Interaction of soluble peptides and proteins from skeletal muscle with volatile compounds in model systems as affected by curing agents.

The effect of curing agents (salt, glucose, nitrate, nitrite, and ascorbic acid) on the binding of skeletal peptides (carnosine and anserine) and a sarcoplasmic protein (myoglobin) with key flavor compounds (hexanal, octanal, 2-pentanone, 2-methylbutanal, and 3-methylbutanal) has been studied by solid-phase microextraction (SPME). Curing agents had an effect on the interaction process between carnosine and volatile compounds, which was higher than the interactions observed with anserine and myoglobin. Sodium chloride decreased the interaction of volatiles with carnosine except for octanal, which was increased, and 2-pentanone, which was unaltered. Ascorbic acid exerted the highest effect by decreasing the interaction of carnosine with all of the volatile compounds except for octanal and 2-pentanone. The interaction with anserine was affected by sodium chloride, nitrate, and nitrite, producing a decrease in the interaction with hexanal, octanal, and methional. Finally, sodium chloride, glucose, and nitrite increased the interaction of myoglobin with hexanal, octanal, and methional. The effect of simulated stages of the curing process on the binding was also studied. A combined effect of the curing agents resulted in a change in the relative proportions of volatile compounds that can lead to different flavor perceptions of dry-cured meat products.

Interactions of soluble peptides and proteins from skeletal muscle on the release of volatile compounds.

The ability of skeletal dipeptides (carnosine and anserine) and a sarcoplasmic protein (myoglobin) to interact with key flavor compounds (hexanal, octanal, methional, 2-pentanone, 2-methylbutanal, and 3-methylbutanal) has been studied using the solid phase microextraction (SPME) technique. Conditions for SPME analysis (fiber coating, sampling time, and linearity of detection) were optimized. The effect of pH on the binding was also investigated. Thermodynamic models were applied to evaluate the binding parameters n (number of binding sites), K (affinity constant), and DeltaG (Gibb's free energy) to all of the flavor compounds studied, and they showed an absence of cooperative effect. Carnosine was the peptide with the highest affinity for all of the volatile compounds except 2-pentanone. Its interaction with hexanal and methional was significantly affected by pH. Anserine showed a lower level of interactions with hexanal, methional, 2-methylbutanal, and 3-methylbutanal, whereas myoglobin interacted with only hexanal and 2-methylbutanal. Differences in aroma retention can thus result in different sensory perceptions of muscle foods.