Changes in lactic acid levels during thawing of lamb chops.

Loins from 20 lambs with an ultimate pH ranging from 5.5 to 6.4 were frozen and stored at -20 °C, then thawed at + 3 °C.

The effects of non-vacuum packaging systems on drip loss from chilled beef.

This study investigated drip loss in chilled beef (hot-boned m. longissimus lumborum (LL)) under conventional packaging systems, in which a vacuum is applied, and non-vacuum packaging systems. The use of vacuum during the packaging process (vacuum packaging, CO(2) atmosphere packaging) was associated with increased drip.

Effects of chopping time, meat source and storage temperature on the colour of New Zealand type fresh beef sausages.

The colour stability of finely chopped fresh sausages made from post-rigor, pre-rigor salt added (1.5% w/w) or pre-rigor no salt added beef mince was evaluated using a Hunter Miniscan (L (∗) a (∗) b (∗)) and sensory colour panel. Batters were chopped for various times and sausages stored at -1.

Efficacy of heat and ethanol spore treatments for the isolation of psychrotrophic Clostridium spp. associated with the spoilage of chilled vacuum-packed meats.

Psychrotrophic Clostridium spp. associated with chilled meat spoilage are difficult to isolate and culture. In this study the kinetics of heat and ethanol spore inactivation was determined as a first step towards optimising the recovery of psychrotrophic clostridial spores from meat and environmental samples.

Post-mortem calpain-system kinetics in lamb: Effects of clenbuterol and preslaughter exercise.

The effect of dietary supplementation with clenbuterol for either 8 days or 55 days in lambs was studied. The 55-day treatment was combined with an immediate preslaughter exercise regime. The effect of these treatments on post-mortem calpain system activities, meat ageing and meat quality was studied.

Effect of NaCl, polydextrose, and storage conditions on the functional characteristics and microbial quality of pre- and post-rigor salted beef.

The functionality and microbial storage life of pre-rigor beef mince stored at -1.5 °C under vacuum or a saturated carbon dioxide atmosphere, or at -18 °C in polyethylene bags, was investigated. Salt (2% w w ) or salt plus the cryoprotectant Polydextrose(®) (2%/2.

Oxytocin and prolactin suppress cortisol responses to acute stress in both lactating and non-lactating sheep.

Cortisol response to stress appears to differ between lactating and non-lactating animals. Lactating (14 d post partum) and non-lactating sheep were fitted with probes so that drugs and hormones could be infused directly into the posterior pituitary and paraventricular nucleus of the hypothalamus. The animals were also fitted with instruments to allow monitoring of heart rate, body temperature and blood cortisol levels.

Acceptability and functional properties of restructured roast from frozen pre-rigor injected beef.

Restructured beef roasts, made to a standardized formulation, were prepared using the following types of meat that had been stored at - 18 °C for 5 or 10 weeks: grass-fed bull beef pre-rigor injected with a salt/phosphate brine; uninjected grass-fed bull beef; uninjected grain-fed beef; a 50:50 blend of pre-rigor injected grass-fed bull beef and grain-fed beef; and a 50:50 blend of uninjected grass-fed bull beef and grain-fed beef. After frozen storage, pre-rigor injected beef had a higher (p < 0.05) ultimate pH than uninjected beef .

Effect of pH at time of salting on the functional properties of pre-rigor beef.

The functional properties of thawed pre-rigor beef that had been minced and salted or not salted when its pH value reached 6.8, 6.6, 6.

Escherichia coli O157:H7 in healthy dairy cows.

Faecal samples were taken from 371 cows originating from 55 dairy farms and slaughtered at one slaughterhouse; tonsils were taken from 215 of these animals. Escherichia coli 0157:H7 was found in the faeces of only two animals and was not found in any tonsils. The farm supplying the first positive cow detected at the slaughterhouse was visited 3 months later and 160 animals (80 cows and 80 heifers) were tested by rectal swabs; E.

Comparison of aerobic and anaerobic methods for the microbiological monitoring of chilled packaged meat during storage.

Aerobic and anaerobic plate counts were compared for routine monitoring of the microflora, dominated by lactic acid bacteria, developing on vacuum- and carbon dioxide-packaged raw meat during chilled storage. No statistical differences were observed between aerobic and anaerobic enumerations, made on plate count and blood agar plates, of the microflora developing on beef striploins packaged under vacuum or carbon dioxide during 14 weeks' storage at 0 degree C. With both techniques the spoilage microflora development differed between the two packaging regimes.

Distribution and sources of microbial contamination on beef carcasses.

Three beef dressing lines of different capacity (160, 440 and 800 head d(-1)) were investigated with respect to contamination associated with carcass/hide and carcass/faeces contacts, the distribution of microbial contamination on carcasses and the antimicrobial efficacy of cold water carcass washes. Swab samples were taken from up to 17 sites for determination of Aerobic Plate Counts at 37 degrees C (APC 37 degrees C) and Escherichia coli enumeration using the Petrifilm procedure. The three beef dressing systems produced virtually identical patterns of microbial contamination.

