textural properties (Choi and Chin, 2003). 

Fig. 3. Quantitation of lipid damage. Borrelia burgdorferi strain B31A3 was grown to a cell density of 5 x 10 cells/mL in BSK II under anaerobic, microaerophilic, or aerobic conditions (A, B and C, respectively) at 34 °C for 3-5 days. Cells were harvested, lysed, and reacted with TBA. The resulting thiobarbituric acid reacting substances (TEARS) are then injected onto a CIS HPLC column and the absorbance at 532 nm monitored. Standards made from pure MDA were used as controls. The data is calculated as microliters MDA per 10 cells.

To evaluate oxidative stability, different methods are used to measure lipid oxidation after the sample is oxidized under standardized conditions to a suitable end-point. In Table 7.1, different lipid oxidation tests are ranked in decreasing order of usefulness in predicting Ae stability or shelf life of a food product. Methods for sensory evaluations, conjugated diene, gas chromatography of volatiles, peroxide values and thiobarbituric acid-reacting substances were discussed in Chapter 5. 

Otero et al (2002) incubated purified human LDL with glucose and LDL oxidation was started by adding CuClj to the media. Glucose delayed the vitamin E consumption, but accelerated the formation of conjugated dienes and increased both the formation of thiobarbituric acid-reacting substances and LDL electrophoretic mobihty. When LDL was enriched with vitamin E, it showed a delay in the formation of conjugated dienes, even in the presence of glucose. 

Oxidation of LDL cholesterol is one of the key steps in the initiation of atherosclerotic lesions by promoting injury to the arterial wall through several mechanisms, including growth factor and chemotactic protein expression, inflammation, and increased local macrophages [140]. Visioli et al. [117] have demonstrated that OL and HT strongly inhibit copper sulfate-induced oxidation of LDL, as result of measure of various indexes of lipid oxidation (vitamin E content, formation of thiobarbituric acid-reacting substances, lipid peroxides, levels of... 

Gutteridge, J. M. C., Stocks, J., and Dormandy, T. L., 1974, Thiobarbituric acid reacting substances derived from autoxidizing linoleic and linolenic acids. Anal. Chim. Acta 70 107. 

The ability of the pyrone molecnles to protect liposomes from photochanicaUy-induced oxidative damage was investigated using the thiobarbituric acid reactive substances (TEARS) assay [5]. This assay is based on the detection of malondial-dehyde (76), an end prodnct of lipid peroxidation commonly used as a biomarker for cell damage (Sect. 1.2.2.3, Scheme 14) [6]. Malondialdehyde (76) reacts with thiobarbituric acid (124), when heated under acidic conditions, to form a conjugated adduct, 125, which absorbs strongly at 532 nm (Scheme 4.2). Thus treatment of a sample of interest with 124, followed by comparison of the absorption with that of a standard curve generated from known quantities of 76, allows the concentration of malondialdehyde (76) to be determined colorimetrically (see Sect 6.3.2 for further details). 

This test is used for both in vitro and in vivo determinations. It involves reacting thiobarbituric acid (TBA) with malondialdehyde (MDA), produced by lipid hydroperoxide decomposition, to form a red chromophore with peak absorbance at 532 nm (Fig. 10.1). The TBARS reaction is not specific. Many other substances, including other alkanals, proteins, sucrose, or urea, may react with TBA to form colored species that can interfere with this assay. 

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