Abstract

ZYBERT, A. et al. Relationship of glycogen and lactate concentrations as a pork quality indicator. S. Afr. j. anim. sci. [online]. 2020, vol.50, n.1, pp.26-37. ISSN 2221-4062.  http://dx.doi.org/10.4314/sajas.v50i1.4.

Muscle metabolites greatly determine pork quality. However, precise threshold values which indicate its deterioration or improvement are not fully known. This study aimed to determine the influences of pork Longissimus lumborum (LL) glycogen and lactate concentrations measured at 45 min post mortem on pH, colour (L*a*b*) and drip loss (DL) measured during 144 hours post mortem in order to prescribe appropriate threshold values. The investigation used 30 gilts and 30 barrows being fattened for slaughter. After slaughter, the carcasses were assigned to groups based on the observed levels of glycogen and lactate: low GlyL with glycogen <35 umol/g, GlyM with glycogen between 35 and 55 umol/g, GlyH with glycogen >55 umol/g; LacL with lactate <40 umol/g and LacH with lactate >40 umol/g. Lower muscle pH was noted up to 24 h post mortem in the LacH group compared to LacL (P <0.01). 24 h post mortem higher pH was found in GlyL than in GlyM and GlyH (P <0.01), which were similar. Similarly no statistical differences were noted between The GlyM and GlyH groups were also similar in L*, DL₉₆ and DL₁₄₄, with lower values found for GlyL (P <0.01). Compared to LacH, LacL had lower L*, DL₄₈, DL₉₆ and DL₁₄₄ (P <0.01) and higher a* and b* values. Muscle pH, drip loss, L^* and a^* values were more affected by lactate concentration if the glycogen concentration >35 umol/g muscle tissue. Thus, metabolite concentration may be a useful and valuable indicator of pork quality.

Keywords : drip loss; glycolytic resources; pork colour; post-mortem muscle metabolism.

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