Peer-reviewed articles

A Comparison of Fresh and Frozen Lamb Meat-Differences in Technological Meat Quality and Sensory Attributes


Guðjón Þorkelsson

Strategic Scientist

Technological meat quality and sensory attributes of fresh and frozen lamb meat were compared. Samples were collected from two abattoirs (one small-scale, one large-scale) that use different slaughter methods in terms of chilling regime and electrical stimulation. The fresh and frozen meat samples included products from both slaughter systems. Ten twin pairs of ram lambs were used in the study, with one of each twin slaughtered at each abattoir. Fresh meat was analyzed after chilling and frozen meat was stored frozen for three months and analyzed after thawing. The Musculus longissimus thoracis et lumborum was analyzed for colour, cooking loss, sensory attributes, Warner-Bratzler shear force (WBSF) and distribution of water and lipid within each meat sample. Meat samples analyzed after frozen storage were darker, less red and more yellow than the fresh meat. Freezing and frozen storage increased fluid loss and WBSF compared with the fresh meat, due to protein denaturation. Frozen storage affected sensory attributes by increasing fatty odor, frying flavor, sour flavor, fatty flavor and liver flavor, and by reducing juicy texture and mushy texture.


Assessment of slaughter in sheep slaughterhouses in the autumn of 2008




Valur Norðri Gunnlaugsson, Óli Þór Hilmarsson, Ásbjörn Jónsson, Guðjón Þorkelsson

Supported by:

National Association of Sheep Farmers


Valur Norðri Gunnlaugsson

Research Group Leader

Assessment of slaughter in sheep slaughterhouses in the autumn of 2008

The Annual General Meeting of the National Association of Sheep Farmers decided in April 2008 that a detailed assessment will be made of the treatment of lamb at slaughter, especially during killing and cooling. An explanatory memorandum to the resolution stated: "The meeting considers it necessary to examine the possible effects of these two factors on the quality of the meat. When the animal is killed by electricity, there is a risk that the carcasses will not be able to bleed sufficiently and there is a risk of cooling hardening with too rapid cooling or freezing. Matís ohf. carried out an assessment of the above factors in the autumn of 2008 where the killing and cooling processes in 6 slaughterhouses were examined, of which one house was visited twice. Monitor the killing of 100 carcasses in each house to see procedures and take out facilities. The acidity and temperature of the carcass were measured regularly as well as the temperature in the slaughterhouses of the slaughterhouses. Carcasses taken in this study followed jogging through the normal process of action in each slaughterhouse, but before freezing, the backbone was removed and frozen. Vertebral muscles were then used in texture measurements to see different gravitational processes between slaughterhouses on the meat of the meat. The results show that the killing method affects the death stiffening process. It was much further in the carcasses of lambs in houses that use the "head-back" method than in houses that had a head clip. Cooling time is clearly too short in some houses. Thus the freezing temperature was highest as it was shortest and well above 6.0 in the house where it was only 4 hours. The viscosity of the meat was lowest in the vertebral carcasses from the slaughterhouse, where the head-back killing method was used, electrical stimulation was used and extensive and long cooling ensured that the meat was almost completely tenderized.

At annual general meeting of sheep farmers association in 2008 was concluded that a general observation ought to take place on treatment of lamb meat at slaughterhouses, particularly at electrocute step and the cooling phase. The aim was to see the influence of these factors on meat quality. Matis ohf. visited 6 slaughterhouses in autumn 2008. The results showed that the electrocution method affected the pH of carcasses. In some slaughterhouses the cooling phase was too short and therefore the pH was too high in carcasses when they were frozen. The tenderest meat came from the slaughterhouse where the meat was electrically stimulated and there was a long cooling paste.

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