Fat-borne volatiles and sheepmeat odour.

The effects of lamb age and diet on volatiles from fat are described. Rendered fat from ram lambs raised on ewe's milk then a corn-based diet was compared with that from lambs raised on milk and a pasture of grass/clover, six treatments in all. An additional treatment comprised very old ewes maintained on pasture.

Effects of brine ingredients and temperature on cook yields and tenderness of pre-rigor processed roast beef.

In semimembranosus (SM) muscles removed pre- and post-rigor and injected 10% (wt/wt) with brines formulated to give 2% salt, 1.5% glucose, 0.3% phosphate, 0.

Effect of post-slaughter processing and freezing on the functionality of hot-boned meat from young bull.

The effects of variation in the times of mincing post mortem (2, 4, or 6 h), pre-rigor salting (1.5% wt wt ) and freezing rate [fast (10 min, liquid nitrogen); medium (4-6 h at -40 °C and 0.8 m s(-1) air velocity); or slow (36-38 h at -10 °C and 0.

Social behaviour in sheep relates to behaviour and neurotransmitter responses to nociceptive stimuli.

Sheep in the field display differences in social behaviour. These differences allow a division into three social groups with distinct behavioural occurrences and frequencies. The behavioural and neurotransmission responses of each of these groups to aversive stimuli were compared.

The hygienic efficiency of conventional and inverted lamb dressing systems.

Aerobic plate counts (APC 37 degrees C and APC 25 degrees C) and Escherichia coli enumerations (Petrifilm) were used to determine sources of bacterial contamination during sheep dressing, determine the hygienic efficacy of hand wash and knife 'sterilization' procedures and compare the hygiene efficiency of conventional and inverted sheep dressing systems. The major slaughterline sources of microbial contamination were: fleece > workers' hands > faecal pellets > knife blades. Aerobic plate counts (APC 37 degrees C) exceeding log 4.

Listeriolysin O production and pathogenicity of non-growing Listeria monocytogenes stored at refrigeration temperature.

Three haemolytic, pathogenic strains of Listeria monocytogenes (a reference strain NCTC 7973, a food-derived strain L70 and a human strain L94) and a control strain of Listeria innocua L27 were held in phosphate-buffered saline (PBS) of pH 7.0 or 5.5 at 4 degrees C for 4 weeks.

Relationship between variations in pathogenicity and lag phase at 37 degrees C of Listeria monocytogenes previously stored at 4 degrees C.

Three haemolytic, pathogenic strains of Listeria monocytogenes (a reference strain, a food-derived strain and a human strain) were held at 4 degrees C for 4 weeks in phosphate-buffered saline pH 5.5 or 7.0, with and without 0.

Association of psychrotrophic Clostridium spp. with deep tissue spoilage of chilled vacuum-packed lamb.

Early spoilage of commercial vacuum-packed chilled lamb legs was manifested as an objectionable 'cheesy', deep tissue odour that became evident when a cut was made into the stifle joint. Investigation of the probable causative agents led to the isolation of two psychrotrophic strains of clostridia. The isolates could not be identified using traditional identification schemes.

Psychrotrophic Clostridium spp. associated with 'blown pack' spoilage of chilled vacuum-packed red meats and dog rolls in gas-impermeable plastic casings.

'Blown pack' spoilage of vacuum-packed chilled beef, lamb and venison, and of a cooked meat product, chilled dog rolls packed in an oxygen-impermeable plastic casing, was characterised by sensory, chemical and microbiological analysis. Investigation of the probable causative agents led to the isolation of eight strains of psychrotrophic clostridia. Three strains have been provisionally identified as C.

Recent developments in sheep and beef processing in Australasia.

New Zealand and Australia have invested heavily in the development of slaughter, dressing and deboning equipment for sheep and beef. A number of sheep dressing and deboning machines are now in commercial use after completing their development. The success of some of these developments has encouraged further investment in sheep dressing and deboning and beef deboning developments.

Multilocus enzyme electrophoresis typing of New Zealand Listeria monocytogenes isolates.

Eighty-five strains of Listeria Monocytogenes, comprising 74 strains isolated from the environment, humans, animals and foods in New Zealand; 10 strains from similar sources in Denmark, and one reference strain, were studied using multilocus enzyme electrophoresis (MEE). Fifty-five electrophoretic types (ETs) were identified among the 85 strains, most (71%) of which were represented by only one isolate. The 74 New Zealand isolates produced 45 ETs, most (67%) of which were represented by only one isolate.

The role of insulin-like growth factor I in clenbuterol-stimulated growth in growing lambs.

We examined the role of IGF-I in muscle growth stimulated by a beta-adrenergic agonist, clenbuterol. Ewe lambs (90 d old, 20.4 kg mean live weight) were allotted to five groups.