Analysis of the juice and water losses in salted and unsalted pork samples heated in water bath. Consequences for the prediction of weight loss by transfer models.

This study has analyzed the effect of different factors on variation of meat weight due to juice loss, and variation of water content of pork samples heated in a water bath. The weight loss (WL) was influenced by initial water content of raw meat which can be connected to meat pH, muscle type, and by pre-salting. WL was also influenced by sample thickness and by nature of the surrounding fluid. These effects were significant at 50°C and in thinner samples but decreased as meat temperature and sample thickness increased. WL showed no significant difference in response to prior freezing, applying a surface constraint during heating or varying meat salt content from 0.8 to 2.0%. The results were interpreted from literature knowledge on protein denaturation, contraction and, transport phenomena. Reliably predicting WL from water content variation during heating hinges on taking into account the loss of dry matter and the possible effects of meat pH, sample size or surrounding fluid.

The effects of low salt concentrations on the mechanism of adhesion between two pieces of pork semimembranosus muscle following tumbling and cooking.

The aim of this research was to gain deeper insight into the effect of salt content on the adhesion between pieces of semimembranosus pork muscle bound by a tumbling exudate gel. Hydrophobic site number, free thiol and carbonyl content were measured in tumbling exudate and meat protein to evaluate the protein-protein interactions involved in the adhesion process. Proteins were far more oxidized in exudate than in meat, and under our experimental conditions, salt content increased protein bonding in the exudate but not in the meat. Breaking stress increased between non-salted meat and 0.8%-salted meat but did not depend on the protein physicochemical properties of the tumbling exudate. Modifying the meat surface by tumbling alone, tumbling and salting, or scarification had no effect on breaking stress. It is suggested that the break between the meat pieces occurred between the tumbling exudate and the meat surface due to weaker chemical bonds at this location.