Escherichia coli LSUFS was injured either by freezing at -10 degrees C or by heating at 57 degrees C for 12 min. Surviving cells were recovered on nonselective tryptone-glucose extract agar and selective violet red bile agar supplemented with compounds that degrade hydrogen peroxide or block its formation. Various concentrations of the following compounds were tested: sodium pyruvate, 3,3'-thio...

OBJECTIVES Some propofol emulsion formulations contain EDTA or sodium metabisulfite to inhibit microbe growth on extrinsic contamination. EDTA is not known to react with propofol formulation components; however, sulfite has been shown to support some oxidation processes and may react with propofol. This study compared the oxidation of propofol and the formation of free radicals by electron para...

The effect of different anti-browning agents on partially purified longan polyphenol oxidase (PPO) activity was investigated by spectrophotometry, using catechol as a phenolic substrate. For this purpose, L-cysteine, potassium metabisulfite, ascorbic acid, and citric acid were used to inhibit the activity of longan PPO at different concentrations (0-10 mM). Lcysteine was found to be the most po...