Technological and sensory pork quality in relation to muscle and drip loss protein profiles

The relationship of pork longissimus muscle pH to mitochondrial respiratory activities, meat quality and muscle structure

“…However, considering the different publications, these alterations did not generally result in significant drip loss differences. For example, the drip loss values of low and normal pH 45 min p.m. pork in the present study or the studies of Schubert-Schoppmeyer et al (2008) and Zelechowska et al (2012) only showed a difference of 0.67%, 1.03%, 1.02%, respectively (P > 0.05), in comparison with Gil et al (2003), Copenhafer et al (2006) and Werner et al (2010a) (1.5%, 4.8%, 3.3%, respectively, P < 0.05). Further investigations are necessary to clarify the relation between rate of pH decline and WHC/drip loss.…”

“…Considering the presented drip loss results, SchubertSchoppmeyer et al (2008) and Zelechowska et al (2012) also found no impact of lower pH 45 min p.m. values on the drip loss values. In contrast to this, in other studies low pH 45 min p.m. values of pork were accompanied with higher drip loss results, especially if MHS pig genotypes were investigated (Fernandez et al, 2002;Gil et al, 2003;Copenhafer et al, 2006;Werner et al, 2010a).…”

“…pH effect on structure and mitochondria in pork Monin and Sellier (1985), Cheah et al (1998), Fernandez et al (2002, Gil et al (2003) and Copenhafer et al (2006) also found, despite clear pH differences 45 min p.m., no impact of the rate of pH decline on the pH 24 h p.m. results. However, other studies, investigating MHS positive and negative pigs, presented lower pH 24 h p.m. values in LMs with low pH 45 min p.m. results (Hamilton et al, 2003;Werner et al, 2010a;Zelechowska et al, 2012). The contrary results are difficult to explain.…”

“…However, Bee et al (2007) showed that in pig meat with low pH 3 h p.m. values, proteolytic degradation of desmin, vinculin and talin, as well as autolytic activation of µ-calpain was reduced indicating that low pH is related with higher shear force values. Zelechowska et al (2012) also found reduced µ-calpain activation, but only tendentially (P = 0.06) lower desmin degradation in pork with low pH 45 min p.m. values (pale soft exudative pork). Beside these proteolytic effects, other parameters (e.g.…”

The relationship between protein changes in porcine longissimus muscle at different courses of meat tenderisation

“…They are strictly connected with the conversion of muscles into meat and its ageing. The course of glycolysis determines the final pH value, which, in consequence, affects the culinary and technological quality of meat [28,56], the scale of protein proteolysis [22,30,56] and the ultimate tenderness of meat [20,25,51].…”