Effect of hot boning on colour stability and antioxidant enzyme activities in beef inner and outer biceps femoris

Meat from double-muscled Belgian Blue cattle is characterized by a fast pH decline and slow temperature fall post mortem (pm), which may provoke heat shortening (pH35°C) and negatively affect meat quality, particularly in deeper muscles of the hindquarter. The aim of this study was to investigate the effect of hot boning (within 2 hours pm) on colour and colour stability and on antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px)) in inner and outer Biceps femoris (IBF and OBF) from 7 Belgian Blue young bulls (mean age and carcass weight 22.7 months and 496 kg respectively). The mean duration of heat shortening was 3.4 hours for the cold-boned IBF, whereas there was no period of heat shortening in the hot-boned IBF and in the cold- and hot-boned OBF. The colour L*-value was higher in the cold-boned IBF than OBF (49.3 and 37.6 respectively; P<0.05) resulting in two-toning, whereas there was no significant difference between hot-boned IBF and OBF (33.8 and 34.3 respectively). Concomitantly, the decrease in a*-value and increase in %metmyoglobin over a 7 day display period was higher (P<0.05) for the cold-boned IBF compared to the hot-boned IBF and the cold- and hot-boned OBF. The activities of CAT, GSH-Px and SOD for the IBF and OBF were not significantly different between hot- and cold-boned samples. Hot boning of Biceps femoris in beef carcasses has distinct advantages over cold boning, especially for avoiding heat shortening in the inner part of the muscle and for increasing the colour uniformity in the muscle

Modelling postmortem evolution of pH in beef M. biceps femoris under two different cooling regimes

A model based on enzyme kinetics was developed to predict differences in postmortem pH change in beef muscles as affected by cooling rate. For the calibration and validation of the model, pH and temperature measurements were conducted at different positions in M. biceps femoris following conventional carcass cooling or faster cooling of the muscle after hot boning. The glycogen conversion, and, hence, the pH fall, was observed to significantly vary with position and cooling regime but only during the initial hours of cooling. Comparison of the cooling regimes indicated that fast cooling following hot boning avoids heat shortening induced by the combined effect of high temperature and low pH

Application of near-infrared spectroscopy for the classification of fresh pork quality in cooked ham production

Destructured zones in the core of cooked ham are associated with PSE in terms of biochemical characteristics. In this study, the potential of near-infrared spectroscopy (NIRS) to predict the suitability of fresh pork for the production of cooked ham was investigated. Using NIR spectra obtained in a first trial (inducing PSE characteristics in Longissimus thoracis et lumborum (LTL) muscles) and in a second trial (collecting Semimembranosus (SM) samples either with or without presence of visual PSE characteristics) resulted in 93.3 and 90.0 % correct classification after cross-validation for respectively the LTL and SM samples. In a third experiment, 48 fresh hams were processed to high-quality cooked hams, sliced, and visually classified as inferior or normal quality (i.e., presence or absence of destructured zones, respectively). Measuring NIR spectra on the Biceps femoris (BF) muscle after deboning resulted in a 56.5 % correct classification after cross-validation for inferior-quality hams. It can be concluded that NIRS has potential to discriminate PSE from normal pork.status: publishe

Application of near-infrared spectroscopy for the classification of fresh pork quality in cooked ham production

Destructured zones in the core of cooked ham are associated with PSE in terms of biochemical characteristics. In this study, the potential of near-infrared spectroscopy (NIRS) to predict the suitability of fresh pork for the production of cooked ham was investigated. Using NIR spectra obtained in a first trial (inducing PSE characteristics in Longissimus thoracis et lumborum (LTL) muscles) and in a second trial (collecting Semimembranosus (SM) samples either with or without presence of visual PSE characteristics) resulted in 93.3 and 90.0 % correct classification after cross-validation for respectively the LTL and SM samples. In a third experiment, 48 fresh hams were processed to high-quality cooked hams, sliced, and visually classified as inferior or normal quality (i.e., presence or absence of destructured zones, respectively). Measuring NIR spectra on the Biceps femoris (BF) muscle after deboning resulted in a 56.5 % correct classification after cross-validation for inferior-quality hams. It can be concluded that NIRS has potential to discriminate PSE from normal pork