INTERACTIONS OF SULFANILAMIDE AND 2-THIOBARBITURIC ACID WITH MALONALDEHYDE - STRUCTURE OF ADDUCTS AND IMPLICATIONS IN DETERMINATION OF OXIDATIVE STATE OF NITRITE-CURED MEATS

Reaction of malonaldehyde (MA) with 2-thiobarbituric acid (TBA) in model systems resulted in the formation of the typical pink adduct (TMT) with absorption maxima at 278, 372, and 532 mm. Reactions of MA with sulfanilamide (SA) produced a bright yellow adduct (SMS) with absorption maxima at 256, 332, and 396 nm. Addition of TBA to the MA-SA system resulted in the disappearance of the characteristic absorption bands of SMS and the appearance of the characteristic absorption bands of TBA-MA as well as a new band at 472 nm. Similarly, addition of SA to the TBA-MA system resulted in the appearance of the 472-nm band without the loss of the previously observed maxima. Reaction of MA, TBA, and SA in model systems resulted in the formation of an adduct (SMT) with absorption maxima at 278, 372, 472, and 532 nm. The structures of these compounds, recovered as crystalline products, were elucidated using ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and mass spectroscopic (MS) techniques. Implications of addition of SA to cured meats in the assessment of their oxidative state are discussed.