Beef glutathione

Rl. Racker, E., Glutathione reductase from bakers yeast and beef liver. J. Biol. Chem. 217, 855-865 (1955). 

The ability of unsaturated ketonucleosides to react with protein sulf-hydryl groups was demonstrated by measuring their inhibitory action towards beef-heart lactate dehydrogenase.75 These results led to the conclusion that the primary targets for unsaturated ketonucleosides are glutathione and reactive thiol groups of proteins. 

The ability of enzyme preparations from various animal tissues to catalyze transfer of the glutamyl unit from glutamine or glutathione to certain a-amino acids and peptides, first observed by Hanes et al. (38), has been examined in several laboratories (32, 35, 39-41). Enzymes of this type have been studied recently by Orlowski and Meister (in hog kidney) (32) and by Szewczuk and Baranowski (in beef kidney) (41)-Results with the hog kidney enzyme will be reviewed here the beef enzyme is quite similar in many respects, but it is not identical in physical properties. 

Tomizawa HH. Properties of glutathione insulin trans-hydrogenase from beef liver. J Biol Chem 1962 237 3393-6. 

Thiamine is another key sulphur precursor used for meat-like process flavours. Bid-mead and co-workers [95] used thiamine as precursor in combination with an aliphatic carboxylic acid to obtain roasted meat flavours. The reaction can be carried out in presence or absence of a carbohydrate. For example, refluxing thiamine, cysteine hydrochloride and a carbohydrate-free HVP (hydrolysed vegetable protein) for 4 hours results in a product with beef flavour. Giacino [69] proposes the reaction of thiamine with a cysteine-containing peptide, e.g. glutathione or an amino acid mixture containing cysteine, and adding aldehydes and ketones after the reaction. The reaction is preferably carried out in fat. 

Ergothioneine is one of several substances which show a protective effect against the degradation of insulin by beef liver enzymes (Williams and Berg, 1956). It is of interest in this connection that the ability of sulfhydryl compounds such as cysteine and glutathione to inactivate insulin in vitro is not exhibited by ergothioneine (Schock et al., 1935). 

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